Quality Changes And Predictive Modeling Of The Shelf-life Of Fresh-cut Red Cabbage In The Cold-chain

Fresh-cut fruits and vegetables processed by trimming,(peeling)cutting,packing,and refrigerating are the fresh fruit and vegetables products.They satisfy the demand of modern life with the advantages of freshness,safety and nutrition.Red cabbage with bright colour is rich in dietary fiber,vitamins and minerals,so it has good dual-use value of medicine and food.Fresh-cut fruits and vegetables easily cause nutrient loss and microbial growth in every part of the process.Vegetables cold-chain logistics refers to vegetables are transported "from the field to the table" always in the appropriate low temperature environment without breaking the chain.Vegetables cold-chain logistics has been widely used in fruits and vegetables industry because of it can maximizely maintain the nutritional value of vegetables,but in the application of fresh-cut red cabbage has not yet been reported.Therefore,this study adopted cold-chain method to prevent the quality deterioration of fresh-cut red cabbage.By single factor methodology,this study optimized the best treatment parameters of the node of pre-cooling,color-keeping impregnation,pressurized argon,pneumatic packaging and shock absorption transportation.Moreover,the study built its shelf-life prediction model of fresh-cut red cabbage,combining optimized each node of cold-chain transportation.Firstly,for exploring the effects of pre-cooling treatments on the quality of fresh-cut red cabbage in the cold-chain,the study investigated the changes in respiration metabolism,browning,nutritional characteristics and physical and chemical indexes.The results showed that pressure-difference pre-cooling reduced the central temperature of the red cabbage to 4?with the shortest time and kept low temperature longest.Pressure-difference pre-cooling could delay the incidence of browning of fresh-cut red cabbage.The results showed that pressurized argon treatments could inhibit respiratory metabolism and the growth of microbes,and the activities of peroxidase(POD)and polyphenol oxidase(PPO)of fresh-cut red cabbage treated with pressurized argon were lower than that of control samples.Moreover,the treatment of pressurized argon could maintain the sensory quality and reduce the loss of the content of anthocyanins,malondialdehyde(MDA)soluble solids and titratable acids in the cold-chain.Secondly,the formulation and process of color-keeping agent of fresh-cut red cabbage in the cold-chain were optimized by single factor test,Plackett-Burman(PB)methodology,steepest climbing methodology and Box-Behnken response surface methodology.The optimal formulation and processing were calcium lactate was 1.06%(m/m),citric acid was 2.00%,ascorbic acid was 1%;cysteine 0.50%,sodium hypochlorite 100 mg/L and soaking time 2.00 min.Moreover,by single factor and Box-Behnken response surface methodology,the multiple regression model of weight loss rate of fresh-cut red cabbage was established to conduct the optimal preparation conditions for the color-keeping agent.The results showed that the best conditions were the pressure argon treatment pressure,1.0 Mpa,pressure holding time,61 min,pressure rate 99 s,and withdrawal pressure rate 148 s,respectively.After 20 d storage,the weight loss rate of fresh-cut red cabbage was 3.57%.The effect of retaining freshness was obviously improved.Finally,the changes in sensory quality,respiratory metabolism,browning degree,nutrition composition and physical and chemical indexes were investigated,for exploring the effects of pneumatic packaging and shock absorption transportation treatments on the quality of fresh-cut red cabbage in the cold-chain.The results displayed that,by comparison,the effect of nitrogen controlled atmosphere storage treatment on fresh-cut red cabbage was inferior to that of argon controlled atmosphere storage.The tightness of polyethylene(PE)/nylon(PA)composite packaging material was superior to PE packaging material,so it could prevent water loss and inhibit sample respiration.Foam box + multilayer corrugated cardboard transportation could effectively reduce the quality deterioration caused by concussion in the cold-chain.Argon controlled atmosphere storage + PE/PA packaging +foam box + multilayer corrugated paperboard treatment was the best way to maintain the quality of fresh-cut red cabbage.After 20 d storage,sensory comprehensive score,weight loss rate,respiration intensity,L,a and b value of samples treated by this treatment were 8.5scores,3.47%,5.05 mg CO2?kg-1?h-1,6.82,5.55 and 1.54,respectively.The contents of VC,total phenol,polyphenol oxidase(PPO)and soluble solids were 21.6 mg/100 g FW,1350.4mg GAE/100 g DM,11.47 U?g-1?min-1 and 13.88%,respectively.By using accelerated shelf life testing(ASLT)and combining optimized each node of the cold-chain,the quality changes of fresh-cut red cabbage were analyzed under different storage temperatures.The study showed that the dynamics model for shelf-life prediction of fresh-cut red cabbage could established based on total colony.The model's activation energy(E)and regression coefficient(K0)was 15.51 KJ/mol and 516.6,respectively.The validation experiments were tested under 3? and 5?,respectively.The results obtained that the relative errors of prediction model were 4.35% and 5.26%,respectively.This dynamic model could predict the shelf-life of fresh-cut red cabbage in the cold-chain.