Determine Anthocyanins By Chromatography And Nutrient Content In Processing Of Black Rice Tea

Chapter 1:The main nutrition contituents (protein, fat, and starch) and functional components (anthocyanins and y-aminobutyric acid) of black rice are briefly introduced. And the structure, extraction, purification, detection and biological activity of anthocyanins are reviewed. The processing method and utilization of black rice are summarized. The aroma substances of rice are also introduced.Chapter 2:Black rice is processed by soaking, steaming and baking for black rice tea. The exterior quality, fragrance, and color of black rice are considered as the quality index. Soaking time, steaming time, baking temperature, and baking time are investigated to get the optimal processing technology. And the optimal processing technology for black rice tea is finally confirmed as follows:soaking 3h, steaming 20min, baking 40min at 150℃.Chapter 3:The high performance liquid chromatography (HPLC) determination methods of anthocyanin andγ-aminobutyric acid (GABA) in black rice have developed in lab before. Based on this, the contents of cyanidin-3-glucoside, peonidin-3-glucoside, and GABA of each processing segment under the optimal processing technology for black rice tea are determined. It shows that the process of soaking, steaming, and baking will all induce the reduction of cyanidin-3-glucoside and peonidin-3-glucoside. Soaking will increase the content of GABA; while steaming and baking drop the trend. At the same time, gas chromatograph-mass spectrometer (GC-MS) is used to determine the essential oil of each processing segment. The essential oil in different segment is different in types and quantity. It indicates that soaking, steaming, and baking all have an affect on the aroma of black rice tea. Chapter 4:The crude protein, crude fat and crude starch of black rice in each segment under optimal processing technology are measured by conventional methods. The results show that none of soaking, steaming, or baking has significant effect on crude protein, crude fat and crude starch of black rice.