Groundnut Oil Adulteration
Groundnut ‘Peanut’ oil is one of the healthiest vegetable oils; has the high percentage of unsaturated fatty acids as compared to the saturated fatty acids, making it good for the heart health. Groundnut ‘Peanut’ oil, due to its relative superiority in terms of health benefits, is more expensive than most of the other cooking oils. Since Peanut oil can fetch a premium, due to higher consumer demand, there is a tendency to adulterate it with cheaper oils to make more profit. While doing do, the adverse impact this adulteration can have on health, is often ignored.
Groundnut oil adulteration is rampart in our country. Though there are clear quality benchmarks and rules and regulations, the adulteration often goes on undetected due to poor consumer awareness, insufficient regulatory monitoring and/or lax punishments for offenders.
FSSAI, the chief regulator of food items in the country, and other regulatory bodies keep on conducting tests to check adulteration on their own or on receiving complaints in this regard.
What is groundnut oil adulterated with?
Peanut oil is often adulterated with cheaper seed oils such as those of palmolein, cottonseed, corn, rapeseed, rice bran, linseed and soybean. It is also adulterated with castor oil, mineral oil, argemone oil and karanja oil.
Adulteration of virgin groundnut oil can also be done with either refined version or rancid groundnut oil. Synthetic colouring and flavouring agents are used to obtain desirable colour and flavours.
How can groundnut oil adulteration be detected?
1/5. Check the details on the packing
It can be detected to an extent from the packing of the oil itself. For the adulterators, it is important to find a way around the rules and regulations. So, if you are aware of the basic rules of packaging of blended edible oils, you will be able to find those which deviate from rules.
- FSSAI had issued a change to edible oil labelling back in December 2018 wherein blended oils had to show “Blended Edible Vegetable Oil” on the pack, name of oil, nature of oil and specific percentages of each oil by weight.
- Font sizes shall be as per the norms. Font of “Blended Edible Vegetable Oil” shall be no less than 5mm (10 mm in case of 5 litre packs or more) whereas that of other information to be no less than 3mm.
- Find whether the ratio of blended oils is also given on packaging label or not.
- In Tamil, they print Nalla Ennai instead of Nallennai for sesame oil. For groundnut oil, they use picture of the groundnut without mentioning the name.
By checking whether these simple rules have been adhered to or not can give a hint for the quality of packaging.
2/5. Visible Detection
Sometimes, you can find adulteration simply by looking at the oil. Any foreign particle present in it, such as dirt, black particles, sediments and even turbidity is sufficient evidence of poor quality of groundnut oil.
3/5. Conventional Method
The conventional method of checking adulteration is based on the freezing points of different oils. The sample is refrigerated and the change in absorbance of different oils is detected. When groundnut oil is adulterated its absorbance value reduces considerably.
4/5. Use of Raman-1 Spectrometer
FSSAI has officially certified the use of Raman-1 Spectrometer for testing of edible oils. Raman-1 technique is an out-of-lab method of testing the adulteration.
Raman-1 is a chalkboard duster size device which makes use of micro-optics, cloud technology, artificial intelligence, mobile technology and machine learning to check for adulteration. Raman-1 technique is a cost-effective technique to check adulteration out of the labs. It is not intended to replace the lab testing methods but gives accurate assessments which have been proven to be correct by lab tests later on.
5/5. Other MethodsOther Methods
A range of other methods are also used in detecting adulterating in edible oils. These include the use of a high performance liquid chromatography (HPLC), isotopic dilution, deoxyribonucleic acid (DNA) barcoding, biomarkers and sensors, nuclear magnetic resonance, mass spectrometry, electronic nose and electro-analytical techniques.
How can adulteration of groundnut oil be harmful?
Groundnut oil has many health benefits. By having higher percentage of unsaturated fats over saturated fats, it is good for our heart. It also has anti-inflammatory, anti-cancer, anti-tumour and anti-diabetic properties that makes it one of the highly recommended oils for cooking purposes.
What adulteration does is to reduce or eliminate these beneficial properties of the oil by altering their chemical composition. So, the very properties which were beneficial in pure groundnut oil are either destroyed or reduced by adulteration. Further, if the oil being mixed has high saturated fats than unsaturated ones, then it actually works contrary to benefits of pure groundnut oil.
 Health Benefits of Peanuts ‘Groundnuts’