Effects of Germination on the Proximate Composition, Antioxidant Property and Eating Quality of Brown Rice (Oryza sativa L.)

摘要

Four selected white and pigmented Philippine rice cultivars with different amylose content were used to evaluate the effects of germination on the proximate composition, antioxidant property and eating quality of brown rice (BR). These include the waxy NSIC Rc13 and black rice (Ominio), the lowamylose NSIC Rc160 and the intermediate-amylose red rice (Chor-chor-os). Their cooking time and cooked rice texture before and after germination, as well as the germination capacity of BR, were likewise determined. The germination capacity of pigmented rice samples was higher than that of the white rice samples. For the proximate composition, some parameters were notably affected by germination while the others remained the same. The ash and fat content of BR samples showed significant reduction after germination except for the ash content of red rice. Only black rice had a significant increase in crude fiber while the other cultivars had a significant reduction. Germination had no effect on the protein and carbohydrate content of BR samples. Black rice samples had the highest values of antioxidant properties, except for antioxidant scavenging activity (ASA) where the highest value was obtained in red rice. Total anthocyanin and phenolic content were significantly reduced by about 23 to 40% and 21 to 28%, respectively. On the other hand, the total carotenoid and vitamin E content of all BR samples increased upon germination, though not significantly for some cultivars. Interestingly, the ASA of the pigmented rice samples was improved significantly while the opposite was observed in the white rice samples. Germinated brown rice (GBR) samples had shorter cooking time and much softer cooked rice compared with BR samples. Germination also considerably enhanced majority of the sensory properties of BR samples. The study concluded that germination is a simple way to improve the cooking and eating quality of BR with minimal effects on its nutritional and antioxidant properties.