Study On Modified Atmosphere Packaging Storage Of Fresh-cut Pineapple

Pineapple (Ananas comosus [L.] Merrill cv. Comte de Paris) was used as experimental material, after fresh cut treatment, the fresh-keeping technology of fresh-cut pineapple was studied. First of all, using different initial gas concentration to preserve fresh-cut pineapple with low oxygen modified atmosphere packaging. Through the research of quality in fresh-cut pineapple,the optimal initial gas concentration was selected. And then fresh-cut pineapple were preserved by the optimal low oxygen MAP and pure oxygen MAP respectively. The preservation effect and preservation mechanism of different MAP were studied. The results were as followed:1. All kinds of initial gas concentrations inhibited the loss of nutrients, and maintained good organoleptic quality. Among them, when the initial gas concentration was4%O2+5%CO2, it had better preservation effect. Therefore, the optimal initial gas concentration ratio was4%O2+5%CO2.2. Low oxygen MAP and pure oxygen MAP all delayed the decrease of firmness, chroma, reducing sugar, and and Vitamin C, inhibited the rise of titratable acid in fresh-cut pineapple, and reduced the incidence of product decay. At the same time, the flavor and taste of the product were good. However, Pure oxygen MAP increased the browning degree of fresh-cut pineapple.3. The coliform group didn’t exist in pure oxygen MAP group and low oxygen MAP group during the whole storage period. Low oxygen MAP and pure oxygen MAP all significantly inhibited the growth in the number of colonies, mold and yeast, and effect of low oxygen MAP group was best. At the last stage of storage, the microorganism quantity of low oxygen MAP group was least4. Low oxygen MAP obviously restrained the rise of PPO activity and increased POD activity. However, pure oxygen MAP increased PPO and POD activity. Accordingly, Pure oxygen MAP accelerated the decline rate of total phenolic and flavonoid contents, however, low oxygen MAP maintained higher total phenolic and flavonoid contents.5. Low oxygen MAP and pure oxygen MAP all delayed the decline of SOD and CAT activity and inhibited the rise of hydrogen peroxide (H2O2) in the meantime. In the early storage period, low oxygen MAP and pure oxygen MAP increased the content of superoxide anion and hydrogen peroxide (H2O2) in fresh-cut pineapple.