Effects of 1-Methylcyclopropene Treatment on Fruit Quality during Cold Storage in Apple Cultivars Grown in Korea

Abstract

The effect of 1-methylcyclopropene (1-MCP) treatment on improving the storability of four apple cultivars (‘Hwangok’, ‘Picnic’, ‘Gamhong’, and ‘Fuji’) was investigated by analyzing the physiological and biochemical factors associated with their postharvest quality attributes. The flesh firmness, titratable acidity, and soluble solids content of the cultivars were higher in treated fruits than untreated fruits, while the opposite results were observed for ethylene production. In the treated fruits, the traits affected by 1-MCP varied depending on the cultivars used. Higher firmness and lower ethylene production were observed in the ‘Hwangok’ and ‘Picnic’ than ‘Gamhong’ and ‘Fuji’ cultivars. However, 1-MCP only affected weight loss in the ‘Gamhong’ cultivar, while the sugar content was affected in all of the cultivars except ‘Hwangok’. When analyzing cell wall hydrolase activities, 1-MCP differently affected the activities (β-galactosidase, α-galactosidase, β-glucosidase, α-mannosidase, β-xylosidase, and β-arabinosidase), with greater effects in the ‘Fuji’ and ‘Picnic’ cultivars and moderate effects in the ‘Gamhong’ and ‘Hwangok’ cultivars. In this study, the suppression of ethylene production by 1-MCP was positively associated with a transcriptional decrease in the ethylene biosynthesis genes MdACS1 and MdACO1. Overall, this study suggests that 1-MCP distinctly enhanced the storability of all apple cultivars, with a greater effect on ‘Hwangok’.

Effects of 1-methylcyclopropene treatment on fruit quality and antioxidant activities of ruby-S apples during cold storage

“…The 1-MCP treatment delays the degradation of fruit cell wall texture and softening in apples (Win et al, 2019;Win et al, 2021b;Yoo et al, 2021), as observed in this study. Yoo et al (2021) reported that firmness and TA are positively correlated, and these attributes generally decrease during fruit ripening, particularly in untreated fruits. The SSC generally increases during ripening because of an increase in fruit starch degradation (Kader, 2008).…”

“…The reduction in flesh firmness is a result of fruit softening caused by the degradation of the fruit cell wall texture (Win et al, 2021b). The 1-MCP treatment delays the degradation of fruit cell wall texture and softening in apples (Win et al, 2019;Win et al, 2021b;Yoo et al, 2021), as observed in this study. Yoo et al (2021) reported that firmness and TA are positively correlated, and these attributes generally decrease during fruit ripening, particularly in untreated fruits.…”

“…The enzyme activities of ACS and ACO and their expression levels are reduced in fruits when 1-MCP blocks ethylene perception at the receptor sites (Jung and Watkins, 2014;Wakasa et al, 2006;Yang et al, 2013). The inhibition of IEC by 1-MCP has also been reported in numerous apple cultivars (Win et al, 2021b;Yoo et al, 2020a;Yoo et al, 2020b;Yoo et al, 2021;Zhang et al, 2020).…”

“…In general, fruit weight loss is associated with fruit respiration and transpiration rate (Win et al, 2021a). In addition, few studies have reported that the effect of 1-MCP on fruit weight loss is highly dependent on the cultivar, storage conditions, and concentration (Kwon et al, 2021;Win et al, 2019;Yoo et al, 2021). However, a concentration of 1 μL/L 1-MCP was used in this study; therefore, the lacking effect of 1-MCP on weight loss might be due to differences in cultivar or storage conditions.…”

“…To determine the IEC, a hypodermic needle (a stainless steel 18-gauge 3.8 cm long) was inserted into the core cavity through the calyx end of the apple fruit, and 1 mL of the internal gas was injected into a syringe through the needle. The sample gas was then inserted into a gas chromatograph (GC-2010 Shimadzu Co., Kyoto, Japan) fitted with a flame ionization detector and Porapak Q column (80/200 2-m, Young In Frontier Co., Seoul, Korea) (Yoo et al, 2021). During the IEC measurements, the oven temperature was set at 90℃, whereas those of the injector and detector were maintained at 200℃.…”