Abstract:

In order to study the extraction, stability and antioxidational effects of the enzymatic browning product in Dimocarpus Longan pericarp, with the total anthraquinones content as evaluation indicator, single factor exploration was performed to find out ethanol concentration, the suitable temperature, ratio material to liquid, extraction time and extracting temperature, and then L9(34) orthogonal design was adopted to select out the best extracting conditions of bath reflux. The stability and antioxidational effects of the enzymatic browning product were investigated, the content as evaluation indicator was determined by spectrophotometry. The results showed that the best extracting conditions of the bath reflux were that 70% of ethanol concentration, 8 h of extraction time, 1:2 of ratio material to liquid, 40℃ of extracting temperature of the enzymatic browning product was good in temperature, but poor under light expecially under ultraviolet radiation, better in a acidic condition than in alkalic and neutral condition, poor respectively in four kinds of food additive. The scavenging activities of the enzymatic browning product were 74.1% for the 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH?) in vitro, when the concentration of the extracts was 9.55 μg/mL. The scavenging activities of the enzymatic browning product were 81.6% for hydroxyl radical (?OH), when the concentration was 4.55 μg/mL. The scavenging activities were 86.1% for superoxide anion radicals (?O2-), when the concentration was 6.70 μg/mL. The enzymatic browning product could be extracted by the bath reflux. The factor of temperature didn’t affect the stability of the enzymatic browning product, but other factors of light, pH, food additive affected the stability of the enzymatic browning product. The enzymatic browning product had the scavenging activities for DPPH?, ?OH and ?O2-.