Composition Of Fats And Oils

What is the chemical composition of groundnut oil, flax seed oil, safflower oil and others?

Peanut or groundnut oil is quite stable for deep frying. Due to moderately high percentage of omega-6 content, it should be used in moderation or with other omega-3 –rich oils like flax seed oil.

Composition of various fats and oils

Type of fat Saturated fat %MUFA %
PUFA
%

 

 

(oleic acid)

Omega -6

(linoleic acid)

Omega -3

(linolenic acid)

Peanut oil

(Groundnut oil)

18 48 34  

Sesame oil

(Til oil)

15 42 43  

Safflower oil

       

Canola oil

(Rape seed oil)

5 57 23 10-15

Olive oil

13 75 10 2

Flax seed oil

9 18 16 57

Palm oil

50 41 9  

Coconut oil

92      

Lard

(Pork fat)

40 48 12  

Beef Tallow

50-55 40 >3  

Chicken fat

31 49 20  

Duck and

goose fat

35 52 13  
 

Let us now examine the composition of different fats and oils in detail:

Composition of Peanut or groundnut oil

Peanut or groundnut oil is quite stable for deep frying. Due to moderately high percentage of omega-6 content, it should be used in moderation or with other omega-3 –rich oils like flax seed oil.

Composition of Sesame oil or Til oil

Sesame oil or Til oil is similar in composition to peanut oil. It can be used for deep frying because it contains certain antioxidants that are resistant to heat. Again due to moderately high percentage of omega-6 fatty acids, this oil too should be used in moderation.

Composition of Olive oil

Olive oil is good for cooking at moderate temperatures due to its high (73%) oleic content. Extra virgin olive oil is also rich in antioxidants. It should be unfiltered (cloudy appearance) and extracted from ripe olives (golden yellow in color)

Composition of Safflower, Corn, Sunflower, Soybean and Cottonseed Oils

Safflower oil, corn oil, sunflower oil, soybean oil (soyabean oil) and cottonseed oil contain very low omega-3 fatty acids. Omega-3 fatty acids are good for heart health. Safflower oil contains about 80% omega-6 fatty acid, which therefore should be consumed minimally or in combination with flax seed oil to rectify the omega-6/omega-3 ratio. All these oils should not be reused after heating once.

Chemical Composition of Flax seed oil

Flax seed oil, with its very high omega-3 fatty acid content (57%), provides a solution to the omega-6/omega-3 imbalance so prevalent today. Flax seed oil should preferably be kept refrigerated. It should never be heated.

Chemical Composition of Canola oil (Rape seed oil)

Canola is actually an improved variety of rapeseed (Mustard, Sarso or Rai) It was developed using conventional breeding from rapeseed, an oilseed plant which has an important place in the diet worldwide. Rapeseed oil has a peculiar taste and an unpleasant greenish colour due to the presence of chlorophyll. It has a sharp pungent smell peculiar of rapeseed oil. It contains a high proportion of erucic acid.

There is some evidence from animal experiments that rapeseed oil, due to the presence of a very long chain fatty acid called erucic acid, when consumed in large quantities may cause fibrotic heart lesions. However, Indian scientists have published their findings which have challenged this claim. [1], [2], [3], [4], [5]

Due to its very low (5%) saturated fat content, good omega-3 content (10-15%) and high (57%) MUFA (mono-unsaturated fatty acid) content, canola oil is supposed to be excellent for heart health. As per the Canola Council of Canada, Canola oil is totally safe and healthiest of all cooking oils. [6]

One should clearly distinguish between the traditional rapeseed oil (Mustard oil) and canola oil despite their similarities and common origin. Rapeseed oil has high contents of erucic acid (which is associated with cancer and rancidity) and glucosinolates. As per US FDA, both these substances are harmful for human health. Whereas Canola oil contains only 0.5 to 1% erucic acid which is well below the level of 2% set by the USDA. Therefore Canola oil should always be preferred against the traditional rapeseed oil.

There are a few negative points against even Canola oil. It goes rancid relatively rapidly and has higher amounts of sulphur. If the oil is deodorized, the heart-healthy omega-3 fatty acids get converted into the ugly trans-fatty acids. In the processing of canola oil vitamin E gets destroyed. We all know that vitamin E is an excellent antioxidant and therefore heart-healthy.

1. Ghafoorunissa (1996). "Fats in Indian Diets and Their Nutritional and health Implications". Lipids 31: S287-S291. 

2. Shenolikar, I (1980). "Fatty Acid Profile of Myocardial Lipid in Populations Consuming Different Dietary Fats". Lipids 15(11): 980-982. 

3. Bellenand, JF; Baloutch, G; Ong, N; Lecerf, J (1980). "Effects of Coconut Oil on Heart Lipids and on Fatty Acid Utilization in Rapeseed Oil". Lipids 15(11): 938-943. 

4. Achaya, KT (1987). "Fat Status of Indians - A Review". Journal of Scientific & Industrial Research 46: 112-126. 

5. Indu, M; Ghafoorunissa (1992). "n-3 Fatty Acids in Indian Diets - Comparison of the Effects of Precursor (Alpha-Linolenic Acid) Vs Product (Long chain n-3 Poly Unsaturated Fatty Acids)". Nutrition Research 12: 569-582. 

6. Canola Oil: The truth!. Canola Council of Canada. (2007) “Canola oil is the healthiest of all commonly used cooking oils. It is lowest in saturated fat, high in cholesterol-lowering mono-unsaturated fat and the best source of omega-3 fats of all popular oils.”

You may also be interested to read the following relevant information about fats:

Good Fats Bad Fats