Effect of chlorine dioxide (ClO2) treatment on postharvest quality of grapes during storage
Dau-Sung Chung, Eun-Ha Chang and Youn-Sak Lee
Abstracts of 27th International Horticultural Congress & Exhibition (IHC 2006), August 13-19, 2006, COEX (Convention & Exhibition), Seoul, Korea. 494 pages.
2006
บทคัดย่อ
This study was conducted to develop sanitizing or freshness agents using chlorine dioxide (ClO2) gas to minimize microbial contamination of fresh produce. After exposing grapes to 20ppm or 40ppm chlorine dioxide for 10 min in a closed container, grapes treated with 20ppm ClO2 were packaged in Ny/PE/L-LDPE pouches, while grapes treated with 40ppm ClO2 were placed in an empty corrugated box with sachet containing ClO2 gas held by silica gel. The free volume of the sachet material allowed the release of ClO2 into the headspace of packages containing the fresh grapes. Control fruit, not exposed to ClO2, was placed in a box and stored at 0°C or 25°C. Weight loss of fruit in Ny/PE/L-LDPE film treated with 20ppm ClO2 barely changed. Fruit treated with 20ppm ClO2 had a lower soluble solid content than control fruit, and the 40ppm ClO2 treated fruit at 0°C or 25°C. There wasno significant differences in pH or acidity of grapes during storage period. But at 0°C 20ppm and 40ppm ClO2 treated fruit in the film package had a lower pH value than control fruit. Anthocyanin content in grapes decreased rapidly over 3 weeks at 25°C. However, anthocyanin content in the grapes at 0°C showed no significant change for 10 weeks. Fruit treated with ClO2 gas had less of a mottled appearance at 0°C and 25°C (author – less mottled than what other treatment? Please clarify). Fruit treated with 20ppm ClO2 had less mold growth than fruit treated with 40ppm ClO2 A large inhibitory effect on mold growth occurred in ClO2 gas treated grapes at 25°C. This result may be attributed to a higher rate of diffusion of ClO2 gas at 25°C, compared to fruit at 0°C and in the control. For comparing gas treatment, Overall grapes treated with 20ppm ClO2 had less weight loss, mold growth, and better overall appearance than fruit treated with 40ppm ClO2 this may be due to a delay in the growth of mold in clean packaged film, compared to fruit placed in a box after sterilizing the surface of grapes.