Controlled germination to enhance the functional properties of rice

The production of prebiotic oligosaccharides during germination of rice has been investigated. Germination of waxy (RD6) and non-waxy (RD17) rice was compared by evaluating the total reducing sugars, free amino nitrogen, pH and enzyme activities over a 7-day period. An increment of amylolytic enzymes and chemical changes were observed in both varieties. RD6 showed higher levels of total reducing sugars and also higher amylolytic activities including α-amylase and α-glucosidase, which reached maximum values at the third day of germination. However, the amount of free amino nitrogen in RD6 was lower than in RD17. Sugar analysis indicates that RD6 produces higher concentration of sugars and oligosaccharides during germination. Based on these results, germinated RD6 at different times was used to produce malted rice syrup through mashing. After saccharification, the malted rice syrup contained different concentrations of sugars and oligosaccharides, particularly isomaltose, panose and isomaltotriose, which have been reported to have prebiotic properties.