Effects of hypobaric storage on quality and flesh leatheriness of cold-stored loquat fruit

The study was conducted to determine the effects of hypobaric storage on quality changes and flesh leatheriness of cold-stored loquat fruit. Freshly harvested loquat fruit were stored for 49 days under 40～50 kPa hypobaric pressure condition at (0±0.5)℃. Nutritional quality, extractable juice rate, flesh firmness, browning index, respiration rate, ethylene production rate, lignin content and activities of phenylalanine ammonium-lyase (PAL) and peroxidase (POD) that related to flesh leatheriness were analyzed at 7-day intervals during storage. The results indicated that hypobaric storage significantly reduced the rates of respiration and ethylene production, inhibited browning index, and maintained high contents of total soluble solids (TSS), total titratable acidity (TA) and vitamin C (Vc). Moreover, hypobaric storage inhibited the increase of POD and PAL activities, reduced their peak values, delayed the increases of flesh firmness and lignin content after 21 days, inhibited the decrease of extractable juice rate, thereby maintaining good eating quality and extending the storage life of cold-stored loquat fruit. In addition, the inhibition of flesh leatheriness development of loquat fruit by hypobaric pressure storage was correlated to the reduced POD and PAL activities. These data indicate that hypobaric storage effectively prevents development of flesh leatheriness of cold-stored loquat fruit. Hypobaric storage in combination with low temperature could be a feasible method for quality maintenance and shelf-life extension of loquat fruit.