Development of Fermented Rice Water to Improve the Quality of Garaetteok , a Traditional Korean Rice Cake

In the rice processing industry, wastewater is an inevitable by-product of rice washing. To increase the utilization of washed rice water (WRW), seven types of fermented washed rice water (FWRW) were prepared using lactic acid bacteria (LAB) and carbohydrate hydrolase. The total concentration of small maltooligosaccharides (MOSs) in the amyloglucosidase (AMG) treatment groups was about ten times higher than in the untreated groups. After 6 h of fermentation, six of the seven FWRW samples reached a pH of 4 due to the increased concentration of organic acids and could, therefore, be used as food acidity regulators. To confirm the applicability of FWRW, the traditional Korean rice cake was prepared with FWRW and stored at 4 °C for 5 days. A texture profile analysis (TPA) revealed that the hardness of treated with FWRW was significantly lower than that of untreated following storage. Differential scanning calorimetry (DSC) showed that FWRW retarded the retrogradation of during storage. The addition of FWRW using with an AMG group was particularly effective for inhibiting microbial activity in during storage. These results suggest that FWRW using AMG-added can be used as a novel food additive for improving the quality of traditional Korean starch foods and could also reduce the volume of waste WRW.