Study On Separation Of Purple Potato Anthocyanins And Processing Technology Of Purple Potato Beverage

Purple potato,as a high-quality sweet potato resource,has always been a research hotspot in the field of food.This paper takes purple potato as the research object.Firstly,the extraction,purification and stability of its anthocyanin were studied.Then,the enzymatic hydrolysis process of purple potato serum was discussed.Finally,the optimization of the formula about purple potato beverage was studied,in order to provide a basis for the application of anthocyanin and development of purple potato products..The main experimental results are as follows:?1?Study on the optimization of extraction process about purple potato anthocyanins..Ultra-high pressure assisted extraction method was used to extract anthocyanins.The optimum extraction process was obtained by response surface optimization method.The concentration of citric acid solution was 2.0%,the ratio of material to liquid was 1:40?g/ml?,the holding time was 3 min,the extraction pressure was 200 MPa,and the yield of anthocyanins was 82.85 mg/100g.Compared with other extraction methods,this method has shorter time and higher utilization rate of equipment.?2?Study on the purification of purple potato anthocyanins.By comparing the static adsorption and desorption properties of six kinds of macroporous resins with different polarities,AB-8 was selected as the ideal resin.The optimum purification conditions were as follows:the optimum adsorption time was 3h;the desorption time was 2h;the sample solution pH 3,80%ethanol solution,and the ratio of macroporous resin to anthocyanin solution was 1:20.Finally,the color value of anthocyanin increased from 10.8 to 47.2.The purification effect was remarkable.?3?Study on the stability of purple potato anthocyanins.When the temperature was lower than 40 C,the stability of anthocyanin was stronger,and higher than 40 C,the stability of anthocyanins of purple potato was decreased.With the increase of pH value,the maximum absorption peak of anthocyanin shifted;the color density?CD?and color intensity?CI?of the solution decreased first and then increased;the color of the solution changed from red to purple,blue-green and green.Natural light direct irradiation is more destructive to the stability of anthocyanins than light avoidance and indoor natural light.Sucrose and lactose can enhance the stability of anthocyanins,while oxidants and reductants will destroy their stability;K⁺,Na⁺have little effect on the stability of anthocyanins,Ca²⁺can increase the stability of anthocyanins,while Cu²⁺,Fe²⁺and Fe³⁺will reduce their stability.?4?Study on the processing technology of purple potato beverage.The optimum conditions for synergistic hydrolysis of purple potato slurry with two enzymes were as follows:the mass ratio of two enzymes was 0.29:1.71 g/g;the feed was 1:6 g/mL;the enzymatic hydrolysis temperature was 67?;the enzymatic hydrolysis time was 84 min.The optimum formula for purple potato beverage was as follows:40%purple potato slurry,9%sugar,0.18%citric acid and 0.09%compound stabilizer?sodium carboxymethyl cellulose:xanthan gum:agar=1:1?.Purple potato functional beverage has bright color,good taste and rich nutrition.Besides,it also has market development value.