Impact of sprouting pretreatment on physicochemical properties and in vitro digestibility of buckwheat milk

BACKGROUND: Buckwheat is a strategic raw material for plant-based milk production due to its gluten-free nature and rich bioactive profile. However, antinutritional factors and starch structure limit the nutritional quality and technological properties of such beverages. This study aims to investigate the effects of sprouting pretreatment (0, 24, 48, and 72 h) on the physicochemical properties, rheological behavior, phytic acid content, and in vitro protein/phenolics digestibility of buckwheat milk. RESULTS: As the sprouting duration increased, the viscosity of buckwheat milk decreased from 31.42 to 15.42 mPa s (at 72 h) due to the enzymatic hydrolysis of starch and proteins. Rheological analysis revealed that all samples exhibited weak gel behavior. Color analysis showed a decrease in lightness (L*) while redness (a*) and yellowness (b*) values significantly increased with sprouting. The results showed that sprouting significantly reduced phytic acid content, reaching its minimum at 72 h. The highest in vitro protein digestibility was observed at 24 h of sprouting, after which a relative decline occurred due to the formation of protein–polyphenol complexes and metabolic amino acid utilization. Furthermore, total phenolic content, flavonoid content, and antioxidant capacities measured after in vitro digestion were substantially higher in sprouted samples, especially at 48 and 72 h, than in the control. CONCLUSION: The results indicate that a sprouting duration of 48 h represents an optimal balance for the physical stability and nutritional enhancement of buckwheat milk. At this stage, significant increases in bioaccessible phenolics were achieved while maintaining a stable colloidal structure.