Low-temperature Plasma Preservation Technology And Shelf-life Prediction Of Fresh-cut Kiwifruit Slices

Fresh-cut kiwi slices are very popular among consumers owing to its sweet and soft taste with freshness,plenty of nutrients,portability and pollution-free.However,the shelf life of kiwi slices will be shorted because of the damage during processing.Preservation technology plays an extremely important role in extending the shelf life of fresh-cut fruit.What’s more,kiwi processing industry couldn’t do well in upgrading and developing in that traditional preservation technology has difficulty in keeping nutrition and ensuring safe eating.Based on above problems,exploring the effect of low temperature plasma treatment on quality and sterilization of fresh-cut kiwi slices,optimizing process parameters and selecting suitable packaging materials were studied and its shelf life predictive model of fresh-cut kiwi slices was established.The conclusions are as follows:1.Total soluble solids content(SSC),titratable acidity(TA),soluble sugar and L*a*and b*value of fresh-cut kiwi slices were observed insignificantly under different treatment of low temperature plasma(P>0.05);Vc content,total phenol content,chlorophyll content,brittleness and hardness did change significantly with time and voltage(P<0.05);APX and POD activity decreased significantly at first and then increased(P<0.05).Low temperature plasma can maintain the sensory,texture and nutritional quality of fresh-cut kiwi slices.It is also beneficial to the extension of shelf life.2.The quality features of 11 indexes of fresh-cut kiwi slices were extracted by factor analysis,including colour difference(△E),brittleness and solid-acid ratio.The regression model can be used to predict and analyze the effect of plasma treatment on sterilization and keeping quality.The brittleness,△E,solid-acid ratio and logarithmic reduction of bacteria are 531.76 g·s,2.25,18.03,2.3 lg(CFU/g)with the optimal parameters voltage 26 kv,time 120 s,slice thickness 10 mm.The fresh-cut kiwi slices taste delicious with the treatment of low temperature plasma.3.The best packaging material for fresh-cut kiwi slices is PVDC.ΔE,brittleness,Vc content and total colony can be used as monitoring indicators to construct shelf life prediction model of fresh-cut kiwi slices;The result showed that zero order equation has the best effect on ΔE of fresh-cut kiwi slices and the average fitness is 0.93864;The first order equation has the best effect on brittleness and Vc content with the average fitness 0.96248,0.97074;Logistics equation can fit total colony and accuracy and deviation factor is 1.30 and 1.05;At 3℃,the relative errors between predicted and measured values of the four shelf life prediction models which is established by fitting equation,Arrhenius and Belehradck model are 4.03%、3.41%、2.4%、2.8%;Compared with SL brittleness and SLΔE,SLVC and SL colony is more accurate in predicting shelf life of fresh-cut kiwi slices under 0-25℃.The application of low temperature plasma to fresh-cut kiwi slices can reduce nutrition loss,inactivate enzyme activity,increase sterilization rate,and prolong fresh-keeping period.The research plays an important role in promoting commercial value of fresh-cut kiwi slices.