Through a notification dated 23 September, 2016 the FSSAI has stated that it would address the issue of amending standards for reused edible oil. The FSSAI has received a number of representations which state that the Enforcement Agencies are testing samples of edible oils repeatedly used in cooking/ frying against standards of the different kinds of edible oils mentioned in the Food Safety and Standards (Food Products Standards and Food Additives) Regulations, 2011.
Samples of edible oil that have been repeatedly used for frying invariably fail to comply with the parameters of EDIBLE OIL as prescribed in the FSS (Food Products Standards and Food Additives) Regulations, 2011. However, it must be clarified that Schedule –IV Part –V clause VI.7 of the Food Safety and Standards (Licensing & Registration of Food Businesses) Regulation, 2011 recognises the possibility of reheating or reusing edible oils.
FSSAI has therefore decided to address the issue by amending the standards so that they can fix the maximum limit of Total Polar Compounds (TPC). Any reused edible oil that crosses this maximum limit of TPC will be considered to be unsafe for use. Till such time as the FSSAI revises these standards the Enforcement Agencies have been asked to refrain from testing samples of repeatedly heated edible oils against standards of fresh or unused edible oil.
About repeated heating of edible oils
Consumption of ready-to-eat and deep fried foods is a common practice in India. Frying foods however, is not limited to India but is popular globally both for industrial as well as in domestic food preparation as most consumers relish the juicy taste, crisp texture and brown colour. Since edible oil is a major ingredient in fried foods the cost of the oil becomes a major factor leading to repeated use for frying. What is important to note is that a number of food establishments continue to use the repeatedly heated oil even after it has deteriorated beyond usability and should actually be discarded. Physical changes in such oils are easily discernible as these edible oils will darken, foam and produce an off-flavour and odour. The indiscernible changes are the deterioration of quality and nutritional value of the edible oils.
Repeated reheating of edible oil in high temperatures, in the presence of air and moisture, leads to a number of complex chemical reactions. These chemical reactions modify the fat constituents in the edible oil through processes like oxidation, hydrolysis, polymerization, and isomerization which result in lipid peroxidation. Lipid peroxidation generates components like free fatty acids, hydrocarbons, trans isomers, cyclic and epoxy compounds. In such cases a peroxide index helps to evaluate the amount of peroxides formed in the edible oils during the oxidation process. The more frequently the oil is reheated and used for frying the higher will be the peroxide value.