5 . 3 . Chemical treatments
Calcium dips may be used to reduce physiolog- ical disorders and maintain firmness in apples and cherries. Bangerth (1976) observed an increase in vitamin C content of apples and tomatoes treated with calcium chloride. Dehydrated pineapples and guava pretreated with cysteine hydrochloride had increased AA retention and reduced color change during storage (Mohamed et al., 1993).Watada et al. (1976) reported that AA content was slightly higher in mature-green tomatoes treated with ethylene than in those ripened with- out added ethylene. Kader et al. (1978) found a significant difference in ethylene-treated versus control mature-green tomato fruit (Table 6). Kiwifruit slices stored in ethylene-free air con- tained 3-fold more AA than controls. When dipped in 1% CaCl2 after cutting and kept in an ethylene-free atmosphere, slices had a slightly higher AA content than those treated with 1% CaCl2 only (Agar et al., 1999).