Last week, the QUAFETY scientists presented the deliverable 3.14 whose objective was to determine the kinetics of quality changes of fresh-cut fruit and vegetables as a function of oxygen partial pressure and storage temperature. The work was led by Dr Manuela Pintado from Universidade Catolica Portuguesa (UCP).Fresh-cut fruits and vegetables trials were performed to allow modelling of the degradation kinetics of quality changes and nutrient losses during post processing storage under different modified atmospheres and temperatures. The number of modified atmospheres and temperatures required (i.e. at least three, including MAP and temperature effects on kinetic parameters), and consequently the number of chambers required for storage (one at each temperature), as well as the extensive storage times for quality changes assessment, represent experimental limitations that were overcome to achieve this deliverable.
In the present deliverable, the kinetics of quality changes of fresh-cut melon and strawberry and ready-to-eat rocket leaves are investigated during storage under different initial oxygen partial pressure (20, 10, 5 and 2.5 % O2) and at different temperatures (10, 5 and 0°C). Kinetic parameters were found by a linear regression for the orders 0, 1, and 2, and through the minimization of the sum of squared errors. Kinetic modelling of experimental data was performed using the general equations of mass balance for normal orders.A confidence level of 95% was set for regression and adequacy of the kinetic models proposed was evaluated by two goodness-of-fit criteria, namely coefficient of determination (R2) and root mean square error (RMSE). The kinetic parameters were determined for all the quality attributes changes (physiological and biochemical), evaluated in all the experiments performed. The selection of the most adequate kinetic order for each quality change in each experiment, shown in results, was achieved through the selection of the highest coefficient of determination and the lowest root mean square error.
The kinetics determined in this deliverable allow the prediction of fresh-cut rocket leaves, fresh-cut melon and strawberries quality changes during storage. The integration of all these results contributes to the understanding of the effects of storage conditions on overall quality of fresh-cut vegetables and fruits and provide useful information for developing processes aimed at the prediction and modulation of nutritional quality and shelf-life. The best conditions found for the preservation of overall (physiological and biochemical) quality of ready-to eat rocket leaves and fresh-cut melon and strawberries are of an initial package atmosphere of 5% oxygen and storage temperature of 5°C.
For further info: www.quafety.eu
Contacts:
Manuela Pintado - mpintado@porto.ucp.pt
Fedele Colantuono - fedele.colantuono@unifg.it