LOW COST METHODOLOGY FOR PACKAGE OPTIMISING FOR FRUIT AND VEGETABLES

Numerous models are published integrating produce respiration data and gas transmission properties for packaging material in order to predict the optimal equilibrium headspace gas atmosphere. Gaining the data needed for input in the models can be cumbersome, and data found in literature are often given in different units and not stated at the desired storage conditions, e.g., gas transmission rates are usually measured at 23°C. Respiration data might also show great variation due to variety, quality and season, and literature data cannot automatically be transferred to own products. In this work a procedure for measuring produce respiration rates and gas transmission rate of the whole package is outlined. The respiration measurements are performed using low cost equipment and commercial packages as respiration chambers. The obtained results from the measurements for tested products were found to be in accordance with respiration data found in literature. The O₂ and CO₂ transmission rates of the whole packages were measured by a static method using a low cost gas analyser. The method can be used for packages with and without perforations, and it was also possible, within an acceptable accuracy, to calculate the transmission rate for a single hole. The respiration rates were measured at low and abused temperature (2 and 6°C for plums and 5 and 10°C for broccoli). Gas transmission rates of the packages were measured at 5, 10 and 23°C. Finally, a simple predictive model integrating produce respiration rates and gas transmission rate data for the whole package was developed. The modelled data were shown to be in accordance with empirical measurements for plums (Prunus domestica L.) packaged in laser-perforated pouches and for broccoli florets (Brassica oleracea) in sealed trays. The described procedure using low cost equipment and commercial packages is an alternative method for laboratories, packaging material producers, farmers and packaging houses to optimize their packages based on own measurements under realistic storage temperatures.