Pineapple peel wastes as a potential source of antioxidant compounds

Indonesia is a large pineapple (Ananas comosus) producing country. Food industries in Indonesia processed this fruit for new products and further resulted wastes of which cause an environmental problems. Approximately, one pineapple fruit total weight is 400 gr of which 60 g is of peel wastes. In order to reduce such pineapple peel wastes (PPW), processing to a valuable product using an environmentally friendly technique is indispensable. PPW contained phenolic compound, ferulic acid, and vitamin A and C as antioxidant. This study aimed to PPW using ethanol and water as well as to analyze its chemical properties. Both dried and fresh PPW were extracted using mixtures of ethanol and water with various concentrations ranging from 15 to 95% (v/v) at room temperature for 24 h. The chemical properties, such as antioxidant activity, total phenolic content (Gallic acid equivalent/GAE), and total sugar content were determined. The results showed that the range of Inhibition Concentration (IC)₅₀ value as antioxidant activity of extracts from dried and fresh PPW were in the range of 0.8±0.05 to 1.3±0.09 mg.mL^-1 and 0.25±0.01 to 0.59±0.01 mg.mL^-1, respectively, with the highest antioxidant activity was in water extract. The highest of total phenolic content of 0.9 mg.g^-1 GAE, was also found in water extract.