Extending shelf-life of fresh-cut 'Fuji' apples with chitosan-coatings.

摘要

The effect of coatings in combination with anti-browning agents (1% chitosan; 2% ascorbic acid + 0.5% CaCl₂ and 2% ascorbic acid + 0.5% CaCl₂ +1% chitosan) on minimally processed apple slices was studied during storage. Chitosan-coating treatments effectively retarded enzymatic browning on minimally processed apples during storage and they effectively retarded or avoided tissue softening, apple slices underwent a little loss of firmness. Chitosan-coating did not perform very well as water vapor barriers in apple slices. To control initial respiration rate of apple slices, edible coatings were applied to cut apples as semi-permeable barriers against air. Initial respiration rate showed a decrease in 2% ascorbic acid + 0.5%CaCl₂ + 1% chitosan apple slices at 5 degrees C. Industrial relevance: Recently, there has been an increasing market demand for minimally processed fruits and vegetables due to their fresh-like character, convenience, and human heath benefits. Minimal processing includes grading, washing, sorting, peeling, slicing, chopping, and then packaging. Since minimal processing results in quality deterioration associated with water loss, softening, microbial contamination, increased respiration and ethylene, and cut-surface browning, minimally processed products become more perishable. Edible coating was used for cut apples to reduced respiration and control physiological changes. The color of products, such as apple slices, is an important quality index. Brown apple slices are aesthetically unattractive. Chitosan has been reported to maintain the quality of fruit and vegetables (EI Ghaouth et al.,1991). The objective of this study was to develop procedures for the use of edible coatings in combination with anti-browning agent and to extend the shelf-life of minimally processed apple slices.