Novel techno-functional properties and starch digestibility of VD20 rice under different processes: Effect of polishing and a newly developed germination process.

VD20 rice, a specialty cultivar from Tien Giang province, Vietnam, holds nutritional potential but remains underexplored in terms of its functional properties. This study aimed to investigate the effects of polishing and germination, including a novel germination method using "Cẩm" leaf polyphenol extract (PES) as soaking solution, on the techno-functional, antioxidant, and digestibility characteristics of VD20 rice. White and brown rice samples were compared with traditionally germinated and PES-enriched germinated rice. The results showed that germination significantly enhanced antioxidant levels, especially in the PES-enriched sample, which exhibited a 4.3-fold increase in total polyphenol content compared to white rice. Pasting viscosity decreased after germination, while setback and final viscosity increased, indicating stronger starch retrogradation. Most notably, the estimated glycemic index dropped from 70.34 in white rice to 58.23 in the PES-treated sample, highlighting its potential as a low glycemic index ingredient. This study demonstrates that combining germination with natural polyphenol enrichment can improve the nutritional and functional quality of rice flour. The findings support the application of VD20 rice in the development of value-added, health-oriented food products, particularly those targeted at glycemic control.