TREATMENT OF USED VEGETABLE OIL USING LOCALLY PRODUCED ABSORBENTS (CARBONIZED, UNCARBONIZED EGGSHELL, KAOLIN CLAY, ULTISOL CLAY)

Cooking oils are oils extracted from seeds or from other parts of fruits like animal (Thomas, 2002). Soybean, Grape seed oil and Cocoa butter are examples of fats from seeds. Olive oil, Palm oil and Rice bran oil are examples of fats from other parts of fruit in common usage. Vegetable oil refers exclusively to vegetable fats which are liquid at room temperature (Saroj et al., 2007). This oil is widely used for cooking of all kind of food worldwide with general acceptability. Cooking oil is estimated to have saturated fat of 14g, polyunsaturated fat 33g, monounsaturated fat 48g which is common in diet (Yanai et al., 2015) and can undergo fortification to meet nutrition requirement which might have been lost during processing.

Cooking oil functions as a heat transfer medium and contributes flavor and texture to food. Cooking oils are composed of naturally occurring phytochemicals such as polyphenol, plant sterols and vitamin E which collectively affect color, flavor, aroma and nutrient value. The repeated use of cooking oil, changes its physical appearance, increases viscosity and darkens in color which alters the fatty acid composition (Kalogeropoulos et al., 2007). Heating causes oil to undergo a series of chemical reactions like oxidation, hydrolysis and polymerization.  Different plant and seed oil variations from most basic ingredients to the more complex ingredients that are used in making vegetable oils, lards, or shortenings, which can be included in part or whole are Soybean oil, Canola oil, Coconut oil, Corn oil, Avocado oil, Peanut oil, Sunflower oil, Palm oil, Flaxseed oil, Cottonseed oil, Linseed oil, Sesame oil, Safflower oil, Sunflower oil, Walnut oil, rapeseed oil, Extra virgin olive oil and other nut oils. Unlike the popular olive oil and coconut oil extraction method of cold pressing the ingredients to create the final product (Gunstone et al., 2001). Vegetable oil is also an ingredient used in desserts, salad dressing kits, vegetarian and vegan-friendly foods, ready-to-go meals, and fried food recipes. Frying methods such as pan fry, stir fry, shallow fry and deep fry are methods of frying that are applicable to cooking but deep frying will be considered in this study because it is a dry heat cooking method utilizing fat or oil to cook pieces of food. the process works by completely submerging food in hot liquid depending on the type of oil chosen and food being fried, a high temperature of up to 2040C is maintained to create golden –brown surface texture in a short amount of time. (Gavin, 2018). The cooking oil will be revitalized to its wholesome state, the cost of revitalizing the cooking oil is not much as absorbent will be use to recover used cooking oil.

 Vegetable oil which was used to fry foods will be recovered, instead of being poured away. This prompted the need for scientific research to treat used vegetable oil and return it back to its wholesome state.

This research will help to save the cost for vegetable oil users and also help to reduce the amount of waste oil discharged into drainage system which will be carried to water bodies and thus affect aquatic lives. 

The main objective of this study was the Treatment   of used vegetable oils using locally produced absorbents (carbonized, uncarbonized eggshell, kaolin clay, ultisol clay)