Hidemi Izumi (Kinki University), Yuji Nakata (Kinki University), Ayano Inoue (Kinki University), Yoshihiko Ozaki (Kinki University)
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 separated by hand. The citrus segments were then submerged in a cellulase solution to eliminate segment membranes. There were no significant differences in the microflora, nutrient value (ascorbic acid and ß-carotene contents), 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 was 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 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 packaging (MAP) at 10 degrees C. The CO2 approached an equilibrium of 3%, 5%, and 8% in respective packages after 4 days of storage. Microbiological, nutritional, and physicochemical quality of the segments was maintained throughout 6 days of storage regardless of the film’s package, suggesting that the shelf life of enzymatically peeled Satsuma mandarin segments as a fresh-cut produce is 6 days in a MAP at 10 degrees C.