Research On Preparation And Characterization Of Prunus Mume Juice Spray-drying Powder

Prunus mume Sieb.et Zucc is a fresh fruit of the rose apricot plant(Prunus mume Sieb.et Zucc),commonly known as sour plum or“fruit plum.”It is also the raw material for Wumei,a medicinal food with rich nutrition and various health benefits.Green plum has a long history of cultivation in China and is widely distributed.It is grown in Yunnan,Guizhou,Sichuan,Guangdong,Fujian,Zhejiang,and other places,as well as in Southeast Asia,such as Korea and Japan.Green plum is a respiratory transition fruit that has problems such as poor post-harvest storage and rapid decay.In this paper,we obtained spray-dried green plum juice powder(SDP)with low water content and good preservation effect by optimizing the juice extraction and spray drying processes of nearly mature fresh green plum juice.We also explored the antioxidant ability of SDP and developed a sour-sweet and delicious green plum juice powder solid beverage.The main results are as follows:(1)Through single factor combined with orthogonal experiment,the optimum enzymatic hydrolysis process of green plum juice was studied:Pectinase 0.08%,enzymatic hydrolysis time 80min,enzymatic hydrolysis temperature 50℃.Under this condition,the juice yield could reach 77.14%.(2)Through the experimental design of single factor and Box-Behnken response surface,the best drying aid for spray drying of green plum juice is DE10-15 maltodextrin,and the optimum spray parameters are as follows:inlet air temperature 160.69℃,feed flow rate0.47L/h,inlet air flow rate 40.15m~3/h.Under these conditions,the powder collection rate can reach 57.06%,the vitamin C content can reach 489.71 mg/100 g,and the sensory value can reach 84.57.(3)The effects of adding microcrystalline cellulose,tricalcium phosphate,silica and CMC-Na anti-caking agents on the water content,moisture absorption,solubility,flowability,color,aroma and morphology of SDP were investigated,and a comprehensive quality scoring model of SDP was established by principal component analysis(PCA)method.The SDP comprehensive score of adding 1.5%CMC-Na was the highest,which could significantly improve the physicochemical properties of SDP.(4)The antioxidant activities of SDP and freeze-dried fruit juice powder(SDP)were compared with those of freeze-dried fruit juice powder(FDP)by scavenging DPPH,ABTS+,hydroxyl radical and hydrogen peroxide radical as indexes.The results showed that SDP and FDP had strong scavenging ability to DPPH,ABTS+and hydroxyl radical,but weak scavenging ability to hydrogen peroxide free radical.SDP and FDP had similar scavenging ability to four kinds of free radical and showed good antioxidant activity in vitro,which indicated that SDP prepared by spray drying could retain the antioxidant activity of green plum juice.(5)Taking the sensory score as the evaluation index,the formula of green plum juice powder solid beverage was optimized by single factor and response surface experiment.Results the best formula of green plum juice powder solid beverage was as follows:SDP 3.86%,stevioside 0.09%,salt 0.37%.The taste of green plum juice powder solid beverage prepared by this process is good,and the sensory score is close to the predicted value of the model,indicating that it is feasible to optimize the blending process of green plum juice powder solid beverage by response surface method.