Conservation of commercial quality and bioactive compounds of guava pieces by application of an alginate-acemannan coating

Abstract

The objective of this study was to evaluate the effect of an edible coating based on alginate and acemannan on the commercial quality and concentration of bioactive compounds of guava pieces stored in refrigeration. Pieces of guava were coated with an alginate film enriched with acemannan (A-Ac), with samples without cover used as a control. The fruit pieces with and without the A-Ac coating were stored for 12 days at 6 ± 2 °C. Analyses of colour, firmness, ethylene production, ascorbic acid, total polyphenols, antioxidant potential, and polyphenol profile were performed at 0, 3, 6, 9, and 12 days of storage. In addition, a sensory analysis was carried out after nine days of refrigeration. The coated guava pieces retained firmness at 2.8 N, while in the uncoated pieces, firmness decreased to 1.3 N. Similarly, the coated pieces showed better colour retention (ΔE<9) and lower ethylene emission during storage. Also, the content of ascorbic acid, total polyphenols, antioxidant capacity, and the concentration of individually identified polyphenols were higher in the pieces of guava coated with the A-Ac film. In addition, coated guava pieces, stored for nine days in refrigeration, showed greater sensory acceptability compared to uncoated samples. Therefore, applying the AAc cover could be a good alternative for conserving sensory attributes and bioactive compounds of guava pieces stored at low temperatures.