Pulsed light treatment enhances starch hydrolysis and improves starch physicochemical properties of germinated brown rice

BACKGROUNDRecently, germinated brown rice (GBR) has gained substantial attention as a functional food because of its nutritional attributes. Notably, pulsed light technology (PLT) has emerged as a promising tool for enhancing rice germination and, consequently, has improved the nutritional and functional qualities of GBR-derived products. However, further research is required to comprehensively understand the impact of PLT on GBR physicochemical properties. The present study aimed to investigate the stimulating effects of PLT on starch hydrolysis, starch structure and functional properties of GBR.RESULTSThe PLT substantially boosted alpha-amylase activity during brown rice germination, leading to a 10.9% reduction in total starch content and a 17.3% increase in reducing sugar content, accompanied by elevated free water levels. Structural analysis indicated no changes in starch crystalline types, whereas gelatinization temperature slightly increased. Pasting properties exhibited a significant drop in peak viscosity. Scanning electron microscopy showed surface erosion of starch granules with microstructural changes. Furthermore, correlation analysis established positive links between alpha-amylase activity, reducing sugar accumulation, starch structure and functional properties in GBR.CONCLUSIONThe present study demonstrates that PLT enhanced the physicochemical properties of GBR starch, significantly improving the stability of GBR products, thereby contributing to expanded applicability of rice starch in the food industry. (c) 2023 Society of Chemical Industry.

Automated summary

The study found that pulsed light technology significantly increased alpha-amylase activity during brown rice germination, resulting in a reduction of 10.9% in total starch content and an increase of 17.3% in reducing sugar content. Structural analysis showed no changes in starch crystalline types, but gelatinization temperature slightly increased. Pasting properties exhibited a significant drop in peak viscosity, and scanning electron microscopy revealed surface erosion of starch granules with microstructural changes. Correlation analysis established positive links between alpha-amylase activity, reducing sugar accumulation, starch structure, and functional properties in GBR.