Pasting properties, texture profile and stress–relaxation behavior of wheat starch/dietary fiber...

Onder Yildiz, Bayram Yurt, Omer Said Toker*, Mehmet Murat Ceylan, Mustafa Tahsin Yilmazand Ayhan Bastürk

Pasting, Textural and Sensory Characteristics ofthe Kofter, A Fruit-Based Dessert: Effect ofMolasses and Water Concentration

Abstract: Kofter is a traditional product which is com-posed of water, molasses and starch. The quality of Kofterdepends on many factors involving concentration of theingredients, starch concentration and type, compositionand type of the molasses and drying temperature andtime. In the present study, the effect of molasses concen-tration (75–25%) on the pasting and textural properties ofthe Kofter samples was investigated. All pasting proper-ties (peak viscosity, trough viscosity, breakdown viscos-ity, final viscosity, setback viscosity, peak time, pastingtemperature) were significantly affected by molasses con-centration used in the formula. The increase in waterconcentration generally caused increase in hardness,adhesiveness, gumminess and chewiness value of theKofter samples. Sensory analysis was also performed todetermine mostly preferred sample regarding appear-ance, color, texture, taste, odor and overall preference.According to the sensory results, Kofter sample including40% molasses and 60% water was found to be mostlypreferred sample.

Keywords: Kofter, molasses concentration, texture, past-ing properties, sensory

DOI 10.1515/ijfe-2014-0313

1 IntroductıonFruit-based dessert products have been attracted attentiondue to increasing tendency of the consumers to consumenatural products. By this way, it is possible to benefit affir-mative effects of the fruits throughout the year. Grape is oneof the fruit types widely produced in Turkey. It is processedto different products without loss of nutritional value, pro-viding possibility to benefit from its health beneficial effectsthroughout a year. Molasses (concentrated grape juice),Kofter (grape juice jel prepared with addition of starch)and pestil (grape leather) are the most famous productsproduced from grapes [1]. Molasses are concentrated fruitjuices and are produced from different fruit juices includinggrape, mulberry and carob samples which are boiledwithout addition of sugar or any other additives [2].Consumption of molasses is recommended to meet energyrequirement of the people especially for children sincemolasses are rich in monosaccharides, especially glucoseand fructose. Molasses are processed to obtain differentproducts such as pestil and Kofter.

Kofter is accepted as a natural dessert which is man-ufactured from the grape molasses, water and starch.Concentrations of them used in the formulation of theKofter are important for quality of the end product, mark-edly affecting consumer acceptability of the product.Therefore, observation of changes in some characteristicsof the midproduct (rheological and pasting properties)and end product (physicochemical, textural and sensoryproperties) based on formulation and production processis required for manufacturing the end product withdesired quality. Till now, we have encountered only twostudies about Kofter in which effect of starch concentra-tion and processing temperature on steady, dynamic andcreep recovery properties of the midproduct (Kofter mix)was investigated. Ostwald de Waele model was found asthe best model describing flow behavior of the sampleand consistency coefficient value of the mix samplesincreased with increasing starch concentration in theformula [1]. Regarding creep and recovery characteristicsof the mix samples, it was seen that resistance of the

*Corresponding author: Omer Said Toker, Department of FoodEngineering, Faculty of Chemical and Metallurgical Engineering,Yıldız Technical University, Esenler, İstanbul, Turkey, E-mail:[email protected] Yildiz, Bayram Yurt, Mehmet Murat Ceylan, Department ofFood Engineering, Faculty of Engineering, Iğdır University, Iğdır,Turkey, E-mail: [email protected],[email protected], [email protected] Tahsin Yilmaz, Department of Food Engineering, Faculty ofChemical and Metallurgical Engineering, Yıldız Technical University,Esenler, İstanbul, Turkey, E-mail: [email protected] Bastürk, Department of Food Engineering, Faculty ofEngineering, Yüzüncü Yıl University, Van, Turkey,E-mail: [email protected]

Int. J. Food Eng. 2015; 11(3): 349–358

Authenticated | [email protected] author's copyDownload Date | 5/28/15 10:35 AM

sample to deformation increased with addition of starch[3]. In addition, aging temperature of the Kofter alsosignificantly influenced 5-HMF (5-hydroxymethylfurfural)content of the sample which was found as higher whenaged at greater temperatures [1]. However, in literature nostudy was found related with the effect of molasses con-centration on pasting, textural and sensory properties ofthe starch gel. Textural and pasting properties of thedifferent starch gels including sugars were investigatedin previous study [4]. However, no study has beenencountered about pasting and textural properties ofthe starch samples in molasses including systems.Determination of pasting properties is very importantsince gelatinization, pasting and gel properties of starchare main factors determining usage purposes of thestarches in the industry [4–10]. Molasses found in theKofter formulation is crucial for product quality since itis rich in sugars which can change thermal and physicalproperties of starchy foods [11]. From this reason, under-standing the thermal and pasting properties of starch/molasses/water system is required for process and pro-duct optimization considering process design, qualityand shelf-life extension [7]. Therefore, molasses concen-tration used in the Kofter should be adjusted regardingpasting, textural and sensory properties of the product,which might have achieved by observation of change inthese properties based on molasses concentration.

In the present study, it was aimed to determine past-ing, textural and sensory properties of the Kofter sampleincluding molasses or water in different concentrations.

2 Materials and methods

2.1 Preparation of the Kofter samples andpasting properties

Kofter formula includes 2.5 g corn starch and 25 g water andgrapemolasses blend (grapemolasses properties: 74.7 ˚Brixand 4.82 pH). The Kofter samples prepared with differentmolasses:water concentrations (75:25, 70:30, 60:40, 50:50,40:60, 30:70 and 25:75) as presented in Table 1 were pro-duced using a Rapid Visco Analyzer (Perten RVA 4500,Australia). About 2.5 g corn starch was directly weighedinto aluminum RVA canisters and then prepared molassesandwater blendwas added. Themixturewas heated to 50°Cand stirred at 160 rpm for 10 s. Then, the samples were heldat 50°C for 1 min, and then heated up to 95°C for 3.42 minand held at that temperature for 5 min, and cooled down to

50°C for 6.18 min. During the preparation of the samples,pasting properties involving (1) peak viscosity (PV) (max-imum paste viscosity achieved in stage 2; the heating stageof the profile); (2) trough viscosity (TV) (minimum pasteviscosity achieved after holding at the maximum tempera-ture, stage 3); (3) breakdown viscosity (BV) (differencebetween PV and trough); (4) final viscosity (FV) (viscosityat the end of run); (5) setback viscosity (SV) (differencebetween final viscosity and trough); (6) peak time (time atwhich PV was recorded) and (7) pasting temperature (tem-perature at which starch granules begin to swell and gela-tinize due to water uptake) were also determined. TheThermocline windows software was used for determinationof the magnitude of the pasting parameters (Perten RVA4500, Australia). All measurements were repeated threetimes with two replications.

2.2 Textural parameters of the Koftersamples

Kofter samples prepared using RVA were used to deter-mine the texture profile analysis (TPA). The Kofter sam-ples in the canisters were covered with parafilm andstored at room temperature (25 � 1°C) for 24 h in thecanisters prior to the textural analyses. The TPA wascarried out using a texture analyzer (TAXT2i, StableMicro Systems Ltd., Surrey, England) equipped with aload cell of 5 kg and a P/25 cylindrical probe suppliedwith Texture Exponent Programs. The Kofter samples inthe RVA canisters were compressed twice using a cylind-rical probe (P/25) at a control force of 5 g at the speed of1 mm/s and the deformation distance was determined as5 mm. Hardness, adhesiveness, springiness, resilience,cohesiveness, gumminess and chewiness were obtainedfrom TPA by using software. The measurements wereperformed in triplicate for each replication.

Table 1: Codes of the Kofter samples and their molasses andwater concentration in the formulation.

Code Molassesconcentration (%)

Water concentration (%)

S

S

S

S

S

S

S

350 O. Yildiz et al.: Pasting, Textural and Sensory Characteristics of the Kofter


2.3 Sensory evaluation of the Koftersamples

The sensory analyses of the Kofter samples were per-formed after 24 h storage at room temperature. TheKofter samples were presented to panelists in white con-tainers. Seven different Kofter samples were divided intotwo groups (4 and 3 samples for each group) meaningthat panelists evaluated all samples in two sessions (fourat first and three at second session). The sensory evalua-tion of the samples was carried out by 10 selected staffand post-graduate students of Food EngineeringDepartment of Igdır University. Before the analyses,panelists were trained about the sensory evaluation tech-niques and the aim of the present study. The panelistsdrank tap water to cleanse their palates prior to theanalyzing next sample. The sensory attributes evaluatedwere appearance, color, texture, taste, odor and overallpreference. Sensory analysis was carried out using anine-point-scale scoring where 1 reflected lowest scoreand 9 highest score.

2.4 Statistical analyses

The results were expressed as mean � SD (standarddeviation). The JMP 5.0.1 (Version 5.0.1a, SAS Institute,Inc., Cary, USA) was used to conduct an analysis ofvariance (ANOVA). Least significant differences (LSD)test was used to determine if the effects of independentvariables (fiber type and concentration) on the pastingproperties and TPA parameters of the Kofter sampleswere significant (P<0.05).

3 Results and discussion

3.1 Pasting properties of the Kofter samples

Pasting properties of the Kofter samples including differentwater/molasses concentration are shown in Figure 1. As canbe seen from this figure, the water concentration signifi-cantly affected the pasting properties. Magnitudes of thepasting parameters (PV, TV, BV, FV, SV, peak time andpasting temperature) of the corn starch prepared with differ-ent combination of molasses and water are presented inTable 2. PV value of the samples changed between 2,785and 4,182 cP. As seen from Table 2, PV value increased up towater concentration of % 60 used in the formulation. Ourfindings were coincided with results reported by Zhang et al.[10] and Pongsawatmanit et al. [11] who investigated that PVof tapioca starch–sucrose blends were found as higher thanthat of control and it increased with increasing sucrose levelin the formulation. PV is related with the swelling degree ofstarch granules during heating, indicating that starch withhigher swelling capacity has higher PV [12]. Swelling abilityof the starch increased with the presence of sugar up toconcentration of 25% [13]. Therefore, increase in PV withincreasing molasses concentration up to 50% concentrationmight have explained by increasing swelling power of thestarch in the presence of sugar. However, PV decreased withaddition of molasses in concentration higher than 50% inthe Kofter formulation. Gunaratne et al. [4] reported that PVof the wheat and potato starches increased with addition ofglucose and sucrose. According to the microscopic analysisdemonstrated by Richardson [14], starch granules keeptogether better in sucrose solution than in pure water.

Figure 1: Effect of molasses concentration on the pasting curves of the Kofter samples (the percentage mentioned in the figure shows themolasses concentration in the Kofter formula).

O. Yildiz et al.: Pasting, Textural and Sensory Characteristics of the Kofter 351


Viscosity of the starch paste increased with the presence ofglucose due to increasing granule mean diameter, which isrelated with swelling capacity of the starch [15]. Moreover,interaction of sugar with starch and water in the mediacaused to increase in PV value of the samples [10]. Themotion of the water molecules is reduced and prevented byinteraction hydroxyl groups of sugars with neighboringwater [10]. As seen from Table 2, PV value started to decreaseas molasses concentration higher than 50% was added tothe formulation, which could be resulted from the penetra-tion of sugar molecules into the interior of starch granulesduring gelatinization process [16]. Up to some sugar compo-sition level, the increase in interaction between sugar andstarch could result in increasing PV; however, more concen-tration could prevent the interaction between starch chains,which could decrease PV value.

Table 2 also shows TV value of corn starch in molassesandwatermedium.As seenwater concentration found in theKofter formulation remarkably influenced TV value of thecorn starch. Change in trough and PVwith addition of waterresembled each other,meaning that TV increased from 2,036to 3,809 cP as the water concentration decreased to 50%from 75%. Adding water in concentration higher than 50%decreased magnitude of TV. Decrease in TV due to the addi-tion of water in a concentration increasing from 50% to 75%could associate with increasing swelling capacity of starchgranule as mentioned above. As knownmolasses are rich insugar content, therefore, increasedwithmolasses concentra-tion in the medium. Interaction between starch granulesincreased with addition of molasses [17] up to concentrationof 50%; therefore, PV and TV values increased.

Another parameter obtained from pasting curve is BVwhich decreased from 1,196 to 306 cP as molasses concen-tration in the molasses/water blends increased up to 50%.BV increased with addition of molasses in concentrationshigher than 50%. Starches are disrupted due to high

temperature and mechanical shear stress applied duringRVA analysis, thus causing leaching out of amylose andalignment [12]. In other words, as BV value is high, integrityof starch granules is lost, thus reducing starch resistance tothe applied shear force [11, 18, 19]. Therefore, starch samplein the blend containing equal amount of water andmolassescan withstand more heating and applied shear stress com-pared to the other blends, which is important for quality ofthe end product, namely,Kofter sinceKoftermix is subjectedto heat and shear stress during manufacturing process. Asthe resistance of the sample to heat and shear is not enough,some of the bonds could be damaged during shearing andheating, thus resulting in product with less quality. Fromthis reason selection of optimum concentrations of waterand molasses in the blend could markedly influence theproduct quality; therefore, consumer acceptability of theproduct might be affected. Addition of molasses concentra-tion higher than 50% increased remarkably BV value of cornstarch in the blends, which is in agreementwith the previousstudies [10, 11]. Zhang et al. [10] reported that tapioca starchand sucrose or glucose blends showed higher BV value thancontrol sample. As sugar was added to the starch solution,sugar bridges are formed between starch chains in amor-phous regions [10], which could be observed in samplesincluding molasses in concentration ranged between 40%and 50%. Therefore, BV values of these samples were foundas lower when compared with the other samples. However,BV value of S6 and S7 was found as higher than the samplesincluding molasses in concentration varied between 40%and 60%, which could be resulted from the deficiency ofsugar bridges since the formulation contained lower sugaramount. As molasses was added in concentration higherthan 60%, as mentioned above the sugar molecules couldpenetrate into the interior of starch granules, which couldweaken the interaction between starch chains. Therefore,BV increased with weakening this interaction, decreasing

Table 2: Pasting properties of Kofter samples including different molasses and water concentration.

Sample PV (cPa) TV (cP) BV (cP) FV (cP) SV (cP) PeT (min) PaT (°C)

S , � d

, � d

, � b

, � d

, � a

. � .a . � .a

S , � d

, � d

, � a

, � cd

, � a

. � .a . � .a

S , � b

, � b

� d

, � a

, � b

. � .a . � .a

S , � a

, � a

� e

, � ab

� d

. � .b . � .b

S , � a

, � a

� d

, � bc

� d

. � .c . � .c

S , � c

, � c

, � c

, � e

� c

. � .d . � .d

S , � c

, � c

, � c

, � e

� c

. � .d . � .d

Notes: Different superscript uppercase letters show differences between samples (P<0.05).a1 cP ¼ 1/12 Rapid-Visco Analyzer Units (RVU).PV, peak viscosity; TV, trough viscosity; BV, breakdown viscosity; FV, final viscosity; SV, setback viscosity; PeT, peak time; PaT, pasting temperature.



resistance of the paste to the deformation caused by appliedstress.

FV is viscosity value at the end of RVA analysis aftercooling of the starch paste and it is important for stabiliza-tion of colloidal system and product handling in the foodindustry [7]. Retrogradation of amylose during cooling of thepaste markedly affected the FV value [20]. Magnitude of theFV of the starch paste regardingmolasses concentrationwasin the following order: 60% >50% >40% >70% >75% >30%>25% (Table 2). As seen, increase in molasses concentrationin the blend up to concentration of 60% increased FV valueof the corn starch. Chantaro and Pongsawatmanit [7]reported that FV of gum-starch pastes increased with addi-tion of sucrose. FV value of tapioca starch increased withincreasing sucrose concentration. Our findings were consis-tent with the previous studies. According to the results,addition of molasses in concentration higher than 60%caused to decrease in FV.

Another important parameter obtained from RVAanalysis is SV related with short-term retrogradation ofstarch [21]. Lower SV indicates lower syneresis [12, 22]. Asseen from Table 2, SV value of the corn starch pastechanged between 605 and 2469 cP. Magnitude of SVwas significantly influenced by molasses concentrationadded. SV of the corn starch paste decreased with addi-tion of molasses up to concentration lower than 50%molasses. However, at concentrations greater than 50%,SV increased with increase in molasses concentration inthe blend. In the present study, as expected similar trendwas observed between BV and SV values where BV andSV values were found as higher in the samples contain-ing molasses in concentrations ranged between 70–75%and 30–25%. The possible reasons were mentioned in thepart related with BV parameter. As known, retrogradationoccurs as a result of reassociation of gelatinized starchmolecules in an ordered structure. According to our find-ings, addition of molasses higher than 50% could accel-erate this reassociation phenomena, leading to highersyneresis. It is not recommended to add molasses atconcentrations higher than 50% when considering longshelf-life of the Kofter. Otherwise, syneresis phenomenamay occur, resulting in deterioration of the quality ofthe product with respect to sensory characteristics.Therefore, molasses concentration in the blend shouldbe carefully determined regarding SV value of the cornstarch paste during manufacturing starch and sugarincluding products. Regarding SV, optimum molassesconcentration was found to be 40%, indicating that thispaste has higher resistance to syneresis and more stableupon cooling after heating [23].

As for the peak time values, they were found to be inthe range of 5.36 and 7.00 min. Peak time increased withmolasses concentration up to 60%. Peak time is consid-ered as duration required for swelling of starch granulesuntil the rupture of them [24]. Pasting temperature isanother parameter obtained from pasting curve. Molassesconcentration significantly altered the pasting temperatureof the corn starch which changed between 83.23°C and94.98°C. As seen in Table 2, pasting temperature increasedwith addition of molasses, which is in agreement withwhat was reported by Chantaro and Pongsawatmanit [7]that pasting temperatures of tapioca starch/xanthan gummixture increased with sucrose addition, which mighthave resulted from the fact that sugar reduces availabilityof water in the system [7]. In addition, increase of pastingtemperature with sugar concentration was reported inprevious studies [25–27]. Increasing gelatinization tem-perature with addition of sugar could be explained bydifferent ways: (1) reduction of the water activity of thesystem due to the competition of sugar with starch mole-cules [28], (2) interaction between sugar and starch mole-cules [25], (3) less plasticizing effect of sugar than water[29]. Relation between pasting temperature and sugar con-centration significantly depends on sugar and starchtypes. Ahmad and Williams [30] reported that gelatiniza-tion of sago starch increased with different sugar typeaddition, in the order of sucrose > maltose > glucose >

fructose > ribose. Generally, it was found that pastingtemperature of starch was increased more by addition ofdisaccharide than by monosaccharide [25, 26, 31].Molasses samples have more monosaccharide contentespecially glucose and fructose contents than disaccharidecontent, and sugar content distribution of the molasseschanges with respect to fruit type processed to molasses.Main monosaccharide types found in the molasses weredetermined as fructose and glucose, which was reportedin different studies [32]. Anti-plasticizing effect of sugarresults in leaching lower amount of amylose, thus retard-ing gelatinization of tapioca starch [30, 33]; therefore,pasting temperature increases [34]. Moreover, sugarcould lead to inhibit hydration of starch granules [35].

3.2 Textural properties of the Koftersamples

After Kofter samples prepared with RVA, their texturalproperties (hardness, adhesiveness, springiness, cohe-siveness, gumminess, chewiness and resilience) weredetermined using TPA analyses. Textural properties of



the samples prepared with water and molasses in differ-ent ratios are shown in Table 3. As seen from Table 3,hardness value of the samples ranged between 128.6 and1,647 g. Hardness value of the Kofter sample increasedwith increase in water concentration in the blend; mean-ing that increase in sugar concentration decreased hard-ness value of the end products. There are contradictoryresults about effect of sugar on hardness value of thestarch gel. The loss factor (tan δ) value of waxy maizestarch-xanthan gum blend increased with addition ofsugar, indicating that sucrose decreased the solid-likeproperties of the waxy maize starch-xanthan gum paste[27], which is strongly related with hardness value of thepastes. Similar result was also reported by Chang et al.[35] and Zhang et al. [10]. Gel hardness prepared withwheat starch decreased with sucrose or glucose additionin concentrations higher than 40%, which might haveexplained by the fact that less amylose leaches due tothe addition of sugar that reduces amylose concentrationin the network [4]; therefore, gel hardness decreases.However, it was reported in other study that the solid-like properties of tapioca starch–xyloglucan mixturesincreased with the addition of sucrose [11]. Gel networkof the paste increased with sucrose addition due to theassociation between sucrose and amylose [11]. Differenttrend between sucrose or sugar addition and hardness valuemight have explained by different factors namely, starchtype, amylose content and experiment conditions performedin the textural analyses [10]. In addition, sugar type alsodifferently affects the gel properties. Chang et al. [36]reported that G′ values of corn starch decreased in thefollowing order regarding sugar type: xylose > sucrose >

glucose. There is only one study encountered in theliterature in which hardness of the Kofter sample includingstarch in different concentrations (5%, 7.5% and 10%) wasfound between 0.92 and 5.83 N [1]. Retrogradation of starch,water syneresis and amylopectin crystallization are main

factors affecting gel firmness [37]. Water and molasses con-centration found in the formulation of the sample should bedetermined regarding hardness value of the sample.

Another textural parameter obtained from TPA ana-lysis is adhesiveness representing the force required toremove sample from the contact surface of the mouth[38]. Adhesive and cohesive forces, viscosity and viscoe-lastic characteristics of the sample simultaneously affectthe adhesiveness value of the Kofter sample [39]. As seenfrom Table 3, adhesiveness value of the Kofter sample issignificantly influenced by water amount added to theKofter formulation. Adhesiveness value of the Koftersample was determined between 158.8 and 299.6 g s.Adhesiveness value of the Kofter sample increased withincreasing water concentration in the water/molassesblend. For the consumers who prefer to consume lessadhesive samples, molasses concentration in the blendshould be increased to increase consumer acceptability ofthe end product.

Springiness value of the sample represents therecovery ability of the sample against first deformationapplied during analysis [39, 40]. As known, food productsare subjected to different forces, resulting in deformationof the product, during storage and transportation.Therefore, springiness value of the product is very impor-tant for the product quality with desired level.Springiness value of the Kofter sample prepared withwater and molasses blend in different concentrationsranged between 0.983 and 0.442 mm. Generally, springi-ness value of the sample decreased with increase in waterconcentration in the blends, indicating that Kofter sampleelasticity is lost with increasing water concentration. Asunderstood from the results, increasing sugar concentra-tion increased springiness value of the sample, whichwas consistent with the results reported by Teng et al. [8].

Cohesiveness is related with the internal structure ofthe sample, which represents the degree of difficulty

Table 3: Textural properties of Kofter samples including different molasses and water concentration.

Sample Hardness (g) Adhesiveness (g s) Springiness (mm) Cohesiveness Gumminess (g) Chewiness (g mm) Resilience

S . � .e . � .d . � .a . � .a . � .e . � .e . � .d

S . � .e . � .d . � .a . � .a . � .e . � .e . � .d

S . � .e . � .c . � .a . � .b . � .e . � .e . � .c

S . � d

. � .b . � .b . � .c . � .d . � .d . � .a

S . � c

. � .b . � .b . � .c . � .c . � .c . � .a

S � b

. � .a . � .c . � .d . � .a . � .b . � .b

S � a

. � .a . � .d . � .c . � .b . � .a . � .c

Note: Different superscript uppercase letters show differences between samples (P<0.05).



occurred during breaking down the internal structure ofthe sample [41]. In addition to viscosity and elasticity ofthe sample, it also includes both of the adhesive andcohesive forces [42]. Cohesiveness value of the Koftersample changed between 0.49 and 0.71. As seen fromTable 3 that cohesiveness value of the Kofter samplereduced generally with increasing water content in theblend. In other words, increase in sugar content with theaddition of molasses resulted in increasing cohesivenessvalue. Therefore, using high concentration molasses inthe formulation could be preferred with respect to thecohesiveness value since high cohesiveness value is con-sidered as a desirable index to obtain gel with goodquality and starchy foods with high acceptability [9].Relation between sugar addition and cohesiveness valueof the starch gel was reported by Teng et al. [8]. Roopaand Bhattacharya [43] found that cohesiveness value ofwheat and corn starch gels ranged between 0.469 and0.500, respectively, meaning that these gels had highplasticity and tendency toward severe textural damages.From this reason, increasing molasses concentration inmolasses/water blend increased resistance of the sampleagainst deformation, which is very important for thequality of the product.

Another important textural parameter of Koftersample obtained from TPA analysis is gumminess char-acteristic property for semi-solid foods with low degree ofhardness and high degree of cohesiveness [40].Gumminess value of the Kofter samples was found tobetween 87.80 and 529.3 g (Table 3), which increased aswater concentration in the Kofter formulation increased.When considering gumminess value which is equal to theproduct of hardness and cohesiveness, factors affectingthese two textural parameters mentioned above alsoaffect gumminess value of the sample. Chewiness isdefined as an amount of energy required for masticatinga semi-solid sample to a steady state of swallowing [39].Chewiness value of the Kofter sample changed between84.55 and 727.7 g mm. Magnitude of the chewiness valueincreased with water concentration in the blend.Therefore, Kofter sample with lower concentration ofwater could be preferred by elderly people or patientsdue to their high energy requirement prior to theswallowing of the product.

The last textural parameter obtained in the presentstudy for Kofter sample is resilience which is relatedwith the capability of the product regaining its originalposition after deformation applied [40]. Resilience valueof the Kofter sample varied between 0.041 and 0.237.Resilience value of the Kofter sample increased withmolasses addition up to the concentration of 50% and

at higher concentration values magnitude of the resili-ence of the sample remarkably decreased. Teng et al. [8]reported that resilience value of the freshly preparedsago and potato gels increased with the addition ofsugar. As can be seen from the texture results, all of thetextural parameters mentioned were significantly influ-enced by water or molasses concentration in the formula;therefore their amount could be adjusted regarding tex-tural characteristics to obtain sample with desired tex-tural properties.

3.3 Sensory properties of the Koftersamples

Sensory scores of the Kofter sample are presented inFigure 2. As seen from Figure 2, sensory properties ofthe Kofter sample were significantly affected by water ormolasses concentration. Among the Kofter samples, themost preferred sample with respect to overall preferencewas found to be sample including 60% water and 40%molasses (S5) in the formulation, which was also mostlyaccepted sample with respect to color, texture, taste andodor scores. Sensory scores (appearance, color, texture,taste, odor and overall preference) of the samples includ-ing molasses in concentrations ranged between 75% and40% were found as very close to each other. However,water concentrations higher than 60% in the blend nega-tively affected sensory scores of the Kofter sample. Thisresult could be explained by the fact that addition ofwater caused to dilute sweet taste, which is not desiredfor desserts. Regarding sensory properties of the Koftersamples, water and molasses concentration found in theformula could be determined considering sensory proper-ties, which directly affect consumer acceptability of theproduct.

4 Conclusion

Pasting, textural and sensory properties of the Koftersample including different water and molasses concen-tration were investigated. All of the properties were sub-stantially influenced by water or molasses concentrationfound in the formulation. General acceptability of theproduct increased with increasing molasses concentra-tion in the blend. Regarding overall preference of theproduct, Kofter sample including 40% molasses and60% water was mostly preferred sample by panelists.Producers of the Kofter should be considered textural



and sensory properties of the end product since theydirectly affected acceptability of the product. In additionrecoverability and resistance of the product against defor-mation occurred during storage, handling or transporta-tion depend on formulation of the product. Therefore,determination of formulation of the Kofter dessert isvery important for quality characteristics of the endproduct.

References

1. Goksel M, Dogan M, Toker OS, Ozgen S, Sarıoglu K, Oral RA.The effect of starch concentration and temperature on grapemolasses: rheological and textural properties. Food BioprocessTech 2013;6:259–71.

2. Toker OS, Dogan M, Ersoz NB, Yilmaz MT. Optimization of thecontent of 5-hydroxymethylfurfural (HMF) formed in somemolasses types: HPLC-DAD analysis to determine effect of

Figure 2: Sensory properties of the Kofter samples.



different storage time and temperature levels. Ind Crops Prod2013;50:137–44.

3. Toker OS, Dogan M. Effect of temperature and starch concentra-tion on the creep/recovery behavior of the grape molasses:modelling with ANN, ANFIS and response surface methodology.Eur Food Res Technol 2013;236:1049–61.

4. Gunaratne A, Ranaweera S, Corke H. Thermal, pasting, andgelling properties of wheat and potato starches in the presenceof sucrose, glucose, glycerol, and hydroxypropyl β-cyclodextrin.Carbohydr Polym 2007;70:112–22.

5. Abu-Jdayil MH, Eassa A. Rheology of wheat starch-milk-sugarsystems: effect of starch concentration, and milk fat content.J Food Eng 2004;64:207–12.

6. Funami T, Nakauma M, Noda S, Ishihara S, Asai I, Inouchi N,et al. Effects of some anionic polysaccharides on the gelatini-zation and retrogradation behaviors of wheat starch: soybean-soluble polysaccharide and gum arabic. Food Hydrocolloid2008;22:1528–40.

7. Chantaro P, Pongsawatmanit R. Influence of sucrose on thermaland pasting properties of tapioca starch and xanthan gummixtures. J Food Eng 2010;98:44–50.

8. Teng LY, Chin NL, Yusof YA. Rheological and textural studies offresh and freeze-thawed native sago starch-sugar gels. I.Optimisation using response surface methodology. FoodHydrocolloid 2011;25:1530–7.

9. Teng LY, Chin NL, Yusof YA. Rheological and textural studies offresh and freeze-thawed native sago starch-sugar gels. I.Comparisons with other starch sources and reheating effects.Food Hydrocolloid 2013;31:156–65.

10. Zhang X, Tong Q, Zhu W, Ren F. Pasting, rheological propertiesand gelatinization kinetics of tapioca starch with sucrose orglucose. J Food Eng 2013;114:255–61.

11. Pongsawatmanit R, Temsiripong T, Suwonsichon T. Thermal andrheological properties of tapioca starch and xyloglucan mix-tures in the presence of sucrose. Food Res Int 2007;40:239–48.

12. Ragaee S, Abdel-Aal EM. Pasting properties of starch andprotein in selected cereals and quality of their food products.Food Chem 2006;95:9–18.

13. Fasihuddin BA, Williams PA. Effect of sugars on the thermal andrheological properties of sago starch. Biopolymers1999;50:401–12.

14. Richardson G, Langton M, Bark A, Hermansson AM. Wheatstarch gelatinization – the effect of sucrose, emulsifiers and thephysical state of the emulsifier. Starch 2003;55:150–61.

15. Al-Malah KI, Azzam MO, Abu-Jdayil B. Effect of glucose concen-tration on the rheological properties of wheat-starch disper-sions. Food Hydrocolloid 2000;14:491–6.

16. Li Q, Li H, Gao Q. The influence of different sugars on cornstarch gelatinization process with digital image analysismethod. Food Hydrocolloid 2015;43:803–11.

17. Zhou Y, Wang D, Zhang L, Du X, Zhou X. Effect of polysacchar-ides on gelatinization and retrogradation of wheat starch. FoodHydrocolloid 2008;22:505–12.

18. Thirathumthavorn D, Charoenrein S. Thermal and pastingproperties of native and acid-treated starches derivatized by1-octenyl succinic anhydride. Carbohydr Polym 1996;66:258–65.

19. Adebowale KO, Olu-Owolabi IO, Olawunmi EK, Lawal OS.Functional properties of native, physically and chemically

modified breadfruit (Artocorpus altilis) starch. Ind Crop Prod2005;21:343–51.

20. Anonymous. 2012. http://www.perten.com/Global/Brochures/RVA/RVA%20Method%20Brochure_20110131.pdf. Accessed:29January 2012.

21. Pongsawatmanit R, Temsiripong T, Ikeda S, Nishinari K.Influence of tamarind seed xyloglucan on rheological propertiesand thermal stability of tapioca starch. J Food Eng2006;77:41–50.

22. Pongsawatmanit R, Srijunthongsiri S. Influence of xanthan gumon rheological properties and freeze–thaw stability of tapiocastarch. J Food Eng 2008;88:137–43.

23. Kaushal P, Kumar V, Sharma HK. Comparative study of physi-cochemical, functional, antinutritional and pasting properties oftaro (Colocasia esculenta), rice (Oryza sativa) flour, pigeonpea(Cajanus cajan) flour and their blends. LWT—Food Sci Technol2012;48:59–68.

24. Yildiz O, Yurt B, Basturk A, Toker OS, Yilmaz MT, Karaman S,et al. Pasting properties, texture profile and stress-relaxationbehavior of wheat starch/dietary fiber systems. Food Res Int2013;53:278–90.

25. Baek MH, Yoo B, Lim ST. Effects of sugars and sugar alcohols onthermal transition and cold stability of corn starch gel. FoodHydrocolloid 2004;18:133–42.

26. Sharma R, Oberoi DP, Sogi DS, Gill BS. Effect of sugar and gumson the pasting properties of cassava starch. J Food ProcessPreserv 2009;33:401–14.

27. Wang B, Wang L, Li D, Ozkan N, Li S, Mao Z. Rheologicalproperties of waxy maize starch and xanthan gum mixtures inthe presence of sucrose. Carbohydr Polym 2009;77:472–81.

28. Spies RD, Hoseney RC. Effect of sugar on starch gelatinization.Cereal Chem 1982;59:128–31.

29. Perry PA, Donald AM. The effect of sugars on the gelatinizationof starch. Carbohydr Polym 2002;49:155–65.

30. Ahmad FB, Williams PA. Effect of sugars on the thermal andrheological properties of sago starch. Biopolymers1999;50:401–12.

31. Eroglu A, Bayrambas K, Eroglu Z, Toker OS, Yilmaz MT, KaramanS, et al. Steady, dynamic, creep/recovery, and textural proper-ties of yoghurt/molasses blends: temperature sweep tests andapplicability of Cox-Merz rule. Food Sci Technol Int 2015;doi:10.1177/1082013214566478

32. Li J, Thava Vasanthan T, Bressler DC. Cationization of field peastarch in salt-free aqueous suspension. Carbohydr Polym2011;83:1598–603.

33. Kohyama K, Nishinari K. Effect of soluble sugars on gelatiniza-tion and retrogradation of sweet potato starch. J Agric FoodChem 1991;39:1406–10.

34. Hirasima M, Takahashi R, Nishinari K. Changes in the viscoe-lasticity of maize starch pastes by adding sucrose at differentstages. Food Hydrocolloid 2005;19:777–84.

35. Yoshimura M, Takaya T, Nishinari K. Effects of konjac-glucoman-nan on the gelatinization and retrogradation of corn starch asdetermined by rheology and differential scanning calorimetry. JAgric Food Chem 1996;44:2970–6.

36. Chang YH, Lim ST, Yoo B. Dynamic rheology of cornstarch–sugar composites. J Food Eng 2004;64:521–7.

37. Miles J, Morris VJ, Ring SG. Gelation of amylose. Carbohydr Res1985;135:257–69.



http://www.perten.com/Global/Brochures/RVA/RVA%20Method%20Brochure_20110131.pdf

http://www.perten.com/Global/Brochures/RVA/RVA%20Method%20Brochure_20110131.pdf

38. Bryant A, Ustunol Z, Steffe J. Texture of cheddar cheese asinfluenced by fat reduction. J Food Sci 1995;60:1216–20.

39. Huang M, Kennedy JF, Li B, Xu X, Xie BJ. Characters of ricestarch gel modified by gellan, carrageenan, and glucomannan:a texture profile analysis study. Carbohydr Polym2007;69:411–18.

40. Bourne MC. Food texture and viscosity: concept and measure-ment, 2nd ed. San Diego, CA: Academic Press, 2002.

41. Sanderson GR. Gellan gum. In: Harris P, editor. Food gels. NewYork: Elsevier Science, 1990:201–32.

42. Phimolsiripol Y, Siripatrawan U, Henry CJ. Pasting behaviour,textural properties and freeze–thaw stability of wheat flour–crude malva nut (Scaphium scaphigerum) gum system. J FoodEng 2011;105:557–62.

43. Roopa BS, Bhattacharya S. Alginate gels: I. Characterization oftextural attributes. J Food Eng 2008;85:123–31.



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