Apparent Viscosity as a Marker of Wheat Germination and Predictor of Bread Quality and Starch Digestibility

Wheat flour (WF) was substituted with germinated Bambara groundnut (Vigna subterranea) flour (GBF) at different proportions (5%, 10%, 15%, 20%, 25%, and 30%) and used in the preparation of bread. The dough mixing, pasting, and gelatinization properties of the blends were evaluated as well as the nutritional quality, in vitro starch digestibility, phytochemical constituents, antioxidant potential, color, texture, and sensory properties of breads. All the wheat dough containing GBF had higher water absorption capacity, gelatinization temperatures, dough development time, low peak, and setback viscosities. The composite breads had significantly higher dietary fiber, minerals, protein digestibility, corrected amino acid scores, resistant starch, slowly digestible starch, total phenolics, total flavonoids, and antioxidant activities and caused significant reduction in rapidly digestible starch content. The addition of up to 15% GBF had no significant impact on the specific volume of wheat bread. Substitution of WF with GBF influenced color and texture properties of bread. Wheat bread supplemented with 20% GBF had significantly higher scores in taste, aroma, and overall acceptability. This study demonstrated the potential of GBF as a functional ingredient in bread making. PRACTICAL APPLICATION: This study provides a suitable possibility of partial substitution of wheat flour with germinated Bambara groundnut, to develop functional and acceptable bread. The dough mixing and pasting results in this study would add to knowledge on the dough handling characteristics as there is limited information regarding the mixing properties of wheat dough with germinated Bambara groundnut.

The aim of this study was to evaluate the influence of buttermilk on the physicochemical and sensory attributes of pan and pita breads. Different amounts of buttermilk (30, 60, and 100% of added water) were mixed with other ingredients of pan and pita bread formulations. The doughs and bread were analyzed for rheological, physicochemical, and sensory qualities. The results demonstrated that incorporation of different concentrations of buttermilk in bread formulations progressively enhanced water absorption capacity, dough development time, gelatinization temperature, and peak viscosity, whereas it reduced the dough stability and temperature at peak viscosity. Supplementation of wheat flour with 30% buttermilk significantly (P ≤ 0.05) enhanced the physical properties of pan bread compared to nonsupplemented control. Incorporation of different percentages of buttermilk in bread formulation concomitantly (P ≤ 0.05) increased protein, oil, and ash contents and it reduced the carbohydrate contents of both types of bread. Incorporation of 60 and 100% of buttermilk in bread formula showed low scores of all sensory attributes compared to control and 30% buttermilk containing pan and pita bread. In conclusion, supplementation of bread formulas with 30% buttermilk is recommended for improving the nutritional and sensorial qualities of pan and pita bread.

Effect of apricot, guar and locust bean gum hydrocolloids on pasting, antioxidant, rheology, thermal and sensory properties of gluten-free breads

To ensure the best quality bread, it is important to consider the speed of digestion of starch and proteins, as well as how time fermentation and storage time influence the rate of starch digestion and the texture of the bread. This study compared the effect of fermentation time and days of storage on the texture, physicochemical, protein and starch digestibility of sourdough bread. Texture profile analysis showed that the fermentation time in recently baked sourdough bread affects hardness, chewiness, and springiness. The electrophoretic profile showed a decrease in band thickness with increase in fermentation time, consistent with a higher percentage of protein digestion. While fermentation time did not significantly affect rapidly digestible starch (RDS) and slowly digestible starch (SDS), storage time resulted in a decrease in RDS and an increase in SDS. Sourdough breads had higher levels of resistant starch (RS). The digestibility characteristics of protein and starch, as well as texture properties, are significantly influenced by fermentation and storage time. The evidence suggests that sourdough bread has the potential to improve the digestion of protein and to effectively regulate the glycemic response, which is due to its higher levels of SDS and RS.

The effects of 10%–30% of wheat flour substitution with potato flour (PF) and sweet potato flour (SPF) on the flour and dough properties, the total polyphenol (TPC), and carotenoid contents (TCC) of bread, as well as their correlation with bread texture and starch digestibility, were investigated. With PF and SPF addition, the peak, breakdown, and setback viscosity of the flour decreased. The addition of PF and SPF reduced the dough formation and stabilization duration, as well as the hardness of the bread. The specific volume of the bread depended on the addition amount of PF and SPF. When the addition of PF and SPF was 15%, the bread had the lowest hardness and highest specific volume. The TPC and TCC in the bread depended on the added flour variety, and negatively influenced specific volume and positively influenced the content of resistant starch (RS).

Fermentation strains play a key role in the quality of bread. The combination of yeast and lactic acid bacteria (LAB) may effectively improve the function and nutritional properties of bread. In this study, the dough was fermented to make bread by using single strain (Saccharomyces cerevisiae, mode A), the combination of two strains (S. cerevisiae and Lactiplantibacillus plantarum, mode B; S. cerevisiae and Lactobacillus delbrueckii, mode C), or three strains (S. cerevisiae, L. plantarum, and L. delbrueckii, mode D). The specific volume, texture, and aroma substances of bread were evaluated. The possibility of mixed fermentation of selected yeast and LAB to replace natural fermentation dough was evaluated. The results showed that the specific volume of bread in mode B was 15.2% higher than that of mode A. The structure was softer and the taste was more vigorous in mode B bread. The content of volatile compounds was highest in mode B bread among the four mode bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol. The cofermentation in mode B made the bread aroma richer and gave better aroma characteristics to bread. Therefore, the fermentation of S. cerevisiae and L. plantarum can be recommended to replace naturally fermented dough to improve the quality of bread. PRACTICAL APPLICATION: L. plantarum and L. delbrueckii, separately or together, assisted in yeast fermentation to make bread. The specific volume, texture, and aroma substances of bread were evaluated to replace natural fermented dough with mixed fermentation. L. plantarum-assisted yeast fermentation improved the specific volume, texture, and aroma of bread. The characteristic flavors were ethyl 2-hydroxypropionate and z-3-hexenol in bread. Therefore, the fermentation of S. cerevisiae and L. plantarum could replace naturally fermented dough to improve the quality of bread.

Background and objectivesSome factors related to rice processing, composition, and grain microstructure may interfere with starch digestibility. The objective of this work was to evaluate the impact of physicochemical properties and rice processing on the starch digestibility of genotypes produced in Brazil. Five traditional white rice genotypes, one black rice, and one red rice genotype were studied. The traditional white rice genotypes were evaluated as brown rice as well as in the polished rice form, while both black and red rice were evaluated in the unpolished form.FindingsThe digestibility ranged from 41.40% to 99.81%, being positively correlated with starch content and peak viscosity and negatively correlated with pasting temperature. The unpolished rice group exhibited lower digestibility value than the polished rice group as a result of the presence of bran. Low amylose cultivars had higher starch hydrolysis percentage.ConclusionsThe type of processing influenced the starch digestibility profile, in which the presence of bran and pigments in whole rice reduce starch hydrolysis percentage. The extent of gelatinization of the starch, identified through the peak viscosity and the pasting temperature of RVA, also had a direct influence on digestibility.Significance and noveltyFor the first time, different types and processing of Brazilian rice genotypes have been studied about the starch viscosity and digestibility profiles and related to other quality traits, what can drive consumption of a greater diversity of rice according to different market demands and energy needs.

Sweet potato leaf and stem, rich in dietary fibre, were used to study their effects on properties of dough and toast bread. Dried and pulverised leaf and stem were separately added at 5, 10 and 15% substitution level. Rheological properties, color and texture of the bread were measured by a farinograph, colorimeter and texture profile analyser, respectively. Results showed water absorption and maximum tolerance index of the dough increased with increasing amount of leaf and stem, while development time, stability and time to breakdown decreased. Bread crumb with substituted leaf was darker than that with substituted stem, and both were significantly darker than the control. Texture analysis indicated little changes in adhesiveness, but hardness and chewiness of bread at the substitution level above 5% were significantly higher than those of the control. Sensory evaluation showed a tendency that the taste, texture, colour, flavour and overall acceptability of bread substituted with 5% stem were better than those with 5% leaf, and comparable to those of the control.

The objective of this research was to determine effects of five enzymes on whole wheat bread properties, particularly loaf volume, bread texture, and staling. Enzymes containing conventional α-amylase (α-amyl), cellulase (cel), glucose oxidase, maltogenic α-amylase (m amyl), and xylanase (xyl) were added at three levels. Vital wheat gluten (VWG) was added as an additional, separate treatment at 2.5% (flour weight basis). Enzymes had minimal effect on water absorption and mixing time. Each enzyme increased specific loaf volume for at least one of the usage levels tested (P <0.01). Among the enzyme treatments, the greatest loaf volume was seen for xyl at the medium and high levels. No enzyme was as effective as VWG at increasing loaf volume. Overall, enzymes did not significantly change cell structure. The greatest reduction in fresh bread hardness was obtained for the high level of xyl. VWG, m amyl, and xyl reduced the rate of bread firming over 7 days. α-Amyl, cel, and m amyl decreased starch retrogradation at day 7 as measured by differential scanning calorimetry (P <0.01). M amyl nearly eliminated the endothermic peak for recrystallized amylopectin. This study demonstrated the specific application of enzymes in whole wheat bread to increase loaf volume and decrease initial crumb hardness and bread staling. PRACTICAL APPLICATION: This study will provide guidance for practical uses of enzymes in improving whole wheat dough and bread quality.

In order to investigate the effects of celery powder (CP) on bread quality, wheat flour was replaced by CP which was produced from two celery varieties ('Jinnan Shiqin' and 'Ventura') at different levels (1, 2, 3 and 5/100g flour). For both kinds of CPs, Mixolab analysis showed that the water absorption of dough increased with the increase of CP, while the protein network weakening (C2), peak viscosity (C3) andcrystallinity of starch (C5-C4) decreased. The specific volume of bread decreased at higher CP level, whereas its crumb hardness and chewiness showed a reverse trend. The addition of CP significantly increased the total phenolics content of bread, and thus caused a significant improvement in antioxidant activities. The addition of CP significantly reduced the content of rapidly digestible starch in bread, while thecontentsof slowly digestible starch and resistant starch wereincreased. Additionally, bread prepared with a higher CP content showed a lower predicted glycaemic index. Based on the results of sensory analysis, bread incorporated with 2g/100g flour for 'Jinnan Shiqin' or 1g/100g flour for 'Ventura' didn't show significant effect on its overall acceptability. The present study indicated that addition of CP could be an effective way to produce a bread with higher antioxidant activity and lower starch digestibility.

Effect of extrusion with hydrocolloid-starch molecular interactions on retrogradation and in vitro digestibility of chestnut starch and processing properties of chestnut flour

Influence of hydrocolloids on dough handling and technological properties of gluten-free breads

Replacing wheat flour in the breadmaking process is a technology challenge since the elimination of gluten has a strong influence on bread quality. Proteins addition are often used to form a protein network capable of mimicking gluten-like structure, giving to dough a foaming support. This study aimed to evaluate the potential of denatured whey proteins coming from fresh curd cheese addition, to strengthening gluten-free dough structure, enhancing the breadmaking performance. Curd cheese additions were tested (5% up to 20%, weight/weight) and the effect on dough rheology behavior and bread quality was evaluated. Findings obtained revealed that the technology and nutritional properties of the bread can be enhanced by curd cheese addition, and such effects should be related to the composition and functionality of denatured whey proteins. Considering higher levels of curd cheese (20%) tested, improvements on bread quality was observed, leading to a considerable increase in bread volume (73%), softness (65%), with a significant reduction on staling kinetics (70%), comparing with control bread. Additionally, an improvement in nutritional value in terms of proteins (80%) and minerals content (P—50.0%, Mg—6.0%, and Ca—360.3%) was obtained, which can give an additional contribution to the nutritional daily requirements of celiac patients. Linear correlations between dough rheology properties and bread quality attributes were found, supporting the good breadmaking performance obtained.

An increase in bread production has been achieved to meet the increasing demand of the growing population. During the manufacturing process, refined wheat flour, the main ingredient for bread making, loses its nutritional qualities. Hence, it is necessary to use additional nutritional sources to maintain nutritional value. In this study, the rheological, physicochemical, and sensory qualities of bread, prepared using camel milk and water, were evaluated. The increase in the camel milk content resulted in the significant increase in the protein, oil, and ash contents of bread and a decrease in the carbohydrate content. The protein content was increased from 11.95% (100% water) to 14.01% (100% camel milk). The use of camel milk resulted in the progressive increase in the content of two essential fatty acids, α-linolenic acid and linoleic acid ( P &lt; 0.05 ; maximum increase: 1.65% and 20.9%, resp.). The rheological properties of bread (peak viscosity, gelatinisation temperature, and water absorption capacity) could be improved using camel milk. However, reduced dough stability and peak viscosity–temperature were also observed. The increase in the water absorption capacity from 61% to 67% indicated that the supplemented dough was more suitable than the original dough for preparing bread. The physical properties of bread prepared using camel milk (30%) and water (70%) were better than the properties of the control bread sample. Improved sensory attributes were observed under these formulation conditions. Bread containing ≥70% camel milk received lower sensory scores. The results indicated that the use of the formulation consisting of camel milk (30%) and water (70%) could enhance the nutritional value of bread without significantly affecting the acceptability. The results can provide a platform for extending the application of camel milk, primarily used to produce fermented milk, in the food industry. It could be potentially used to address the global problem of acute malnutrition.

Recent advances in application of modified starches for breadmaking