Effect of Different Drying Processing Method on the Physicochemical Properties of Watermelon Powder

Abstract

Watermelon is a seasonal fruit high in essential ingredients such as lycopene. Due to high water content and water activity, watermelon fruit is susceptible to microbial and enzymatic deterioration. Thus, drying fruit juices into powders has been one of the common methods used to preserve the fruit. A study was conducted to produce watermelon powders using spray dryer and freeze dryer techniques. The major concern is to produce high-quality watermelon fruit powders. Four watermelon extract samples were used on two concentrations of maltodextrin, which were 5% and 13% towards spray drying and freeze-drying technique. The powders were analysed for water content, water activity, colour, and solubility. Results demonstrated that the water activity of watermelon powder using the spray drying technique is less than freeze-drying (0.23-0.27 and 0.44-0.47, respectively). The colour analysis showed that freeze-dried watermelon powder has higher redness (a* value), and yellowness (b* value) than the spray dried powder. The water content of the watermelon powder showed that spray-drying yields lower water content than freeze-drying techniques for both 5% (w/w) and 13% (w/w) of maltodextrin. The solubility of the watermelon powder showed that freeze-drying has a higher solubility time than spray drying. The study found that the spray drying technique is the preferable method to preserve and producing high quality watermelon powder.