Quality and Shelf Life of Minimally Processed Shredded Carrots in Modified Atmosphere Packaging

Abstract

Modified atmosphere packaged Ready-to-eat shredded carrots (Daucus carota L., cv. Nantes) are an increasingly popular product, yet sales are restricted due to rapid deterioration during storage. Objective of this study was to investigate the effects of different gas composition on quality and shelf life of minimally processed shredded carrots. A range of physic-chemical and sensory qualities responsible for deterioration of carrot quality was monitored. Shredded carrots of 250 g were packaged in 30cm x 20cmbags, prepared from 20 µ polyethylene(PE), 20 µ polyvinylchloride (PVC), 10 µ micro-porous MY-15 (MY) and 10 µ oriented polypropylene (OPP)films. Packaged shredded carrots were stored at 4 or 10˚Cand quality characteristics were evaluated during storage. An equilibrium modified atmosphere was reached in most packs by 2-3 days of storage. The CO2 levels ranged from 10-12% in microperforated MY-15packs to 35-40% in the OPP bags at 4˚C during state of equilibrium. Levels of CO2 in other packs were dependent on film permeability and high permeability resulted in low CO2levels. The in-pack O2 and CO2 levels were also affected by storage temperature and levels were lower at 4˚C compared with 10˚C.Ascorbic acid content remained relatively constant in carrots during storage under all treatment conditions, whereas a highly significant decrease (P<0.01) was observed in PVC packs at 10˚C. β-carotene content decreased from 8943 µg/100g during storage in shredded carrots in MA packs with 73% of initial content after 14 days in OPP packs. Carrots packed in MY-15 films of which the ˚Brix increased from 6.45 to 6.74 during storage at 4°C indicated an increase in total soluble solids. Based on results, Micro-porous MY-15 films with high permeability of oxygen and carbon dioxide at storage temperature of4°C, should be considered together in order to maintain quality and to extend shelf life of shredded carrots for 14 days.