Uso de um revestimento comestível antioxidante com extrato de resíduo de pracaxi (Pentaclethra Macroloba) na conservação pós-colheita da acerola (Malpighia Emarginata DC)

Abstract

Fruit short shelf-life is a considerable drawback concerning distribution chains, causing great losses in the production and exportation for several countries. Packaging is an essential part of a long-term process to reduce losses. Edible films and coatings are being increasingly developed to enhance highly perishable products safety and quality after harvest. These coatings are thin layers of materials applied on food products that are able to create a protective barrier against mechanical damage, physical, chemical and microbiological spoilage. Bioactive edible coatings, are edible packaging incorporated with bioactive compounds to produce new functional foods, enhancing its shelf life, nutritional quality and increasing consumer acceptance of these commodities. In order to seek an alternative to prolong the short shelf life of acerola fruit (Malpighia emarginata DC) - a species of great economic importance for Brazil, and a way of reusing the residue of the pracaxi seed pressing (Pentachletra macroloba (Wiild.) Kuntze ) - a raw material rich in phenolic compounds - the objective of this work was to develop and analyze the efficiency of a bioactive coating based on carnauba wax, citric pectin, vegetable glycerin and pracaxi cake extract, on the shelf life of acerola fruits .This coating was applied on fruit by immersion, and fruits were stored at refrigerated (4 ± 2 °C) and room (30 ± 1 °C, 80% RH) conditions. Control treatments were acerola fruit without coating (GO) and acerolas with coating but without pracaxi residue extract (GA). Changes in color, pH, total soluble solids (°Brix), weight loss, ascorbic acid, phenolics content, carotenoid and anthocyanin content were monitored during 13 and 6 days for fruit stored at refrigerated and room conditions respectively. Bioactive coatings with pracaxi (GP) demonstrated to have antioxidant activity until the end of the storage period and was effective in prolonging fruit quality for 3 and 7 days longer than control samples (GO) at room and refrigerated conditions, respectively. GP treatments significantly reduced weight loss, maintaining 84% and 77% of the original weight for room and refrigerated conditions, and preserved fruit color until the end of the experiments. The bioactive coating also retained the highest ascorbic acid levels (65.5% and 92% of the initial values for room and refrigerated conditions, respectively) and preserved the highest levels of carotenoids and phenolic compounds, including anthocyanins until the last days of storage. This bioactive coating is a promising, easy and cheap alternative for preservation of quality and shelf life prolongation of acerola fruit stored at refrigerated and room conditions.