Research on effects of hot water and chemical treatments on storage of some citrus species and varieties

Citrus industry have a great potential in Cukurova region. Regarding the limitations of chemicals usage lead to increase of the postharvest physical treatments treatments like heat treatments and it is combination with the low dosage of fungicides. During the first year of this study the most suitable hot water temperatures for Marsh Seedless, Star Ruby, Rio Red were tested at 53, 56, 59 oC, for Minneola tangelo and Robinson mandarin varieties 50, 53, 56 oC and dip duration were 30 s and 60 s tested for dipping time. The most suitable treatments were 56 oC water temperature and 60 s dipping time for grapefruit whereas it was 50 oC, 30 s for the Mineola tangelo and Robinson mandarins accoring the results. Additional treatments of 500 ppm Imazalil, 500 ppm Imazalil+hot water combination were tested and compared with Control during second year. In conclusion, water losses increased, TSS decreased, vitamin C content decreased, total sugar content decreased whereas reduced sugars increased, red peel color maintained during storage. Hot water dips decreased the losses in both years storage without the any negative effect on the fruit quality. It can be concluded that hot water dip with combination of low dose Imazalil can be used very efficient for storage of the citrus, grapefruit varieties can be stored 5 months, tangerine and mandarin varieties can be stored 2 months under these conditions. Key Words: Hot water, Imazalil, storage, quality, citrus.