Research On Lingwu Long Jujube Beverage

Lingwu long jujube is an excellent variety of jujube in Ningxia.It is nutritious and famous throughout the country.Lingwu long jujube has a long history of cultivation and became characteristic industries in the locality.However,in recent years,with the increase of production,Lingwu long jujube sales less than the output and most of the jujube is used as raw material into the market.According to these problems,Lingwu long jujube was studied in four aspects,such as pretreatment,extraction,clarification and formulation.The purpose is to improve the taste and increase the nutritional value.Thus,develop a new type of drink in order to suitable for both young and old.The main conclusions are as follows:(1)Development of pretreatment technology in Lingwu long jujube juice.The principle of Maillard reaction is used to produce special flavor compounds such as esters,ketones and furans.Lingwu jujube was baked by hot-blast air and microwave to study the effect of different processing conditions on the aroma formation of jujube.Under the optimum conditions,the content of soluble solids was respectively 14.73%and 10.28%,and the content of flavonoids was 0.0607 mg/mL and 0.0230 mg/mL.The results showed that isoamyl butyrate and 2-acetylpyrrole could be produced by hot-blast air baking,and the relative content of furans could be increased.Baking temperature was 105? and baking time was 120 min under the optimum process.Therefore,the best conditions of hot-blast air baking can effectively improve the flavor and nutritional level of jujube juice.(2)Optimization of extraction technology for Lingwu long jujube juice.Taking extraction rate as an indicator,the conditions of hot water extraction and enzymatic extraction were studied.The condition of hot water extraction is that the extraction temperature is 100? and the extraction time is 12.5 min.The conditions of enzymatic hydrolysis were as follows:the addition of pectinase was 0.4%,the enzymatic hydrolysis time was 4 h,the temperature of enzymatic hydrolysis was 50? and the pH value was 3.5.They are 8 times the amount of water added.The jujube juice was extracted from four ways by hot water extraction,enzymatic hydrolysis,hot water enzymolysis and enzymatic hydrolysis.The results showed that the extraction rate of digestion and enzymatic hydrolysis was 52.03%,which was 16.55%and 18.11%higher than that of hot water and enzymatic hydrolysis respectively.(3)Study on clarification technology of Lingwu long jujube beverage.According to the transmittance index,the processed conditions of gelatin clarification and chitosan clarification were studied.The results showed that the transmittance of natural standing,gelatin clarification and chitosan clarification were respectively 82.97%,89.54%and 94.12%.The best clarification method is chitosan clarification.The optimum clarification conditions are as follows:dosage,clarification time and clarification temperature was respectively 1.4 g/L,60 min and 55?.(4)Formulation technology of Lingwu long jujube beverage.According to the sensory score,the best formula of beverage was determined.The addition of baked jujube juice was 17.99%,that of clear jujube juice was 55.00%,that of sucrose was 2.95%,and that of sugar to acid was 53:1.This formula has moderate acidity and sweetness,and strong aroma of jujube.Its sensory score was 96.50,and the content of soluble solids,flavonoidsds and total phenols was respectively 7.83%,0.0227 mg/mL and 0.1690 mg/mL.