Improvement of starch fine structure, physicochemical properties and digestive characteristics of adlay seeds by fermentation with Lactobacillus plantarum and Lactobacillus paracasei.

2026-04
International journal of biological macromolecules 355

PubMed: 41861878
DOI: 10.1016/j.ijbiomac.2026.151547

Study Design

Methods: This study systematically investigated the effects of co-fermentation with Lactobacillus plantarum and Lactobacillus paracasei on the starch multi-scale structure, physicochemical properties, and in vitro digestive characteristics of adlay seeds.

Adlay seeds (Coix lacryma-jobi L.) have the dense structures, high hardness, and strong chewiness, leading to inferior palatability. This study systematically investigated the effects of co-fermentation with Lactobacillus plantarum and Lactobacillus paracasei on the starch multi-scale structure, physicochemical properties, and in vitro digestive characteristics of adlay seeds. Fermentation exerted a synergistic improvement on the textural properties of adlay seeds, with hardness declining markedly from 1784.26 g to 813.71 g and chewiness from 305.62 g to 73.95 g. In contrast, the free water content increased from 93.11% to 95.75%, and the volumetric expansion rate rose from 145.35% to 197.90%. Scanning electron microscopy observations revealed that fermentation induced porosity in starch granules, roughened the cross-sectional surfaces of adlay seeds, and expanded the internal spatial network structure. Meanwhile, X-ray diffraction and solid-state ¹³C CP/MAS NMR confirmed a crystal form transition from A-type to A + V-type during fermentation, with the relative crystallinity increasing from 3.23% at 0 h to 17.12% at 48 h. High-performance anion-exchange chromatography analysis revealed an increased proportion of A-chains (DP 6-12) and a concomitant reduction in B-chains in starches. These structural modifications led to a significant increase in resistant starch content from 25.44% to 32.26% and a 16.18% reduction in rapidly digestible starch. Based on the dynamic rheological analysis results, both storage modulus (G') and loss modulus (G″) declined while maintaining G' > G″. Collectively, fermentation mediates starch degradation and molecular rearrangement in adlay seeds, enhancing edible quality and forging a theoretical foundation for the development of fermented adlay-based functional foods.

Research Insights

Supplement	Dose	Health Outcome	Effect Type	Effect Size	Source
Lactobacillus paracasei	—	Improved Palatability and Textural Quality	Beneficial	Large	View source Fermentation exerted a synergistic improvement on the textural properties of adlay seeds, with hardness declining markedly from 1784.26 g to 813.71 g and chewiness from 305.62 g to 73.95 g. In contrast, the free water content increased from 93.11% to 95.75%, and the volumetric expansion rate rose from 145.35% to 197.90%.
Lactobacillus paracasei	—	Increased Resistant Starch	Beneficial	Moderate	View source These structural modifications led to a significant increase in resistant starch content from 25.44% to 32.26% and a 16.18% reduction in rapidly digestible starch.
Lactobacillus paracasei	—	Reduced Rapidly Digestible Starch	Beneficial	Moderate	View source These structural modifications led to a significant increase in resistant starch content from 25.44% to 32.26% and a 16.18% reduction in rapidly digestible starch.