苹果双变气调贮藏

Study on Two-Dimensional and Dynamic Controlled Atmosphere Storage of Apple Fruits

苹果双变气调贮藏(TDCA)是在产地简易气调贮藏基础上,总结发展形成的一项新的理论与技术。与传统气调不同,TDCA贮藏初期采用较高温度(10℃或更高),高CO_2(10％以上),并在贮藏期间变动,由高到低。对比试验证明,TDCA贮藏效果优于冷藏,与气调相近。其生理机制在于显著抑制呼吸作用;抑制乙烯的生成和催熟作用,减弱叶绿素和原果胶分解;保持果实色泽和硬度,抑制虎皮病的发生。初步确定的双变模式在生产上应用获得良好效益。同时还讨论了贮藏期间温度和气体成分变动之间相互依赖的辨证关系以及环境因子变动的合理性。

Storage under two-dimensional and dynamic controlled atmosphere (TDCA) is a novel technology based on a new concept which was developed for apple storage on the basis of experiences in simplified controlled atmosphere (CA) storage under the climate of apple production area in China and by precisely controlled experiments. The storage temperature and CO_2 in TDCA are not constant as in traditional CA storage where cold temperature(about0℃)and constant gas composition of 3% O_2 and 3% CO_2 are kept throughout the period of storage. It is kept at temperature 10～15℃ during the early storage stage but is then giadually lowered to 0℃. The concentration of CO_2 is also gradually lowered after being kept at 10%～15% during the early stage of storage (Fig. 3). Apple fruits (Red Delicious and Golden Delicious) stored under different storage conditions were studied. In treatments Ⅰ, Ⅱ, and Ⅲ, apples were all stored under low temperature (0℃)throughout the storage period (150～180 days). The gas composition was 21% O_2 and 0% CO_2 (0℃)in treatment Ⅰ(control); 3% O_2 and 3% CO_2 in treatment Ⅱ, and 3% O_2 throughout the whole storage period and 12% CO_2 in the first 45 days, then decreased to 9% in the next 45 days, and kept at 6% in the following 90 days in treatment Ⅲ (high CO_2). Apples in treatments Ⅳ, Ⅴ and Ⅵ were stored under higher and varied temperatures. The temperature was about 10° at the beginning of the storage, then gradually decreased to 0℃ in the first 90 days and kept at 0℃ in the next 90 days. The gas compositions in treatments Ⅳ (high temperature control), Ⅴ (high temperature CA) and Ⅳ (TDCA) were the same as in treatments Ⅰ, Ⅱ and Ⅲ, respectively. When apple fruits were stored by TDCA for 6 months, the rigidity, skin colour and quality were much better than those stored by refrigeration (Ⅰ) and were similar to the fruits of CA storage (Ⅱ) (Tables 1 , 2). The results indicate that the higher concentration of CO_2 for early storage substitutes well for low temperature to keep the freshness and grmness of fruits, and higher tempearture is needed during early storage to establish higher CO_2 concentration caused by higher respiration rate and to avoid injury by CO_2, which often occurs under low temperature (Table 1). Under TDCA, respiration (Table 3), degradation of chlorophyll (Table 2) and protopectin (Table 4), biosynthesis of ethylene (Fig. la, b) and surface scald (Fig. 2) were marked inhibited. The results showed that TDCA could effectively suppress the ripening and senescence of fruits and thereby preserve their quality and rigidity. The optimual temperatures and gas composition for TDCA were investigated (Table 5, 6, 7), and a model was established (Fig. 3). Considerable economic benefits have been obtained by using TDCA.