Individual effects of enzymes and vital wheat gluten on whole wheat dough and bread properties

Combined effects of α-amylase, xylanase, and cellulase coproduced by Stachybotrys microspora on dough properties and bread quality as a bread improver

This study aims to explore the feasibility of introducing, during the manufacture of bakery bread, an enzymatic cocktail coproduced by the fungus Stachybotrys microspora: α-amylases, xylanases and cellulases, using wheat bran as a nutrient source. Among the characteristics of the alveograph (dough tenacity "P" and dough extensibility "L"), the addition of a cocktail of enzymes at a concentration of 2 %, to weak wheat flour, has made it possible to significantly reduce its P/L ratio from 2.45 to 1.41. Furthermore, the use of enzyme cocktails at 2 %, 4 %, and 6 % concentrations increases the brown color of the bread crust. The great reduction in the rate of bread firmness, during storage over 5 days, was obtained in the presence of an enzyme cocktail in comparison with bread control (65.13 N for the control and 22.99 N, 23.24 N, and 18.24 N for bread enriched with enzyme cocktail at 2 %, 4 % and 6 % concentrations, respectively). In conclusion, the enzyme cocktail added can synergistically improve bread dough rheology and bread properties.

Influence of starch spherulites with different allomorphs and morphologies on reducing gastrointestinal digestibility in bread

This study aimed to enhance the resistance of bread to gastrointestinal digestion by partially substituting wheat flour with starch spherulites. Three types of starch spherulites, specifically A-type (exhibiting an A-type crystalline pattern with mostly positive birefringence), B(-)-type (B-type crystalline with negative birefringence), and B(+)-type (B-type crystalline with positive birefringence), were investigated. The A-, B(-)-, and B(+)-type spherulites showed significantly higher resistant starch contents of 63.5, 63.8, and 89.2 %, respectively, compared to the control wheat flour (7.4 %). The melting temperatures of A-type and B(+)-type spherulites were notably higher than those of the control wheat flour, suggesting the potential preservation of certain enzyme-resistant starch during the baking process. The partial substitution of wheat flour with spherulites resulted in a denser crumb structure, increased bread hardness and chewiness, and a pale brown color in the case of B(+)-type spherulite. However, these variations in physicochemical properties did not significantly impact consumer acceptability. Remarkably, in bread containing A- or B(+)-type spherulite, residual ordered spherulite structures were present after baking, as confirmed by differential scanning calorimetry. This resulted in significantly lower digestibility during in vitro gastrointestinal digestion. These findings are useful for the rational design of bread with sustained glucose release during gastrointestinal digestion.

Technological and Nutritional Aspects of Bread Production: An Overview of Current Status and Future Challenges

Bakery products, especially bread, exist in many homes worldwide. One of the main reasons for its high consumption is that the main raw material is wheat, a cereal that can adapt to a wide variety of soils and climates. However, the nutritional quality of this raw material decreases during its industrial processing, decreasing the value of fibers, proteins, and minerals. Therefore, bread has become a product of high interest to increase its nutritional value. Due to the high consumption of bread, this paper provides a general description of the physicochemical and rheological changes of the dough, as well as the sensory properties of bread by incorporating alternative flours such as beans, lentils, and soy (among others). The reviewed data show that alternative flours can improve fiber, macro, and micronutrient content. The high fiber content reduces the quality of the texture of the products. However, new processing steps or cooking protocols, namely flour proportions, temperature, cooking, and fermentation time, can allow adjusting production variables and optimization to potentially overcome the decrease in sensory quality and preserve consumer acceptance.

Mechanism of action of three different glycogen branching enzymes and their effect on bread quality

Bread staling adversely affects the quality of bread, but starch modification by enzymes can counteract this phenomenon. Glycogen branching enzymes (GBEs) used in this study were isolated from Deinococcus geothermalis (DgGBE), Escherichia coli (EcGBE), and Vibrio vulnificus (VvGBE). These enzymes were characterized and applied for starch dough modification to determine their role in improving bread quality. First, the branching patterns, activity on amylose and amylopectin, and thermostability of the GBEs were determined and compared. EcGBE and DgGBE exhibited better thermostable characteristics than VvGBE, and all GBEs exhibited preferential catalysis of amylopectin over amylose but different degrees. VvGBE and DgGBE produced a large number of short branches. Three GBEs degraded the starch granules and generated soluble polysaccharides. Moreover, the maltose was increased in the starch slurry but most significantly in the DgGBE treatment. Degradation of the starch granules by GBEs enhanced the maltose generation of internal amylases. When used in the bread-making process, DgGBE and VvGBE increased the dough and bread volume by 9 % and 17 %, respectively. The crumb firmness and retrogradation of the bread were decreased and delayed significantly more in the DgGBE bread. Consequently, this study can contribute to understanding the detailed roles of GBEs in the baking process.

Effect of fermentation methods on properties of dough and whole wheat bread

BACKGROUND

Whole wheat bread is high in nutritional value but poor in technological quality; therefore, research on how to improve its technological quality has attracted extensive attention. The effects of fermentation methods, including straight dough(STD), sourdough (SOD), sponge dough (SPD), and refrigerated SPD (RSD) methods, on the dough and bread quality of whole wheat bread were investigated, focusing on pasting properties, rheological properties, thermal properties, microstructure, basic quality, and starch digestibility.

RESULTS

The rapid viscosity analysis and rheological results demonstrated that SOD had the highest pasting temperature and the lowest viscosity, indicating an inhibition of starch pasting and partial protein hydrolysis, whereas the opposite trend presented by SPD and RSD indicated a greater starch hydration and a stronger gluten network. Thermal gravimetric analysis and differential scanning calorimetry results indicated reduced starch thermal degradation and increased starch pasting enthalpy in SOD and RSD. Scanning electron microscopy images revealed that the starch granules of SOD and RSD were tightly wrapped by a gluten network. SOD and RSD breads had the largest specific volume, the softest texture, and the lowest glycemic index.

CONCLUSION

The effects of different fermentation methods on dough and bread structure can provide instructive information for future studies on their applications in whole wheat bread production. © 2023 Society of Chemical Industry.

Combined Effects of Particle Size and Dough Improvers on Improving the Quality of Purple-Colored Whole Wheat Bread

Consumers' interest in healthy products is increasing. However, the production of excellent-quality whole wheat bread (WWB) faces challenges due to the reduced gluten functionality and varied particle sizes of whole wheat flour (WWF). This study aimed to explore the enhancement of purple-colored WWB quality by controlling the particle size of WWF and using dough improvers. Six purple-colored WWFs were obtained using an ultra-centrifugal mill with different sieve openings (0.5 and 1.0 mm) and rotor speeds (6000, 10,000, and 14,000 rpm). The average particle diameter (d50) of the smaller particle size group (S) and the larger particle size group (L) based on the sieve opening ranged from 115 to 258 μm and 294 to 492 μm, respectively. Group S demonstrated higher water absorption, damaged starch, and gluten strength compared to group L. Additionally, group S exhibited a greater bread volume and height compared to group L. Among the tested dough improvers (vital wheat gluten, vitamin C, enzymes, and emulsifiers), vital wheat gluten was the most effective in improving the quality of purple-colored WWB. The improvement effect was significantly greater in group S than in group L. These findings suggest that controlling the particle size of purple-colored WWFs and utilizing dough improvers can result in superior-quality WWB.

A combined use of different functional additives for improvement of wheat flour quality for bread making

BACKGROUND

Low-protein wheat flour can produce bread with poor texture and appearance, reducing its nutritional value and market appeal. This is a growing concern for both the food industry and consumers relying on wheat as a dietary staple. The present study evaluated the individual and combined effects of bacterial xylanase (BX), maltogenic α-amylase (MG), vital gluten (VG) and ascorbic acid (AA) with respect to improving weak flour properties for bread making.

RESULTS

BX, VG and AA improved gluten Index (GI), whereas MG was employed for optimizing amylolytic-activity in flour. VG increased the water absorption (WA) capacity of flour and prolonged dough development time (DDT). The dough stability (DST) was increased by BX and VG. BX and MG decreased crumb firmness (CF) and showed anti-staling effect. All additives reduced bake loss, increased loaf volume (LV) and retained or improved sensory attributes of bread. However, MG at 60 mg kg-1 (MG60), BX at 30 mg kg-1 (BX30), VG at 5% (VG5) and AA at 50 mg kg-1 (AA50) were found to be the most suitable for evaluating in combinations. Ternary combinations of MG60, BX30, VG5 or AA50 imparted significantly (P < 0.05) positive impacts on GI, WA, DDT, DST, CF, LV and sensory attributes compared to control, individual and binary combinations.

CONCLUSION

The PCA suggested that a combination of MG60 + VG5 was more similar to MG60 + BX30 + VG5, whereas, MG60 + BX30 and MG60 + AA50 were more related to MG60 + BX30 + AA50 combination, but all of these combinations showed the improvement in the characteristics compared to control flour. © 2023 Society of Chemical Industry.

Influence of α-amylase, xylanase and cellulase on the rheological properties of bread dough enriched with oat bran

A better understanding of dough rheology during processing is crucial in the bakery industry, since quality attributes of the final product are influenced by those properties. In this study, we investigated the effects of xylanase, α-amylase and cellulase on the rheological properties of bread dough enriched in oat bran. A DoughLAB was used to measure the mixing characteristics of dough. According to the results, adding a single enzyme did not significantly affect the water absorption, development time, or stability of oat bran dough. In contrast, when blended enzymes were used at high concentrations (10, 120, and 60 ppm), the water absorption, development time, and stability of the oat bran dough were significantly reduced compared to using the single enzyme (62.1%, 7.1 and 6.6 min). It was found that combining α-amylase, xylanase and cellulase resulted in better extensibility and stickiness (16.5 mm and 60.8 g) of oat bran dough than using these enzymes individually. As a result, α-amylase, xylanase and cellulase complemented each other in determining the rheology of bread dough.

Effect of Enyzmes on the Quality and Predicting Glycaemic Response of Chinese Steamed Bread

The present study investigates the individual and interactional effects of α-amylase (6 and 10 ppm), xylanase (70 and 120 ppm) and cellulase (35 and 60 ppm) on the physicochemical characteristics and nutritional quality of Chinese steamed bread (CSB) incorporated with 15% oat bran. As a result, the single enzyme can significantly improve the specific volume and texture of CSB. Compared to the single enzyme, the combined enzymes improved the specific volume of CSB up to the highest value (2.51 mL/g) and decreased the hardness to the minimum value (233.61 g) when the concentration was 6, 70 and 35 ppm. With respect to chemical and nutritional properties, the addition of single enzyme had no great changes, while the combined enzymes (6, 70 and 35 ppm) significantly (p < 0.05) decreased the total starch from 37.52 to 34.11% and hence increased the area under the reducing sugar release curve during 2 h in vitro digestion (AUC) from 344.61 to 371.26. Consequently, enzymes combination can significantly improve the quality of oat bran CSB whereas reduce the nutritional value of oat bran CSB.

Biochemical characterization of a GH10 xylanase from the anaerobic rumen fungus Anaeromyces robustus and application in bread making

Anaeromyces robustus is an anaerobic rumen microorganism which can produce plant cell wall degrading enzymes. In this study, a new GH10 xylanase gene xylAr10 from A. robustus was identified, cloned and expressed in Pichia pastoris GS115. The recombinant protein ArXyn10 was characterized after being purified by Ni-NTA. The optimal pH and temperature of ArXyn10 was determined at 5.5 and 40 °C, respectively. ArXyn10 was stable at the pH range of 4.0-8.0, and could maintain high stability from 35 to 45 °C. The hydrolysis products released from beechwood xylan by ArXyn10 showed chromatographic mobility similar to xylobiose and xylotriose according to thin-layer chromatography analysis. It was shown that the addition of 7.5 mg of ArXyn10 in 100 g high-gluten wheat flour during bread making could increase the reducing sugar content by 10.80%, indicating that xylo-oligosaccharides were produced. With the addition of ArXyn10, the hardness and chewiness of the bread decreased and the quality was improved. The new discovered xylanase ArXyn10 have potential application prospect in bread making.

A review on mechanistic aspects of individual versus combined uses of enzymes as clean label-friendly dough conditioners in breads

Numerous dough improvers are used alone or in combination to enhance the quality of baked goods such as breads. While modern consumers demand consistent quality, the expectations for ingredients have changed over the past few years, and reformulations have taken place to provide "clean label" options. However, the effects and mechanisms of blended dough conditioners suitable for such baked products have not been systematically summarized. In this review, dough and bread properties as affected by different improver combinations are examined, with a focus on additive or synergistic interactions between enzymes or between enzymes and ascorbic acid. The combination of enzymes that hydrolyze starch and cell wall polysaccharides has been shown to reduce textural hardness in fresh and stored bakes goods such as breads. Enzymes that hydrolyze arabinoxylans, the main nonstarch polysaccharide in wheat, have synergistic effects with enzymes that result in cross-linking of wheat flour biopolymers. In some studies, the effects of bread improvers varied for wheat flours of different strength. Overall, bread products in which wheat is used in whole grain form or in a blend with other flours especially benefit from multiple improvers that target different flour constituents in doughs.