Effect of chitosan coating in preventing deterioration and preserving the quality of fresh-cut papaya 'Maradol'

BACKGROUND: Chitosan can form antimicrobial, semi-permeable barriers that limit gas exchange and reduces water loss in fruits. Consumer interest in fresh-cut papaya fruit is leading to increasing demand because of its sensorial and antioxidant properties. However, papaya is a highly perishable product that is prone to loss of weight, loss of firmness and microbial attack. The aim of this study was to evaluate the effect of chitosan coatings on the overall quality of fresh-cut papaya. Chitosan coatings of low (LMWC), medium (MMWC) and high (HMWC) molecular weights, at concentrations of 0.01 and 0.02 g mL(-1), were applied to fresh-cut papaya cubes. The treated cubes were stored at 5 degrees C and changes in quality were evaluated. RESULTS: MMWC maintained the highest color values (L* and b*) and firmness. Chitosan coatings suppressed mesophilic plate count, and the growth of molds and yeast, compared to controls. The MMWC coatings at 0.02 g mL(-1) resulted in the highest antimicrobial activity and decreased the activity of the enzymes polygalacturonase and pectin methylesterase, followed by low and high MW chitosan coatings at 0.02 g mL(-1). CONCLUSION: The application of the MMWC treatment at 0.02 g mL(-1) could be used to reduce deteriorative processes, maintain quality and increase the shelf life of fresh-cut papaya stored at 5 degrees C. (C) 2008 Society of Chemical Industry