Optimization Of Extraction And Purification Process Of Cranberry Anthocyanins And Preparation Of Microcapsules

Cranberry is a kind of huckleberry belongs to Ericaceae,and the natural functional components of cranberry are abundant,such as vitamin group,proanthocyanidins,flavonoids,anthocyanins,dietary fiber,pectin and various organic acids.Cultivated area of Cranberry in our country is mainly concentrated in Da Hinggan Mountains and The Northeast Three Provinces,and cranberry is an emerging small berry.Domestic research on cranberry is in the ascendant.The main research is concentrated in the field of cultivation,lacking the scientific and in-depth analysis of functional areas.In this paper,the extraction technology,purification technology,species identification,antioxidant capacity,microcapsule preparation,microcapsule stability and controlled release property of cranberry anthocyanins were studied,the main results were as follows:(1)Single factor test and response surface test are used to optimize the process conditions of conventional solvent extraction,ultrasonic assisted extraction and ultra-high pressure assisted extraction.The three extraction methods are compared in terms of test period,energy consumption,consumables and other aspects,and the extraction of cranberry anthocyanins is the index.The optimum conditions of conventional solvent extraction are ethanol concentration 64%,extraction temperature 40℃,extraction time 2 h,ratio of material to liquid at 1:10,pH 2.0,and the extraction amount is 581.60±3.35μg/g.The optimum conditions of ultrasonic assisted extraction are ethanol concentration 60%,ultrasonic power 140 W,ultrasonic temperature 44℃,ultrasonic time 52 min,ratio of material to liquid at 1:10,pH 2.0,and the extraction amount is 739.40±4.06μg/g.The optimum conditions of ultra-high pressure assisted extraction are ethanol concentration 52%,ultra-high pressure 300 MPa,ultra-high pressure temperature 24℃,ultra-high pressure time3 min,ratio of material to liquid at 1:10,pH 2.0,and the extraction amount is 779.85±4.63μg/g.Compared with the other two methods,ultra-high pressure assisted extraction has the advantages of high extraction,short time and other else.(2)Macroporous resin method is used to purify cranberry anthocyanins.Based on the adsorption rate and desorption rate as the optimization index,AB-8 is selected as the most suitable resin for purified cranberry anthocyanin in terms of test period,ene rgy consumption,consumables and other aspects.The optimum conditions of AB-8 res in are adsorption time 2 h,desorption time 2 h,sample concentration 0.4 g/mL,eluen t ethanol volume fraction 70%,sample pH 3,ethanol eluent pH 4,sample flow rate1 mL/min,eluent flow rate 2 mL/min.After purifying,the purity of cranberry anthocy anins is increased from 4.61%to 30.92%,which is 6.71 times higher.High perform ance liquid chromatography-mass spectrometry is used to identify the composition of c ranberry anthocyanins.Seven anthocyanins are identified,which are peonidin-3,5-dihexo side,cyanidin-3-galactoside,cyanidin-3-glucoside,cyanidin-3-arabinoside,peonidin-3-gala ctoside,peonidin-3-glucoside,peonidin-3-arabinoside,and peonidin-3,5-dihexoside is id entified for the first time in cranberry.Cranberry anthocyanins has the ability to scave nge DPPH free radicals,ABTS~+·free radicals and total antioxidant capacity,and the s ame concentration of cranberry anthocyanins has higher antioxidant capacity than Vc.(3)Single factor test and response surface test are used to optimize the preparation conditions of cranberry anthocyanins microcapsules.Based on the embedding rate as the optimization index,the ultrasonic method is selected as the most suitable resin for preparing microcapsules in terms of test period,energy consumption,consumables and other aspects.The optimum conditions of ultrasonic method are the ratio of wall to core 12:1,SPI:MD 1:3,embedding time 35 min,embedding temperature 45℃,and the embedding rate is 89.53±2.29%.The microcapsules obtained by vacuum freeze-drying are irregular in shape,uniform in size,small in particle diameter,and the surface is smooth.Microcapsules can effectively inhibit anthocyanin degradation under the influence of temperature,light and oxygen,and play a good sustained-release role in simulated gastro-intestinal fluid.Compared with the traditional extraction methods,the effect of ultra high pressure assisted extraction of cranberry anthocyanins is better.The antioxidant activity of the purified cranberry anthocyanins is higher than that of Vc.The effect of microencapsulation is good.