The magic of Christmas and the magic in the frying pan!
Monthly bulletin on Oils & Fats for December
20th December, 2019
Most people love eating fried foods from time to time and for centuries it brought man-, woman-and humankind many culinary pleasures. When vegetables, meat or fish are brought in direct contact with hot oil something magical happens.
The oil in not only a heat transfer medium, but apart from losing moisture, the food changes color and texture, it develops a crust, fried flavors and aromas. Hmmm…. we all love potato chips, chipito’s, bugles, French fries, fish sticks, chicken fingers, “bitter balls”, croquettes, “oil balls” and everything else that is fried.
Frying food is done at home, in restaurants or at an industrial scale. We have pan frying and deep-frying (submerging the food in the oil), depending on what is fried and on what scale. And we should not eat food fried in just any kind of oil. But by using the right oils at a correct temperature, we can enjoy the delicious fried foods without worries.
The magic happening in the frying pan is a complex process where chemical reactions take place. We discussed some of the changes occurring in the food but there are also changes happening in the oil. After a certain time, the oil will begin to break down (turn dark, smell bad, taste bad, oxidize, polymerize, produce free radicals etc.).
Negative changes in the fryer can be prevented by:
- Choosing suitable oils that are heat-stable, more resistant to oxidation, with a very low linolenic acid (C18:3) content.
- Not exceeding a temperature of 170° C.
- Limiting the heating time.
- Avoiding frying excessively wet or seasoned food.
- Avoiding frying different types of food in the same oil.
- By regularly filtering the oil and by changing the oil regularly, before it turns dark, starts to smoke…
How do we choose the best oils to cook and fry with?
All chemical reactions are accelerated by heat, and in our oils many reactions can be seen with the naked eye, like bubbling, foaming, turning dark, and for example polymerization which is like a layer of varnish forming on the fryer. Polymerization is when broken down molecules stick together. This typically happens when the oil contains high levels of poly unsaturated fatty acids. Polyunsaturated acids content in the oil must be low in order to provide maximum oxidative stability.
Linseed oil is used in oil paints and coatings like varnish. It is rich in tri-unsaturated fatty acids, which tends to harden in the presence of oxygen. This hardening process is typical for so-called drying oils. It is caused by a polymerization process that begins with oxidation (oxygen molecules attacking the oil). Linseed oil is NOT suited as a frying oil. It would taste very bad and be very unhealthy. But also, classic sunflower oil, soybean oil and corn oil in the fryer are sensitive to polymerization.
When frying or cooking at a temperature close to 180°C, the molecular structures of the oils and fats change. They react with oxygen in the air to form aldehydes and lipid peroxides. At room temperature something similar happens, but more slowly. Oils and fats can become rancid (= oxidized). But saturated fats hardly undergo this oxidation reaction at all, they are more stable.
Typical fatty acid composition of some common vegetable and animal* oils and fats:
Choosing a good frying oil will always be a compromise. Some people will not use animal fats. Others will tend to avoid saturated fatty acids, while others will fry in expensive saturated coconut oil. In a BBC program Professor M. Grootveld (Leicester School of Pharmacy at De Montfort University) once advised:
Hope you enjoy your Christmas dinner and your New Year’s Eve dinner and all meals and drinks in between, before and after. But above all we wish you a safe transition to 2020 and a healthy and remarkable future!
Giáng Sinh vui vẻ
Aveno's Monthly OILS & FATS bulletins:
Don't forget to check out our other bi-weekly updates!
There is some complexity to the business we daily operate in. To help understand the business of being an edible oil and fat producer we've launched a bi-weekly newsletter.
Sign-up for Aveno's newsletters!
Unless otherwise mentioned the crude oil values quoted in these documents are prices landed in EU without import duties, handling, storage, financing, refining, packing, transport or any other cost related to bring the product to market. They are used as market trend illustration. Substitution of oils is possible but different oils have different fatty acid profiles and are not all interchangeable for all applications. One can make biodiesel from all oils and fats but one cannot make mayonnaise from coconut oil. This document is exclusively for you and does not carry any right of publication or disclosure. This document or any of its contents may not be distributed, reproduced, or used for any other purpose without the prior written consent of AVENO. The information reflects prevailing market conditions and our present judgement, which may be subject to change. It is based on public information and opinions which come from sources believed to be reliable; however, AVENO doesn’t guarantee the correctness or completeness. This document does not constitute an offer, invitation, or recommendation and may not be understood, as an advice. This document is one of a series of publications undertaken by AVENO and aims at informing broadly a targeted audience about the edible oils & fats market. AVENO’s goal is to keep this information timely and accurate however AVENO accepts no responsibility or liability whatsoever with regard to the given information.
Read in browser »