Effect of Heat or 1-Methylcyclopropene on Antioxidative Enzyme Activities and Antioxidants in Apples in Relation to Superficial Scald Development

Abstract

<jats:p>`Granny Smith' apples [<jats:italic>Malus sylvestris</jats:italic> (L.) Mill. var. <jats:italic>domestica</jats:italic> (Borkh.) Mansf.] were harvested in two seasons and stored at 0 °C air storage with no pretreatment (control), after heating for 4 d at 38 °C, or after treating for 16 hours at 20 °C with 1 μL·L<jats:sup>-1</jats:sup> 1-methylcyclopropene (1-MCP). The effects of the two treatments on superficial scald development were consistent over both seasons. Scald began to appear after 8 weeks in control fruit, after 16 weeks in heated fruit but not on 1-MCP treated fruit. α-Farnesene accumulation and oxidation were slower in the skin of heated than in control fruit, and almost entirely absent in 1-MCP treated fruit. The activities of five antioxidant enzymes, ascorbate peroxidase, catalase, glutathione reductase, peroxidase and superoxide dismutate, were measured at two-week intervals in the apple peel, quantitatively as total activity and qualitatively by isozyme analysis. Enzyme activities either increased or remained stable during 16 weeks of storage, except for superoxide dismutase activity, which decreased. Ascorbate oxidase activity was higher in heated than control apples and there was an additional peroxidase isozyme present in activity gels. The activities of antioxidant enzymes were lower in 1-MCP treated fruit except for catalase during the first month of storage. Lipid soluble antioxidant activity was higher in 1-MCP treated fruit than the fruit of the other treatments, and water soluble antioxidant activity was higher in both treatments than in control fruit during the time that scald was developing in control apples. Both free and total phenol contents in the peel fluctuated during storage but no consistent trend was detected. The differences in enzyme activity and antioxidant content of the peel of 1-MCP and heated apples may play a role in preventing or delaying the appearance of superficial scald.</jats:p>

Short anaerobiosis period prior to cold storage alleviates bitter pit and superficial scald in Granny Smith apples

“…The very low ethylene production in LO2‐treated fruits during the first 3 months of cold storage at 0 °C is consistent with results obtained with avocados treated with LO2 for 24 h prior to cold storage,34 and with our previous results with Granny Smith apples that were pretreated with LO2 for 7 days at 20 °C 12. The inhibition by LO2 treatment of ethylene production during subsequent cold storage was similar to the inhibition by 1‐MCP that was described in previous reports 4, 9, 35. However, in LO2‐treated fruits there was a burst of ethylene production when the fruits were transferred to 20 °C, whereas this did not occur in 1‐MCP‐treated fruits (Fig.…”

Effect of harvest date and 1-MCP (SmartFresh™) treatment on ‘Golden Delicious’ apple cold storage physiological disorders

“…The effect of 1-MCP content has been investigated by Larrigaudière et al (2004) who reported an increase in the enzymatic antioxidant capacity following 1-MCP treatment in 'Blanquilla' pears, and interpreted it as a sign of a general metabolic change influenced by ethylene. In contrast, Shaham et al (2003) observed low activities of most antioxidant enzymes in 1-MCP treated 'Granny Smith' apples. In this study, no clear effect of treatment on phenols or antioxidant activity can be attributed to 1-MCP.…”

Response of 1‐methylcyclopropene Treated “Granny Smith” Apple Fruit to Air and Controlled Atmosphere Storage Conditions

“…The same positive effect was also noted under CA, though at lower levels. One of the positive results obtained in the studies carried out with different apple cultivars on the efficacy of 1-MCP is the reduction in the ISS and SSS (Watkins et al 2000;Deell et al 2002;Johnson 2003;Shaham et al 2003;Zanella 2003). the PRF in 1-MCP + NA at quite lower levels compared with NA alone at the end of shelf life.…”