The presence of residual endogenous quality-related fruit and vegetable enzymes in either raw or processed fruit or vegetable products may cause loss of quality during processing or storage. The content and properties of such enzyme in these raw sources vary widely with type, species, and variety of the sources and the nature of the environment in which they grew. This study was carried out to determine the optimum conditions (pH and temperature) and total initial activities of two quality-related hydrolysis enzymes: pectin methyl esterase (PME) and polygalacturonase (PG) in three fruit varieties, mango (Mangifera indica var. Zebda), banana (Musa cavendishii var. Enana) peel and pulp, olive (Olea europaea var. Picual) and three vegetables, green beans (Phaseolus vulgaris var. Littel Marvel), tomatoes (Lycopersicon esculentum var. Marmand) and cucumber (Cucumis sativus var. Ria) grown in Egypt. The PME and PG activities were detected in the six examined homogenates. The optimum pH and temperature values for high enzyme activities were varied according to the type of fruits and vegetables. The highest amount of PME was found in tomato extract (0.037 unit mg-1 protein of the sample) and the lowest amount was for mango (0.008 unit mg-1 protein). However, the green beans extract had the lowest content of PG whereas the highest content was for cucumber.
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