Effects of ε-Polylysine/Chitosan Composite Coating and Pressurized Argon in Combination with MAP on Quality and Microorganisms of Fresh-Cut Potatoes

Effects of ε-polylysine/chitosan (ε-PL/CS) composite coating and pressurized argon (Ar) in combination with modified atmosphere packaging (MAP) on the quality and the microbial load of fresh-cut potatoes during refrigeration were studied. Sliced potatoes were treated with pressurized Ar at 4 MPa for 1 h, and then immersed in ε-PL (1 g L−1)/CS solution for 1 min. Treated samples were sealed in MAP (94% N2, 4% O2, 2% CO2), and stored at 4 °C. Water loss, ascorbic acid content, respiration rate, malondialdehyde content, color, firmness, enzyme activities, and microbial load were measured at 3-day intervals. Results indicated that synergistic treatment (ε-PL/CS + pressurized Ar) significantly delayed the losses of water, ascorbic acid, color, and firmness, and inhibited the increase of respiratory rate, MDA content, and enzyme activity (PPO and POD). The microbial loads including coliform, mold, and yeast counts were significantly reduced. Preservation effect of pressurized Ar was noted to be superior to that of ε-PL/CS composite coating. Therefore, ε-PL/CS composite coating and pressurized Ar in combination with MAP is an effective method for maintaining the quality and improving the safety of fresh-cut potatoes during refrigeration.