A comparison of the functional characteristics of wheat stored as grain with wheat stored in spike...

Original article

A comparison of the functional characteristics of wheat stored as

grain with wheat stored in spike form

Mehmet Murat Karaoglu,* Melek Aydeniz, Halis Gurbuz Kotancilar & Kamil Emre Gercelaslan

Food Engineering Department, Faculty of Agriculture, Ataturk University, 25240, Erzurum, Turkey

(Received 10 April 2009; Accepted in revised form 18 September 2009)

Summary In this study, wheat grain and wheat spike with 12%, 14% and 16% moisture content were stored at 10, 20

and 30 �C for 0, 3, 6 and 9 months. After storage, wheat samples were investigated for hectolitre weight,

gluten content, Zeleny sedimentation volume, enzyme activity, acidity, phytic acid and L colour value.

Storage of wheat at different storage forms (spike and grain) and storage conditions showed considerable

changes in grain quality. In general, the storage period of 3 months positively affected wheat quality.

However, hectolitre weight, gluten, Zeleny sedimentation, enzyme activity, acidity and colour of wheat got

worse at storage periods beyond 3 months. Hectolitre weight, wet and dry gluten, Zeleny sedimentation,

phytic acid content and L Colour value of wheat stored in both spike and grain form significantly decreased

during storage. However, the increase in grain moisture content, storage time and temperature resulted in

significant increase in total titratable acidity and falling number values of wheat. Falling Number and phytic

acid values of wheat stored in spike form were generally lower than wheat stored in grain form. Storage in

spike form had a positive effect on especially wet gluten content of wheat stored at non-optimal storage

conditions such as high grain moisture content and high temperature. Wet gluten of wheat stored in spike

form was higher than that of wheat stored grain form after storage at 30 �C for 6 and 9 months. Wheat

stored in spike form is more resistant than wheat stored in grain form against adverse storage conditions

such as high moisture content and temperature and longer storage time.

Keywords Functional characteristics, quality, spike, storage conditions, wheat.

Introduction

Wheat is the most widely produced cereal in the world,most of which are used as sources of energy and proteinin the human diet throughout the world. Wheat grain isgenerally produced once during the year and its culti-vation is limited to specific areas of the country. For thisreason, wheat is stored for about 1 year after harvest oruntil the harvest of the next crop so that wheat isavailable during the end of season. Wheat is stored asgrain form. Wheat spike is the technical name for thehead in a grassy plant and is the part of the plant wheregrain is formed. Consequently, storage of wheat in spikeform is a process in which grain is stored as whole spike.Time and temperature of storage and moisture

content of grain are the most important factors in termsof wheat quality. These factors have been reported tobring about significant changes in the functional char-

acteristics of stored wheat (Srivastava & Rao, 1994; Mis,2003; Wang & Yu, 2009).Storage of wheat is generally done in silos equipped

with temperature and moisture measuring systems, andaeration and fumigation equipment in the grain form.Wheat grain is significantly influenced by environmentalfactors and as it respires, dry matter is lost, andfunctional and nutritional characteristics are modifiedduring storage period (McDonougha et al., 2004). Muchresearch has been conducted to examine the effects ofdifferent storage conditions on quality characteristics ofwheat such as Zeleny sedimentation volume, glutencontent and water absorption. Mao & Rayas-Duarte(2001) stored wheat at different temperatures (26, 30, 40and 50 �C) for 60 days. They found that farinograms ofstored wheat showed sharper hydration peaks andlonger development times compared to the control.Specific volume of loaves produced stored wheat wasdifferent at 0 days and decreased at different ratesduring storage. Srivastava & Rao (1994), Gudaczewskiet al. (1999) and Karunakarana et al. (2001) havestudied changes occurring in wheat stored under adverse

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e-mail: [email protected]; [email protected]

International Journal of Food Science and Technology 2010, 45, 38–4738

doi:10.1111/j.1365-2621.2009.02101.x

� 2010 The Authors. Journal compilation � 2010 Institute of Food Science and Technology

conditions. It was stated that storage of wheat at hightemperature and moisture showed considerable deteri-oration in grain quality as time increased.Phytic acid, myo-inositol 1, 2, 3, 4, 5, 6-hexakisphos-

phate, is the major phosphorus storage compound ofmost seeds and cereal grains and it may account formore than 70% of the total phosphorus. Phytic acid hasa strong ability to chelate multivalent metal ions such aszinc, calcium and iron. The complex of phytic acid andmineral elements, in the form of phytate, results in amarked reduction in bio-availability of these nutrientelements. Generally in many plant species, 90% ofphytic acid is localised in the aleurone layer and only10% in the embryo. There are many factors, such asgenetics, environmental fluctuations, location, irrigationconditions, type of soils, year and fertiliser applicationthat can be affect the phytic acid content and phospho-rus availability in cereal grains. During germination,phytate salt is degraded by the action of phytasesenzymes, which provides the growing seedling withphosphate (Garcia-Estepa et al., 1999; Liu et al., 2005;Dost & Tokul, 2006). Little work has been done inexamining phytic acid variation in wheat stored atdifferent storage time and temperatures.In the storage studies, wheat has been stored as grain

form until now. Spike form of wheat was not used inthese researches. Wheat is an annual plant made uproots, a stem, leaves, and the head which is also called aspike. Spike is the part of the plant where grain isformed and is generally made up of a zigzag central axisalong which are alternating spikelets. Spikelets developat nodes in the spike and in these spikelets the flowersand seeds develop. Wheat grain is enclosed between thelemma and palea of each spikelet (Magness et al., 1971;Miller, 2003). In this respect, wheat spike can be thoughtas natural package for wheat grain. While a lot ofinformation is available on the storage of wheat in grainform, there is no information about storage of wheat inspike form. The main objectives of this study were toevaluate the effect of storage in wheat spike form understorage conditions such as temperature and storagetime, and moisture content of grain on the quality offlour milled from the wheat stored.

Materials and methods

Wheat ‘Bezostaya’ variety was used in this study in grainand spike form. The wheat was obtained from Agricul-tural Research and Extension Center of AgriculturalFaculty of Ataturk University. Wheat spike was gath-ered by hand from the same field.

Sample preparation and storage

After harvesting, wheat grain was cleaned manually toget rid of the dust and other foreign materials. Wheat

grain and wheat spike were moistened to 12%, 14% and16%, packed in air-tight plastic containers, and storedin incubators maintained at 10, 20 and 30 �C for aperiod of 9 months. Containers were aired weekly toprevent accumulation of CO2 and the moisture contentof samples were adjusted weekly to the desired levelduring storage period. The samples were drawn after 3,6 and 9 months of storage for analytical purposes. Afterstorage in spike form, wheat grains were separated fromwheat spike. Wheat was conditioned to 15% moisturefor 24 h and milled to flour with approximately 65%yield by a laboratory mill (Buhler, 202, Switzerland).

Analytical methods

Hectolitre and thousand kernel weights of wheat wasdetermined as described by Elgun et al. (1999). Moisturecontents were determined according to AACC approvedmethods 44-15 (Anonymous, 1995). Wet and dry glutencontent was determined according to ICC standardmethod 137-1 (Anonymous, 2000) using the Glutomatic2200 system (Perten, Huddinge, Sweden). Falling num-ber values and Zeleny sedimentation volumes weredetermined according to the AACC method 56-81(Anonymous, 1983), IACC (Anonymous, 1972). Colourintensity was determined using the Minolta ColorimeterCR-200 (Minolta Camera Co., Osaka, Japan) (Elgunet al., 1999). All determinations were carried out intriplicate. The titratable acidity was expressed as sodiumhydroxide required to neutralise the acids in a 100 gsample using phenolphthalein as an indicator (Elgunet al., 1999). For phytic acid determination, the methoddescribed by Febles et al. (2002) was used.

Statistical analysis

spss 10.0 software for Windows was used to performstatistical analyses (SPSS, 1999). Differences in storedwheat because of different storage conditions were testedfor significance using analysis of variance techniques(anova). Duncan’s multiple-range test was used whenanova indicated significant difference in means. A levelof significance of P < 0.05 was used throughout theanalysis. All data were presented as the mean ± SE.

Result and discussion

The general effect of storage form, grain moisturecontent, storage time and temperature on hectolitreweight, wet and dry gluten, Zeleny sedimentation,falling number, phytic acid, total titratable acidity andL colour values of stored wheat are shown in Tables 1and 2. Wet and dry gluten content, Zeleny sedimenta-tion, falling number and phytic acid content of wheatstored in spike form were significantly (P < 0.01) lowerthan those of wheat stored in grain form, however,

Comparison of functional characteristics of wheat M. M. Karaoglu et al. 39

� 2010 The Authors. Journal compilation � 2010 Institute of Food Science and Technology International Journal of Food Science and Technology 2010

hectolitre weight was significantly higher. The increasein grain moisture content, storage time and temperatureresulted in a significant decrease (P < 0.01) in hectolitreweight, wet and dry gluten, Zeleny sedimentation andphytic acid content of stored wheat as compared withthe freshly harvested wheat. However, total titratableacidity and falling number significantly increased withincreasing grain moisture content, storage time andtemperature.

The hectolitre weight of wheat stored at differentgrain moisture, time and temperature in both spike andgrain form are shown in Fig. 1. The change in hectolitreweight of wheat stored in spike form was found to besimilar to that of wheat stored in grain form duringstorage period. In general, decrease in hectolitre weightof wheat stored in grain form was greater than that ofwheat stored in spike form at the end of 6 months ofstorage, whereas the opposite effect was observed at the

Table 1 The general effects of storage form,

grain moisture content, storage temperature

and storage time on hectolitre weight, wet

and dry gluten content, Zeleny sedimentation

and falling number values of wheat

(mean ± SE)

n

Hectolitre weight

(kg hL)1)

Wet gluten

(%)

Dry gluten

(%)

Zeleny

sedimentation

(cm3)

Falling

number (s)

Storage form

Spike 72 66.59 ± 0.45a 36.04 ± 0.54b 11.93 ± 0.14b 50.96 ± 1.32b 1291 ± 60b

Grain 72 66.32 ± 0.43b 37.06 ± 0.71a 12.23 ± 0.19a 52.44 ± 1.30a 1467 ± 64a

P ** ** ** ** **

Moisture content (%)

12 48 68.3 ± 0.31a 37.69 ± 0.70a 12.40 ± 0.20a 52.98 ± 1.58a 1323 ± 77b

14 48 66.2 ± 0.49b 37.43 ± 0.59a 12.32 ± 0.19a 52.21 ± 1.51b 1333 ± 67b

16 48 64.9 ± 0.65c 34.53 ± 0.92b 11.52 ± 0.21b 49.90 ± 1.71c 1481 ± 84a

P ** ** ** ** **

Storage temperature (�C)

10 48 67.0 ± 0.37a 37.61 ± 0.81a 12.35 ± 0.23a 56.25 ± 1.28a 1084 ± 23c

20 48 66.6 ± 0.53b 36.38 ± 0.54b 11.90 ± 0.15b 51.96 ± 1.46b 1384 ± 86b

30 48 65.7 ± 0.66c 35.65 ± 0.91b 11.99 ± 0.22b 46.87 ± 1.76c 1668 ± 78a

P ** ** ** ** **

Storage time (months)

0 36 69.7 ± 0.02a 38.21 ± 0.00b 12.30 ± 0.00b 62.80 ± 0.03a 1063 ± 17d

3 36 68.0 ± 0.36b 40.63 ± 0.82a 13.29 ± 0.28a 54.41 ± 1.70b 1241 ± 55c

6 36 65.6 ± 0.44c 36.17 ± 0.83c 11.92 ± 0.19c 49.95 ± 1.36c 1406 ± 72b

9 36 62.5 ± 0.64d 31.19 ± 0.73d 10.80 ± 0.18d 39.63 ± 1.13d 1806 ± 122a

P ** ** ** ** **

Means with different letters in the same column are statistically different at (P < 0.05); *P < 0.05;

**P < 0.01.

Table 2 The general effects of storage form,

grain moisture content, storage temperature

and storage time on phytic acid, acidity

and L colour values of wheat grain

(mean ± SE)

n Phytic acid (mg g)1) TTA (ml NaOH) Grain L colour value

Storage form: Spike 72 10.407 ± 0.20b 2.55 ± 0.04a 52.58 ± 0.34b

Grain 72 10.839 ± 0.18a 2.55 ± 0.06a 53.36 ± 0.32a

P ** **

Moisture content (%): 12 48 10.721 ± 0.23a 2.43 ± 0.03c 53.17 ± 0.37a

14 48 10.687 ± 0.23a 2.55 ± 0.06b 53.20 ± 0.41a

16 48 10.461 ± 0.25b 2.69 ± 0.09a 52.54 ± 0.45b

P ** ** **

Storage temperature (�C): 10 48 10.861 ± 0.23a 2.43 ± 0.04b 53.11 ± 0.42a

20 48 10.645 ± 0.25b 2.46 ± 0.04b 53.08 ± 0.39a

30 48 10.363 ± 0.23c 2.77 ± 0.10a 52.73 ± 0.42b

P ** ** *

Storage time (months): 0 36 12.865 ± 0.01a 2.30 ± 0.01c 56.62 ± 0.14a

3 36 11.207 ± 0.17b 2.22 ± 0.03c 51.70 ± 0.22c

6 36 9.468 ± 0.08c 2.67 ± 0.06b 53.45 ± 0.32b

9 36 8.952 ± 0.09d 3.05 ± 0.10a 50.12 ± 0.30d

P ** ** **

Means with different letters in the same column are statistically different at (P < 0.05); *P < 0.05;

**P < 0.01.

Comparison of functional characteristics of wheat M. M. Karaoglu et al.40

International Journal of Food Science and Technology 2010 � 2010 The Authors. Journal compilation � 2010 Institute of Food Science and Technology

end of 9 months of storage. Storage in spike form hadgenerally better preserving effect on hectolitre weightthan storage in grain form at 16% moisture content forall storage time and temperature. In addition to this,storage in grain form was affected by the increase ofgrain moisture content more than storage in spike form.The reduction in hectolitre weight is mainly attributableto the decrease in grain density during storage period.Similar results were found by others who investigatedthe effect of storage at high temperatures (27, 37 and50 �C) on functional characteristics of wheat. Hectolitreweight decreased as the duration of the storage periodincreased (Srivastava & Rao, 1994). Hectolitre weight isa grain quality indicator and is the weight of a fixedvolume of grain (kg hL)1). It is used as an approximatemeasure of the expected flour yield (Hollins et al., 2004).Generally greater the hectolitre weight, better thequality and yield of flour (Kunert et al., 2007).Wet gluten gives a quantitative measure of the gluten

forming proteins in flour that are mainly responsible forits dough mixing and baking properties (Anjum &Walker, 2000; Karaoglu, 2006).Wet gluten content of wheat stored in both spike and

grain form tended to decrease as storage periodincreased (Fig. 2). However, wet gluten generallyincreased after third month of storage (especially inthe wheat stored at grain form) in comparison to at theharvesting stage (0 day of storage). In the seeds ofstored wheat, several separated good definable andseveral interaction may happen and the quality of wet

gluten improves (Mezei et al., 2007). Wet gluten ofwheat stored in spike form was higher than that ofwheat stored in grain form after storage at 30 �C for 6and 9 months. For example, wheat stored in spike formand at 16% grain moisture had 32.59% wet glutencontent after storage at 30 �C for 6 months while wheatstored in grain form and at 16% moisture had 25%gluten. It may be said that, wheat stored in spike formare more tolerant than wheat stored in grain form toadverse storage conditions such as high moisture con-tent, temperature and longer storage time. The drygluten content of wheat stored at different grainmoisture, time and temperature in both spike and grainform are shown in Table 3. The change in dry glutenwas similar to that of wet gluten for all storageconditions. Wet gluten is a highly swollen colloidal gelcontaining 60–70% water, dry matter being made up of75–90% gluten proteins (gliadins and glutenins). Thewater-binding ability is defined as the difference betweenwet gluten and dry gluten.The Zeleny sedimentation test is used as a rapid means

of estimating baking quality of wheat flour. It relies onthe relationship between flour baking strength and glutenhydration capacity, assumed as a function of glutenquantity and quality. The Zeleny test involves measure-ment of the rate of sedimentation of the solid phasefollowing suspension of the flour in an aqueous lacticacid solution. During the sedimentation test, glutenproteins swells and precipitate as a sediment (Sozinov &Poperelya, 1980). Because Zeleny sedimentation volume

Figure 1 Effect of storage form, moisture

content of grain (h12%, 14%, j16%),

storage temperature and storage time on

hectolitre weight of wheat. Different letters

indicate significantly (P < 0.05) different

values for each storage temperature and

storage form. Each value represents a mean of

two replicates and bars indicate SEs.



depended on both gluten quality and quantity, the effectof storage conditions on Zeleny sedimentation wasgenerally the same as that of wet and dry gluten(Fig. 3). In general, at higher storage temperatures,greater decrease in Zeleny sedimentation was observed,and as it mentioned about wet gluten, increasing thestorage time led to decrease the Zeleny sedimentation.Similar results were reported by Srivastava & Rao

(1994). Wheat stored in spike form had better Zelenysedimentation values than wheat stored in grain formafter storage at 16% grain moisture content and alltemperature for 6 and 9 months.The falling number is an indicator of a-amylase

activity and a measurement of how far the break-downof starch has progressed in the kernel through enzymaticactivities (Ibanoglu, 2002). It is expressed in seconds and

Table 3 Dry gluten content of wheat stored in spike and grain form at different temperature, time and grain moisture content (mean ± SE)

Storage time (Months)

Storage temperature

10 �C 20 �C 30 �C

Moisture content Moisture content Moisture content

12% 14% 16% 12% 14% 16% 12% 14% 16%

Stored in spike form

0 12.3 ± 0.0b 12.3 ± 0.0ab 12.3 ± 0.0b 12.3 ± 0.0b 12.3 ± 0.0a 12.3 ± 0.0a 12.3 ± 0.0a 12.3 ± 0.0b 12.3 ± 0.0a

3 14.6 ± 0.2a 11.4 ± 0.2b 15.0 ± 0.8a 13.8 ± 0.4a 11.4 ± 0.2ab 10.3 ± 0.0c 11.6 ± 0.0a 14.1 ± 0.2a 10.8 ± 0.0b

6 11.5 ± 0.4b 13.0 ± 0.3a 11.5 ± 0.1b 11.9 ± 0.0b 11.9 ± 0.6a 11.3 ± 0.3b 13.2 ± 0.1a 11.9 ± 0.4b 10.9 ± 0.1b

9 9.9 ± 0.1c 1 1.5 ± 0.4b 11.1 ± 0.9b 10.4 ± 0.2c 10.2 ± 0.4b 10.6 ± 0.1bc 12.5 ± 0.9a 12.5 ± 0.4b 9.7 ± 0.1c

P ** * * ** * ** * **

Stored in grain form

0 12.3 ± 0.0bc 12.3 ± 0.0c 12.3 ± 0.0a 12.3 ± 0.0a 12.3 ± 0.0ab 12.3 ± 0.0a 12.3 ± 0.0a 12.3 ± 0.0b 12.3 ± 0.0b

3 15.4 ± 0.1a 16.2 ± 0.0a 12.0 ± 0.1a 13.8 ± 0.6a 12.8 ± 0.0a 13.5 ± 0.0a 14.4 ± 0.1a 14.9 ± 0.1a 13.5 ± 0.4a

6 13.7 ± 0.7b 13.0 ± 0.1b 10.4 ± 0.2b 12.4 ± 0.4a 11.5 ± 0.5b 12.4 ± 0.9a 12.1 ± 0.9a 12.8 ± 0.5ab 9.2 ± 0.1c

9 10.9 ± 0.4c 10.5 ± 0.3d 10.8 ± 0.1b 11.3 ± 0.8a 11.2 ± 0.3b 11.2 ± 0.8a 10.5 ± 0.1a 11.0 ± 1.1b 8.5 ± 0.1d

P ** ** ** * * * **

Mean values with different letters in the same column are statistically different at (P < 0.05); *P < 0.05; **P < 0.01.



storage temperature and storage time on wet

gluten of wheat. Different letters indicate

significantly (P < 0.05) different values for

each storage temperature and storage form.

Each value represents a mean of two

replicates and bars indicate SEs.



generally provides a measure of a-amylase enzymeactivity in the grain. A high falling number indicatesminimal activity, whereas a low falling number indicatesmore substantial enzyme activity (Curic et al., 2002).

There were fewer changes in falling number values forthe wheat stored in spike form than grain form at 10 �C(Fig. 4). Falling number values of wheat stored in spikeform were lower than that of wheat stored in grain form




Zeleny sedimentation value of wheat. Differ-

ent letters indicate significantly (P < 0.05)

different values for each storage temperature

and storage form. Each value represents a

mean of two replicates and bars indicate SEs.




falling number value of wheat. Different

letters indicate significantly (P < 0.05)

different values for each storage temperature

and storage form. Each value represents a

mean of two replicates and bars indicate SEs.



for all grain moisture content, storage time andtemperature except for those stored at 20, 30 �C and16% moisture content and also at 30 �C and 14%moisture content for 9 months. It can be concluded thata-amylase enzyme is better protected towards chemi-cally breaking down in spike form. Similar results wereobtained by Srivastava & Rao (1994) and Pirgozlievet al. (2006). The increase in the falling number may beattributed to degradation of amylase enzyme and thevariation of starch gelatinisation properties duringstorage period.The change in the grain moisture content had minimal

effect on phytic acid of wheat stored at 10 �C (Fig. 5).However, general increase in the grain moisture contentcaused significant decrease in phytic acid level of wheatstored in spike form at 20 �C and in spike and grainform at 30 �C. The values of phytic acid in wheat rangedbetween 7.92 mg g)1 (wheat stored in spike form, at12% grain moisture and 20 �C) and 12.86 mg g)1

(freshly harvested wheat). Phytic acid decreased byapproximately 35% after storage for 9 months at alltemperature levels. The decrease in phytic acid contentof wheat during storage period might be due to activityof the phytase enzyme present in cereal. Phytase activityin wheat grain is approximately 3000 U kg)1 (Steineret al., 2007). Phytic acid is known as an antinutrientfactor which is able to bind divalent minerals, thuslowering the mineral bioavailability. Therefore, thedecrease in phytic acid has a positive effect on mineralbioavailability (Astuti et al., 2000). Because wheat

stored in spike form had lower phytic acid values, itcan be concluded that phytase activity was higher inwheat stored in spike form than that of wheat stored ingrain form. For this reason, flour produced from wheatstored in spike form may be considered more beneficialfor human health.It is apparent from Fig. 6 that data that total

titratable acidity of wheat increased to various extentsduring storage at different temperatures and grainmoisture content. An increase in total titratable aciditystarted appearing just after 6 months of storage at 10, 20and 30 �C. In general, the increase in storage temper-ature and grain moisture content caused to an increasein acidity of wheat. Similar results were reported byother researchers (Srivastava & Rao, 1994; Gudaczewskiet al., 1999; Mis, 2003; Pirgozliev et al., 2006). The totaltitratable acidity at 30 �C storage temperature and 16%moisture content was 3.7 mL NaOH 100 g)1 for wheatstored in spike form and 4.8 mL NaOH 100 g)1 forwheat stored in grain form after 9 months, while it was2.3 mL NaOH 100 g)1 for freshly harvested wheat. Theresults are consistent with the results of Rehman & Shah(1999) and Mecham & Mossman (1974) who reportedan increase in acidity during storage period of wheat andwheat products. The increase in the acidity in storedwheat grains could be attributed to the increasingconcentration of the free fatty acid because of lipaseactivity (Salman & Copeland, 2007) and phosphateswhich resulted from increased grain deterioration (Reh-man & Shah, 1999).




phytic acid content of wheat. Different letters







L colour value is a useful indicator of darkness duringstorage, ranging from 0 (black) to 100 (white). As shownin Table 4, L colour values of stored wheat were loweras compared to the freshly harvested wheat (Table 4). Ingeneral, the extent of change in colour was higher insamples stored at 12% grain moisture and 20 �C(Table 2). The decrease in L value or the increase indarkness of wheat grain after storage could be attributed

to non-enzymatic browning. In addition, increasedacidity of wheat during storage accelerated the rate ofMaillard-type reactions (Singh & Bains, 1988).

Conclusions

In this study, the effects of storage form (grain ⁄ spike)of wheat, grain moisture content, storage time and



storage temperature and storage time on total

titratable acidity of wheat. Different letters





Table 4 L colour values of wheat grain stored in spike and grain form at different temperature, time and grain moisture content (mean ± SE)

Storagetime (months)

Storage temperature

10 �C 20 �C 30 �C

Moisture content Moisture content Moisture content

12% 14% 16% 12% 14% 16% 12% 14% 16%

Storage in spike form

0 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a

3 49.5 ± 0.1b 50.5 ± 0.0c 50.7 ± 0.2c 51.6 ± 0.1b 52.8 ± 0.0b 52.7 ± 0.2b 50.9 ± 0.2b 50.6 ± 0.1bc 50.3 ± 0.2c

6 50.9 ± 0.1b 53.3 ± 0.0b 52.8 ± 0.1b 51.8 ± 0.0b 52.3 ± 0.5b 52.6 ± 0.2b 55.3 ± 0.1a 53.3 ± 1.0b 53.9 ± 0.1b

9 51.3 ± 0.9b 47.9 ± 0.2d 50.9 ± 0.0c 51.4 ± 0.2b 52.1 ± 0.7b 47.3 ± 0.1c 49.7 ± 0.5b 49.8 ± 0.7c 47.4 ± 0.0d

P * ** ** ** ** ** ** ** **

Storage in grain form

0 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a 56.6 ± 0.8a

3 50.7 ± 0.3b 53.5 ± 0.3b 53.7 ± 0.0b 50.2 ± 0.2c 53.5 ± 0.4b 53.1 ± 0.1b 51.9 ± 0.1c 53.3 ± 0.2b 51.1 ± 0.5b

6 55.1 ± 0.3a 57.3 ± 0.6a 55.3 ± 0.6ab 55.0 ± 0.3a 55.2 ± 0.1ab 51.8 ± 0.4b 54.7 ± 0.1b 51.3 ± 1.2b 50.1 ± 0.3b

9 52.1 ± 0.0b 51.1 ± 0.0c 48.4 ± 0.2c 52.1 ± 0.3b 50.9 ± 0.2c 47.8 ± 0.1c 52.3 ± 0.0c 48.4 ± 0.1c 51.5 ± 0.2b

P ** ** ** ** ** ** ** ** **

Means with different letters in the same column are statistically different at (P < 0.05); *P < 0.05; **P < 0.01.



temperature on the some quality parameters such ashectolitre weight, gluten content, Zeleny sedimentation,enzyme activity, acidity and phytic acid of the storedwheat were studied. From this investigation, it wasconcluded that storage in spike form had a positive effecton wet gluten content and hectolitre weight of wheatstored under non-optimal storage conditions such as highgrain moisture content and high temperature. Wet glutenof wheat stored in spike form was higher than that ofwheat stored in grain form after storage at 30 �C for 6 and9 months. Storage in spike form had generally betterpreserving effect on hectolitreweight than storage in grainform at 16% moisture content and all storage time andtemperature. Because of the falling number values ofwheat stored in spike form were generally lower thanwheat stored in grain form, we can say that a-amylaseenzyme is better protected towards chemically breakingdown in spike form. Similarly, phytic acid values of wheatstored in spike formwere lower thanwheat stored in grainform. Therefore it is easily concluded that flour producedfrom wheat stored in spike form may be considered morebeneficial for human health. As conclusion, it may be saidthat, wheat stored in spike form is more tolerant thanwheat stored in grain form to adverse storage conditionssuch as high moisture content and temperature andlonger storage time.

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A comparison of the functional characteristics of wheat stored as grain with wheat stored in spike...

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