Lipoxygenase activity in apples in relation to storage and physiological disorders

Synergistic Influence of Pre-Harvest Calcium Sprays and Postharvest Hot Water Treatment on Fruit Firmness, Decay, Bitter Pit Incidence and Postharvest Quality of Royal Delicious Apples (<i>Malus x domestica</i> Borkh)

“…Although, the mechanism by which calcium prevents physiological disorders is not well understood, however it is known that it principally acts on middle lamella of cell wall and play its role of cross-linking [29,30], where it may influence membrane bound enzymes, like lipoxygenase (LOX), that converts the unsaturated fatty acids like linoleic and linolenic to their hydroperoxidate derivatives [30,31]. Although, LOX is found in tissues of a wide variety of higher plants, there are many questions with regard to its functions in plant lipid metabolism, yet scientists world over largely agree that it is responsible for the typical breakdown of linolenic acid, and thus responsible for the development of some physiological disorders [32], which demonstrates the participatory role of LOX in fruit senescence. Postharvest heat treatment has been reported to reduce storage disorders such as superficial scald and bitter pit [7,33].…”

Biochemistry of apple aroma: A review

“…Fig. 2 shows the formation of volatile aroma compounds from linoleic and linolenic acids through the LOX pathway, and Table 3 shows some studies that have been performed on enzymes from the LOX pathway in diff erent developmental stages of apples (13,15,34,40,44,45,54,72,73,75,79,85,96,106,(118)(119)(120)(121)(122)(123)(124)(125)(126)(127)(128)(129)(130)(131)(132)(133)(134)(135)(136).…”

Avocado Fruit Development and Ripening Physiology

“…Laties (1982) reports that an Arrhenius plot of succinate oxidation by callus of chilling-sensitive Cornus showed a sharp break in the presence of SHAM at the chilling damage temperature, indicating the importance of the alternative respiratory pathway at low temperatures. The physiological consequences of this situation in avocado are unknown, but the results of Nel et al (1984) indicate that lipoxygenase, which may be a key enzyme in the oxidation of structural lipids (Feys et al 1980) could become important as a source of residual respiration (Solomos 1983) at low temperature, which may result in membrane destruction. The alternative pathway may also result in the formation of superoxides and hydrogen peroxide, also causing membrane damage (Solomos 1977).…”