Optimization of Ethanol Extracting Process of Anthocyanin from Black Rice

In order to improve the yield of anthocyanin of black rice by the method basing on anhydrous ethanol as solvent,its effect was investigated by comparing the yield of anthocyanin of black rice influenced on different extracting factors. Single factor experiment design was used to research the effect of ethanol volume fraction,extracting time,ratio of solid-liquid,temperature and pH of extracting solution on anthocyanin extracting of black rice. The optimum condition of anthocyanin extracting from black rice was determined by orthogonal experiment design. Results showed that extracting rate of anthocyanin of black rice was mainly influenced by extracting pH,the following being extracting time. The optimum extracting condition was as follows:Ethanol volume fraction 80% as the extracting agent,60 min of extracting time,extracting temperature at 45℃,ratio of solid-liquid at 1:7 (g:mL)and extracting pH1.0. The content of anthocyanin of black rice in extracting solution arrived at 34.34 μg/mL if using the process. The optimum extraction times was three,and having 99.29% of total extraction ratio and 298.23 μg/g of yield. The process would support commercial development of anthocyanin extracting from black rice and in favor of industrialization of anthocyanin of black rice.