Study And Application Of The Gaseous Fruit & Vegatable Preservatives

In chapter one, the domestic and foreign developments of the methods and problems existed in controlling postharvest decay of strawberries,pepper and grape were summed up. The development, production, determination and application methods of ClO₂ were reviewed. As a new high effective fungicide, ClO₂ has been used in many fields because of its oxidation ability, which can be used as new fruit preservatives. Prospect will be bright if new ClO₂ generators can be applied to preservative strawberries, peppers and to prolong the shelf life of fruit. SO₂ will still take an important role in fruit preservation in resent future.In chapter two, the SO₂ injury threshold of four different varieties table grapes in Xinjiang municipality at different fumigation level were investigated. And the soluble solid content (SSC),rigidity,pH,SO₂ accumulation in pericarp and sarcocarp were determined at the end of the shelf life . The results showed that SSC and rigidity were declined compared with the control. The pH was not significantly changed. The results of continuous SO₂ fumigation showed that the total sulfur was increased during the storage time. But the excessively accumulation of sulfite was not appeared both in pericarp and sarcocarp.In chapter three, the efficacy of gaseous ClO₂ and O3 as a sanitizer for inhibiting 7 pathogenic germs from XinJiang melon was investigated. By the bacteriostasis experiment, gaseous ClO₂ and ozone showed different bacteriostasis capacity in different concentration and temperature.In chapter four, strawberry fruit were fumigated with ClO₂ immediately after harvest. Results showed slightly effect on pH, total soluble sugars and TA. Total flavones, Vitamin C and Anthocyanins remained in all treatments. The mold growth was delayed compare to the blank and thus extending strawberry shelf-life. It is suggested that after harvest, ClO₂ treatment is efficient for extending the shelf-life and maintaining the quality of strawberry.In chapter five, ClO₂ was applied to the postharvest preservation of green pepper. Results showed that the decay index and after-ripening index was effetely reduced by ClO₂, and the weight loss was not significantly effected. The content of capsaicinoid in pepper was conserved for longer time. It is suggested that after harvest, ClO₂ treatment is efficient for extending the shelf-life and maintaining the quality of green pepper.