Analytical Methods to Evaluate the Quality of Edible Fats and Oils: The JOCS Standard Methods for Analysis of Fats, Oils and Related Materials (2013) and Advanced Methods

Edible fats and oils are among the basic components of the human diet, along with carbohydrates and proteins, and they are the source of high energy and essential fatty acids such as linoleic and linolenic acids. Edible fats and oils are used in for pan- and deep-frying, and in salad dressing, mayonnaise and processed foods such as chocolates and cream. The physical and chemical properties of edible fats and oils can affect the quality of oil foods and hence must be evaluated in detail. The physical characteristics of edible fats and oils include color, specific gravity, refractive index, melting point, congeal point, smoke point, flash point, fire point, and viscosity, while the chemical characteristics include acid value, saponification value, iodine value, fatty acid composition, trans isomers, triacylglycerol composition, unsaponifiable matters (sterols, tocopherols) and minor components (phospholipids, chlorophyll pigments, glycidyl fatty acid esters). Peroxide value, p-anisidine value, carbonyl value, polar compounds and polymerized triacylglycerols are indexes of the deterioration of edible fats and oils. This review describes the analytical methods to evaluate the quality of edible fats and oils, especially the Standard Methods for Analysis of Fats, Oils and Related Materials edited by Japan Oil Chemists' Society (the JOCS standard methods) and advanced methods.