桂花色素是一种性能优良的天然色素,在食品加工工业中具有广阔的应用前景.试验以浦城桂花为原料,通过单因素试验考察了桂花品种、乙醇浓度、超声功率、超声时间、液料比对桂花色素得率的影响,进一步进行响应面试验优化其提取工艺.同时通过牛津杯法验证提取的桂花色素对7种菌株(4株细菌,2株丝状真菌,1株酵母菌)的抑菌效应.试验结果表明,超声辅助法提取桂花色素的最佳提取条件为乙醇浓度60%、液料比25∶1(mL/g)、超声功率200 W、超声时间30 min,在此条件下,桂花色素的得率最高,达到61.56%.此外,抑菌试验证实桂花色素对枯草芽孢杆菌、金黄色葡萄球菌、大肠埃希菌、藤黄微球菌、酿酒酵母具有显著的抑制作用,而对桔青霉和米曲霉的抑制效应相对较弱.
Osmanthus fragrans pigment is a kind of natural pigment with excellent performance,which has broad application prospect in the food processing industry.In this test,with Pucheng Osmanthus fragrans as the raw material,the effects of Osmanthus fragrans varieties,ethanol concentration,ultrasonic power,ultrasonic time and liquid-solid ratio on the yield of Osmanthus fragrans pigment are investigated by single factor test,and the extraction process is further optimized by response surface test.At the same time,Oxford cup method is used to verify the antibacterial effects of Osmanthus fragrans pigment on seven strains(including four strains of bacteria,two strains of filamentous fungi and one strain of yeast).The results show that the optimal extraction conditions of Osmanthus fragrans pigment by ultrasonic-assisted extraction method are ethanol concentration of 60%,liquid-solid ratio of 25∶1(mL/g),ultrasonic power of 200 W and ultrasonic time of 30 min.Under these conditions,the yield of Osmanthus fragrans pigment is the highest,reaching 61.56%.In addition,in the antibacterial test,it is confirmed that the Osmanthus fragrans pigment has significant inhibitory effects on Bacillus subtilis,Staphylococcus aureus,Escherichia coli,Micrococcus luteus and Saccharomyces cerevisiae,while the inhibitory effects on Penicillium citrinum and Aspergillus oryzae are relatively weaker.