Development of pineapple peel vinegar

Pineapple peel is part of the by-products from pineapple processing industries and harvesting activities. The pineapple waste produced from rising demands of pineapple products worldwide will eventually disturb the environmental balance and contribute to environmental pollution. Further utilization of pineapple waste into valuable products can reduce the waste generated, conserve the environment, and potentially generate income from the developed products. In this study, peel from four types of Malaysian pineapple namely Morris, Josephine, MD2 and N36 were used to produce vinegar. Vinegar has been reported to offer beneficial health effects when taken regularly. This study's objective is to determine the vinegar characteristics produced from each pineapple peel by evaluating the physicochemical analysis and antioxidant activity. The vinegar was prepared by adding pineapple peels with sugar, distilled water, viable yeast, and yeast nutrient to a beaker. Sodium bicarbonate was added to adjust the pH to 4.0. The beaker was sealed, and the fermentation was allowed to take place at 25 - 28˚C for two days. The fermenter was then filtered, the filtrate was covered and further fermented for another 11 days. Results obtained indicate that the suitable pineapple peel for production of vinegar was the peel of MD2. MD2 peel vinegar showed the lowest pH, browning values and total acidity compared to others. Meanwhile for antioxidant activities using DPPH method, MD2 pineapple peel showed the highest antioxidant activity among the other types of pineapple peel.