COMPOSITION AND ANTIOXIDANT ACTIVITY OF POTATO PEEL EXTRACT STERILIZED BY AUTOCLAVING AND IRRADIATION

The industrialization of potato (Solanum tuberosum), generate a large quantity of potato peel waste, which may become contaminated. However, this waste can be used as a natural source of antioxidants following decontamination. The objective of the present study was to examine the composition and antioxidant properties of potato peel extracts (PPEs) sterilized by two methods (autoclaving and irradiation). To obtain the extracts, potato peels were macerated for 48 h, mixed with two solvents (water and 1:1 ethanol:water), and sterilized by autoclaving (121 degrees C/15 min) or gamma irradiation (2.5 kGy). To determine the effectiveness of the sterilization methods, we evaluated the microbial loads. Afterwards, the extracts were lyophilized, and total phenolic and chlorogenic acid contents in addition to antioxidant activity (DPPH and ABTS) were evaluated. Autoclaving was more effective in sterilizing the PPEs than irradiation, eliminating the microorganisms in both extracts without affecting phenolic content, also inhibited 100 % of DPPH and ABTS radicals. Irradiation reduced the microbial load by only 62 % and 34 % in the 1:1ethanol:water and water extracts, respectively, and did not affect antioxidant activity or phenolic content. The use of autoclaving as a method to decontaminate PPEs was more effective that gamma irradiation and did not affect the composition or antioxidant properties of the PPEs.