Research Of The Watercore Change During Fuji Fruit Storage

Watercore is one of the major physiological diseases of apple. It occurs commonly in high-latitude and the major apple production area in the loess plateau. And it has a high probability of occurrence in the dry and the high temperature weather of apple growing season. Apple with watercore will turn brown during its storage and this surely has a bad effect on commodity quality of apple.Recently, we have met some problems in the study of watercore with existing noninvasive detecting method. For example, the accuracy of detecting online is low, the technology is immature, and its fee of detecting is high. So it hasn't been used in apple's postharvest production practice. That is to say, we still need a guideline for the detecting, identifying and judging the extent of water core in postharvest system. Our study just commits to obtain a technical guidance for Fuji apple's scientific management by detecting, counting and analyzing the occurrence and developing law of watercore in production and storage practice.Regarding the bagged"Fuji"apple in Laomiao town Luochuan county as the research subject, we picked apples every five days During the period of maturation, then detected the index of starch and the occurrence of watercore randomly to study the relationship of them. Lastly every month we detected the random samples stored in three different conditions(Controlled Atmosphere condition, low-temperature condition and low-temperature with 1-MCP treatment condition) to study the occurrence and developing law of watercore from this October to next June. The experimental results run as follows:(1) The incidence of watercore has increased with the process of ripening. On September 23, the index of starch was 2.45, the occurrence of water core was 0; On October 21, the index of starch was 5.74, the occurrence of watercore was 12.96%.(2) The incidence of watercore has decreased during storage. The most effective way to disappear the symptoms of watercore was in low-temperature condition (RH,90%～95%;temperature,0±0.5℃), Controlled Atmosphere condition(with O2, 2.5%; CO2, <1.5%; RH,90%～95%; temperature,0.5±0.5℃) prolonged the disappearring time, and the low-temperature with 1-MCP treatment condition also needed more time than low-temperature condition. (3) We Storaged the Fuji apple with Different harvesting time in Controlled Atmosphere condition(with O2, 2.5%; CO2, <1.5%; RH,90%～95%), at the 60 day the occurrence of water core was 3.67%, the symptom of the apples whose disease index was lower than 1.98 was disappearred, at the 120 day the occurrence of watercore declined to 1.73%, the symptom of the apples whose disease index was lower than 4.36 was disappearred.At the 120 day, some watercore apples browned in the affected parts. The brown rate was 0.35%, 2.08% in apples whose disease index was higher than 9.88.