Studies On The Technology Of Processing Lycium By Pneumatic Puffing Drying And Its Quality

With Lycium barbarum L. the main raw material , this dissertation ismainly on the research of crisp , fragrant and sweet lycium by utilizing one ofnew technology of food industry low temperature pneumatic-puffingdrying technology . This paper comprises two parts:the first part acquiredoptimum parameters by single factor experiment ,then through quadraticcross rotary design method ,the fit parameters.The second part studies itsquality changes after explosion-puffing drying. It includes sensory score ofexplosion-puffed lycium and non-puffed lycium,the shelf life , soluble solid inwater with puffed lycium and non-puffed lycium,amylose soak rate,changes ofnutriant and the texture.The results are as follows:1.The paper discussed the technology for abtaining the best puffedlycium,analyzed the effect of moisture equilibrum time ,pre-drying moisturelevel, operation temperature ,residence time as well as pressure difference onpuffed lycium's qualities.Theresults: moisture equilibrum time 2 days.pre-drying moisture level 17%, operation temperature 85℃,residence time12min,pressure difference 100KPa.2.In the experiment rehydration rate has positive relation to puffing degree,thegreater the puff degree ,the more porous the product ,and the more readily the water ispicked up when rehydration.3.The optimum parameters singled out through single factor experiment isregarded as 0 level ,then by using quadratic cross rotary design method ,tworegression equations are established in which x is coded value ,Y is equivalentto the index of qualities according to the results and statisticsanalytical .Through further optimization and test ,get the fit parameter ofpneumatic-puffing drying ,the coded value is :0.04,-0.04,-0.04.4.Explosion puffed lycium is more popular than non-puffed lycium by sensoryanalysis . Also, the hot water with explosion puffed lyciym is more popularthan the hot water with non-puffed lycium. 2山东农业大学硕士论文5.The lycium can weather through the hot and high humidity summer packedwith a fit wrappage which has no desiccant .6.High temperature can quicken the lycium rehydration rate ,soluble solidsoaked out and amylose soaked out . The quantity of amylose soaked our ofpuffed lycium is more than that of no-puffed lycium.7.The hardness of hot-air drying lycium is much bigger than explosion puffedlycium.After rehydtation for 4 hours, the hot-air drying lycium is harder thanexplosion puffed lycium. The crispness of explosion puffed lycium is reducedwhen the water content is 4%.