Used cooking oil has the potential to be used as raw material for biodiesel. However, the high Free Fatty Acid (FFA) content in used cooking oil can interfere with the transesterification process. This issue will affect the quality of biodiesel yields. Therefore, FFA content in used cooking oil must be reduced through a pre-treatment process by adding activated carbon adsorbent from charcoal. In this study, the adsorption process was carried out by mixing used cooking oil and activated carbon using 20% NaOH for 3 hours. Then the degumming process was carried out by adding 0.5% v/v HCl from the volume of used cooking oil. Then add 0.5% NaOH by weight of used cooking oil and distilled water gradually, accompanied by heating to a temperature of 120 °C. In the esterification stage, the variables used are the comparison of methanol with a ratio of 1: 2, 1: 4, 1: 6, 1: 8, and 1:10. In this study, the lower acid number obtained from all variables was 2,24 mg KOH/g sample. Meanwhile, the most optimal result was the 1: 2 variables with a density of 0.8531 g/ml, and the kinematic viscosity at 40°C was 4.94 mm2/s.

The use of synthetic coatings as Food Additives consumed in the long term can damage human health. These horrible effects have paved the way for the development of edible films and natural edible coatings. One of the edible film ingredients is scorched rice which can be used as a coating in fruit preservation. However, the use of this edible film on food ingredients has some problems, especially its mechanical properties which tend to be fragile (not flexible). This article examines the mechanical characteristics of scorched rice with variations in the concentration of glycerol and carrageenan. Based on these results, it was concluded that the higher the volume of glycerol used, the percent elongation increased. The greatest elongation was obtained in the ratio of 3 g of carrageenan with 8 ml of glycerol. However, the addition of glycerol volume causes the biodegradable plastic to tear more easily. The greatest tensile strength value was obtained with a ratio of 5 g of carrageenan and 4 ml of glycerol. The edible film can prevent the spoilage of apples tested for 10 days.