Control of Superficial Scald On ‘?Anjou’ Pears by Ethoxyquin: Oxidation of α‐Farnesene and its Inhibition

Abstract

cr-Famesene in the skin tissue of 'd'Anjou' pears (Pyms communis, L.) increased to a maximum after 3 months of storage in air at -1°C and then declined. a-Farnesene was oxidized to conjugated trienes and its oxidation was inhibited by.ethoxyquin. The split application by drenching fruit with 1,000 ppm ethoxyquin at hatvcst and then line-spraying 1,700 ppm after 1, 2 or 3 months of storage inhibited the oxidative activity of a-farnesene similar to the single application with 2,700 ppm ethoxyquin by drenching fruit at harvest. Incidence of superficial scald was highly correlated with the level of conjugated trienes. The control of scald by ethoxyquin was due to its antioxidant action and/or its inhibition of conjugated trienes biosynthesis.

Changes in Ripening Behaviors of 1-MCP-Treated ‘d’Anjou' Pears After Storage

“…After 3 months of storage, control fruit had a high incidence of scald with concomitant accumulations of FAR and CT (Table 2). Our previous study confirmed that the mechanism of scald induction in 'd'Anjou' pears was the same as apple fruit (Chen et al, 1990b). In the skin of apple fruit and 'd'Anjou pears, FAR progressively accumulated to its maximum level and then declined during stor- Significance: *** (P < 0.001); ** (P < 0.01); * (P < 0.05); NS (not significant) age while CT continued to increase to a level that eventually caused damage of epidermal cells.…”

“…The incidence of scald was expressed as the percentage of fruit affected with slight which was < 9% scald or > 9% scald, which was considered commercially unacceptable. After assessment of scald incidence, 5 fruits from each replicated box were used for the determination of α-farnesene (FAR) and its oxidative products, conjugated trienes (CT), according to the method described by Chen et al (1990b).…”

An insight into the role of fruit maturity at harvest on superficial scald development in ‘Beurré D’Anjou’ pear

“…The pattern of ␣-farnasene (AF) accumulation observed in this experiment was similar to that previously described for apples (Huelin and Coggiola, 1968;Anet, 1972;Whitaker et al, 1997;Giné Bordonaba et al, 2013) and pears (Chen et al, 1990;Isidoro and Almeida, 2006;Whitaker et al, 2009) with low initial values at harvest that increased during the first 3 months of cold storage and then decreased due to its in vivo oxidation. Conjugated trienols (CTols) have been identified as the predominant in vivo oxidation products of AF both in apples and pears (Whitaker, 2007) (Fig.…”

“…2). As it occurs in apples, it is assumed that scald incidence in pears is proportional to AF oxidation (Anet, 1972) and that susceptible cultivars are those that exhibit higher levels of CTols (Chen et al, 1990;Whitaker et al, 1997;Gapper et al, 2006;Tsantili et al, 2007). In this work, we observed that CTols, and especially AF, accumulated faster in fruit of advanced maturity (H 2 and H 3 ), hence explaining, at least in part, the higher incidence and severity of superficial scald of these fruit (Figs.…”

Re-initiating softening ability of 1-methylcyclopropene-treated ‘Bartlett’ and ‘d’Anjou’ pears after regular air or controlled atmosphere storage

“…Superficial scald in apples and pears has been linked with the accumulation of ␣-farnesene and CTs in fruit peel (Anet, 1972;Chen et al, 1990;Whitaker et al, 1997). Table II shows that application of 1-MCP inhibited the accumulation of ␣-farnesene and CTs.…”