IMPROVING THE QUALITY OF FRESH-CUT MELON THROUGH INACTIVATION OF DEGRADATIVE OXIDASE AND PECTINASE ENZYMATIC ACTIVITIES BY UV-C TREATMENT

This work investigated the effect of exposure of fresh-cut melon (Cucumis melo L. var. reticulatus) to ultraviolet-C (UV-C, 254 nm, 0.04 kJ s)1 m)2) radiation for different times (30, 60, 120 s) on main degradative enzymatic activities (polyphenol oxidase, peroxidase, pectin methylesterase and polygalacturonase) and quality parameters (firmness, colour) during storage at 5 C. Enzymatic activities in samples washed with water and treated with UV-C radiation were similar to samples washed with 100 mg L)1 NaOCl and significantly lower than untreated samples, especially after 7 days of storage at 5 C. Tissue softening was noticed in all samples although those treated with UV-C light resulted 7–12% firmer than untreated ones. The lowest perceptible colour variation, expressed as DE*, was in samples exposed to 120 s radiation (DE = 8.58), while the highest value was noticed in untreated sample (DE = 11.06). Postcut UV-C fruit treatment was effective in extending the shelf life of minimally processed ‘Galia’ melon.