| Black grape fruit with rich nutrition,contains a variety of vitamins and essential amino acids.The pigment of Black grape pomace is a edible,natural pigment,anthocyanins with nutritional value and medicinal value.This paper used Black grape pomace as raw materials,studied its extraction,purification,structure identification,and prepared Black grape anthocyanins microcapsules through the spray drying method in order to improve its stability,on the basis of the previous conclusions.This paper mainly includes the following four parts:(1)The study optimized the analysis method of Black grape pomace anthocyanins in quantitative analysis.In order to prevent phosphoric acid from damaging mass spectrometry analyzer,in this experiment,we choosed the formic acid solution as mobile phase.Through the optimization of mobile phase gradient,flow velocity,sample quantity,column temperature,we got the the best separation conditions of Black grape pomace anthocyanins for HPLC.The mobile phase was consisted of acetonitrile(A)and 1%formic acid,15%acetonitrile(B).A gradient program was used for HPLC-DAD as follows:100%B as initial condition,linear gradient to 88%B over 12 min,then linear gradient to 78%B over 20 min,then linear gradient to 70%B over 25 min,and stop at 30 min.The injection vulume was 10 ?L.The mobile phase flow rate was 1 mL/min.The detector was monitored at 520 nm for anthocyanins and 45 ? was set as column temperature.Black grape pomace anthocyanins monomer got better separation on this basis.We used Cyanidin-3-O-glucoside chloride to establish standard curve,maked quantitative analysis.Black grape pomace anathocyanins contents were carried out by pH differential method and HPLC method.The result showed that the HPLC results was 1.3 times higher than pH differential method.(2)Through single factor(extraction time,extraction power,solid-liquid ratio and ethanol concentration)and response surface test,we optimized the two kinds of extraction process including microwave assisted extraction and ultrasonic-microwave synergistic extraction.The best extraction conditions of microwave assisted extraction was following:extracting time was 6 min,microwave power was 500w,material liquid ratio was 1:30,ethanol concentration was 60%.Under the condition of this extraction,anthocyanins content was 208.13mg/100g.The best extraction conditions of ultrasonic-microwave synergistic extraction was following:extracting time was 3 min,microwave power was 400w,material liquid ratio was 1:30,ethanol concentration was 80%.Under the condition of this extraction,anthocyanins content was 244.92mg/100g.Comparing two extraction methods,we got ultrasonic-microwave synergistic extraction method which not only has higher extraction yield,but has shorter extraction time,lower power,was better extraction method.(3)The Black grape pomace contains a lot of impurities.We screened the best macroporous resin by experiment,researched following factors:equilibrium time,sample concentration,pH of static adsorption and alcohol concentration of static desorption,flow velocity of dynamic adsorption and desorption.It was concluded that the best optimization condition for:X-5 macroporous resin,the static adsorption balance time was 1h,the sample concentration was 84 mg/L,pH=2,the static desorption alcohol concentration was 70%,the dynamic adsorption velocity was 2 mL/min,the dynamic desorption velocity was 1mL/min.The anthocyanins color value of purified was 59.8 and was 16.2 times than before purification.The purity of anthocyanins after purified was 14.7%.The recovery rate of macroporous resin after purification was 74.3%.11 kinds of anthocyanins monomer composition was identified by HPLC/ESI-MS/MS method.The anthocyanins with delphinium element and mallow as mother nucleus was main anthocyanins,accounted for 36.9%and 34.6%of the total anthocyanins.(4)The experiments used the method of spray drying to prepare anthocyanins microcapsules to improve the anthocyanins stability.The microcapsulation efficiency,moisture,loss ratio and color value were the key indicators of microcapsules.Firstly,we selected the right wall,then studied the core to wall ratio,pH value,inlet temperature and outlet temperature.So,the best conditions of the spray drying was that:the core wall ratio(v:w)was 5:3,inlet temperature was 170?,the outlet temperature was 75?.HPLC method was used to study on the influence of the anthocyanins active ingredients by spray drying.The infrared spectroscopy and scanning electron microscopy was used to study on microstructure of anthocyanins microcapsules.The stability of microcapsulation product was researched by temperature,illumination and metal ions factors. |
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