Study on two dimensional and dynamic controlled atmosphere storage of apple fruits
Liu Y.; Wu Y M.; Hua X Z.; Fang J X.; Qi S C.; Wang C S.; Li Z Q.
Acta Phytophysiologica Sinica 16(4): 401-409
1990
Accession: 007840888
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 CO2 in TDCA are not constant as in traditional CA storage where cold temperature (about 0.degree. C) and constant gas composition of 3% O2 and 3% CO2 are kept throughout the period of storage. It is kept at temperature 10-15 .degree. C during the early storage stage but is then gradually lowered to 0.degree. C. The concentration of CO2 is also gradually lowered after being kept at 10%-15% during the early stage of storage. 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.degree. C) throughout the storage period (150-180 days). The gas composition was 21% O2 and 0% CO2 (0.degree. C) in treatment I (control); 3% O2 and 3% CO2 in treatment II, and 3% O2 throughout the whole storage period and 12% CO2 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 CO2). Apples in treatments IV, V and VI were stored under higher and varied temperatures. The temperature was about 10.degree. at the beginning of the storage, then gradually decreased to 0.degree. C in the first 90 days and kept at 0.degree. C 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 color and quality were much better than those stored by refrigeration (I) and were similar to the fruits of CA storage (II). The results indicate that the higher concentration of CO2 for early storage substitutes well for low temperature to keep the freshness and firmness of fruits, and higher temperature is needed during early storage to establish higher CO2 concentration caused by higher respiration rate and to avoid injury by CO2, which often occurs under low temperature. Under TDCA, respiration, degradation of chlorophyll and protopectin, biosynthesis of ethylene and surface scald were markedly inhibited. The results showed that TDCA could effectively suppress the ripening and senescence of fruits and thereby preserve their quality and firmness. The optimal temperature and gas composition for TDCA were investigated, and a model was established. Considerable economic benefits have been obtained by using TDCA.