响应面法优化超声辅助提取黄瓜多酚工艺及其对酪氨酸酶的抑制作用

Optimization of ultrasonic- assisted extraction of cucumber polyphenolby response surface methodology and its tyrosinaseinhibitory activities

为确定超声辅助提取黄瓜多酚的最佳工艺条件,并评价黄瓜多酚对酪氨酸酶的抑制作用,以黄瓜为原料,以多酚提取率为响应值,对影响响应值的超声时间、液料比、乙醇含量和超声温度4个因素进行单因素和响应面优化试验,并考察了黄瓜多酚对酪氨酸酶的抑制作用。结果表明,所考察的各工艺条件对黄瓜多酚提取率影响的顺序为:超声温度>乙醇含量>液料比>超声时间。提取工艺的最佳条件:超声时间为30 min,液料比为27 mL·g^(-1)、乙醇含量(φ,下同)为64%、超声温度为68℃,在此条件下,黄瓜多酚提取率为11.33 mg·g^(-1)。黄瓜多酚对酪氨酸酶具有一定的抑制作用,且多酚浓度与酪氨酸酶抑制率存在量效关系,表明黄瓜多酚可作为天然的酪氨酸酶抑制剂,是一种潜在的天然美白添加剂,为黄瓜多酚的提取与开发提供新的方向。

The aim was to determine the best process conditions of ultrasound-assisted extraction of cucumber polyphenols,and to evaluate the inhibitory activities of cucumber polyphenols on tyrosinase.The single factor experiment and response surface methodology were performed on the four factors involving ultrasonic time,liquid-to-material ratio,ethanol concentration and ultrasonic temperature using cucumber as raw material and the extraction yield of polyphenols as the response value.Inhibition effect of cucumber polyphenols on tyrosinase was also examined.The results showed that the significant order of the effects of the investigated technological conditions on the extraction yield of cucumber polyphenols was as follow:ultrasonic temperature,ethanol concentration,liquid-material ratio and ultrasonic time.The optimal conditions for the extraction process were:ultrasonic time 30 min,liquid-material ratio 27 mL·g^(-1),ethanol concentration 64%and ultrasonic temperature of 68℃.Under these conditions,the cucumber polyphenol extraction yield was11.33 mg·g^(-1).Cucumber polyphenols had a good inhibitory effect on tyrosinase and there was a dose-effect relationship between the concentration of polyphenols and the tyrosinase inhibition rate.It indicated that cucumber polyphenol could be a natural tyrosinase inhibitor and a potential natural whitening additive,which provided a new direction for the extraction and development of cucumber polyphones.