1 23

Applied Microbiology andBiotechnology ISSN 0175-7598Volume 93Number 2 Appl Microbiol Biotechnol (2012)93:473-485DOI 10.1007/s00253-011-3707-3

Applications of microbial fermentationsfor production of gluten-free products andperspectives

Emanuele Zannini, Erica Pontonio,Deborah M. Waters & Elke K. Arendt

1 23

Your article is protected by copyright and

all rights are held exclusively by Springer-

Verlag. This e-offprint is for personal use only

and shall not be self-archived in electronic

repositories. If you wish to self-archive your

work, please use the accepted author’s

version for posting to your own website or

your institution’s repository. You may further

deposit the accepted author’s version on a

funder’s repository at a funder’s request,

provided it is not made publicly available until

12 months after publication.

MINI-REVIEW

Applications of microbial fermentations for productionof gluten-free products and perspectives

Emanuele Zannini & Erica Pontonio &

Deborah M. Waters & Elke K. Arendt

Received: 18 August 2011 /Revised: 21 October 2011 /Accepted: 2 November 2011 /Published online: 18 November 2011# Springer-Verlag 2011

Abstract A gluten-free (GF) diet is recognised as being theonly accepted treatment for celiac disease—a permanentautoimmune enteropathy triggered by the ingestion of gluten-containing cereals. The bakery products available in today’sgluten-free market are characterised by lower palatability thantheir conventional counterparts and may lead to nutritionaldeficiencies of vitamins, minerals and fibre. Thus, theproduction of high-quality gluten-free products has becomea very important socioeconomical issue. Microbial fermenta-tion by means of lactic acid bacteria and yeast is one of themost ecological/economical methods of producing andpreserving food. In this review, the role of a fermentationprocess for improving the quality of GF products and fordeveloping a new concept of GF products with nutraceuticaland health-promoting characteristics will be examined.

Keywords Microbial fermentation . Gluten-free foods .

Gluten-free beverages . Lactic acid bacteria . Functionalfoods

Introduction

Celiac disease (CD) is a chronic enteropathy triggered ingenetically susceptible children and adults by peptidesequences within the prolamine fractions of ingested wheat(gliadins), barley (hordeins) and rye (secalins) (Wieser and

Koehler 2008) and, in some people, oats (avenin) (Butt etal. 2008). The incidence of CD in the USA is approximately 1in 100 whereas it is 1 in 266 worldwide. However, the trueprevalence of CD is difficult to ascertain due to unclearclinical symptoms (Farrell and Kelly 2002) or the diversityand/or sensitivity of the diagnostic criteria used to supportthe diagnosis of CD (Biagi et al. 2010).

To date, no pharmacological treatment is available forgluten intolerant patients. Medical nutrition therapy withsupportive nutritional care (Hopman et al. 2006; Tack et al.2010) is the only safe and accepted treatment for CD. Thegluten-free (GF) diet requires ongoing education of patientsand their families by both doctors and dieticians. Compli-ance with a strict gluten-free diet (GFD) is not easy because(a) harmful gluten may contaminate food during processingsteps; (b) it is socially limiting, exerting a significantnegative impact on the perceived quality of life and mayproduce considerable psychological, emotional and eco-nomic stress; (c) GF products are generally not widelyavailable, are more expensive and have lower palatabilitythan conventional products (Arendt et al. 2008) and (d) maylead to nutritional deficiencies of B vitamins, calcium,vitamin D, iron, zinc, magnesium and fibre (Hager et al.2011; Kupper 2005; Hopman et al. 2006). Thus, theproduction of high-quality gluten-free products has becomea very important socioeconomical issue (Gallagher et al.2004; Berghofer and Schonlechner 2009).

In the past decades, several approaches have beeninvestigated for the development of GF products (and inparticular for GF baked goods) such as the use of (a)different GF flours (rice, sorghum, oat, buckwheat, ama-ranth, quinoa, teff, corn), (b) ingredients/additives (starches,dairy products, egg proteins, dietary fibre, gum and hydro-colloids) (Gallagher et al. 2004; Ibanoglu and Ercelebi2007) and (c) alternative technologies such as enzymaticand high hydrostatic pressure processing (Vallons et al.

E. Zannini (*) : E. Pontonio :D. M. Waters : E. K. ArendtSchool of Food and Nutritional Sciences,University College Cork,Western Road,Cork, Irelande-mail: e.zannini@ucc.ie

E. Zannini : E. K. ArendtNational Food Biotechnology Centre, University College Cork,Cork, Ireland

Appl Microbiol Biotechnol (2012) 93:473–485DOI 10.1007/s00253-011-3707-3

Author's personal copy

2010; Renzetti et al. 2008, 2010). Despite the appealingresults obtained so far, the inclusion of these ingredients/additives in GF bread formulations presents several disadvan-tages such as (a) excessive prices of the ingredients/additivesused (Moroni et al. 2009) and (b) allergic reaction to one ormore of the ingredients (lactose, egg proteins) (Ortolani andPastorello 2006). Moreover, additives do not meet theconsumers’ requirements for natural products. Thus, even ifan improvement of GF product quality has been achieved inthe last years, the increasing demand for high-quality GFproducts and particularly for GF bread is far from fullyaddressed. Extensive research is still needed in this area.

In this review, the role of the fermentation process forimproving the quality of GF products and for developing anew concept of GF products with nutraceutical and health-promoting characteristics will be examined. This will focusalmost entirely on lactic acid bacteria (LAB) whose activityin fermented foods and whose biochemical and metabolicproperties are well characterised.

Microbial fermentation

Microbial fermentation is one of the oldest and mosteconomically and ecologically friendly methods of produc-ing and preserving foods. According to Steinkraus (1995),microbial fermentation plays several functions in foodprocessing, such as (a) enrichment of the diet throughdevelopment of a diversity of flavour, aromas and texturesin food substrates, (b) preservation of substantial amountsof food through lactic acid and alcoholic fermentations, (c)enrichment of food substrates biologically with compoundsthat originate either from biotransformation reactions(protein, essential amino acids, essential fatty acids) orbiosynthesis (vitamins) and (d) detoxification during foodfermentation processing. These fermentative activities havebeen utilised, since the beginning of human civilisation, inthe production of fermented foods and beverages that aredefined as those products that have been subordinated tothe effect of microorganisms or enzymes to cause desirablebiochemical changes (Blandino et al. 2003). Nowadays,several fermented GF cereal products and beverages arewidely available on store shelves in Western countries suchas bakery products (Arendt et al. 2008), beers (Zweytickand Berghofer 2009) and functional drinks (Salovaara1996). Apart from these, several other African and Asiantraditional fermented GF cereal products (corn-based Ogi,Kenkey, Pozol and sorghum-based Kisra) and beverages(rice-based Sake and corn-based Chicha) are commonlyproduced (Blandino et al. 2003). In the following para-graphs, we present the contributions of microbial fermen-tative activity on the development of high-quality GFcereal-based products.

Microbiota of GF sourdoughs

The most recent approach that has been investigated toimprove the quality of the GF bread is the use of sourdough(SD) technology, which represents one of the oldest biotech-nological processes in cereal food production. Sourdoughbread is prepared from a mixture of flour and water that isfermented with LAB, mainly heterofermentative strains andyeast. Sourdough has been used in bread production for morethan 5,000 years in order to improve the texture and flavour ofbaked cereals, and still today, sourdough is very important toimpart superior flavours, texture and shelf life to wheat andparticularly rye bread (Hansen and Schieberle 2005). Conse-quently, the exploitation of SD technology for the productionof GF bread appears tempting. As a starting point, the abilityof the starter strains to dominate the fermentation and inhibitthe growth of contaminants has to be considered the sine quanon condition for the successful development of sourdoughGF products (Minervini et al. 2010; De Vuyst et al. 2009).Firstly, sourdoughs from rice flours are already available onthe market and are fermented by starters developed for wheatand rye SD (Meroth et al. 2004). Meroth et al. (2004)showed that during rice sourdough fermentation, substrate-specific LAB and yeast species become established whichare different from the common microbiota of wheat and ryesourdoughs. Furthermore, Vogelmann et al. (2009) investi-gated the adaptability of a great variety of LAB and yeasts toSDs prepared from gluten-containing cereals (wheat, rye andbarley), GF cereals (oat, rice, maize, millet), pseudocereals(amaranth, quinoa, buckwheat) and also cassava. They foundthat, even if each substrate was established with the samestarter mixture and fermented under the same technologicalconditions, competitiveness of some strains was substrate-specific. Consequently, among other factors, the type of GFflour used determines the microbiota of the resulting SD.These findings indicate that exogenous starter cultures are notsuitable, as such for the fermentation of GF materials, andspecific starters should be developed for such fermentations(Vogelmann et al. 2009; Moroni et al. 2010). On the otherhand, ecological studies on GF sourdoughs, either developedby starters or by spontaneous fermentation, indicate that GFflours harbour novel and competitive LAB and yeasts strainswhich are not commonly isolated in traditional sourdoughsand which could serve as suitable candidates for starterdevelopment (Table 1) (Sanni et al. 1998; Moroni et al.2010; Vogelmann et al. 2009; Meroth et al. 2004; Edema andSanni 2008; Sterr et al. 2009; Arendt et al. 2010; Huttner etal. 2010). These studies indicate that Lactobacillus fermen-tum, Lactobacillus plantarum and also Lactobacillus para-limentarius are frequently isolated from the GF sourdoughsof rice, maize, buckwheat, teff and amaranth flours.Furthermore, species such as Lactobacillus gallinarum,Lactobacillus graminis, Lactobacillus sakei and Pediococcus

474 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

pentosaceus, which are not commonly associated withconventional sourdoughs, were part of the dominant

microbiota of various GF sourdoughs (Moroni et al.2009). Recently, GF rice and quinoa dried sourdoughs

Table 1 Microbiota of gluten-free sourdoughs

a L., Lactobacillus; Lc.,Leuconostoc; P., Pediococcus ;W., Weissella; S., Saccharomy-ces; C., Candida; I., Issatchen-kia; P., Pichia; K., Kazachstania

Sourdough Dominant microbiotaa Reference

LAB Yeast

Rice Lactobacillus paracasei Saccharomyces cerevisiae Vogelmann et al. (2009)

Lactobacillus paralimentarius Candida krusei Meroth et al. (2004)

Lactobacillus perolens Pichia membranifaciens

Lactobacillus fermentum Issatchenkia orientalis

Lactobacillus gallinarum

Lactobacillus kimchii

Lactobacillus plantarum

Lactobacillus pontis

Lactobacillus helveticus

Oats Leuconostoc argentinum Huttner et al. (2010)

Pediococcus pentosaceus

Weissella cibaria

Lactobacillus coryniformis

Buckwheat Leuconostoc argentinum Arendt et al. (2010)

Lactobacillus fermentum

Lactobacillus helveticus

Lactobacillus paralimentarius Vogelmann et al. (2009)

Lactobacillus plantarum

Lactobacillus pontis

Teff Lactobacillus reuteri Kazachstania barnetti Arendt et al. (2010)

Lactobacillus fermentum Saccharomyces cerevisiae

Lactobacillus helveticus

Amaranth Lactobacillus paralimentarius Saccharomyces cerevisiae Vogelmann et al. (2009)

Lactobacillus helveticus Sterr et al. (2009)

Lactobacillus plantarum

Lactobacillus sakei

Pediococcus pentosaceus

Maize Lactobacillus paralimentarius Saccharomyces cerevisiae Vogelmann et al. (2009)

Lactobacillus helveticus Issatchenkia orientalis Sanni et al. (1998)

Lactobacillus fermentum Candida albicans Edema and Sanni (2008)

Lactobacillus pontis Saccharomyces pombe Annan et al. (2003)

Lactobacillus brevis Candida krusei

Lactobacillus casei

Lactobacillus plantarum

Leuconostoc mesenteroides

Leuconostoc destranicum

Pediococcus acidilactici

Millet Lactobacillus helveticus Saccharomyces cerevisiae Vogelmann et al. (2009)

Lactobacillus fermentum

Lactobacillus pontis

Quinoa Lactobacillus paralimentarius Vogelmann et al. (2009)

Lactobacillus plantarum

Lactobacillus fermentum

Appl Microbiol Biotechnol (2012) 93:473–485 475

Author's personal copy

have been developed and characterised by Brandt andBodé (2009). The latter showed that the quality of GFbreads, fermented with dried rice and quinoa sourdoughs,was improved in terms of specific volume, flavour,mouthfeel and texture when compared to control breads.Thus, even though further studies are required, thepositive baking performance of GF sourdoughs placesthem in a promising position to develop a new approachfor the industrial production of GF sourdough breads.

Texture, flavour and aroma development in GFcereal-based products and beverages by microbialfermentation

In baking applications, the absence of wheat gluten poses achallenge to the maintenance of good sensory quality,especially bread structure and/or retention of softnessduring storage. The use of sourdough in GF bread hasbeen efficient for improving product texture and to delaygluten-free bread staling (Table 2). In more detail, positiveeffects of SD fermentation on crumb structure of GFsorghum breads were observed by Schober et al. (2007).Furthermore, Moore et al. (2008) obtained softer GF breadwhen L. plantarum FST 1.7 was used as SD starter culture.

Oat sourdough has also been shown to increase both loaf-specific volume and crumb texture of oat bread, regardless theaddition level or sourdough type, therefore enhancing its finalquality (Huttner et al. 2010). Recently, the use of exopoly-saccharide (EPS)-producing LAB strains in GF bread wasshown to be a potential replacer of hydrocolloids (Galle et al.2010) which are essential ingredients in GF baking to obtainacceptable product quality in terms of volume, texture andshelf life (Lazaridou et al. 2007).

The applicability of the EPS-producing strains Lactobacil-lus reuteri LTH5448 and Weissella cibaria 10 M wasinvestigated in GF sourdoughs by Schwab et al. (2008).The strains were able to ferment sorghum and quinoa flours,producing levan (fructo-oligosaccharides) and dextran (gluco-oligosaccharides, GOS), respectively. GF breads containingsourdough fermented by W. cibaria were softer than the onescontaining no EPS. Moreover, GOS produced by W. cibariawere not digested by baker’s yeast, and they were still presentin the final bread increasing its potential prebiotic content.Furthermore, Galle et al. (2011) report that heteropolysac-charides produced from Lactobacillus buchneri FUA3154significantly influenced the rheology of sorghum sourdoughs,reducing their resistance to deformation which, in turn, resultsin an increased specific bread volume and decreased crumbhardness (Huttner et al. 2010; Renzetti and Arendt 2009).

Table 2 Effects of sourdough fermentation on GF dough/batter and bread

Sourdough properties Effects on dough or GF batter Effects on bread

Starch hydrolysis Increased amaranth dough softness (Houben et al.2010)

Delayed staling of sorghum sourdough bread(Moore et al. 2007)

Protein hydrolysis Decreased starch viscosity of oat batter (Huttneret al. 2010)

Improved loaf-specific volume of oat sourdoughbread (Huttner et al. 2010)

Acidification Formation of strong starch gel in sorghum batter(Schober et al. 2007)

Improved textural properties of sorghumsourdough bread (Schober et al. 2007)

Hydrolysis of toxic polypeptides Elimination of gluten from GF flours (Giuliani etal. 2006)

Production of wheat and rye bread tolerated bycoeliac patients (De Angelis et al. 2006a, b; DiCagno et al. 2010a; Rizzello et al. 2007; DiCagno et al. 2010b)

Production of EPS Decreased resistance of deformation and elasticity(Galle et al. 2011)

Increased volume, softer crumb and delayedstaling of GF bread (Schwab et al. 2008)

Production of gluco-/fructo-oligosac-charides

Improved nutritional quality of sorghum bread(Schwab et al. 2008)

Synthesis of flavouring compounds(esters, carbonyls, alcohols, acids,phenolic compounds, diacetyl,aldehydes)

Enriched aroma of maize dough (Annan et al.2003; Edema and Sanni 2008) and acidfermented gruels based on sorghum, millet,maize (Mugula et al. 2003)

Degradation of antinutrientcompounds/digestibility

Reduction trypsin and amylase inhibitoryactivities, phytic acid and tannin contents ofsorghum dough (Osman 2004)

Improved nutritional quality, taste anddigestibility of products based on maize(Mawe’, Kenkey) (Hounhouigan et al. 1993;Annan et al. 2003) and rice (Koh and Singh2009)

Reduction of phytic acid and increase of aminoacid content on rice dough (Koh and Singh2009)

Production of antifungal metabolite Prolonged shelf life of GF bread (Moore et al.2008)

476 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

Sourdough fermentation also strongly influences theflavour profile of the bread. This flavour modification isdependent on the raw material, type of starter cultures,fermentation and baking conditions applied (Gobbetti1998). The fermentation of GF flours by LAB has beenshown to induce the production of different flavourcompounds. For example, fermentation of sorghum for theproduction of towga, a traditional Tanzanian lactic acidfermented gruel (Mugula et al. 2001), generated differentflavour compounds (Mugula et al. 2003). Diacetyl wasproduced in high concentrations when the fermentation wascarried out with L. plantarum and P. pentosaceus andalcohols were produced in significant amount if Issatch-enkia orientalis was used in combination with Lactobacil-lus brevis or L. plantarum. The L. plantarum/yeasts co-fermentation also induced the production of aldehydes.Fermentation with mixed cultures containing L. plantarumenhanced the diacetyl content in maize-fermented meals(Edema and Sanni 2008). Finally, Annan et al. (2003)identified 73 compounds contributing to the characteristicaroma of the Ghanaian fermented maize mush for kenkey.The compounds generated by LAB/yeast fermentation wereidentified by gas chromatography–mass spectroscopy andincluded 21 carbonyls, 19 alcohols, 17 esters, 12 acids, afuran, an alkene and 2 phenolic compounds.

Finally, preliminary studies conducted by Wijngaard andArendt (2006) and Zweytick et al. (2005) showed that beersproduced using different GF raw materials such as sorghum,maize, millet, amaranth, quinoa and buckwheat were charac-terised by acceptable flavour as well as different foamstability and colour. However, in order to produce GF beerswith comparable technological and sensorial characteristics toconventional brewed beers, the authors suggest that acombination of different GF raw materials as well as theuse of exogenous enzymes could improve foam stability, wortfermentability and, therefore, the final taste. Thus, lactic acidbacteria and/or yeast fermentation represent promising toolsto produce flavour enhancing compounds which will improvethe poor sensory quality of GF cereal products and beverages.

Microbial shelf life of GF cereal-based products

Bread is a widely consumed food, also for celiac patients,and its quality is rapidly depleted due to staling andmicrobial spoilage. The microbial stability of the GF breadsis mainly compromised by its high water activity (aw). Thisis primarily due to the fact that the majority of GF productsare based on gluten-replacer hydrocolloids, which are ableto bind a high amount of water leading to a higher aw in GFbreads than in their wheat containing counterparts. Thisincrease in GF bread aw leads to a significant reduction inits microbial stability due to the growth of mould. For this

reason, the use of modified atmosphere packaging and/orchemical preservatives is necessary.

Since consumers prefer foods with few chemical preserva-tives, the interest in the concept of food biopreservation,referring to extended shelf life and enhanced safety of foodsusing natural or added microflora and their antimicrobialproducts, is increased (Ryan et al. 2011). LAB with antifungalactivity represents a promising alternative to chemicalpreservation (Lowe and Arendt 2004; Ryan et al. 2011; DalBello et al. 2007; Lavermicocca et al. 2003; Schnurer andMagnusson 2005; Rouse and van Sinderen 2008; Batish etal. 1997). Moore et al. (2008) reported that GF breadcontaining a mixture of brown rice, corn starch, buckwheatand soya flours fermented with the antifungal strain L.plantarum FST 1.7 (Dal Bello et al. 2007) retards the growthof Fusarium culmorum by up to 3 days when compared tothe control bread. Furthermore, Rizzello et al. (2009) showedthat the combination of the water-soluble extract ofAmaranthus spp. seeds, containing antifungal peptides, andsourdough Lactobacillus sanfranciscensis E9, used for GFbread production, delay the growth of the most importantbread mould contaminants belonging to the genera Penicil-lium, Aspergillus and Eurotium. In particular, the mouldgrowth of Penicillium roqueforti, considered one of the moreresistant fungi to chemical preservatives, was delayed until21 days of storage.

Dike and Sanni (2010) also reported the positiveinfluence of bacteriocin-producing L. plantarum OG3 onthe shelf life of agidi, a traditional African-fermented GFcereal product. The bacteriocin-producing strain was able toretard the mould growth of Aspergillus flavus and Asper-gillus niger by up to 4 days when compared to thetraditionally produced agidi, used as control. Additionally,Edema and Sanni (2008) showed that fermented maizedough inoculated with different LAB species, isolated fromthe spontaneous fermentation of maize meal, was able toexert antimicrobial activities against a wide range ofpathogenic bacteria (Salmonella typhi, Staphylococcusaureus, Escherichia coli) and aflatoxigenic mould (A.flavus). In particular, the antifungal activity of sour maizemeal started on a mixed culture of L. plantarum and L.brevis was assumed to be due to the production ofbacteriocin-like substances (Edema and Sanni 2008).

Natural enrichment of GF cereal-based productsthrough microbial fermentation

A new application of food-grade LAB and yeast is their useas ‘cell factories’ for the production of health-promotingnutrients, also known since the 1980s as ‘nutraceuticals’(Pszczola 1992). Nutraceuticals can be defined as food andfood components that provide medical, or health benefits,

Appl Microbiol Biotechnol (2012) 93:473–485 477

Author's personal copy

including the prevention and treatment of disease (Brower1998). Clear examples are the B-vitamins: riboflavin (B2),folate (B11) and cobalamin (B12). Folate is an essentialcomponent in the human diet. It is involved, as a cofactor,in several metabolic reactions, including the biosynthesis ofnucleotides, the building blocks of DNA and RNA. It isalso known to prevent neural tube defects in newborns(Wald 1991).

Yazynina et al. (2008) found that the folate content in GFproducts was lower than in their gluten-containing counter-parts. In fact, starches and low protein flours commonly usedas main components in GF products appeared to be poorfolate sources with a folate content of 6 μg/100 g freshweight. Therefore, the use of nutrient-dense ingredients isimportant to improve the nutritional quality of GF products.Yeast is one example of such an ingredient. It is a rich folatesource and may contribute considerably to folate content inbakery products (Keagy et al. 1975). Yazynina et al. (2008)report that the folate content in GF yeast breads (15.1–35.9 μg folate/100 g fresh weight) was comparable with thefolate content of similar gluten-containing breads (26–75 μg/100 g) (Livsmedelsverket 2002).

Another strategy to improve the folate content of GFproducts is to include pseudocereals, specially quinoa andamaranth, in the product recipe as folate-rich sources. Infact, the total folate values ranged from 52 to 70 μg/100 gdry matter (dm) in the amaranth species, and with 132.7 μg/100 gdm, quinoa possessed about ten times more totalfolate than spring wheat (Schoenlechner et al. 2010).

Additionally, an important breakthrough in this area isthe discovery by Centro de Referencia para Lactobacilos(CERELA-CONICET) in Argentina, of a vitamin B12-producing LAB (Taranto et al. 2003). This probioticbacterium L. reuteri, isolated from sourdough, was identi-fied as producing vitamin B12 (cobalamin); an importantcompound involved as cofactors in a variety of enzymaticreactions. This discovery opens some interesting avenuesfor naturally enriched (fermented) foods with this importantand very complex B-vitamin.

Microbial fermentation of GF substrates also represents atool to increase the functional value of the grains. Coda etal. (2010) reported how L. plantarum C48 and Lactococcuslactis subsp. lactis PU1, used for sourdough fermentation ofcereal, pseudo-cereal and leguminous flour, were able tosynthesise high levels of γ-aminobutyric acid (GABA), anon-protein amino acid that possesses well-known physio-logical functions such as neurotransmission, induction ofhypotension and diuretic and tranquiliser effects (Siragusaet al. 2007).

The highest biosynthesis of GABA was detected whenbuckwheat (643±13 mg/kg) and quinoa (415±10 mg/kg)were fermented with L. plantarum C48. L. lactis subsp.lactis PU1 revealed the best results when amaranth (816±

11 mg/kg) and chickpea (1,031±9 mg/kg) were used assubstrates. A blend of selected flours was also fermentedwith two GABA-producing strains; the best performancewas found when L. plantarum C48 was applied withGABA production levels of 989±10 mg/kg. In conclusion,the use of a blend of pseudo-cereal and leguminous flourssubjected to sourdough fermentation by selected GABA-producing strains might be a promising tool for enhancingthe nutritional quality of GF bread.

Another major problem associated with a strict GFD isthe higher incidence of children being overweight (72%)compared to children not following a strict GFD (51%) andhealthy matched controls (47%) (Mariani et al. 1998). Thiscondition was also confirmed by Castelluzzo et al. (2011)who showed how obesity and CD are two very prevalentconditions which can occasionally overlap in the paediatricage. Moreover, once CD has been diagnosed, the normal-isation of absorptive processes generally tends to increaseweight (Castelluzzo et al. 2011). This is mainly due to anunbalanced diet as a consequence of poor alimentarychoices among the GF products, generally characterisedby a higher percentage of calories originating from fatrather than carbohydrates (Ciacci et al. 2002).

LAB fermentation also has great potential to reducestarch digestibility of the bread (Liljeberg et al. 1995). Inparticular, the presence of organic acids like lactic andacetic acid in bread, formed during sourdough fermentation,has been reported to reduce acute glycaemic and/orinsulinaemic responses (Liljeberg et al. 1995).

The physiological mechanisms for the acute effects ofacids appear to vary, whereas acetic and propionic acidsprolong the gastric emptying rate (Liljeberg and Björck1998) and lactic acid appears instead to lower the rate ofstarch digestion in bread (Liljeberg et al. 1995). Moreover,chemical changes taking place in sourdough seem todiminish the degree of starch gelatinisation (Östman 2003)which would partly explain the lower digestibility offermented cereal foods.

To date, only one work has investigated the use ofmicrobial fermentation to reduce acute insulinaemic responsein GF cereal products. In this study, Alminger andEklund-Jonsson (2008) evaluate the impact of high β-glucan oat and barley tempe, a fermented food native ofIndonesia and originally made from soybeans inoculatedwith a mould of the genus Rhizopus, on postprandialglucose and insulin response in healthy adults. Oat tempesignificantly reduced the insulin response after the mealwhen compared with high β-glucan barley tempe. Theauthors conclude that the metabolic benefits of using highfibre content whole grain, as well as microbial fermenta-tion, appear to work synergistically to affect the digestionand absorption of carbohydrates. Thus, even if furtherstudies are required, it is not speculative to assume that

478 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

microbial fermentation can be also used to reduce acuteglycaemic and/or insulinaemic responses in GF cerealproducts.

Fermentation also provides the optimum pH conditionfor enzymatic degradation of phytate which is present incereals and pseudocereals in the form of complexes withpolyvalent cations such as iron, zinc, calcium, magnesiumand proteins. Such a reduction in phytate can increase theamount of soluble iron, zinc and calcium several fold(Kabak and Dobson 2011). Phytase activity has beeninvestigated during fermentation of some GF crops. Inparticular, fermentation of sorghum and pearl millet wasshown to induce a decrease in the phytic acid content, andtwo phytase-positive strains, i.e. L. plantarum and L.fermentum, were isolated from fermenting pearl millet(Songre-Ouattara et al. 2009).

LAB fermentation can also effectively reduce theanti-nutritional factors such as tannins (Obizoba andAtii 1994) and enzyme inhibitors (protease and amylaseinhibitors, polyphenols) from millet and sorghum (Holzapfel1997) and some non-digestible poly- and oligosacchar-ides (raffinose, stachyose, verbascose) from soy flour(Holzapfel 1997) normally used in the formulation of theGF products.

Microbial fermentation also represents a powerful toolfor the biological enrichment of GF products basically byincreasing the content of the essential amino acids (Adams1990). For example, fermentation significantly improvesthe protein quality as well as the level of lysine in oats, rice,millet and maize (Hamad and Fields 1979; Lee et al. 1999).In the same way, during the fermentation of corn meal, theconcentrations of available lysine, methionine and trypto-phan increase (Nanson and Fields 1984), as well as theprotein digestibility and non-protein nitrogen content(Yousif and El Tinay 2000). Even if the effect of microbialfermentation on the nutritive value of cereals is variable(McKay and Baldwin 1990), the evidence for improvementis substantial.

Microbial detoxification during food fermentationprocessing

Mycotoxin contamination in maize, rice, sorghum, millet,buckwheat and teff, commonly utilised in the formulationof GF products, has been widely reported (Ayalew et al.2006; Reddy et al. 2009; Bresler et al. 1995; Taylor andEmmambux 2008; Tanaka et al. 2007; Adams 1990). Inaddition, mycotoxins are generally thermostable com-pounds and, thus, are not destroyed during most foodprocessing operations, such as baking (Bullerman andBianchini 2007) and may therefore contaminate the finalGF cereal-based foods.

Ostry and Ruprich (1998) found that 88% of the corn-based foods (gluten-free diet) in the Czech Republic arepositive for fumonisins. Schollenberger et al. (2005) foundthat 61% of the total corn-based GF foods marketed inGermany were toxin positive. Zearalenone and deoxyniva-lenol were detected in 57% and 39% of samples,respectively. A similar scenario was also found fromDall’Asta et al. (2009) who reported that 90% of GFcorn-based foods, sold in the Italian market, were contam-inated with fumonisin. The occurrence of mycotoxins in GFgrains is regarded as a major economical problem (Dalie etal. 2010) and is also potentially dangerous, particularly forCD sufferers.

Detoxification of mycotoxins in food through LABfermentation has been demonstrated over the years(Mokoena et al. 2005; Chelule et al. 2010; Schnurer andMagnusson 2005; Gourama and Bullerman 1995; Dalie etal. 2010; Oluwafemi and Da-Silva 2009; Mokoena et al.2006). Using LAB fermentation for detoxification isadvantageous since it is a milder method which preservesthe nutritive value and flavour of decontaminated food(Bata and Lasztity 1999). In addition to this, LABfermentation irreversibly degrades mycotoxins withoutleaving any toxic residues. The detoxifying ability isbelieved to be through the toxin binding effect (El-Nezamiet al. 2002; Haskard et al. 2001; Turbic et al. 2002). Otherauthors allude to the possibility of an enzymatic interaction,although this was not thoroughly investigated (Zinedine etal. 2005).

The binding property displayed by some selected LAB,resulting in a decrease of mycotoxin bioavailability, couldtherefore be used in novel approaches to decontaminate GFproducts. However, little is known at this time about thestability and toxicity of LAB–mycotoxin complexes. Manyquestions must still be answered before they can bepractically applied at the industrial level. However, thepotential anti-mycotoxigenic activity of LAB places themin a promising position for the development of a newapproach for detoxification of mycotoxins in GF products.As in the case of mycotoxin detoxification, LAB fermen-tation has also been successful in the detoxification ofcassava toxins (cyanogens) following fermentation ofcassava food products such as gari. As a fermented food,gari is an example of a food being rendered safe for humanconsumption which would otherwise be toxic due to highinherent levels of cyanogenic glucosides (Caplice andFitzgerald 1999).

Microbial fermentation by LAB has also been suggestedas new tool for gluten detoxification in food processing forceliac persons (De Angelis et al. 2006a; Di Cagno et al.2008). Gluten detoxification by LAB is due to a verycomplex system capable of hydrolysing some of thepotential toxic peptides where proline is involved (Kunji

Appl Microbiol Biotechnol (2012) 93:473–485 479

Author's personal copy

et al. 1996). Thus, in order to have a complete hydrolysis ofpro-rich peptides, including the 33-mer peptide (the mostpotent inducer of gut-derived human T cell lines in celiacdisease patients), a pool of sourdough lactobacilli is needed.In this regard, Gobbetti et al. (2007) developed a mixture ofprobiotic strains showing an ability to decrease the toxicityof wheat flour during long-time fermentations (Gobbetti etal. 2007). Additionally, long-time fermentation of dough byselected LAB was also shown to be a potential tool todecrease the risk of rye contamination of GF products forceliac patients (De Angelis et al. 2006a). Studies conductedby Di Cagno et al. (2004, 2005) and De Angelis et al.(2006b) showed that a pool of LAB under specificprocessing conditions (long-time and semi-liquid fermenta-tion) had the capacity to markedly hydrolyse the wheatgliadin fraction in pasta and bread products. However, evenif this approach is not yet applied for the industrialproduction of GF products, sourdough fermentation startedwith LAB strains able to hydrolyse wheat flour gliadinswould eliminate any traces of toxic peptides in processedfoods, minimising the long-term risks and improving thequality of life for individuals affected by CD.

GF cereal-based functional foods

The claimed health benefits of fermented functional foodsare expressed either directly through the interaction ofingested live microorganisms, bacteria or yeast with thehost (probiotic effect) or indirectly as a result of ingestionof microbial metabolites produced during the fermentationprocess (biogenic effect) (Stanton et al. 2005).

Non-dairy probiotic products are of worldwide impor-tance due to the ongoing trend of vegetarianism and to ahigh prevalence of lactose malabsorption in celiac patients(secondary hypolactasia) (Bode and Gudmand-Hoyer1988). Moreover, in accordance with Swagerty et al.(2002), in northern Europe, the number of lactose-intolerant (primary hypolactasia) (Vesa et al. 2000) indi-viduals is around 5% and in some Asiatic countries (Japan,China) it reaches 100%. Therefore, both forms of hypo-lactasia represent major drawbacks in relation to theconsumption of probiotic dairy products, not only for celiacpatients but also for a large portion of the population.Hence, it is evident that the development of lactose-freefunctional products is a necessary task.

Lactobacilli and bifidobacteria are fastidious organismsthat have complex nutritional requirements (carbohydrates,amino acids, peptides, fatty acid esters, salts, nucleic acidderivates and vitamins) (Severson 1998). Milk, whichcontains carbohydrates, fat, casein protein, vitamins andminerals, is a very nutritious growth medium for manymicroorganisms (Marshall and Tamime 1997). Thus, most

companies opt for milk-based media for probiotic bacterialcell mass production (Gilliland et al. 1985). Generally, thepopulation of lactobacilli in fully fermented GF sourdoughis greater than 109 cfu g−1, while the LAB/yeast ratio isgenerally 100:1 (Vogelmann et al. 2009). Good growth ofLAB in GF cereals suggests that the incorporation ofprobiotic strains (both human and nonhuman derivedstrains) in GF cereal substrates under controlled conditionswould produce a fermented food with defined andconsistent characteristics and possibly health-promotingproperties combining the probiotic and prebiotic concept(Charalampopoulos et al. 2002b). When compared to milk,GF cereals have a higher content of some of the essentialvitamins, have increased dietary fibre and mineral levels(especially phosphorous), but a lower amount of ferment-able carbohydrates (usually less than 1%). Charalampopouloset al. (2002a) reported that malt, barley and wheat extractwere able to support the human derived strains of L.reuteri, L. plantarum, Lactobacillus acidophilus and L.fermentum without the addition of any supplements. In themalt medium, all strains attained high maximum cellpopulations, mainly due to the increased amount ofsoluble carbohydrates (maltose, fructose, glucose andsucrose) and amino nitrogen. These findings suggest thatmalting technology might represent a potential tool toimprove the growth performance of the probiotic strainwhen GF cereal grains are used as growth substrates.Marklinder and Lönner (1992), as well as Johansson et al.(1998), reported that after appropriate processing, oats are asuitable substrate for LAB fermentation. Enzymaticallytreated oat bases have been developed and applied, byMårtensson et al. (2001, 2002a, b), as substrates for lacticacid fermentation using dairy starter cultures. Furthermore,Angelov et al. (2006) developed a new oat-based symbioticdrink (product that uses a prebiotic and probiotic combina-tion) (Roberfroid 1998) combining the health benefits of aprobiotic culture with the oat prebiotic beta-glucan. Theprobiotic and prebiotic characteristics of the oat drink wereensured for 21 days of storage due to both an unchangedcontent of the beta-glucan within this storage time and aviable cell count of 106–107 cfu ml−1 at the end of thestorage (which ensure the probiotic characteristics of thedrinks) (Gomes and Malcata 1999; Shortt 1999).

In recent years, GF cereals such as maize, rice, oat,sorghum and millet have been investigated as raw mediaand used for the development of non-dairy probioticproducts (Angelov et al. 2006; Blandino et al. 2003;Boonyaratanakornkit 2000; Helland et al. 2004; Mårtenssonet al. 2002a, b; McMaster et al. 2005; Santos 2001)(Table 3).

Despite the aforementioned GF cereal raw materials,there is a wide variety of GF cereals which have notreceived the scientific attention they deserve. Among them,

480 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

quinoa might represent an ideal substrate for LAB growthsince the quality of its protein matches that of the milkprotein casein and its concentration of fermentable carbo-hydrates, around 2% (Valencia Chamorro 2003), is suffi-cient to ensure a prompt LAB growth.

Future prospects

According to the Packaged Facts report entitled “Gluten-free Foods and Beverages in the U.S. 3rd Edition 2011”,the market research organisation predicts that the GFmarket will continue to grow over the next 5 years, eventhough at a slower rate, and now projects the US market forGF foods and beverages to approach $5.5bn by 2015. TheGF market was estimated to have been $2.64bn in 2010.

The Packaged Facts organisation carried out an onlinenationwide survey of 1,881 adults, in 2010, including 277consumers of GF products. It found that, in addition topeople following a GF diet out of necessity because theysuffer from CD or a food allergy, a growing number ofpeople are GF by choice as:

(a) GF diet may treat medical conditions includingdermatitis herpetiformis, irritable bowel syndrome,neurologic disorders, rheumatoid arthritis, diabetesmellitus and HIV-associated enteropathy

(b) A personal choice towards achieving a “healthier wayto live” finding that living GF simply makes peoplefeel better

(c) A tool for weight loss(d) Member of the household has a CD sufferer or

intolerance to gluten, wheat or other ingredients(e) GF products are generally considered to be higher quality

Considering the results of the survey, it is evident thatfew consumers buy GF foods to address CD or dietaryintolerance and CD may have little influence on the soaringGF market. Moreover, the results obtained from the surveyhighlight a lack of information regarding GF products anddiet. In fact, the strength of evidence for the use of a GFD

in the non-celiac disease segment of the population varies,and future research is necessary to define the benefits of aGFD for those conditions with weak existing evidence (El-Chammas and Danner 2011; Johnson et al. 2011). More-over, the GF diet has a poor vitamin and mineral status(Kupper 2005; Hallert et al. 2002) with a higher percentageof calories being obtained from fat and, to a lesser extent, fromcarbohydrates (Ciacci et al. 2002). Diet response studiessuggest that gluten exclusion is associated with a significantincrease in body fat stores, although the studies have beenconducted on patients with a body mass index significantlylower than healthy controls (Capristo et al. 2000; Smecuol etal. 1997). Furthermore, Dickey and Kearney (2006) report anincrease in weight of already overweight patients afterdietary gluten exclusion for 2 years.

In order to match the celiac and non-celiac consumerexpectations, a tangible improvement of GF product qualitymust be attained. In particular, the bakery segment of GFproducts continues to present the biggest technical chal-lenges for GF manufactures in terms of texture, nutritionand shelf life. LAB and yeast fermentation options for themanufacture of GF products and beverages represent apowerful ecological/economical tool to address what mostconsumers are looking for. This includes functionality, cost,clean label, clear benefits, natural ingredients, better shelflife and improved nutritional quality.

Moreover, there is a rapid increase in the understandingof how microbial fermentation can be employed to deliverhealth benefits by means of food intake. The developmentof GF cereal-based probiotic products represents an area ofhuge growth potential for the food industry. The importanceof this research lies in the lack of bakery products availablein today’s gluten-free market. Those that are available arecharacterised by low palatability and may lead to nutritionaldeficiencies of vitamins, minerals and fibre. It is of utmostimportance that the division between conventional bakedcereal products and GF goods is addressed based onconsumer and industry demands. This field may beexplored through the development of new ingredients,processes and products. For this purpose, new studies must

Table 3 Recently developedgluten-free cereal-based probi-otic products

Products References

Rice-based yogurt Boonyaratanakornkit (2000)

Oat-based drink Angelov et al. (2006)

Oat-based products Mårtensson et al. (2002a, b)

Yosa (oat-bran pudding) Blandino et al. (2003)

Mahewu (fermented maize beverage) McMaster et al. (2005)

Maize-based beverage Wacher et al. (2000)

Maize, sorghum, and millet malt fermented probiotic beverages Blandino et al. (2003)

Millet or sorghum flour fermented probiotic beverages Muyanja et al. (2003)

Appl Microbiol Biotechnol (2012) 93:473–485 481

Author's personal copy

be carried out to investigate more raw material options thatare not yet used industrially (re-discover ancient grains suchas quinoa and amaranth), to optimise the fermentationprocess selecting the optimal microbial starter cultures, toreengineer products and processes and to prove that thisnew generation of GF products can effectively match theceliac and non-celiac consumers demands.

Acknowledgements The authors would like to acknowledge finan-cial support by the Seventh Framework Program of the EuropeanCommunity for research, technological development and demonstra-tion activities (2007–2013) and Specific Programme “Capacities”—research for the benefit of SMEs (262418 GLUTENFREE). Theauthors acknowledge that this research was also partly funded byFIRM Ireland. This publication solely reflects the authors’ views andthe Community is not liable for any use that may be made of theinformation contained in this publication.

References

Adams MR (1990) Topical aspects of fermented foods. Trends FoodSci Technol 1:140–144

Alminger M, Eklund-Jonsson C (2008) Whole-grain cereal productsbased on a high-fibre barley or oat genotype lower post-prandialglucose and insulin responses in healthy humans. Eur J Nutr47(6):294–300

Angelov A, Gotcheva V, Kuncheva R, Hristozova T (2006)Development of a new oat-based probiotic drink. Int J FoodMicrobiol 112(1):75–80

Annan NT, Poll L, Plahar WA, Jakobsen M (2003) Aroma characteristicsof spontaneously fermented Ghanaian maize dough for kenkey. EurFood Res Tech 217(1):53–60

Arendt EK, Morrissey A, Moore MM, Dal Bello F (2008) Gluten-free breads. In: Elke KA, Fabio Dal Bello (eds) Gluten-freecereal products and beverages. Academic, San Diego, pp289–319

Arendt EK, Moroni AV, Morrissey JP, Dal Bello F (2010) Develop-ment of buckwheat and teff sourdoughs with the use ofcommercial starters. Int J Food Microbiol 142(1–2):142–148

Ayalew A, Fehrmann H, Lepschy J, Beck R, Abate D (2006) Naturaloccurrence of mycotoxins in staple cereals from Ethiopia.Mycopathologia 162(1):57–63

Bata A, Lasztity R (1999) Detoxification of mycotoxin-contaminatedfood and feed by microorganisms. Trends Food Sci Technol 10(6–7):223–228

Batish VK, Roy U, et al (1997) Antifungal attributes of lactic acidbacteria—a review. Crit Rev Biotechnol 17(3):209–225

Berghofer E, Schonlechner R (2009) Overview of gluten-free (cerealsand other) raw materials and their properties. In: Arendt EK,DalBello F (eds) The science of gluten-free foods and beverages.AACC International, Saint Paul

Biagi F, Klersy C, Balduzzi D, Corazza GR (2010) Are we not over-estimating the prevalence of celiac disease in the generalpopulation? Ann Med 42(8):557–561

Blandino A, Al-Aseeri ME, Pandiella SS, Cantero D, Webb C (2003)Cereal-based fermented foods and beverages. Food Res Int 36(6):527–543

Bodé S, Gudmand-Høyer E (1988) Incidence and clinical significanceof lactose malabsorption in adult coeliac disease. Scand JGastroentero 23(4):484–488

Boonyaratanakornkit M (2000) Development of a yoghurt-typeproduct from saccharified rice. Kasetsart Journal 34:107–116

Brandt MJ, Bode R (2009) Gluten-free sourdough starter andproducts. Baking+Biscuit International (1):34–36

Bresler G, Brizzio SB, Vaamonde G (1995) Mycotoxin-producingpotential of fungi isolated from amaranth seeds in Argentina. IntJ Food Microbiol 25(1):101–108

Brower V (1998) Nutraceuticals: poised for a healthy slice of thehealthcare market? Nat Biotechnol 16(8):728–731

Bullerman LB, Bianchini A (2007) Stability of mycotoxinsduring food processing. Int J Food Microbiol 119(1–2):140–146

Butt MS, Tahir-Nadeem M, Khan MKI, Shabir R, Butt MS (2008)Oat: unique among the cereals. Eur J Nutr 47(2):68–79

Caplice E, Fitzgerald GF (1999) Food fermentations: role of micro-organisms in food production and preservation. Int J FoodMicrobiol 50(1-2):131–149

Capristo E, Addolorato G, Mingrone G, De Gaetano A, Greco AV,Tataranni PA, Gasbarrini G (2000) Changes in body composition,substrate oxidation, and resting metabolic rate in adult celiacdisease patients after a 1-y gluten-free diet treatment. Am J ClinNutr 72(1):76–81

Castelluzzo MA, Massoud M, Valitutti F, Renato T, Rea F, DiIorio L, Polito A, Minò G, Cotugno N, Paone FM (2011)Coexisting celiac disease and overweight/obesity in an Italianpediatric population. Gastroenterology 140(5, Supplement 1):S-685

Charalampopoulos D, Pandiella SS, Webb C (2002a) Growth studiesof potentially probiotic lactic acid bacteria in cereal-basedsubstrates. J Appl Microbiol 92(5):851–859

Charalampopoulos D, Wang R, Pandiella SS, Webb C (2002b)Application of cereals and cereal components in functionalfoods: a review. Int J Food Microbiol 79(1–2):131–141

Chelule PK, Mbongwa HP, Carries S, Gqaleni N (2010) Lactic acidfermentation improves the quality of amahewu, a traditionalSouth African maize-based porridge. Food Chem 122(3):656–661

Ciacci C, Cirillo M, Cavallaro R, Mazzacca G (2002) Long-termfollow-up of celiac adults on gluten-free diet: prevalence andcorrelates of intestinal damage. Digestion 66(3):178–185

Coda R, Rizzello CG, Gobbetti M (2010) Use of sourdoughfermentation and pseudo-cereals and leguminous flours for themaking of a functional bread enriched of gamma-aminobutyricacid (GABA). Int J Food Microbiol 137(2–3):236–245

Dal Bello F, Clarke CI, Ryan LAM, Ulmer H, Schober TJ, Ström K,Sjögren J, van Sinderen D, Schnürer J, Arendt EK (2007)Improvement of the quality and shelf life of wheat bread byfermentation with the antifungal strain Lactobacillus plantarumFST 1.7. Journal of Cereal Science 45(3):309–318

Dalie DKD, Deschamps AM, Richard-Forget F (2010) Lactic acidbacteria—potential for control of mould growth and mycotoxins:a review. Food Control 21(4):370–380

Dall’Asta C, Galaverna G, Mangia M, Sforza S, Dossena A, MarchelliR (2009) Free and bound fumonisins in gluten-free foodproducts. Mol Nutr Food Res 53(4):492–499

De Angelis M, Coda R, Silano M, Minervini F, Rizzello CG, DiCagno R, Vicentini O, De Vincenzi M, Gobbetti M (2006a)Fermentation by selected sourdough lactic acid bacteria todecrease celiac intolerance to rye flour. J Cereal Sci 43(3):301–314

De Angelis M, Rizzello CG, Fasano A, Clemente MG, Simone CD,Silano M, Vincenzi MD, Losito I, Gobbetti M (2006b) VSL#3probiotic preparation has the capacity to hydrolyze gliadinpolypeptides responsible for Celiac Sprue probiotics and glutenintolerance. Biochimica et Biophysica Acta (BBA)—MolecularBasis of Disease 1762(1):80–93

De Vuyst L, Vrancken G, Ravyts F, Rimaux I, Weckx S (2009)Biodiversity, ecological determinants, and metabolic exploitation

482 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

of sourdough microbiota. Food Microbiol 26(7):666–675.doi:10.1016/J.Fm.2009.07.012

Di Cagno R, De Angelis M, Auricchio S, Greco L, Clarke C. DeVincenzi M, Giovannini C, D’Archivio M, Landolfo F, Parrilli G,Minervini F, Arendt E, Gobbetti M (2004) Sourdough breadmade from wheat and nontoxic flours and started with selectedlactobacilli is tolerated in celiac sprue patients. Appl EnvironMicrob 70(2):1088–1096

Di Cagno R, De Angelis M, Alfonsi G, De Vincenzi M, Silano M,Vincentini O, Gobbetti M (2005) Pasta made from durum wheatsemolina fermented with selected lactobacilli as a tool for apotential decrease of the gluten intolerance. J Agr Food Chem 53(11):4393–4402

Di Cagno R, Rizzello CG, De Angelis M, Cassone A, Giuliani G,Benedusi A, Limitone A, Surico RF, Gobbetti M (2008) Use ofselected sourdough strains of Lactobacillus for removing glutenand enhancing the nutritional properties of gluten-free bread. JFood Protect 71(7):1491–1495

Di Cagno R, Barbato M, Di Camillo C, Maiella G, Pannone V,Rizzello CG, De Angelis M, Giuliani G, De Vincenzi M,Gobbetti M, Cucchiara S (2010a) PA29 presumptive safety forceliac patients of wheat baked goods rendered gluten-freeduring sourdough fermentation. Digestive and Liver Disease 42(Supplement 5):S353

Di Cagno R, Barbato M, Di Camillo C, Rizzello CG, De Angelis M,Giuliani G, De Vincenzi M, Gobbetti M, Cucchiara S (2010b)Gluten-free sourdough wheat baked goods appear safe for youngceliac patients: a pilot study. J Pediatr Gastroenterol Nutr 51(6):777–783

Dickey W, Kearney N (2006) Overweight in celiac disease:prevalence, clinical characteristics, and effect of a gluten-freediet. Am J Gastroenterol 101(10):2356–2359

Dike KS, Sanni AI (2010) Influence of starter culture of lactic acidbacteria on the shelf life of agidi, an indigenous fermented cerealproduct. Afr J Biotechnol 9(46):7922–7927

Edema MO, Sanni AI (2008) Functional properties of selected startercultures for sour maize bread. Food Microbiol 25(4):616–625

El-Chammas K, Danner E (2011) Gluten-free diet in nonceliacdisease. Nutr Clin Pract 26(3):294–299

El-Nezami H, Polychronaki N, Salminen S,Mykkanen H (2002) Bindingrather than metabolism may explain the interaction of two food-grade Lactobacillus strains with zearalenone and its derivativealpha-zearalenol. Appl Environ Microbiol 68(7):3545–3549

Farrell RJ, Kelly CP (2002) Celiac sprue. N Engl J Med 346(3):180–188

Gallagher E, Gormley TR, Arendt EK (2004) Recent advances in theformulation of gluten-free cereal-based products. Trends FoodSci Technol 15(3–4):143–152

Galle S, Schwab C, Arendt E, Ganzle M (2010) Exopolysaccharide-forming Weissella strains as starter cultures for sorghum andwheat sourdoughs. J Agric Food Chem 58(9):5834–5841

Galle S, Schwab C, Arendt EK, Ganzle MG (2011) Structural andrheological characterisation of heteropolysaccharides producedby lactic acid bacteria in wheat and sorghum sourdough. FoodMicrobiol 28(3):547–553

Gilliland SE, Nelson CR, Maxwell C (1985) Assimilation ofcholesterol by Lactobacillus-Acidophilus. Appl Environ Microb49(2):377–381

Giuliani GM, Benedusi A, Di Cagno R, De Angelis M, Luisi A,Gobbetti M (2006) Miscela di batteri lattici per la preparazione diprodotti da forno senza glutine.

Gobbetti M (1998) The sourdough microflora: interactions of lacticacid bacteria and yeasts. Trends Food Sci Technol 9(7):267–274

Gobbetti M, Rizzello CG, Di Cagno R, De Angelis M (2007)Sourdough lactobacilli and celiac disease. Food Microbiol 24(2):187–196

Gomes AMP, Malcata FX (1999) Bifidobacterium spp. and Lactoba-cillus acidophilus: biological, biochemical, technological andtherapeutical properties relevant for use as probiotics. TrendsFood Sci Technol 10(4–5):139–157

Gourama H, Bullerman LB (1995) Antimycotic and antiaflatoxigeniceffect of lactic-acid bacteria—a review. J Food Prot 58(11):1275–1280

Hager AS, Axel C, Arendt EK (2011) Status of carbohydrates anddietary fiber in gluten-free diets. Cereal Foods World 56(3):109–114

Hallert C, Grant C, Grehn S, Granno C, Hulten S, Midhagen G, StromM, Svensson H, Valdimarsson T (2002) Evidence of poorvitamin status in celiac patients on a gluten-free diet for 10 years.Alimentary Pharmacology and Therapeutics Aliment PharmTherap 16(7):1333–1339

Hamad AM, Fields ML (1979) Evaluation of the protein quality andavailable lysine of germinated and fermented cereals. J Food Sci44(2):456–459

Hansen A, Schieberle P (2005) Generation of aroma compoundsduring sourdough fermentation: applied and fundamental aspects.Trends Food Sci Technol 16(1–3):85–94

Haskard CA, El-Nezami HS, Kankaanpaa PE, Salminen S, Ahokas JT(2001) Surface binding of aflatoxin B(1) by lactic acid bacteria.Applied Environmental Microbiology 67(7):3086

Helland MH, Wicklund T, Narvhus JA (2004) Growth and metabolismof selected strains of probiotic bacteria in milk- and water-basedcereal puddings. Int Dairy J 14(11):957–965

Holzapfel W (1997) Use of starter cultures in fermentation on ahousehold scale. Food Control 8(5–6):241–258

Hopman EG, le Cessie S, von Blomberg BM, Mearin ML (2006)Nutritional management of the gluten-free diet in young peoplewith celiac disease in the Netherlands. J Pediatr GastroenterolNutr 43(1):102–108

Houben A, Gotz H, Mitzscherling M, Becker T (2010) Modificationof the rheological behavior of amaranth (Amaranthus hypochon-driacus) dough. J Cereal Sci 51(3):350–356

Hounhouigan DJ, Nout MJR, Nago CM, Houben JH, Rombouts FM(1993) Composition and microbiological and physical attributesof Mawe, a fermented maize dough from Benin. Int J Food SciTechnol 28(5):513–517

Huttner EK, Dal Bello F, Arendt EK (2010) Identification of lacticacid bacteria isolated from oat sourdoughs and investigation intotheir potential for the improvement of oat bread quality. Eur FoodRes Technol 230(6):849–857

Ibanoglu E, Ercelebi EA (2007) Thermal denaturation and functionalproperties of egg proteins in the presence of hydrocolloid gums.Food Chem 101(2):626–633

Johansson ML, Nobaek S, Berggren A, Nyman M, Björck I, Ahrné S,Jeppsson B, Molin G (1998) Survival of Lactobacillus plantarumDSM 9843 (299v), and effect on the short-chain fatty acidcontent of faeces after ingestion of a rose-hip drink withfermented oats. Int J Food Microbiol 42(1–2):29–38

Johnson C, Handen B, Zimmer M, Sacco K, Turner K (2011) Effectsof gluten free/casein free diet in young children with autism: apilot study. Journal of Developmental and Physical Disabilities23(3):213–225

Kabak B, Dobson ADW (2011) An introduction to the traditionalfermented foods and beverages of Turkey. Crit Rev Food SciNutr 51(3):248–260

Keagy PM, Stokstad ELR, Fellers DA (1975) Folacin stability duringbread processing and family flour storage. Cereal Chemistry 52(3):348–356

Koh BK, Singh V (2009) Cooking behaviour of rice and black gramin the preparation of idli, a traditional fermented product ofIndian origin, by viscography. Journal of Texture Studies 40(1):36–50

Appl Microbiol Biotechnol (2012) 93:473–485 483

Author's personal copy

Kunji ERS, Mierau I, Hagting A, Poolman B, Konings WN (1996)The proteolytic systems of lactic acid bacteria. Anton Leeuw Int JG 70(2-4):187–221

Kupper C (2005) Dietary guidelines and implementation for celiacdisease. Gastroenterology 128(4, Supplement 1):S121–S127

Lavermicocca P, Valerio F, Visconti A (2003) Antifungal activity ofphenyllactic acid against molds isolated from bakery products.Appl Environ Microbiol 69(1):634–640

Lazaridou A, Duta D, Papageorgiou M, Belc N, Biliaderis CG (2007)Effects of hydrocolloids on dough rheology and bread qualityparameters in gluten-free formulations. Journal of Food Engineering79(3):1033–1047

Lee JH, Lee SK, Park KH, Hwang IK, Ji GE (1999) Fermentation ofrice using amylolytic Bifidobacterium. Int J Food Microbiol 50(3):155–161

Liljeberg H, Björck I (1998) Delayed gastric emptying rate mayexplain improved glycaemia in healthy subjects to a starchy mealwith added vinegar. Eur J Clin Nutr 52(5):368–371

Liljeberg HGM, Lonner CH, Bjorck IME (1995) Sourdough fermen-tation or addition of organic acids or corresponding salts to breadimproves nutritional properties of starch in healthy humans. JNutr 125(6):1503–1511

Livsmedelsverket (2002) Riksmaten 1997–98. Kostvanor och näringsin-tag i Sverige, Metod och resultatanalys. Livsmedelsverket, Uppsala

Lowe DP, Arendt EK (2004) The use and effects of lactic acid bacteriain malting and brewing with their relationships to antifungalactivity, mycotoxins and gushing: A review. J I Brewing 110(3):163–180

Mariani P, Viti MG, Montouri M, La Vecchia A, Cipolletta E, CalvaniL, Bonamico M (1998) The gluten-free diet: a nutritional riskfactor for adolescents with celiac disease? J Pediatr GastroenterolNutr 27(5):519–523

Marklinder I, Lönner C (1992) Fermentation properties of intestinalstrains of Lactobacillus, of a sourdough and of a yoghurt starterculture in an oat-based nutritive solution. Food Microbiol 9(3):197–205

Marshall VM, Tamime AY (1997) Starter cultures employed in themanufacture of biofermented milks. Int J Dairy Technol 50(1):35–41

Mårtensson O, Andersson C, Andersson K, Öste R, Holst O (2001)Formulation of an oat-based fermented product and its comparisonwith yoghurt. J Sci Food Agric 81(14):1314–1321

Mårtensson O, Oste B, Holst O (2002a) The effect of yoghurt cultureon the survival of probiotic bacteria in oat-based, non-dairyproducts. Food Res Int 35(8):775–784

Mårtensson O, Staaf J, Duecas-Chasco M, Irastorza A, Oste R, HolstO (2002b) A fermented, ropy, non-dairy oat product based on theexopolysaccharide-producing strain Pediococcus damnosus.Advances in Food Sciences 24:4–11

McKay LL, Baldwin KA (1990) Applications for biotechnology:present and future improvements in lactic acid bacteria. FEMSMicrobiol Lett 87(1–2):3–14

McMaster LD, Kokott SA, Reid SJ, Abratt V (2005) Use of traditionalAfrican fermented beverages as delivery vehicles for Bifidobac-terium lactis DSM 10140. Int J Food Microbiol 102(2):231–237

Meroth CB, Hammes WP, Hertel C (2004) Characterisation of themicrobiota of rice sourdoughs and description of Lactobacillusspicheri sp. nov. Syst Appl Microbiol 27(2):151–159

Minervini F, De Angelis M, Di Cagno R, Pinto D, Siragusa S,Rizzello CG, Gobbetti M (2010) Robustness of Lactobacillusplantarum starters during daily propagation of wheat floursourdough type I. Food Microbiol 27(7):897–908

Mokoena MP, Chelule PK, Gqaleni N (2005) Reduction of fumonisinB1 and zearalenone by lactic acid bacteria in fermented maizemeal. J Food Prot 68(10):2095–2099

Mokoena MP, Chelule PK, Gqaleni N (2006) The toxicity anddecreased concentration of aflatoxin B1 in natural lactic acidfermented maize meal. J Appl Microbiol 100(4):773–777

Moore MM, Juga B, Schober TJ, Arendt EK (2007) Effect of lacticacid bacteria on properties of gluten-free sourdoughs, batters, andquality and ultrastructure of gluten-free bread. Cereal Chemistry84(4):357–364

Moore MM, Dal Bello F, Arendt EK (2008) Sourdough fermented byLactobacillus plantarum FST 1.7 improves the quality and shelflife of gluten-free bread. European Food Research and Technology226(6):1309–1316

Moroni AV, Dal Bello F, Arendt EK (2009) Sourdough in gluten-freebread-making: an ancient technology to solve a novel issue?Food Microbiol 26(7):676–684

Moroni AV, Arendt EK, Morrissey JP, Dal Bello F (2010) Develop-ment of buckwheat and teff sourdoughs with the use ofcommercial starters. Int J Food Microbiol 142(1–2):142–148

Mugula JK, Nnko SAM, et al (2001) Changes in quality attributesduring storage of togwa, a lactic acid fermented gruel. J FoodSafety 21(3):181–194

Mugula JK, Nnko SAM, Narvhus JA, Sorhaug T (2003) Microbio-logical and fermentation characteristics of togwa, a Tanzanianfermented food. Int J Food Microbiol 80(3):187–199

Muyanja CMBK, Narvhus JA, Treimo J, Langsrud T (2003) Isolation,characterisation and identification of lactic acid bacteria frombushera: a Ugandan traditional fermented beverage. Int J FoodMicrobiol 80(3):201–210

Nanson NJ, Fields ML (1984) Influence of temperature of fermenta-tion on the nutritive value of lactic acid fermented cornmeal. JFood Sci 49(3):958–959

Obizoba IC, Atii JV (1994) Evaluation of the effect of processingtechniques on the nutrient and antinutrient contents of pearlmillet (Pennisetum glaucum) seeds. Plant Foods Hum Nutr 45(1):23–34

Oluwafemi F, Da-Silva FA (2009) Removal of aflatoxins by viableand heat-killed Lactobacillus species isolated from fermentedmaize. Journal of Applied Biosciences 16:871–876

Ortolani C, Pastorello EA (2006) Food allergies and food intolerances.Best Pract Res Clin Gastroenterol 20(3):467–483

Osman MA (2004) Changes in sorghum enzyme inhibitors, phyticacid, tannins and in vitro protein digestibility occurring duringKhamir (local bread) fermentation. Food Chem 88(1):129–134

Östman, E (2003) Fermentation as a means of optimizing theglycaemic index—food mechanisms and metabolic merits withemphasis on lactic acid in cereal products. Ph.D. thesis, LundUniversity, Department of Applied Nutrition and Food Chemistry

Ostry V, Ruprich J (1998) Determination of the mycotoxinfumonisins in gluten-free diet (corn-based commodities) inthe Czech Republic. Central European Journal of PublicHealth 6(1):57–60

Pszczola DE (1992) The nutraceutical initiative: a proposal foreconomic and regulatory reform. Food Biotechnology 46:77–79

Reddy KRN, Abbas HK, Abel CA, Shier WT, Oliveira CAF,Raghavender CR (2009) Mycotoxin contamination of commer-cially important agricultural commodities. Toxin Reviews 28(2–3):154–168

Renzetti S, Arendt EK (2009) Effects of oxidase and proteasetreatments on the breadmaking functionality of a range ofgluten-free flours. European Food Research and Technology 229(2):307–317. doi:10.1007/s00217-009-1048-6

Renzetti S, Behr J, Vogel RF, Arendt EK (2008) Transglutaminasepolymerisation of buckwheat (Fagopyrum esculentum Moench)proteins. Journal of Cereal Science 48(3):747–754

Renzetti S, Courtin CM, Delcour JA, Arendt EK (2010) Oxidative andproteolytic enzyme preparations as promising improvers for oatbread formulations: rheological, biochemical and microstructural

484 Appl Microbiol Biotechnol (2012) 93:473–485

Author's personal copy

background. International Journal of Food Microbiology FoodChemistry 119(4):1465–1473

Rizzello CG, De Angelis M, Di Cagno R, Camarca A, Silano M,Losito A, De Vincenzi M, De Bari MD, Palmisano F, Maurano F,Gianfrani C, Gobbetti M (2007) Highly efficient gluten degrada-tion by lactobacilli and fungal proteases during food processing:new perspectives for celiac disease. Appl Environ Microbiol73(14):4499–4507

Rizzello GC, Coda R, De Angelis M, Di Cagno R, Carnevali P,Gobbetti M (2009) Long-term fungal inhibitory activity of water-soluble extract from Amaranthus spp. seeds during storageof gluten-free and wheat flour breads. Int J Food Microbiol131(2-3):189–196

Roberfroid MB (1998) Prebiotics and synbiotics: concepts andnutritional properties. Br J Nutr 80(4):S197–S202

Rouse S, van Sinderen D (2008) Bioprotective potential of lactic acidbacteria in malting and brewing. J Food Protect 71(8):1724–1733

Ryan LA, Zannini E, Dal Bello F, Pawlowska A, Koehler P, ArendtEK (2011) Lactobacillus amylovorus DSM 19280 as a novelfood-grade antifungal agent for bakery products. Int J FoodMicrobiol 146(3):276–283

Salovaara H (1996) The time of cereal based functional foods is here:introducing Yosa®, avellie. 26th Nordic Cereal Congress,Haugesund, Norway, Haugesund

Sanni AI, Onilude AA, Fatungase MO (1998) Production of sourmaize bread using starter-cultures. World J Microbiol Biotechnol14(1):101–106

Santos MCR (2001) Desenvolvimento de bebida e farinha lácteafermentada de ação probiótica a base de soro de leite e farinha demandioca por cultura mista de Lactobacillus plantarum A6,Lactobacillus casei Shirota e Lactobacillus acidophilus.Engenharia de Alimentos. Curitiba, Brasil Universidade Federaldo Paraná. MSc 106

Schnurer J, Magnusson J (2005) Antifungal lactic acid bacteria asbiopreservatives. Trends Food Sci Technol 16(1–3):70–78

Schober TJ, Bean SR, Boyle DL (2007) Gluten-free sorghum breadimproved by sourdough fermentation: biochemical, rheological,and microstructural background. J Agric Food Chem 55(13):5137–5146

Schoenlechner R, Wendner M, Siebenhandl-Ehn S, Berghofer E(2010) Pseudocereals as alternative sources for high folatecontent in staple foods. Journal of Cereal Science 52(3):475–479

Schollenberger M, Muller HM, Rufle M, Suchy S, Planck S, DrochnerW (2005) Survey of Fusarium toxins in foodstuffs of plant originmarketed in Germany. Int J Food Microbiol 97(3):317–326

Schwab C, Mastrangelo M, Corsetti A, Ganzle M (2008) Formation ofoligosaccharides and polysaccharides by Lactobacillus reuteriLTH5448 and Weissella cibaria 10 M in sorghum sourdoughs.Cereal Chemistry 85(5):679–684

Severson DK (1998) Lactic acid fermentations. In: Reed TWNaG (ed)Nutritional requirements of commercially important microorgan-isms. Esteekay Associates, Milwaukee, pp 258–297

Shortt C (1999) The probiotic century: historical and currentperspectives. Trends Food Sci Technol 10(12):411–417

Siragusa S, De Angelis M, Di Cagno R, Rizzello CG, Coda R,Gobbetti M (2007) Synthesis of gamma-aminobutyric acid bylactic acid bacteria isolated from a variety of Italian cheeses.Appl Environ Microbiol 73(22):7283–7290

Smecuol E, Gonzalez D, Mautalen C, Siccardi A, Cataldi M, NiveloniS, Mazure R, Vazquez H, Pedreira S, Soifer G, Boerr LA,Maurino E, Bai JC (1997) Longitudinal study on the effect oftreatment on body composition and anthropometry of celiac diseasepatients. Am J Gastroenterol 92(4):639–643

Songre-Ouattara LT, Mouquet-Rivier C, Icard-Verniere C, Rochette I,Diawara B, Guyot JP (2009) Potential of amylolytic lactic

acid bacteria to replace the use of malt for partial starchhydrolysis to produce African fermented pearl millet gruelfortified with groundnut. Int J Food Microbiol 130(3):258–264

Stanton C, Ross RP, Fitzgerald GF, Van Sinderen D (2005) Fermentedfunctional foods based on probiotics and their biogenic metabolites.Curr Opin Biotechnol 16(2):198–203

Steinkraus KH (1995) Handbook of indigenous fermented foods.Marcel Dekker, New York

Sterr Y, Weiss A, Schmidt H (2009) Evaluation of lactic acid bacteriafor sourdough fermentation of amaranth. Int J Food Microbiol136(1):75–82

Swagerty DL Jr, Walling AD, Klein RM (2002) Lactose intolerance.Am Fam Physician 65(8):1845–1850

Tack GJ, Verbeek WHM, Schreurs MWJ, Mulder CJJ (2010) Thespectrum of celiac disease: epidemiology, clinical aspects andtreatment. Nat Rev Gastroenterol Hepatol 7(4):204–213

Tanaka K, Sago Y, Zheng Y, Nakagawa H, Kushiro M (2007)Mycotoxins in rice. Int J Food Microbiol 119(1–2):59–66

Taranto MP, Vera JL, Hugenholtz J, De Valdez GF, Sesma F (2003)Lactobacillus reuteri CRL1098 produces cobalamin. J Bacteriol185(18):5643–5647

Taylor JRN, Emmambux MN (2008) Gluten-free foods andbeverages from millets. In: Elke KA, Fabio Dal B (eds)Gluten-free cereal products and beverages. Academic, SanDiego, pp 119–148

Turbic A, Ahokas JT, Haskard CA (2002) Selective in vitro binding ofdietary mutagens, individually or in combination, by lactic acidbacteria. Food Addit Contam 19(2):144–152

Valencia Chamorro SA (2003) Quinoa. In: Caballero B (ed)Encyclopedia of food science and nutrition. Academic, Amsterdam,pp 4895–4902

Vallons KJR, Ryan LAM, Arendt EK (2010) Promoting structureformation by high pressure in gluten-free flours. LWT Food SciTechnol 44:1672–1680

Vesa TH, Marteau P, Korpela R (2000) Lactose intolerance. J Am CollNutr 19(suppl 2):165S–175S

Vogelmann SA, Seitter M, Singer U, Brandt MJ, Hertel C (2009)Adaptability of lactic acid bacteria and yeasts to sourdoughsprepared from cereals, pseudocereals and cassava and use ofcompetitive strains as starters. Int J Food Microbiol 130(3):205–212

Wacher C, Canas A, Barzana E, Lappe P, Ulloa M, Owens JD (2000)Microbiology of Indian and Mestizo pozol fermentations. FoodMicrobiol 17(3):251–256

Wald N (1991) Prevention of neural tube defects. Results of theMedical Research Council vitamin study. Lancet 338:131–137

Wieser H, Koehler P (2008) The biochemical basis of celiac disease.Cereal Chem 85(1):1–13

Wijngaard HH, Arendt EK (2006) Optimisation of a mashing programfor 100% malted buckwheat. J I Brewing 112(1):57–65

Yazynina E, Johansson M, Jägerstad M, Jastrebova J (2008) Lowfolate content in gluten-free cereal products and their mainingredients. Food Chem 111(1):236–242

Yousif NE, El Tinay AH (2000) Effect of fermentation on proteinfractions and in vitro protein digestibility of maize. Food Chem70(2):181–184

Zinedine A, Faid M, Benlemlih M (2005) In vitro reduction ofaflatoxin b1 by strains of lactic acid bacteria isolated fromMoroccan sourdough bread. International Journal of Agricultureand Biology 7(1):67–70

Zweytick G, Berghofer E, (2009) Production of Gluten-Free Beer.Gluten-Free Food Science and Technology, Wiley-Blackwell,pp 181–199

Zweytick G, Sauerzopf E, Berghofer E (2005) Production of gluten-free beer. AACC-Annual Meeting Orlando, FL, USA

Appl Microbiol Biotechnol (2012) 93:473–485 485

Author's personal copy