Effects of Aqueous Extracts from Wheat Bran Layers on the Functional Properties of Wheat Starch and Gluten

TL;DR

This study explores how water extracts from different parts of wheat bran affect the properties of wheat starch and gluten, which could help improve whole-wheat food quality.

Contribution

The novelty lies in identifying how specific bran layers and their components influence gluten and starch functionality during food processing.

Findings

AL-rich extracts had higher content (30.6%) than NAL-rich extracts (15.1%) due to higher cellular content in AL.

Aqueous extracts reduced gluten's storage and loss moduli, mainly due to polysaccharides, while protein and ash fractions increased them at suitable dosages.

Extracts increased starch gelatinization temperature but decreased enthalpy and pasting viscosity due to protein and ash effects.

Abstract

Wheat bran (WB) is rich in bioactive compounds, but its incorporation into food products often negatively affects dough properties. The soluble components in WB, including polysaccharides, minerals, and proteins, exhibit significant variations across different bran layers and may dissolve and interact with flour components during food processing, affecting dough properties. This study aims to investigate the influence of aqueous extracts from different WB layers (aleurone layer, AL; non-aleurone layer, NAL) and their components on the functional properties of wheat starch and gluten. The results indicate that the AL-rich fraction yielded a higher extract content (30.6%) compared to the NAL-rich fraction (15.1%), attributable to the higher cellular content in the AL. Both the extracts and residues from AL and NAL significantly lowered the denaturation temperature of wheat gluten. The aqueous extracts reduced the storage (G′) and loss (G″) moduli of wheat gluten, primarily attributed to the effect of polysaccharide components, whereas the protein and ash fractions elevated the G′ and G″ at suitable dosages. The extracts elevated the gelatinization temperature of starch, but reduced enthalpy (ΔH). Moreover, the pasting viscosity of starch with WB extract decreased due to the combined effects of protein and ash fractions. These findings provide insights into the roles of water extracts from different WB layers and their components in modulating wheat-based product quality. This study also offers a theoretical basis for optimizing WB utilization in foods, thus providing a theoretical foundation for promoting whole-wheat foods or foods containing WB.

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