Improvement Quality and Shelf Life Assessment of Minimally Processed Apples by Use of Protein Coatings

Abstract

Minimally processed fruits offer a convenient and practical product to the consumer, with quality and freshness similar to the in natura product. The aim of this study was to apply coatings of croaker protein isolate (Micropogonias furnieri) with organoclay (montmorillonite) on minimally processed apples during 12 days of storage at 5 ± 1 °C. The apples were washed, peeled and cut into cubes. Coatings were then applied where T1 (control sample), T2 (croaker protein isolate coating) and T3 (croaker protein isolate coating and montmorillonite (MMT). The pieces were allowed to drain into sieves and these were stored in polyethylene terephthalete (PET) packaging for a period of 12 days at 5 ± 1 °C. Analyses of weight loss, firmness, color (Lightness (L*), Chroma a* and b*), pH, and microbiological analyses (psychrotrophic, yeasts and molds, Salmonella and Escherichia coli) were carried out. The analyses were carried out in triplicate and evaluated at the times of 1, 3, 5, 7, 9 and 12 days of storage. The use of croaker protein isolate coating and MMT proved promising in keeping weight loss, microbiological counts, enzymatic browning and firmness loss at minimum in minimally processed apples.