The Impact of Varying Enzymatic Pretreatment Durations of Wheat Gluten on the Flavour Characteristics of High-Moisture Plant-Based Extrudates

TL;DR

This study shows that enzymatic pretreatment of wheat gluten for 40 minutes optimizes flavor in plant-based extrudates by enhancing umami and sweetness while reducing off-flavors.

Contribution

The study identifies optimal enzymatic pretreatment duration and six key volatile compounds for flavor regulation in high-moisture plant-based extrudates.

Findings

Moderate enzymatic pretreatment (40 min) maximized sensory scores and enhanced umami and sweetness.

Extended pretreatment reduced beany off-flavors and increased meaty aroma compounds like furans and pyrazines.

Excessive pretreatment (>40 min) led to burnt odors due to pyrazine accumulation, reducing flavor acceptance.

Abstract

This study examined the effects of varying enzymatic pretreatment durations (0–80 min) of wheat gluten on flavour characteristics of high-moisture plant-based extrudates (HMPEs). Through a comprehensive analysis involving sensory evaluation, electronic tongue, free amino acid (FAA) profiling, electronic nose, and headspace solid-phase microextraction-gas chromatography-mass spectrometer (HS-SPME-GC-MS) analysis of volatile odour compounds, it was found that HMPEs with moderate enzymatic pretreatment (40 min) achieved the highest overall sensory score. Electronic tongue and FAA results confirmed a significant enhancement in umami and sweetness, while electronic nose effectively discriminated differences in odour profiles. Extending pretreatment durations gradually reduced beany off-flavours substances (hexanal reduced by up to 174.7 μg/kg) and encouraged the formation of meaty aroma compounds (furans and pyrazines). However, excessive pretreatment (>40 min) reduced acceptance due to burnt odour caused by the excessive accumulation of pyrazines, particularly 2,3-diethyl-5-methylpyrazine. Six key volatile odour compounds were identified by integrating the analysis of variable importance projection (VIP ≥ 1) and relative odour activity value (ROAV ≥ 1), offering a foundation for targeted flavour regulation in HMPEs.

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