Extraction,Biological Activity And Application In Yogurt Of Anthocyanins From Xinjiang Perilla Leaves

Perilla is an important homologous raw material for food and medicine,and its seed,leaves,and stems can all be used as medicine.Anthocyanins are the principal bioactive components in perilla leaves,which have various physiological functions such as antioxidant,antibacterial,anti-tumor,and lipid-lowering.This study used Xinjiang perilla leaves as raw materials and first optimized the extraction and purification process of anthocyanins from perilla leaves using Response Surface Methodology（RSM）;Secondly,liquid chromatography mass spectrometry（LC-MS/MS）was used to qualitatively and quantitatively analyze anthocyanins and anthocyanins in the extract;Further research was conducted on its in vitro antioxidant and antibacterial activities;Finally,the optimal production process of Perilla anthocyanin yogurt was optimized.The main conclusions are as following:（1）The optimal extraction conditions for ultrasonic assisted acidification ethanol extraction of anthocyanins from Perilla leaves are:material liquid ratio 1:20（g/mL）,ultrasonic temperature 47,ultrasonic time 57 minutes,and ethanol concentration 62%.Under these conditions,the extraction rate of anthocyanins is 7.18 mg/g DW.（2）optimal purification conditions for Perilla anthocyanins were optimized through dynamic adsorption analysis using macroporous resin AB-8.The sample concentration was 1.5mg/mL,the sample solution pH was 2.5,the sample flow rate was 1 mL/min,and the sample volume was 120mL;The concentration of the analytical solution（ethanol volume fraction）is 70%,the analytical flow rate is 1.0mL/min,and the analytical volume is 75 mL.The color value of anthocyanins before and after purification is 3.13 and 21.23,respectively.The color value of anthocyanins after purification is 6.8 times that of before purification.（3）The results showed that the anthocyanins in perilla leaves were mainly composed of cyanidin,delphinidin 3-O-glucoside,and cyanidin 3-O-glucoside,with content of 290.32,respectivelyμg/g DW、118.83μg/g DW and 34.58μg/g DW.The highest scavenging rates of DPPH and ABTS free radicals by Perilla leaf anthocyanins were 82.91%and 98.41%,respectively,with IC₅₀values of 0.49 mg/mL and 0.32mg/mL,respectively.Within the experimental concentration range,the minimum inhibitory concentration of Perilla leaf anthocyanins against Staphylococcus aureus was 160 mg/mL,and there was no significant antibacterial activity against Escherichia coli.（4）optimal fermentation conditions for Perilla anthocyanin yogurt were optimized using response surface methodology as follows:anthocyanin addition of 1.3%,sugar addition of 6%,fermentation temperature of 38,and fermentation time of 7 hours.Under these conditions,the sensory score of the product is 93.68 points.The product is pink purple in color,with uniform and consistent color,stable organizational state,smooth surface,uniform clots,and no whey precipitation;Moderate viscosity without bubbles;The taste is delicate and has the unique flavor and aroma of lactic acid fermentation.The aroma is harmonious and pure,without any adverse odors,and the microbial indicators comply with applicable regulations.