Process intensification in concentration of watermelon juice by air strip** under high gravity

Abstract

The industry is faced with the task of introducing novel products with significant added value due to the rising customer demand for ingredients derived from sustainable sources and organic processes. Lycopene, a red pigment with well-known antioxidant effects, is particularly abundant in watermelon. They are also a remarkable source of different nutrients, but because of a specific harvesting period, seasonal production in certain agro-climatic zones, watermelon fruit have a relatively short shelf life. Therefore, the fruits are processed into juice concentrates, which extends their shelf life, lowers the cost of transportation and storage, and makes the fruit available year-round, even when it is out of season. Evaporation is the typical process used for producing juice concentrates. The main drawbacks of various evaporators, however, include the increase in viscosity brought on by the concentration of the juice and the fouling of the heat transfer surface. In this study, concentration is achieved by strip** water from the juice by an unsaturated air stream, under a high centrifugal field in a rotating packed bed with wire mesh packing. The performance of the contactor is studied by varying the operating parameters (rotating speed, air flow rate, juice flow rate, and temperature). The highest concentration obtained in the study after two hours of operation is ~21.9 °Brix which is remarkable.