They’re tasty, they’re crispy and they make your mouth water! That’s right, we’re talking about fries! Deep frying is one of the most widespread culinary and industrial cooking techniques in the world. But with healthy eating on the rise, information about food sources has become more important to consumers. So, even though the appeal of fried food remains strong, it is prudent to offer the consumer some assurance of care and attention to detail regarding the health and quality of your menu items and fried products. Monitoring the composition of fryer oil for its polar content is a key step in producing a desirable, quality fried product.
How are polar compounds created?
The technique of deep-frying involves a series of complex processes that affect the composition of both the oil and the product being fried. Each type of product has several variables that affect the optimum deep-frying conditions:
- Frying time
- Continuous or discontinuous deep frying
- Composition of the oil
- Food moisture
- Food coating
- Food volume/surface
The moisture contained in food, atmospheric oxygen, and high temperatures (320° – 400° F) produce reactions such as hydrolysis, oxidation,and polymerization. These reactions change and modify the chemical composition of the used frying oils, releasing free fatty acids and free radicals that in turn combine to make monoglycerides, diglycerides, and polymeric triglycerides. All of these products of alteration are considered polar compounds and grouped under the term Total Polar Compounds, which is a reliable benchmark for measuring the degradation of the oil.
FSSAI has notified the Food Safety and Standards (Licensing and Registration of Food Businesses) First Amendment Regulation, 2017 in the Official Gazette. The amendment is regarding the quality of vegetable oil for repeated frying. The FSSAI has included a total polar compound as a criterion for the quality of vegetable oil to be re-used.
In the Food Safety and Standards (Licensing and Registration of Food Businesses) Regulations, 2011, in Schedule 4, under SPECIAL REQUIREMENTS FOR HIGH-RISK FOODS in the category Fried Foods, to the existing provisions FSSAI has now added the clause
“However, vegetable oil having developed Total Polar Compound more than 25% shall not be used.”
Methods for determining polar compounds in cooking oil
The Total Polar compounds are determined by reference methods such as ISO 8420:2002 and AOAC Official Method 982.27 which are generally recognized as standard methods for measurement of oil deterioration during frying.