Quality and shelf-life of enzymatically peeled and segmented citrus fruits in Japan

Several Japanese citrus fruits, Hassaku, Sweet spring, May pummelo, and Satsuma mandarin, were either peeled by vacuum infusion of a pectinase solution or by hand and then the sections were separated by hand. The citrus segments were then submerged in a cellulase solution to eliminate the segment membranes. There were no significant differences in the microflora, nutrient value (ascorbic acid content and β-carotene equivalent), physiology (respiration and ethylene production rates), and physicochemical properties (texture, juice leakage, color index, and pH) between enzyme-peeled and hand-peeled segments of Hassaku, Sweet spring, and May pummelo. When enzyme-peeled Satsuma mandarin segments were compared with segments chemically peeled using HCl and NaOH solutions in preparation for a conventional canned product, no differences were found in quality, except that the microbial diversity and color index were less in enzyme-peeled segments, and the respiration rate was less in chemically peeled segments. Enzyme-peeled citrus segments were preferable to hand- or chemically peeled segments for their visual appearance. Enzyme-peeled Satsuma mandarin segments were stored in three types of package films with different O₂ permeability to estimate the shelf-life in a modified atmosphere package (MAP) at 10°C. CO₂ approached equilibrium concentrations of 3, 5, and 8% in films of OTR 7000, 1000 and 500 mL m^-2 d^-1 atm^-1, respectively, after 4 d of storage. Microbiological, nutritional, and physicochemical quality of the segments was maintained throughout 6 d of storage regardless of the film package, suggesting that the shelf-life of enzymatically peeled Satsuma mandarin segments as a fresh-cut produce is 6 d in a MAP at 10°C.