45F-4 |
Effect solid content of whey protein isolate-beeswax edible coatings on color change of fresh-cut apples |
M. B. PÉREZ-GAGO1, M. Serra2, M. Alonso1, M. Mateos2, and M. A. Del Río1. (1) Postharvest Department, Instituto Valenciano de Investigaciones Agrarias, Moncada, 46113, Spain, (2) Biotechnology Department, Instituto Tecnologico Agroalimentario, Paterna, 46980, Spain Fresh-cut apples are extremely sensitive to enzymatic browning. The combination of antibrowning agents and edible coatings has been used for fresh-cut fruits to reduce respiration rate and inhibit surface browning. Coating performance depends, among other factors, on composition and formulation’s solid content. Optimizing these factors, previous to the addition of antibrowning agents, could be important to improve coating performance. The objective of this work was to evaluate the effect of solid content of whey protein isolate (WPI)-beeswax (BW) coatings on weight loss and color change in fresh-cut apples. WPI-BW edible composite coatings with 30% BW (d.b.) content were prepared with a solid content of 8%, 12%, 16% and 20%. Golden apples were cut and subjected to 5 different treatments: (1) immersion in citric acid and hypochlorite (control), and (2-5) immersion in citric acid and hypochlorite, followed by coating application (different solid content). Samples were stored at 20 ºC for 24h in open trays, and at 5 ºC for 7 days in open trays, and sealed trays with 6 small pin holes to prevent an anaerobic environment. Weight loss and color (CIE L*, a*, b*, and browning index (BI)) were evaluated periodically and at the end of each storage period. Results show that coated apples were higher L*, and presented lower BI than uncoated apples, which indicates that whey proteins exert an antibrowning effect. BI decreased as solid content of the coatings increased, observing 2 groups: (1) WPI-BW coatings with 8% and 12% solid content and (2) WPI-BW coatings with 16% and 20% solid content. Coating application did not reduced weight loss in fresh-cut apples, probably due to the high relative humidity of the product. This results suggest that WPI-BW coatings on cut apples can be beneficial reducing browning and this effect can be improved by increasing the formulation’s solid content.
Session 45F, Fruit & Vegetable Products: Fruits (Fresh)
|