Effet de la température et la qualité de l'emballage sur l'acidité de quelques aliments conservés

Abstract

Our study was carried out with the aim of evaluating the pH of their diet and the shelf life of two varieties of plants: vegetables and fruits. We studied the variations in pH and the effect of packaging under different temperatures: + 4 ° C (refrigeration temperature), 25 ° C (room temperature) and at 30 ° C (oven) for a week (at fresh). The results obtained showed the conformity of the initial pH values of the samples (carrot, tomato, banana and apple) with the standards of physicochemical assays. A slight difference in pH was recorded in the present study (5.88 for carrots; 4.20 for tomatoes; 5.37 for bananas and 4.5 for apples) at 25 ° C without packaging. Regarding the packaged samples, the pH values were in the order of (5.76 and 5.70; 4.20 and 4.31; 5.09 and 5.05; 4.80 and 4.40) at 25 ° C for wrappers by cellophane and aluminum foil respectively. The evolution of the pH varies between 4,06 and 6,49 for samples (with and without packaging) at 4°C and from (5,87-4,85) at 30°Cfor packed samples . these pH values vary between 3,64 and 4,73 for samples ( wrapped and unpacked ) at 30°C.