Modified atmosphere packaging and quality determination of fresh cut 'Mazetto' almond kernels

In Tunisia, the production of almonds is widely cultivated from the north to the south. Consumers have a big interest in fresh cut green almond kernel during early summer season. The aim of the present work is to determine the quality of fresh cut shelled almond kernel and the use of MAP. 'Mazetto' green almonds were harvested when kernel was completely formed. Crucked, shelled, disinfected and filled in trays (60 g) wrapped with PE films, two different packaging material were applied; MAP1 trays were packed with PE film transparent and MAP2 trays were in cristal semitransparent bags with injection of CO₂ gas to activate the atmosphere (CO₂=85% in air) and a control in air. Quality evaluation was done in processing day, after 7 or 14 days shelf-life; weight loss, colour (L*,C*: chroma and whiteness index were calculated), bioactive (total phenols, antioxidant activity) and organic sugars were determined. MAP significantly reduced weight loss, colour parameters was affected by MAP type compared to control. Phenols and antioxidant activity of almonds were maintained, compared to control with no significant difference. The most dominant organic sugar in shelled kernels was fructose which was significantly maintained by MAP treatment compared to unpacked almonds, glucose and sucrose were not affected by treatment.