Detecting and Preventing Adulteration in Ghee

Ghee holds a prized position in Indian kitchens-valued for its rich flavour, high smoke point, and deep-rooted cultural significance. But this same demand and premium pricing make ghee one of the most frequently adulterated dairy products in the country. Cheaper fats are routinely blended into ghee to boost profits, and the result is a product that falls short on nutrition, safety, and authenticity. Understanding what goes into adulterated ghee-and how to catch it-is essential knowledge for dairy science students, food safety professionals, and everyday consumers.

Why ghee is a target for adulteration 🔗

The market price of ghee is roughly three times higher than most edible vegetable oils and fats. At the same time, India’s supply of genuine ghee consistently falls short of demand. This gap between price and availability creates a strong financial incentive for unscrupulous traders. By mixing cheaper substances into ghee, they can increase volume, reduce production costs, and sell the adulterated product at higher margins.

What makes the problem worse is that ghee’s analytical constants naturally cover a wide range, depending on factors like the animal breed, feed quality, and season of production. This variability means a fairly high degree of adulteration can go undetected if the analytical values still fall within accepted limits. Adulterators exploit this scientific loophole deliberately.

Common adulterants found in ghee 🔗

Ghee can be adulterated at multiple stages-sometimes starting as early as the milk or cream stage itself. The adulterants typically fall into two broad categories: vegetable fats and animal body fats.

Vegetable oils and hydrogenated fats 🔗

Coconut oil is one of the most preferred adulterants because its analytical constants-such as Polenske value, iodine value, and butyro-refractometer reading-closely resemble those of genuine ghee. This similarity makes detection through routine physical tests difficult.

Vanaspati (hydrogenated fat) is the single most common adulterant. It is essentially vegetable oil (usually palm, cottonseed, or soybean oil) that has been hydrogenated to mimic ghee’s solid, semi-solid texture and even its characteristic granular appearance. Groundnut-based vanaspati is especially favoured because its melting point sits just below 37°C, making it physically indistinguishable from real ghee to the untrained eye.

Other vegetable oils used for adulteration include palm oil, soybean oil, groundnut oil, and sunflower oil. Synthetic flavours and colours are sometimes added alongside these oils to replicate ghee’s natural aroma and golden hue.

Animal body fats 🔗

Cheaper animal fats such as tallow (beef fat) and lard (pig fat) are also mixed into ghee. This is particularly concerning in a country like India, where such adulteration raises serious religious and cultural issues beyond the health risks. Since these animal fats also contain cholesterol-just like genuine milk fat-they are harder to detect through certain standard tests.

Other adulterants 🔗

Starch and mashed potato are occasionally added to increase volume. Even mineral oils, coal tar dyes, and colouring agents have been found in adulterated ghee samples. The adulteration can start right at the milk stage: water emulsions of cheap oils are added to milk or cream, transferred into butter during churning, and then carried into the final ghee product during heating.

Health risks of consuming adulterated ghee 🔗

Adulterated ghee is not just a quality problem-it is a public health hazard. The specific health risks depend on the adulterant involved, but the consequences can be severe.

Trans fats from vanaspati are among the most dangerous. The hydrogenation process used to manufacture vanaspati creates trans fatty acids (TFAs), which simultaneously raise LDL (“bad”) cholesterol and lower HDL (“good”) cholesterol. Research has linked the consumption of contaminated oils and trans fats to cardiovascular diseases, digestive disorders, and even cancer. The hydrogenation process may also introduce trace amounts of nickel, a catalyst used during manufacturing, which can accumulate in the body over time.

Adulteration with non-food-grade animal fats can introduce bacterial contamination and rancid compounds. Coal tar dyes are known carcinogens. Even seemingly harmless adulterants like starch diminish ghee’s nutritional value by replacing its fat-soluble vitamins (A, D, E, and K) with nutritionally empty fillers. The effects are often chronic rather than immediate, making them harder for consumers to trace back to adulterated food.

Standard chemical tests for detecting adulteration 🔗

Food scientists have developed a range of tests-from simple colour-change reactions to highly sophisticated instrumental analyses-to identify adulterants in ghee.

The Baudouin test 🔗

The Baudouin test is one of the most important and widely used screening tests for ghee adulteration. It was designed to detect the presence of sesame oil in ghee. Under India’s Vegetable Oil Products Control Order, all vanaspati manufactured in India must contain 5% sesame oil as a mandatory marker. So if sesame oil is found in a ghee sample, it indicates vanaspati contamination.

The test works by adding furfural and hydrochloric acid to the ghee sample. In the presence of sesame oil, the compound sesamol reacts with the reagent and produces a characteristic pink or red colour in the acidic layer. A clear layer indicates the sample is free of sesame oil contamination. Under both the Prevention of Food Adulteration (PFA) rules and AGMARK standards, the Baudouin test result must be negative for ghee to pass quality certification.

The phytosterol acetate test 🔗

While the Baudouin test targets vanaspati through its sesame oil marker, the phytosterol acetate test directly targets the presence of vegetable oils in ghee. The science behind it is straightforward: ghee, being an animal fat, contains cholesterol as its primary sterol. Vegetable oils, on the other hand, contain phytosterols (plant-based sterols like β-sitosterol).

When sterol acetates are prepared from pure ghee, they have a melting point of approximately 114.6°C. However, if vegetable oils are present, phytosterol acetates raise this melting point above 125°C. This sharp change makes detection reliable and unambiguous. The AGMARK grading rules specifically require that the phytosterol acetate test be negative for ghee to receive certification. One limitation, however, is that this test cannot detect animal body fats like tallow and lard, since these also contain cholesterol rather than phytosterols.

The Furfural test 🔗

Sometimes confused with the Baudouin test, the Furfural test is a related but distinct method specifically aimed at detecting sesame oil adulteration. While the Baudouin test is used as a marker for vanaspati (which contains mandated sesame oil), the Furfural test directly identifies the presence of sesame oil itself. Sesame oil reacts with furfural in the presence of hydrochloric acid to produce a rose-red colour.

Other conventional tests 🔗

Several additional physicochemical tests are part of routine ghee quality analysis. The Butyro-Refractometer (BR) reading measures the refractive index of ghee, which changes when foreign fats are present. The Reichert-Meissl (RM) value measures volatile water-soluble fatty acids-genuine ghee has a minimum RM value of 28 under AGMARK standards. The Polenske value and iodine value provide additional data points about the fatty acid profile of the sample. Deviations from established ranges for any of these parameters can indicate adulteration.

For detecting specific adulterants, targeted colour-change tests also exist. For example, mixing melted ghee with dilute sulphuric acid and sugar produces a crimson colour if vanaspati is present. A few drops of iodine tincture added to ghee will turn blue if starch has been added. Palm oil can be identified using a DPPH solution test, where the colour shifts from violet to yellow in contaminated samples.

Advanced analytical methods 🔗

While traditional chemical tests are useful as screening tools, they have limitations-particularly when adulterants are present in small quantities or when multiple adulterants are used together. This is where modern instrumental techniques come in.

Gas chromatography (GC) and HPLC 🔗

Gas chromatography separates and identifies the individual fatty acid components in a ghee sample and compares the resulting profile against the known composition of pure ghee. Any deviation signals adulteration. Gas liquid chromatography is considered the best method for detecting adulteration in ghee, offering far more precision than traditional colour-change tests.

High-Performance Liquid Chromatography (HPLC), particularly its reverse-phase variant (RP-HPLC), is used to detect β-sitosterol-a marker compound for vegetable oil contamination. HPLC can not only confirm the presence of an adulterant but also quantify its concentration, providing detailed evidence that simple tests cannot match.

Spectroscopic techniques 🔗

Fourier-Transform Infrared (FTIR) spectroscopy identifies molecular vibrations unique to different fat types, enabling analysts to distinguish between pure and adulterated ghee. A recent study demonstrated that ATR-FTIR coupled with chemometric techniques could detect even 1% vanaspati adulteration in ghee, making it remarkably sensitive. Raman spectroscopy offers a complementary approach that is especially useful for detecting non-polar molecular bond differences in fat-based foods.

Nuclear Magnetic Resonance (NMR) spectroscopy provides deep insights into the chemical composition of ghee samples and can identify foreign substances with high specificity.

Electronic nose (e-nose) technology 🔗

An emerging area in ghee testing involves electronic nose systems that use metal oxide semiconductor gas sensors combined with machine learning algorithms. These devices detect characteristic aroma patterns in ghee and can rapidly distinguish between pure and adulterated samples. While still largely in the research phase, e-nose technology holds promise for fast, on-site screening.

The main drawback of these advanced methods is their cost and complexity. They require expensive instrumentation, trained analysts, and longer processing times compared to simple bench-top tests. For this reason, they are typically used as confirmatory tools after initial screening with traditional methods.

Regulatory framework: PFA, FSSAI, and AGMARK 🔗

India has a well-established regulatory structure for ghee quality control. The Prevention of Food Adulteration (PFA) Act (now largely superseded by the Food Safety and Standards Act, 2006) laid the groundwork for mandatory testing and quality standards. Today, the Food Safety and Standards Authority of India (FSSAI) sets the primary regulations.

According to FSSAI standards, ghee must contain a minimum of 99.6% milk fat, and adulteration with non-milk fats, synthetic colours, or additives is strictly prohibited. FSSAI has also been developing improved analytical methods-including β-sitosterol detection via chromatography-to stay ahead of increasingly sophisticated adulterators.

The AGMARK certification system, administered by the Directorate of Marketing and Inspection under the Government of India, classifies ghee into three grades based on free fatty acid content: Special (maximum 1.4% FFA), General (maximum 2.5% FFA), and Standard (maximum 3.0% FFA). For any grade, the Baudouin test, phytosterol acetate test, and tests for non-milk animal fats must all be negative. AGMARK-certified ghee provides consumers with a government-backed assurance of purity and quality.

Practical tips for consumers 🔗

While laboratory tests remain the gold standard, consumers can take several precautions to reduce their risk of buying adulterated ghee.

Buy from reputable brands that carry FSSAI licensing and AGMARK certification. Check packaging for batch numbers, manufacturing dates, and expiry dates. Be cautious of ghee priced significantly below prevailing market rates-if it seems too cheap, there is likely a reason.

Sensory evaluation can provide useful clues. Pure ghee has a characteristic golden colour (yellow for cow ghee, white with a slight greenish tint for buffalo ghee), a granular texture when solidified, and a distinct nutty aroma. Any unusual smell, taste, or colour should raise concern.

Some simple home tests can serve as preliminary checks. The palm test involves placing a small amount of ghee on your palm-pure ghee melts quickly from body heat, while adulterated ghee may remain solid longer. Heating ghee in a pan should produce a uniform melt and a pleasant aroma; sputtering or unusual odours suggest contamination. Adding a few drops of iodine to melted ghee can reveal starch adulteration if the colour turns blue or purple.

However, keep in mind that home tests are not definitive. They can catch obvious cases of adulteration but will miss sophisticated blending that only laboratory analysis can detect.

The road ahead: emerging technologies 🔗

The fight against ghee adulteration is evolving. Researchers are working on DNA-based testing methods that can verify the species of milk used to make ghee, ensuring that what is labelled as cow ghee actually comes from cow milk. Hyperspectral imaging, portable FTIR devices, and sensor-based rapid screening kits are being developed to make quality testing faster and more accessible-even at the point of sale.

On the regulatory front, FSSAI has been tightening enforcement. In recent years, food safety authorities across Indian states have conducted raids on fake ghee manufacturing units, seizing large quantities of adulterated products. Consumer awareness is also growing, driven by media coverage and government education campaigns.

Ultimately, combating ghee adulteration requires a multi-pronged approach: strong regulations, advanced testing capabilities, honest manufacturers, and informed consumers working together.

What do you think? Given that many advanced detection methods are expensive and require specialized labs, how can testing be made more accessible for small-scale dairy producers and rural markets? And as a consumer, what steps do you currently take to verify the purity of the ghee you buy?

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC11751471/
2. https://envirocarelabs.com/complete-guide-to-ghee-testing/
3. https://upload.indiacode.nic.in/showfile?actid=AC_CEN_23_31_00011_193701_1535099362507&type=rule&filename=ghee_grading_and_marking_rules,_1938_amended_in1950,1961,1966,1981,1991.pdf
4. https://safemilklabs.com/baudouin-test-for-vanaspati-ghee-or-sesame-oil/
5. https://wdra.gov.in/web/wdra/ghee
6. https://atlaslab.in/ghee-testing.php
7. https://www.sciencedirect.com/science/article/abs/pii/S0956713525003500
8. https://www.thepharmajournal.com/archives/2021/vol10issue9/PartA/10-10-80-761.pdf