Integrated modified atmosphere and humidity package design for minimally processed Broccoli (Brassica oleracea L. var. italica)

摘要

Broccoli is often over wrapped in polymeric films (with low water vapour transmission rates) or packaged in macro-perforated films, which results in a water vapour saturated headspace (with approximate to 100%) or suboptimal relative humidity. This study investigated the effects of appropriate design of modified atmosphere and humidity packaging systems (based on package type, presence of micro-perforation and the use of ethylene scavenger) on the postharvest quality of minimally processed broccoli branchlets stored at 10 degrees C for 11 d. Package design optimization (with a cellulose-based film window on polymeric film and/or micro-perforations) was performed using respiration and transpiration rate data at temperatures of (4, 10 and 16 degrees C) and 100% RH, respectively, in order to establish desired gas and water vapour transmission rate of packaging materials. Equilibrium modified atmosphere and humidity of approximate to 97% and 95% was established in the headspace of bi-axially oriented polypropylene (BOPP) packages with 20% of cellulose film window area. Further use micro-perforations reduced humidity to 92% and prevented the accumulation of volatile sulphur compounds. Packages incorporated with cellulose-based film window effectively prevented water vapour condensation on the film surface when compared to bi-axially oriented polypropylene and cling-wrapped commercial control. Non-perforated packaging system with cellulose-based film window better retained surface colour and maintain quality attributes at 10 degrees C for 11 d, but at the expense of a significantly (p 0.05) higher difference in product mass loss compared to the control package. (C) 2016 Elsevier B.V. All rights reserved.