Conservation of papaya minimally processed with the use of edible coating based on xanthan gum

Abstract

The objective of this study was to evaluate the preservation of papaya minimally processed by the use of edible coatings based on xanthan gum for 12 days at 4±1 °C. Different treatments were performed: control (T1) uncoated; 1 % glycerol and 0.5 % xanthan gum (T2); 1 % glycerol, 0.5 % xanthan gum and 1 % chitosan (T3); 1 % glycerol, 0.5 % xanthan gum and 0.25 % guar gum (T4); 1 % glycerol, 0.5 % xanthan gum, 0.25 % guar gum and 1 % chitosan (T5). Such coatings were prepared in aqueous solution and added to them 1% glycerol. In the control treatment and the coated pieces of papaya were analyzed weight loss, firmness, pH, titratable acidity, color, and microbiological groups: psychrophilic, Salmonella spp., total coliform and thermotolerant. The different coatings based on xanthan gum were effective in preserving papaya minimally processed, relative to control sample. The addition of guar gum to xanthan coatings influenced negatively in the weight loss and the parameters of color, lightness, a* and b*. The addition of chitosan (T3) beneficially influence in reducing weight loss, maintenance of luminosity and a smaller reduction in parameters a* and b*, however, was not observed antimicrobial effect. Thus, it is suggested as an edible coatings papaya minimally processed coatings composed only xanthan gum (T2), which caused a reduction of weight loss, maintenance of lightness and b* and smaller reduction in a*. However, experiments aimed at maintaining firmness, pH and acidity should be conducted in future.