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

Abstract

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.

The Effect of Electrospun Polycaprolactone Nonwovens Containing Chitosan and Propolis Extracts on Fresh Pork Packaged in Linear Low-Density Polyethylene Films

“…Raw propolis cannot be used directly as a raw material due to its high content of pollutants, which mainly consists of waxes and resins [ 32 ]. Therefore, it is necessary to extract polar and non-polar active components of propolis using an appropriate solvent.…”

“…However, other studies demonstrated significant antioxidant activity when chitosan was used as a base polymer, both in pork loins [ 61 ] and in ready-to-cook meat products [ 62 ]. Additionally, significant antioxidant activity was demonstrated when PE was used in meat and fish products [ 23 , 32 ]. The negligible antioxidative effect of PE observed in the current study might be due to the low concentration of the bioactives present in the pork samples that conferred a minimal protective effect against lipid oxidation.…”

“…For instance, PE has been used in the development of different antimicrobial nonwovens derived from other polymers, such as polyvinylpyrrolidone, polyurethane, poly (lactic acid), and zein. Nonwovens developed with PE have been mostly used for biomedical applications [ 25 , 26 , 27 , 28 , 29 , 30 ] but also for several food applications [ 31 , 32 , 33 ].…”

Candelilla Wax Edible Coating with Flourensia cernua Bioactives to Prolong the Quality of Tomato Fruits

“…The application of edible films and coating can contribute to delaying the microbiological damage of fruit. Additionally, the addition of polyphenolic compounds considerably improves the antifungal potential of the formulations [32,36].…”

Strategies for Microbial Decontamination of Fresh Blueberries and Derived Products

“…The use of pullulan coatings, an exopolysaccharide produced by the fungus Aureobasidium pullulans, combined with propolis extract reduced the population of bacteria and moulds by 3-4.5 log in fresh blueberries stored at 16 • C for 21 days. In addition, these coatings contributed to the delay in the ripening of blueberries and the decrease in water loss [136]. The application of allyl isothiocyanate, a natural compound present in plants of the Cruciferae family, reduced blueberry decomposition during storage at 10 • C for 21 days, which was associated with the generation of reactive oxygen species.…”