Physicochemical, microbiological, and microstructural changes in germinated wheat grain

Author: mycolabadmin
9/9/2025
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Summary

When wheat grains are exposed to moisture and warm conditions, they begin to sprout, which damages their quality and usefulness. This research studied how different moisture, temperature, and time conditions affect sprouted wheat grain. Scientists found that sprouting significantly changes the grain’s structure, reducing its starch content and increasing microbial contamination. The findings suggest that sprouted wheat can be processed into useful products if grown under carefully controlled conditions.

Background

Pre-harvest sprouting (PHS) in wheat grain severely compromises grain quality and causes significant economic losses globally, with up to 40% of soft wheat in Kazakhstan classified as non-standard due to PHS. Understanding germination-induced changes in wheat grain offers insights into potential utilization strategies for sprouted grain. Climate variability and extreme weather events are expected to exacerbate PHS incidence in major wheat-growing regions.

Objective

This study investigates the physicochemical, microbiological, and microstructural changes in soft wheat grain during germination under varying moisture, temperature, and time conditions. The research aims to identify optimal germination parameters for technological applications and develop strategies for effective utilization of sprouted wheat grain in food and non-food industries.

Results

Physical properties showed strong correlation with germination time: thousand-kernel weight decreased by 8.2%, test weight by 22%, and falling number by 74%. Starch content ranged from 66.13% to 70.02%, with optimal starch content achieved at 22% moisture, 31°C, and 84 hours. Optimal protein content (14.75%) was achieved at 21% moisture, 30°C, and 72 hours. Microbial contamination reached 10¹⁰ CFU/g during germination, with minimal levels (10⁸ CFU/g) at 14% moisture, 33°C, and 8 hours. SEM and optical microscopy revealed transformation from dense vitreous endosperm to porous, disorganized structure with degraded starch granules.

Conclusion

Soft wheat grain undergoes significant physical, chemical, and structural changes during germination that are strongly dependent on temperature, moisture, and time. Germination-induced starch modification through pore formation and granule degradation offers sustainable alternatives to chemical modification for industrial applications. The identified optimal germination parameters provide a foundation for processing germinated soft wheat into value-added products in food and non-food industries, particularly beneficial for regions facing increasing pre-harvest sprouting challenges.

Published in:PLoS One,
Study Type:Experimental Study,
Source: 10.1371/journal.pone.0331620, PMID: 40924775