Study On Process Optimization And Quality Analysis Of Purple Potato Wine

Purple potato is a kind of special potato varieties.In addition to containing all the nutrients of ordinary potato,it is also rich in water-soluble anthocyanins,which not only makes purple potato foods attractive color,but also plays an important role in maintaining a healthy,such as anti-oxidation,prevent cancer and cardiovascular disease.Therefore,it is of great significance to develop a new type of healthy and nutritious food using purple potatoes as raw material.At present,Potatoes are mainly eaten as fresh food,with few deep-processed products.With the development of the economy,new healthy and nutritious foods are becoming more and more popular among consumers.The purple potato contains a lot of starch and is a good raw material for wine making.Using purple potatoes as raw materials for wine making can well retain the anthocyanins and present a unique color.Therefore,in order to make full use of the purple potato resources and develop new potato products,this article has carried out research on the technology related to the brewing of purple potato wine.Using purple potato as raw material and flour as auxiliary material,the fermentation process of purple potato wine was optimized,and the physical and chemical indicators,phenolic substances,antioxidant activity,color aroma and their correlation of purple potato wine during fermentation were studied.clarifying agent was studied on the effects of the purple potato wine,measured the quality of the finished purple potato wine,and initially formulated the quality standard of purple potato wine,which provided a new way for the high-value utilization of purple potato resources.The main findings are as follows:1.Optimized the fermentation process of purple potato wine.Taking the alcohol content as an indicator,the influence of different amount of flour added on the alcohol content of purple potato wine was analyzed,and the best ratio of purple potato to flour was determined to be 1:0.6(g/g).Using response surface analysis,a mathematical regression model between the anthocyanin content of purple potato wine and fermentation process parameters was established and verified.The results show that the suitable fermentation process parameters of purple potato wine are as follows:the ratio of material to water is 1:1(g/mL),the amount of α-amylase added is 8.5 U/g,and the amount of koji added is 0.45%.Under these conditions,the anthocyanin content of purple potato wine was 179.22 mg/L,and the alcohol content is 13.5%vol.2.Explore the changes of phenolic substances and quality of purple potato wine during the fermentation.During the fermentation process,the alcohol content showed an upward trend,and the total sugar showed a downward trend.In the later stage of the fermentation,the alcohol content and total sugar showed a flat trend.The total phenol content and anthocyanin content both showed a trend of increasing at first and then decreasing.The chromaticity gradually decreased and tended to be gentle,the hue gradually increased and tended to be gentle,the browning index and the polymerization chromaticity both gradually increased,1,1-diphenyl 2-Trinitrophenylhydrazine(DPPH)free radical scavenging rate,2,2’-diazo-bis-3-ethylbenzothiazoline-6-sulfonic acid(ABTS+)free radical scavenging rate,Superoxide anion radical scavenging rate and hydroxyl radical scavenging rate both increased first and then decreased.Pearson correlation analysis is used for phenolic substances,color,and antioxidant capacity.The results show that the change of anthocyanin content can affect the color change,and the content of anthocyanin and total phenol content have great contribution to DPPH free radical scavenging rate,ABTS+ free radical scavenging rate,superoxide anion free radical scavenging rate,and hydroxyl free radical scavenging rate.A total of 44 compounds were isolated and identified during the fermentation of purple potato wine,mainly alcohols,esters,and acids.Among them,14 kinds of alcohol substances,19 kinds of ester substances,4 kinds of acid substances,1 kind of phenolic substances,1 kind of ketone substances,2 kinds of alkyne substances,3 kinds of hydrocarbon substances and 4 kinds of other substances.Alcohols began to decrease after reaching the maximum relative content(43.13%)on the sixth day.And among them,the relative content of isoamyl alcohol and phenethyl alcohol was relatively high;the relative content of esters gradually increased during the fermentation process,which was mainly ethyl caprylate,ethyl decanoate,ethyl laurate,and phenethyl acetate;acids are mainly caprylic acid and capric acid;other substances also contribute to the aroma components.Purple potato wine mainly has mellow,rose,fruity,sweet and creamy flavors,among which the relative content of mellow,rose and fruity aroma is relatively large.3.The effect of different clarifying agents on the clarification effect of purple potato wine was studied.The effects of polyvinylpyrrolidone(PVPP),bentonite,gelatin and chitosan on the light transmittance,anthocyanin content,total phenol content and color of purple potato wine were analyzed.As the concentration of the four clarifying agents increases,the light transmittance gradually increases.When the concentrations of the four clarifying agents are PVPP 0.4 g/L,bentonite 0.4 g/L,gelatin 0.3 g/L and chitosan 0.4 g/L,continue to increase the concentration of clarifying agent,and the light transmittance does not increase significantly.With the increase of the concentration of the four clarifying agents,the anthocyanin content,total phenol content,and chromaticity value decreased significantly compared with the blank(P<0.05).The principal component analysis method was used to comprehensively analyze the effects of different clarifying agents on the overall quality of purple potato wine.The results show that the contribution rate of the first principal component(PC1)is 79.4%,the contribution rate of the second principal component(PC2)is 16.4%,and its cumulative contribution rate is 95.8%.From the perspective of anthocyanin content,total phenol content and color value,the use of gelatin to clarify the purple potato wine can retain the substances in the purple potato wine to the greatest extent.The content of anthocyanins and total phenols is higher,and the color value changes less.Comprehensive consideration 0.3 g/L gelatin is used as the clarifying agent of purple potato wine.4.The quality of purple potato wine was determined and the quality standard was established.The sensory quality and physical and chemical indexes of purple potato wine were measured,and 8 anthocyanin monomers were identified and their contents were determined.With reference to《NY/T 1508-2017 Green food fruit wine》and《GB 2758-2012 National food safety standard fermented wine and its blended wine》,the quality standards for sensory evaluation,physical and chemical indicators and microbial indicators of purple potato wine have been formulated.