Effects Of Modified Atmosphere Packaging And Pulsed Light On Browning And Nutritional Quality Of Fresh-cut Potatoes

Fresh-cut potatoes are made from fresh potatoes.After cleaning anddisinfection,peeling andcutting（shredding,dicing,slicing or slicing）andother processing procedures,they enter the catering andfoodenterprises through coldchain logistics for reprocessing or enter the supermarket.The ready-to-eat potato products soldare rich in vitamins,minerals andother nutrients,andhave the characteristics of convenience,nutrition andeconomy.With the increase in demandfor fresh-cut potatoes,the problems of browning andquality deterioration in the process of the industrial chain have gradually emerged In this project,the"Helan No.15"potato was usedas the material.Through the screening of CO₂ modifiedatmosphere concentration andpulsedstrong light intensity,the optimal conditions for modifiedatmosphere packaging andpulsedstrong light to inhibit the browning of fresh-cut potatoes were obtained The study methodpreliminarily exploredthe mechanism of CO₂ modifiedatmosphere to maintain the quality of fresh-cut potatoes,andprovidedtechnical support andtheoretical basis for the maintenance of safe andeconomical quality of fresh-cut potatoes.The main results are as follows:（1）10%CO₂+90%N₂,20%CO₂+80%N₂,30%CO₂+70%N₂ modifiedatmosphere packaging was usedto explore the effect of CO₂ modifiedatmosphere packaging on the browning andstorage quality of fresh-cut potatoes.Boxedfresh-cut potatoes were storedat 4℃,andthe CK group sufferedsevere browning andlost its commercial value when storedfor 2 days.Browning didnot occur in the three treatment groups within 8days of storage,and CO₂ atmosphere significantly inhibitedpolyphenol oxidase（PPO）,peroxidase（POD）,phenylalanine ammonia lyase Phenylalanine ammonialyase（PAL）activity rises,reduces the accumulation of polyphenols,reduces the loss of ascorbic acidandsoluble solids content,maintains firmness,flavor andtaste,andthe optimal conditions for CO₂ modifiedatmosphere are 30%CO₂+70%N₂ treatment group.（2）The mechanism of CO₂-modifiedatmosphere inhibiting the browning of fresh-cut potato was studiedfrom the perspective of transcriptome.The results showedthat CO₂-modifiedatmosphere inducedthe expression of a large number of stress response-relatedproteins,secondary metabolites,transcription factors andother relatedgenes.Comparedwith 2 d CK and2 d CO₂,there were 2385 differentially expressedgenes,of which 1735 were up-regulatedand650 were down-regulated Through in-depth analysis of differentially expressedgenes,seven differentially expressedgenes relatedto browning were screenedout,namely Soltu.DM.02G027240,Soltu.DM.08G022700,Soltu.DM.04G034310,Soltu.DM.08G000910,Soltu.DM.01G030140,Soltu.DM.12G016710 and Soltu.DM.07G017660,andcarriedout KEGG enrichment analysis on the differentially expressedgenes（DEGs）of fresh-cut potatoes under modifiedatmosphere packaging conditions during storage,andfoundthat the main enrichment in（Glutathione metabolism）glutathione metabolic pathway.（3）Using pulsedstrong light with different intensities（8,10,12 J/cm²）to treat fresh-cut potatoes andcombinedwith 30%CO₂+70%N₂ modifiedatmosphere packaging to study the sterilization of fresh-cut potatoes by pulsedstrong light combinedwith CO₂ modifiedatmosphere andbrowning effects.The results showedthat comparedwith the CK group（30%CO₂+70%N₂ modifiedatmosphere packaging）,the pulse combinedwith modifiedatmosphere treatment group significantly reducedthe total number of colonies in fresh-cut potatoes,maintainedthe color of fresh-cut potatoes,andsignificantly inhibitedthe activities of PPO,POdand PAL.increase,reduce the accumulation of total phenols,andbetter maintain its hardness andflavor.Among them,12 J/cm² combinedwith 30%CO₂+70%N₂ modifiedatmosphere packaging treatment group maintainedthe best quality of fresh-cut potatoes.