JUICE AND CAROTENOID YIELD FROM PROCESSED WATERMELON

Most watermelon in the U.S. is consumed fresh. Development of value-added products from watermelon is desirable for new market niches, and provides alternative markets for fruit that are cosmetically undesirable for the fresh market. The objective of this experiment was to determine if different processing techniques changed the lycopene and quality aspects of juices and concentrates. Watermelon flesh was macerated, followed by holding at room temperature (no heat) or heating to 50 °C. Macerate was then placed in a hydraulic press to obtain juice. Adding heat to macerate increased juice yield by 1% to 2% and increased lycopene content by 1 to 2 mg·kg–1. The residual pomace (waste from juicing) also contained lycopene, about 110% of that found in the juice, or 10% from the original macerate. In a second experiment, juice was subjected to pasteurization, which caused a slight loss of lycopene and beta-carotene compared to the unpasteurized juice. In a third study, juice was concentrated to 42 °Brix using either 40 or 50 °C heat treatments, followed by pasteurization. Heating juice to 50 °C concentrated the lycopene by 17% compared to heating to 40 °C. Pasteurization increased the lycopene content of the 40 °C concentrate by 10% but not of the 50 °C concentrate. In summary, the addition of heat at various steps during processing and pastuerization of watermelon concentrated but did not degrade lycopene. Additionally, the residual pomace created from juice manufacturing is a concentrated source of carotenoids and may have potential use as a value added nutraceutical product.