Layer-by-layer edible coatings based on mucilages, pullulan and chitosan and its effect on quality and preservation of fresh-cut pineapple (Ananas comosus)

Abstract

Edible coatings (ECs) based on chitosan (CH), pullulan (PU), linseed (LM), nopal cactus (NM) and aloe mucilage (AM) were applied by layer-by-layer technique to preserve the quality and prolong the shelf-life of fresh-cut pineapple. Pineapples were washed, disinfected, dried and cut into 2cm side cubes. Fresh-cut fruit was coated by dipping using four treatments (CH+PU, CH+LM, CH+NM and CH+AM), packed into polyethylene terephthalate containers and stored for 18 d at 4°C. Uncoated fruit was used as control. Application of layer-by-layer ECs decreased (P<0.05) the weight loss, pineapple softening, and, retarded the fall on total soluble solids content and color (L* and a*). CH+AM EC was effective in delaying (P<0.05) ascorbic acid degradation. In contrast, ECs did not affect titratable acidity (P>0.05). Microbiological analyses demonstrated the effectiveness (P<0.05) of the layer-by-layer ECs against spoilage microorganisms, L. monocytogenes and S. typhi. CH+PU EC was the most effective in controlling microbial levels. Sensory analysis demonstrated that layer-by-layer ECs helped to preserve (P<0.05) the quality properties (color, odor, flavor, texture and overall acceptance). In conclusion, layer-by-layer ECs based on CH+PU, CH+LM, CH+NM and CH+AM improved the quality and prolonged the shelf-life of fresh-cut pineapple by six days compared with control.