Non-Destructive Evaluation of Edible Coatings Effects on Keeping Quality of European Plums (Prunus domesticaL.) by Laser Light Backscattering Imaging

摘要

Fruits of European plum (Prunus domesticaL.) show high rates of transpiration. Consequently, they are highly perishable fruit. In the present study, the potential of an edible coating (Versasheen (R)-based with sorbitol as plasticizer) to improve storage life and keeping quality was evaluated on fruit of the plum cultivars Jojo' and Tophit plus'. Plums were picked at commercial harvest date and stored at 20.5 degrees C (90 +/- 2% rh) for up to 28d plus 2d at 20 degrees C to simulate shelf life. Every seventh day, plums were analysed for transpiration, colour changes and laser light backscattering imaging (LLBI) at awavelength of 785nm to non-destructively investigate variations in quality properties of plums. Finally, fruit flesh firmness, soluble solids content, and titratable acidity were determined destructively. Results indicated that coating of fruit of both cultivars increased their surface resistance against water vapour transfer resulting in lower transpiration rates and thus lower mass losses compared to controls. Consequently, coating of fruit considerably delayed the decrease in flesh firmness. Moreover, edible coating retarded the increase of FWHM785 in coated plums. In this context, FWHM785 proved as arapid and non-destructive tool to monitor changes in mechanical properties in heavily coloured plums. Results highlight that edible coatings successfully extend post-harvest life of plums.