Effect of Microwave Treatment on Protease Activity, Dough Properties and Protein Quality in Sprouted Wheat.

In this study, the effects of microwave treatment on protease activity, dough properties and protein quality in sprouted wheat were investigated. Microwave treatment led to a significant (p < 0.05) reduction in protease activity in sprouted wheat. Proteases with a pH optimum of 4.4 (cysteine proteinases) were more susceptible to microwave heating, which contributed mostly to protease inactivation. Significant improvements (p < 0.05) in the dough properties and gluten quality of sprouted wheat were observed, which are probably attributable to the synergistic effectiveness of protease inactivation and heat-induced gluten cross-linking. After microwave treatment, the decrease in the solubility and extractability of protein in sprouted wheat indicated protein polymerization, which was induced by intermolecular disulfide bond cross-linking. The changes in gliadin were less pronounced due to the relatively low temperature of the microwave treatment. The cross-linking in sprouted wheat that occurred after microwave treatment seemed to mainly involve glutenin, especially B/C low-molecular-weight glutenin subunits (B/C-LMW-GSs) in the range of 30-50 kD.

Structure-activity relationship between gluten and dough quality of sprouted wheat flour based on air classification-induced component recombination.

BACKGROUND: Air classification can separate sprouted wheat flour (SWF) into three types: coarse wheat flour (F1), medium wheat flour (F2) and fine wheat flour (F3). The gluten quality of SWF can be indirectly improved by removing inferior parts (F3). In order to reveal the underlying mechanism of this phenomenon, the composition and structural changes of gluten, as well as the rheological properties and fermentation characteristics of gluten in recombinant dough in the process of air classification of all three SWF types, were analyzed in this study. RESULTS: Overall, sprouting significantly reduced the content of high-molecular-weight subunits, such as glutenin subunit and ω-gliadin. It also destroyed the structural content, such as disulfide bonds, α-helix and ß-turn contents, which maintained the stability of gluten gel. Air classification made the above changes in F3 more severe but reversed them in F1. Moreover, rheological properties were more affected by gluten composition, whereas fermentation characteristics were more affected by gluten structure. CONCLUSION: After air classification, particles rich in high molecular weight subunits from SWF are enriched in F1, and the gluten of F1 has more secondary structure that maintain gel stability, which ultimately lead to improved rheology properties and fermentation characteristics. F3 relatively exhibits the opppsite phenomenon. These results further reveal the potential mechanism of improvement of SWF gluten by air classification. Moreover, Thus, this study provides new perspectives for the utilization of SWF. © 2023 Society of Chemical Industry.

Optimization of fermentation conditions in Barbari bread based on mixed whole flour (barley and sprouted wheat) and sourdough.

The purpose of this study was to use a mixture of whole wheat-barley flour mixture in the preparation of traditional Iranian bread (Barbari) in the optimum condition of fermentation to benefit from all available nutrients. In this study, bread parameters such as specific volume, porosity, textural characteristics, zinc, iron, phytic acid and organoleptic properties were investigated. In this research, different percentages of sourdough (15-30%) and fermentation time (30 - 120 min) were applied. Results showed that the phytic acid content significantly decreased (p < 0.05) (0.23 - 0.14) by increasing sourdough and fermentation time, which result in increasing in zinc (17.49 - 22.89%) and iron (36.44 - 45.32%) content. Both the sourdough content and fermentation time parameters had a significant effect (p < 0.05) on the better porosity (9.05 - 13.50%) and overall acceptability of bread (2.15 - 3.85). The hardness, gumminess, chewiness, porosity, phytic acid and overall acceptance parameters were used to optimize the fermentation conditions of Barbari bread by response surface methodology using a central composite design. Optimal conditions for the production of Barbari bread were 29.53% sourdough and 120 min fermentation time. Under optimal conditions, the overall acceptance, hardness, porosity, chewability, gumminess and phytic acid were 3.84, 60.81 N, 14.09%, 302.01 N/mm, 41.37 N and 0.15%, respectively.

Changes in Bread Quality, Antioxidant Activity, and Phenolic Acid Composition of Wheats During Early-Stage Germination.

This study reported changes in baking properties, total phenolic content (TPC), antioxidant activity, and phenolic acid composition of three hard red winter wheat varieties during the early stage of seed germination. The wheats were sprouted at 30 °C and 95% relative humidity to achieve different germination levels based on falling number ranges (550 s for control flour; 350 s [low], 250 s [medium], and 120 s [high] for sprouted flours, respectively). Average germination times were 7, 8, and 10 hr for the low, medium, and high germinated samples, respectively. Most baking properties of sprouted whole flour were comparable to the control flour. However, TPC, flavonoid content, phenolic acids, and antioxidant activity of sprouted flour were lower than the control flour. To our knowledge, this is the first study that reported both baking properties and antioxidant potential of sprouted whole wheat flour from early-stage germination. The study deepens the understanding of seed germination and the potential use of sprouted flour in baking industry. PRACTICAL APPLICATION: This study evaluates the baking quality and nutraceutical value of sprouted whole wheat flour, which are key factors determining the application of sprouted flour in the baking industry. The results will contribute to the production of quality bakery products with enhanced nutraceutical benefits.

Effects of controlled germination on selected physicochemical and functional properties of whole-wheat flour and enhanced γ-aminobutyric acid accumulation by ultrasonication.

Using hard red spring (HRS), hard white (HW), and soft white (SW) wheat, this study examined how germination time affected the functionality of whole-wheat flour (WWF) and enhancement of γ-aminobutyric acid (GABA) content through ultrasonication. The falling number values significantly decreased and the glucose content increased by 227-357% after 15h of controlled germination. The setback value of WWF paste decreased from 654 to 6cP (HW), 690 to 9cP (SW), and 698 to 7cP (HRS), respectively, showing significant decreases of starch retrogradation in an aqueous system. The gluten quality and dough mixing performance of WWF after 5-15h of controlled germination was enhanced since gluten is less weakened during the dough heating stage of Mixolab testing. After a 72h germination, the GABA content increased by 339% of the non-sprouting counterpart. Furthermore, the GABA content in the ultrasound-treated SW sample was 30.7% higher than that without ultrasound treatment.

Standardization of Fat:SNF ratio of milk and addition of sprouted wheat fada (semolina) for the manufacture of halvasan.

Traditional Indian Dairy Products such as Halvasan are manufactured in India using an age old practice. For manufacture of such products industrially, a standard formulation is required. Halvasan is a region specific, very popular heat desiccated milk product but has not been studied scientifically. Fat and Solids-not-fat (SNF) plays an important role in physico-chemical, sensory, textural characteristics and also the shelf life of any milk sweet. Hence for process standardization of Halvasan manufacture, different levels of Fat:SNF ratios i.e. 0.44, 0.55, 0.66 and 0.77 of milk were studied so that an optimum level yielding best organoleptic characteristics in final product can be selected. The product was made from milk standardized to these ratios of Fat:SNF and the product was manufactured as per the method tentatively employed on the basis of characterization of market samples of the product in laboratory. Based on the sensory results obtained, a Fat:SNF ratio of 0.66 for the milk has been selected. In the similar way, for standardizing the rate of addition of fada (semolina); 30, 40, 50 and 60 g fada (semolina) per kg of milk were added and based on the sensory observations, the level of fada (semolina) addition @50 gm/kg of milk was adjudged the best for Halvasan manufacture and hence selected.

Development of sprouted wheat based probiotic beverage.

Present study was carried out to evaluate the potential of Lactobacillus acidophilus (L. acidophilus) for development of wheat based probiotic beverage and to optimize the proportion of different ingredients viz. sprouted wheat flour, sprouted wheat bran, oat and stabilizer using response surface methodology. Acidity, pH and probiotic count of samples prepared with L. acidophilus NCDC-14 was higher than that of L. acidophilus NCDC-16 culture. Being more compatible, L. acidophilus NCDC-14 was selected for this study. Acidity (in terms of lactic acid), pH and probiotic count of the different samples ranged from 0.21 to 0.45 %, 4.0 to 4.9, and 8.30 to 10.95 log10 cfu mL(-1), respectively. Probiotic count increased with increasing amount of sprouted wheat and oat. Optimized levels for sprouted wheat flour, oat, wheat bran and guar gum were 7.86, 5.42, 1.42 and 0.6 g, respectively per 100 mL of water. Optimized probiotic beverage provided 13.19 % total solids, 1.19 % protein, 0.33 % fat, 0.10 % ash, 0.42 % crude fibre, 1.45 mg iron, calcium 15.74 mg, 11.56 % carbohydrates, 54 kcal calories and 10.43 log10 cfu mL(-1) probiotic count. Thus, Lactobacillus acidophilus NCDC-14 can be used for development of potentially probiotic beverage with sprouted wheat and oat.

Phenolic acid composition of sprouted wheats by ultra-performance liquid chromatography (UPLC) and their antioxidant activities.

The phenolic acid profiles of flours from two Canadian wheat classes, Canadian Western Red Spring (CWRS) and Canadian Western Amber Durum (CWAD), were investigated using two different extraction mediums and analysed on an ultra-performance liquid chromatography (UPLC) system at different degrees of sprout damage. A sound (non-sprouted) control sample as well as two different sprouted sub-samples, derived from different germination protocols of the control, were prepared for both the CWAD and CWRS. Free phenolic acids were extracted from the ground whole wheat meal using three repetitive 80% ethanol extractions. Bound phenolic compounds were subsequently released from the residue by alkaline hydrolysis followed by triplicate extraction with diethyl ether:ethyl acetate (1:1, v/v). Twelve phenolic acid standards were clearly resolved and quantified using a short 5min elution gradient. Seven phenolic acids (4-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, ferulic and sinapic) were detected in the CWRS and CWAD alcoholic and alkaline extracts. Syringic acid was the main compound in the free phenolic alcoholic extracts of the wheat meal representing 77.0% and 75.3% of the total amount of detected free phenolic compounds for CWRS and CWAD, respectively. However, the major released phenolic compound detected in the alkaline hydrolysed extracts was ferulic acid accounting for 72.3% and 71.0% for CWRS and CWAD respectively total bound phenolics. During germination, syringic acid levels rose as the length of germination time increased, resulting in the increase in total phenolic compound and antioxidant activity of the sprouted wheat flours. There was an increase in total phenolic compounds and the antioxidant activity of the alcoholic extracts from the CWRS and CWAD wheat flours as the germination time was extended. As a result, the sprouted wheats exhibits better nutritional properties than un-germinated wheat and could be used to improve the nutrition value in food products.