Biodegradable Coatings on Blueberries Postharvest Conservation Refrigerated in a Modified Atmosphere

Abstract

Aims: The aim of the present study was to evaluate the effect of edible coatings based on manioc starch, kefir and chitosan on the physicochemical and microbiological characteristics of blueberry subjected to refrigerated storage in a modified atmosphere. Study Design:  The experimental design was completely randomized in a two-factorial scheme. Place and Duration of Study: Department of Crop Science, Fruit Science Laboratory, Faculty of Agronomy Eliseu Maciel and Center for Chemical Sciences, Pharmaceutical and Food, Federal University of Pelotas, between October 2015 and September 2016. Methodology: The treatment factors were composed of edible coating (cassava starch, Kefir, chitosan and uncoated, which corresponded to the control), and the periods of refrigerated storage in a BOD chamber simulating the shelf life (9, 18, 27, 36 days). The physicochemical analyses were a mass loss; texture; color parameters (L, a*, b* and Hue); soluble solids (SS); pH; titratable acidity (TA); and SS/TA ratio. In addition, total and thermotolerant coliforms were counted and the presence or absence of Escherichia coli and Salmonella spp. were observed. Results: Edible coatings based on kefir grains and chitosan maintained the physicochemical characteristics of blueberry during refrigerated storage in modified atmosphere. Fruits are in compliance with the microbiological standards established by the legislation. Conclusion: Extending storage time of chilled blueberries under a modified atmosphere promotes an increase in mass loss after application of the coatings and after 27 days.