DEVELOPMENT OF CUCUMBER PEEL (Cucumis sativus) SNACK-FILMS

Vegetables are rich in nutrients, however, peels are generally discarded, generating by-products rich in active compounds. Therefore, peels can be used to produce high nutritional value foods, besides that it can reduce the environmental impacts of its discard. Thus, the aim of this work was to evaluate the antioxidant properties of cucumber peel snack-films (CPSF) produced by tape-casting. Peels were sanitized, steamed (30 min) and processed in a blender to obtain a puree (16 mesh). For CPSF production, agar-agar (1 g/100 g of solution) was solubilized under mechanical stirring (100°C/5 min) and the puree was incorporated (80 g/100 g of snack-film mass - SFM). SFM was kept under stirring (800 rpm/5 min), spread on acrylic plates using a spreader, with a temperature of 40°C and a speed of 10 mm/s, and dried in air circulating oven (50°C/6 hours). CPSF was characterized by water solubility index (WSI), color parameters (L*, a*, b*), total phenolic content (TPC) and antioxidant activity by FRAP and ABTS methods. WSI was 0.108 ± 0.007%, indicating a low water solubility. CPSF color parameters were 33.8 ± 1.0 (L*), 5.7 ± 0.5 (a*) and 32.6 ± 2.5 (b*) and the color difference between CPSF and puree was ∆E = 8.5 ± 1.0, which indicates an alteration of the original color, which may occur due to pigment degradation during its processing. TPC was 123 ± 13 mg gallic acid equivalent/100 g of dry matter (DM), it was lower than for cucumber peel reported in other researches. Antioxidant activity by FRAP was 7.9 ± 2.0 µmol Trolox equivalent (Teq)/100 g DM and by ABTS was 410 ± 10 µmol Teq/100 g DM. Results show the presence of active and antioxidant compounds in the snack-film, so the use of these by-products presents potential to develop snacks with nutritional value.