Effect of hexanal vapor to control postharvest decay and extend shelf-life of highbush blueberry fruit during controlled atmosphere storage

Song, J., Fan, L., Forney, C., Campbell-Palmer, L. and Fillmore, S. 2010. Effect of hexanal vapor to control postharvest decay and extend shelf-life of highbush lueberry fruit during controlled atmosphere storage. Can. J. Plant Sci. 90: 359-366. Postharvest disease control has become more challenging due to the limited number of registered fungicides, fungicide resistance, consumers' desire for reduced fungicide residues and demand for blemish-free, high-quality product. The interest in the use of natural alternatives to prevent fungal growth has markedly increased. Many biologically active volatile compounds, including hexanal, a natural plant volatile with antifungal properties, have been reported to reduce postharvest diseases. In this study, highbush blueberry fruit (Vaccinium corymbosum 'Duke', 'Brigitta' and 'Burlington') were treated with hexanal vapor at 900 μL L-1 for 24 h either once immediately before storage or repeated after 1 and 2 wk of CA storage (10-12 kPa O 2 and 12-15 kPa CO2) at 0.5°C for up to 15 wk. Fruit removed from storage after 3, 5, 7, 9, 12 and 15 wk were evaluated following 1 or 7 d at 10°C. Decayed fruit were significantly reduced by 50-70% in treated fruit compared with the control. A 17% reduction of split Duke fruit was also found in hexanal treated fruit after 9 wk CA storage followed by 7 d at 10°C. Marketable fruit in all three cultivars was 20-40% greater in hexanal treatments after 12 wk of storage as compared with controls. Fruit firmness increased during storage in Burlington. No significant changes in weight loss were found. These results indicate that postharvest application of hexanal vapor can reduce fruit decay, maintain fruit quality and extend storage life. It has potential as an alternative fungicide to reduce postharvest decay in highbush blueberry fruit.