Effect of abiotic stress on bioactive compound production in germinated brown rice

Abstract Background and objectives The objective of this study was to evaluate the effect of germination and various abiotic stresses on the technological, nutritional, and sensorial characteristics of brown rice. The seeds were soaked at 40°C and 30% humidity. The soaked seeds were allowed to germinate at 30°C for 36 hr in BOD chamber. The soaked rice grains were subjected to stress conditions in the last 4 hr of germination using saline (SBR/S), low temperature (4°C) (SBR/C), or a combination of saline and low temperature (SBR/B) and, after, it was analyzed the effect of germination and those abiotic stresses on the technological, nutritional, and sensorial characteristics of brown rice by the color parameters, texture profile, γ‐aminobutyric acid content, protein, and starch digestibilities. Findings The sprouted grains (SBR) were darker than the brown rice. The germinated rice grains exposed to cold stress were more resistant to crushing and chewing compared to grains exposed to salinity stress and those exposed to both cold and salinity stresses. Germination enhanced the γ‐aminobutyric acid (GABA) content and starch digestibility. The GABA content increased further, whereas the protein digestibility decreased in the germinated grains upon exposure to abiotic stresses. Conclusions The best conditions for germination and alternative processes that can help them to intensify the nutritional value of germinated grains must be elucidated. The results of this study were satisfactory for the nutritional and technological parameters, and thus, exposure of germinated grains to abiotic stress can be an alternative method for enriched rice production. Significance and novelty Color and texture parameters change with germination and vary according to abiotic stresses. For the same reason, the content of GABA is increased. Protein digestibility is reduced, differently about the starch digestibility.