Effects of aleurone‐rich fraction on the hydration and rheological properties attributes of wheat dough

Insight into konjac glucomannan-retarding deterioration of steamed bread during frozen storage: Quality characteristics, water status, multi-scale structure, and flavor compounds

Konjac glucomannan (KGM), a water-soluble hydrocolloid, holds considerable potential in the food industry, especially for improving the quality and nutritional properties of frozen products. This study explored the alleviative effect of KGM on the quality characteristics, water status, multi-scale structure, and flavor compounds of steamed bread throughout frozen storage. KGM significantly improved the quality of steamed bread by slowing down the decrease in water content and the increase in water migration while maintaining softness and taste during frozen storage. Notably, KGM also delayed amylopectin retrogradation and starch recrystallization, thus preserving the texture and structure of the steamed bread. At week 3, the microstructure of the steamed bread with 1.0 % KGM remained intact, with the lowest free sulfhydryl content. Additionally, heat map analysis revealed that KGM contributed to flavor retention in steamed bread frozen for 3 weeks. These results indicate that KGM holds promise as an effective cryoprotectant for improving the quality of frozen steamed bread.

Study on the quality characteristics of hot-dry noodles by microbial polysaccharides

The effect of curdlan gum (CG), gellan gum (GG), and xanthan gum (XG) on the quality characteristics of hot-dry noodles (HDN) was investigated. The rheology properties were used to evaluate the quality of the dough, the textural, viscosity, cooking characteristics and water states were investigated to study the quality changes of HDN. Three microbial polysaccharides were found that it could improve the quality of wheat flour and significantly increase the starch viscosity of HDN and delay the water migration rate of HDN. When 0.2% CG, 0.5% GG, and 0.5% XG were added, the HDN showed the best flour swelling power, texture, and tensile properties, and the structure of gluten network was significantly improved. The flourier transform infrared spectroscopy results showed that microbial polysaccharides with appropriate concentrations changed the formation of hydrogen bond in HDN, decreased α-helix and increased β-turn content. Meanwhile, the relative continuous and complete gluten network was formed, which could be proven by microstructure observation. This study provides a reference for functionality applications of HDN with microbial polysaccharides.

The Wheat Aleurone Layer: Optimisation of Its Benefits and Application to Bakery Products

The wheat aleurone layer is, according to millers, the main bran fraction. It is a source of nutritionally valuable compounds, such as dietary fibres, proteins, minerals and vitamins, that may exhibit health benefits. Despite these advantages, the aleurone layer is scarce on the market, probably due to issues related to its extraction. Many processes exist with some patents, but a choice must be made between the quality and quantity of the resulting product. Nonetheless, its potential has been studied mainly in bread and pasta. While the nutritional benefits of aleurone-rich flour addition to bread agree, opposite results have been obtained concerning its effects on end-product characteristics (namely loaf volume and sensory characteristics), thus ensuing different acceptability responses from consumers. However, the observed negative effects of aleurone-rich flour on bread dough could be reduced by subjecting it to pre- or post-extracting treatments meant to either reduce the particle size of the aleurone's fibres or to change the conformation of its components.

Effects of different gelatinization degrees of starch in potato flour on the quality of steamed bread

The effect of four kinds of potato flour with different gelatinization degrees on the quality of steam bread was investigated in the present study. Results showed that medium-well flour (MWF) and potato flakes (PF) steamed bread, particularly MWF steamed bread, possessed the desired product properties liked by consumers. The MWF steamed bread had the highest appearance score (42.78) and total sensory evaluation score (81.60), and the PF steamed bread exhibited the highest specific volume (1.84 mL/g) and taste score (43.05). An increase in the degree of potato flour gelatinization led to an increase in dough gas retention coefficient from 80.20 mL/100 mL to 85.17 mL/100 mL and a more uniform and dense dough microstructure. During dough preparation, the increased gelatinization degree of potato flours enhanced the hydroscopicity competition between potato starch and gluten, resulting in a flocculent gluten network and increased potato starch volume during steaming. During steaming, steamed bread with higher gelatinization degree of potato flour formed a homogenous and dense starch gel-gluten double network, making them softer with more uniform gas cells and larger specific volume. Thus, this study provides a perspective of the effect of starch gelatinization on steamed bread quality.

Effects of Konjac glucomannan with different viscosities on the rheological and microstructural properties of dough and the performance of steamed bread

Konjac glucomannan (KGM) is used as an additive to improve the properties of wheat products. The effects of three types of KGM on the rheological properties and microstructure of dough, as well as the performance of steamed bread were investigated in this study. Particularly, dough with KGM displayed new features such as reduced peak viscosity, breakdown and setback. As the viscosity of KGM increased, the stability of the dough structure increased, while the viscosity and fluidity of the dough decreased. More interestingly, the gluten film of dough also increased with increasing substitution level and viscosity of KGM. Consistently, KGM with higher viscosity improved the quality of steamed bread. Generally, three types of KGM have different effects on the rheological characteristics and microstructure of dough, as well as the performance of steamed bread, which provide useful information for the proper application of KGM in wheat-based foods.

The Effect of Arabinoxylan and Wheat Bran Incorporation on Dough Rheology and Thermal Processing of Rotary-Moulded Biscuits

Wheat bran incorporation into biscuits may increase their nutritional value, however, it may affect dough rheology and baking performance, due to the effect of bran particles on dough structure and an increase in water absorption. This study analyzed the enrichment effect of wheat bran and arabinoxylans, the most important non-starch polysaccharides found in whole wheat flour, on dough rheology and thermal behaviour during processing of rotary-moulded biscuits. The objective was to understand the contribution of arabinoxylans during biscuit-making and their impact when incorporated as wheat bran. Refined flour was replaced at 25, 50, 75, or 100% by whole flour with different bran particle sizes (fine: 4% > 500 μm; coarse: 72% > 500 μm). The isolated effect of arabinoxylans was examined by preparing model flours, where refined flour was enriched with water-extractable and water-unextractable arabinoxylans. Wheat bran had the greatest impact on dough firmness and arabinoxylans had the greatest impact on the elastic response. The degree of starch gelatinization increased from 24 to 36% in biscuits enriched with arabinoxylans or whole flour and coarse bran. The microstructural analysis (SEM, micro-CT) suggested that fibre micropores may retain water inside their capillaries which can be released in a controlled manner during baking.

Physicochemical and Antioxidant Properties of Wheat Bread Enriched with Hazelnuts and Walnuts

The aim of this study was to evaluate the effect of wheat bread enrichment using hazelnuts and walnuts (1%, 3%, 6%, 9%) on the nutritional value and selected physicochemical and antioxidant properties. The dough and bread yield, volume, specific volume and porosity were also determined. The crumb texture was analyzed by texture profile analysis (TPA) test using a texture meter. The color of the crumb was assessed in the CIE L*a*b* color space. Antioxidant properties were determined by the ABTS⁺ radical method. The contents of phenolic acids, flavonoids and total polyphenols were also determined. The test demonstrated that the enrichment of bread with nuts increased the level of minerals, protein, fiber and fat. Breads containing walnuts were characterized by the highest content of these nutrients. The bread with a 9% walnut content by the smallest volume (380 cm³) had lowest value of L*. The crumb of the enriched breads was characterized by greater hardness, gumminess and chewiness, the values of these parameters generally increasing in parallel to the nut content. Breads enriched with walnuts were characterized by a higher average total content of polyphenols (35.77 mg gallic acid equivalent (GAE)/100 g dry mass (DM)) compared to the breads enriched with walnuts (25.35 mg GAE/100 g DM).