The Effects of Postharvest Mineral Element and Lecithin Treatments on the Storage Disorders of Apples

Effects of lecithin, calcium, and antioxidant formulations on superficial scald and internal breakdown of ‘Granny Smith’ apples

“…The inhibitory effect of lecithin + Ca on bitter pit of 'Cox's Orange Pippin' apples is partially due 59 to atmosphere modification within the fruit (Watkins et al 1982a), and presumably superficial scald is inhibited in this cultivar by a similar mechanism (Sharples et al 1979). Although the internal atmospheres in 'Granny Smith' apples were modified by lecithin + Ca in the present study, no effect on superficial scald was found.…”

“…The observation of Sharples et al (1979) that addition of Ca to lecithin enhanced the inhibitory effects of the compound on scald holds true for 'Cox's Orange Pippin', but does not apply with 'Granny Smith'.…”

“…Although lecithin may be a potential inhibitor of superficial scald on some cultivars (Staden 1961(Staden , 1969, our study and others (Staden & Witmondt 1967;Sharples et al 1979) show that it will not serve as a general treatment for scald control. The observation of Sharples et al (1979) that addition of Ca to lecithin enhanced the inhibitory effects of the compound on scald holds true for 'Cox's Orange Pippin', but does not apply with 'Granny Smith'.…”

“…Although lecithin coatings enhance Ca movement into fruit (de Villiers & Hanekom 1977), control of bitter pit by lecithin + Ca probably results from modification of gas exchange, as well as increased Ca uptake (Watkins et al 1982a). Sharples et al (1979) found that superficial scald was not affected by lecithin dips alone but was controlled by lecithin + Ca. They suggested that a combination of both chemicals could provide control of superficial scald in those cultivars in which lecithin alone is ineffective.…”

“…Lecithin reduced soft scald on 'Jonathan' apples (Wills et al 1980), and inhibited Jonathan spot and skin browning in 'Jonathan' and 'Golden Delicious', respectively, as well as reducing weight loss, and maintaining greenness and flesh firmness of both cultivars (Staden 1967a.b). The use of calcium (Ca) together with lecithin as a post-harvest dip enhanced bitter pit control in 'Cox's Orange Pippin' (Reid & Padfield 1975;Sharples et al 1979). Although lecithin coatings enhance Ca movement into fruit (de Villiers & Hanekom 1977), control of bitter pit by lecithin + Ca probably results from modification of gas exchange, as well as increased Ca uptake (Watkins et al 1982a).…”