포장방법과 저장온도가 신선편이 양파의 품질 및 미생물 생장에 미치는 영향

Abstract

Inappropriate storage of fresh-cut onions may result in losses of good quality. To understand storage conditions for shelf-life and quality of fresh-cut onions, The effect of packing type and storage temperature on the quality of fresh-cut onions was evaluated. Onions stored at 0℃ for 2 months were peeled off after removing root and shoot parts. Each three peeled onions were packed in a polyethylene film (PE, 50 μm) or in a polyethylene/polypropylene film (PE/PP, 100 μm) with vacuum treatment (70 cmHg) and stored at different temperatures (4, and 10℃) for 21 days. The following analyses were examined to evaluate the quality of fresh-cut onions: microbial population, surface color, titratable acidity and pH, respiration rate, and sensory quality. Fresh-cut onions stored at 4℃ showed less aerobic and coliform bacterial population than those stored at 10℃ during observation periods. Fungal populations of fresh-cut onions packed in PE film stored at 10℃ increased significantly after 13 days. E. coli was not detected in all treatments during whole storage periods. Surface colors of fresh-cut onions were not affected by packing type and storage temperature, however, color difference (ΔE) of fresh-cut onions in PE/PP film stored at 10℃ was significantly higher than those of other treatments. Titratable acidity of fresh-cut onions was not affected by packing type and storage temperature. However, pH of fresh-cut onions packed in PE film stored at 10℃ increased gradually over the whole storage period. Fresh-cut onions packed in PE film showed higher CO2 and less O2 concentrations at 10℃ than those at 4℃. The sensory quality of fresh-cut onions was significantly affected by packing type and storage temperature after 13 days. Particularly, vacuum treatment in PE/PP film showed better sensory quality than that of PE film package at the same storage temperature. It was concluded that vacuum treatment and storage at 4℃ could be effective to prolong the quality of fresh-cut onions up to 21 days.