the physiological effect of fruit maturity and 1-methylcyclopropene on ‘hass’ avocado fruit exocarp colour and chilling injury during ripening

Purpose: this study was undertaken to investigate the influence of harvest maturity and 1-methylcyclopropene (1-mcp) treatment on exocarp colour development and chilling injury of ‘hass’ avocado fruit during ripening. research method: ‘hass’ avocado fruit harvested at three different maturity stages, early (21% dm), mid- (28% dm) and late (35% dm) were treated with 300 g mol-1 of 1- mcp for 16 hours and stored at 5.5 °c for 28 days, subsequently, ripened at 21 °c. the physico-chemicals quality parameters evaluated every 2 days includes exocarp subjective (visual colour), objective (lightness-l*, chroma-c* and hue angle-ho), chlorophyll-a and -b, total anthocyanin, cyanidin 3-o-glucoside and chilling injury. findings: 1-mcp delayed ripening for early and mid-matured fruit and extended ripening by 2-4 days when compared with untreated fruit. in this study, exocarp colour development of ‘hass’ avocado fruit was improved by 1-mcp treatment as measured visual and objectively. the accumulation of total anthocyanins and cyanidin 3- o-glucosides in 1-mcp-treated fruit was slower than that in untreated fruit, however, 1-mcp treatment was associated with higher concentrations after fruit had reached ‘eat-ripe’ firmness, irrespective of maturity. the study found that 1-mcp reduced the development of chilling injury symptoms for early harvested and mid-harvested ‘hass’ avocado fruit. research limitations: the main limitation of the present study is the lack of evaluation of ethylene production. originality/value: the study found that different maturity stages of ‘hass’ avocado fruit responded differently to 1- mcp treatment. thus, 1-mcp had a positive effect on early and midharvest fruit exocarp colour and ci development during ripening.