Influence of modified atmosphere packaging on postharvest quality of cherry tomatoes held at 20 °C

Abstract

The effects of passive modified atmosphere packaging (MAP) achieved with a 30μm thick continuous oriented polypropylene (OPP) film (Film A) or by the same film either laser-perforated with increasing levels of perforation (Films B–E) or macro-perforated (Film F) on overall qualitative changes and decay was studied on cherry tomatoes cv ‘Dorotea’ and ‘Trebus’ harvested at the red-ripe stage and stored for 7, 14 or 21d at 20°C 60% RH. Respiratory activity of both cultivars decreased as permeability of macro- and laser-perforated films decreased but increased in tomatoes sealed with Film A, which led to anaerobic conditions. In laser perforated films average in-package CO2 and O2 were around 3kPa and above 15kPa, respectively, with moderate variations among Films B–E, while in Film A average CO2 and O2 were around 12kPa and 6kPa, respectively. In-package gas composition of Film F only slightly differed from air. Air composition and high in-package humidity of laser perforated films controlled water loss and delayed loss of firmness and of titratable acidity, total soluble solids, vitamin C, but increased decay of the very susceptible to cracking ‘Dorotea’ tomatoes. The high in-package CO2 of Film A reduced pathogens growth, but decay incidence was lowest in unwrapped tomatoes and packages of Film F. ‘Trebus’ tomatoes were more resistant to decay than ‘Dorotea’ ones. MAP with moderate levels of CO2 (around 3kPa), O2 not below than 12kPa and RH not higher than 90% could prolong overall quality and reduce decay of red-ripe cherry tomatoes at 20°C.