FRESH-CUT CARROT COATED WITH STARCH/MONTMORILLONITE FILMS AND SUBJECTED TO MODIFIED ATMOSPHERE PACKAGING

Starch/montmorillonite films have potential as edible coatings on intact and fresh cut fruits and vegetables. The dispersal of montmorillonite (MMT) clay into edible coatings affects the barrier properties and can reduce the mass loss of fruits and vegetables. Its use should be accompanied with the proper choice of packaging, to ensure an ideal modified atmosphere to extend the shelf life of those products. The goal of this work was to evaluate fresh cut carrot (FCC) coated with MMT subjected to modified atmosphere packaging. Carrots were sanitized with sodium hypochlorite, cooled, peeled, sliced, sanitized again and centrifuged. Half of FCC was coated with starch/MMT film and another half was not. FCC, with or without coating, was packed in polypropylene rigid tray, covered with polypropylene rigid lid or sealed with polyethylene + propylene film (60 μm), setting up 4 treatments (RL = rigid lid; RLC = rigid lid + coating; ST = sealed tray; STC = sealed tray + coating). FCC was stored at 4°C and analyzed weekly for 4 weeks (mass loss, firmness, L*, hue angle, C*, organic acids, O₂, CO₂ and respiration rate). The sealed packages, in spite of coating of FCC, reduced mass loss compared with packages with rigid lid. FCC without coating had greater firmness than coated FCC. Higher L* occurred in RL, whereas higher C*, in RLC. RL promoted higher concentrations of citric and malic acids at the end of storage. The internal atmosphere of packages covered with rigid lid did not change over the storage period whereas the level of O₂ decreased to 14% and CO₂ increased to 17%, in sealed packages, after 7 days. The starch/MMT coating did not affect the respiration rate of FCC, but slowed the mass loss of FCC packed in PP with RL.