The use of pullulan coatings with propolis extract to extend the shelf life of blueberry (Vaccinium corymbosum) fruit

摘要

Consuming fresh blueberries has many health benefits due to the extremely high level of phytonutrients. During storage, the berries spoil due to microbial contamination. The aim of the work was to investigate the effect of pullulan coating containing 5% and 10% propolis extract on reducing the number of bacteria and mould and on the physicochemical properties of coated blueberries during storage. The results showed that the count of microorganisms was reduced by 3-4.5 logarithmic cycle after 21 days (16°C, RH of 58-63%). It was also found that coatings delayed blueberry ripening as well as decreased weight loss. During storage, minor increase were found in titratable acidity values and no change the total soluble solid values in blueberries covered with pullulan coating containing propolis extract in comparison with the uncoated ones. Thus, the pullulan coating with propolis extract has the potential as microbiological protection for blueberry fruit.