Packaging strategies to prolong the shelf life of fresh carrots (Daucus carota L.)

Abstract

In this work, different strategies aimed to prolong the shelf life of fresh carrots are presented. Dipping into a hydro-alcoholic solution, and its combination before and after coating with sodium alginate, were investigated. Untreated samples were also used as the controls. After treatments, carrots were packaged into a micro-perforated polypropylene film (thickness 30 μm) under passive MAP and stored at 4 °C. The sole coated samples were also packaged under active MAP (10% O2, 10% CO2). Headspace gas concentrations, pH, mass loss, sensory quality and viable cell loads of main spoilage microorganisms were monitored. Results suggested that the coating treatment under both passive and active MAP enhanced product quality by preventing dehydration and microbial proliferation and delaying the respiratory activity. In fact, while mesophilic bacteria increased rapidly in the uncoated samples, for coated samples cell loads remained constant (3 Log cfu/g) until 7 days of storage and then increased up to 5.6 Log cfu/g. From the sensory point of view, coated samples were appreciated for about two weeks, whereas all the other fresh carrots were refused after only 2 days. Fresh-cut vegetables market has grown rapidly in recent years as a result of changes in consumer attitudes. There is a real need to find methods for preservation of minimally processed food products that can gain widespread acceptance by the industry. This paper suggests effective packaging solutions to delay the quality decay kinetic of fresh-cut carrots.