The quality of Ulva lactuca fatty acid microemulsion with ascorbic acid antioxidant during storage

This study aims to determine the effect of temperature and storage duration on Ulva lactuca fatty acid quality in microemulsion with ascorbic acid antioxidants. U. lactuca is a green algae obtained from coastal areas in Trenggole, Yogyakarta. The stages in this study were extraction of U. lactuca fatty acid, production of its microemulsion, and addition of ascorbic acid antioxidant. The extraction of fatty acid was carried out using hexane and ethanol solvents with a ratio of 1:19 (v/v) at 70°C for 3 hours. Furthermore, the microemulsion production was done by using three different types of surfactants, including Tween 80, Tween 20, and Span 80, at a ratio of 7,0:7,5:5,5 (v/v), respectively, with 80 water content and 200 ppm of U. lactuca fatty acid. This study consisted of three treatments of ascorbic acid antioxidants, namely 0, 100, and 200 ppm. The microemulsions with ascorbic acid were stored at 10, 30, and 50°C. The quality measurements were carried out between 4 to 20 days. The results showed the temperatures and storage time significantly affected turbidity, antioxidant activity, peroxide, and TBA value up to the 20th day of storage. The turbidity value increased more than 1 on the 20th day, while the peroxide and TBA values were still in the standard of food products. Therefore, the use of ascorbic acid as an antioxidant with a concentration of 200 ppm was appropriate to inhibit the rate of damage to the microemulsion.