What Influences the Quality of Ghee? Composition and Analytical Factors

Ghee is far more than just clarified butter – it is a complex dairy fat whose quality, texture, colour, and even nutritional value depend on a range of interconnected factors. Whether you pick up a jar of golden cow ghee or white-grained buffalo ghee, the product you hold is the result of the animal’s species, what it ate, the time of year, and how the ghee was manufactured. Understanding these factors is essential for dairy professionals, quality control labs, and anyone who wants to make sense of the analytical numbers printed on a ghee specification sheet.

Why does ghee composition vary in the first place? 🔗

Milk fat – the raw material for ghee – is a mixture of roughly 500 different fatty acids and their derivatives. However, about 80% of both cow and buffalo milk fat is made up of just five fatty acids: palmitic, oleic, stearic, myristic, and butyric. The proportions in which these five acids occur determine nearly everything about ghee – its hardness, grain size, melting point, colour, and the values that show up in laboratory tests like the Reichert-Meissl (RM) number, Polenske value, and Butyro-refractometer (BR) reading. When any external factor shifts the ratio of these fatty acids in milk, it ripples through to the final ghee product.

Effect of animal species on ghee quality 🔗

The most visible difference in ghee quality comes from the species of the dairy animal. Cow ghee and buffalo ghee look, feel, and behave very differently, and the reasons are rooted in their distinct fatty acid profiles.

Cow ghee characteristics 🔗

Cow ghee is typically softer in texture with a characteristic yellow to golden colour. The yellow tint comes from carotene, a pigment that cows absorb from green fodder and transfer into their milk fat. Buffalo milk, by contrast, converts most dietary carotene into colourless vitamin A, which is why buffalo ghee appears white. Research published in the Journal of Dairy Science confirms that cow breeds like Sahiwal show notably higher oleic acid and conjugated linoleic acid (CLA) content compared to buffalo breeds, contributing to a softer, more spreadable ghee.

Cow ghee also tends to have a higher proportion of short-chain fatty acids such as butyric and caproic acid. This results in a lower melting point and smaller, less defined grains. In laboratory terms, cow ghee generally shows a higher Polenske value (around 1.76) and a higher iodine value (around 33.7) compared to buffalo ghee.

Buffalo ghee characteristics 🔗

Buffalo ghee is harder, whiter, and displays larger, well-defined grains. This is because buffalo milk fat contains higher levels of long-chain saturated fatty acids – especially palmitic and stearic acids. These high-melting-point fats make the ghee firm and give it that distinctive granular texture that many consumers in the Indian subcontinent prefer.

Analytically, buffalo ghee shows a higher RM value (around 32.3 versus 26.7 for cow ghee) and a higher Kirschner value. A study on seasonal variations in ghee found that buffalo ghee consistently recorded Kirschner values between 26.84 and 33.96, while cow ghee ranged from 20.74 to 24.14 – making the Kirschner index a reliable marker for distinguishing between the two types.

Effect of feed on ghee composition 🔗

What a dairy animal eats has a direct and dramatic effect on the fatty acid profile of its milk fat, and consequently on ghee quality. Different feed components influence ghee in distinct ways.

Oil-rich seeds and cakes 🔗

Feeding animals oilseeds or their cakes – such as cottonseed, groundnut, sesame, or safflower – sharply increases the levels of oleic acid and stearic acid in milk fat. According to dairy science literature, feeding cottonseed oil or cake can increase oleic acid content by about 10 units, while stearic acid levels can nearly double, reaching up to 20%. In compensation, palmitic acid and lower fatty acids decrease proportionally.

The practical result is significant: ghee produced from animals fed on these oil-rich diets tends to be harder, more granular, and sometimes even waxy. In the lab, such ghee shows a lower RM value, lower Polenske value, lower saponification value, and a higher BR reading and iodine value. This is an important consideration for regions like India’s cotton-growing belt, where cottonseed feeding is common and produces ghee with distinctly altered analytical constants. In fact, the FSSAI has established separate standards for cotton tract area ghee, recognising that its BR reading ranges from 41.5 to 45.0 and RM value minimum is set at 21, compared to 24 for normal ghee.

Green fodder, pasture, and roughage 🔗

Feeding animals on fresh pasture grass, silage, or green fodder promotes the synthesis of lower (short-chain) fatty acids like butyric and caproic acid. This results in ghee with a higher RM value and Polenske value – and a softer, more spreadable texture. Excessive green grass feeding can also yield butter with a high iodine value due to increased unsaturated fatty acids.

On the other hand, feeding large quantities of roots – which are fibre-rich but protein-poor – produces milk fat with a very low iodine value (around 30) and relatively high RM and Polenske values.

Coconut cake and rape oil 🔗

Coconut cake in the diet increases lauric and myristic acid levels in milk fat. Rape oil elevates oleic acid while depressing palmitic acid, which decreases the RM value and increases the iodine value of the resulting ghee.

Impact on vitamins and carotene 🔗

Feed also controls the vitamin content of ghee. Carotene in milk fat is entirely of dietary origin – it comes from green fodder. When animals are fed more oil cakes and less green fodder, both carotene and vitamin A levels in ghee drop. Similarly, α-tocopherol (vitamin E) in ghee is diet-dependent. Animals with access to vitamin E-rich feed produce ghee with better tocopherol levels. According to data from NIFTEM’s ghee processing resources, cow ghee typically contains 3.2-7.4 mg/g of carotene and 26-48 mg/g of tocopherol, whereas buffalo ghee lacks carotene entirely and has lower tocopherol levels (18-31 mg/g).

Effect of season on ghee quality 🔗

Season does not change ghee composition directly. Rather, it works indirectly through changes in feeding practices and animal physiology. As seasons shift, so does the availability of different feeds – and with it, the fatty acid profile of milk fat.

Monsoon and post-monsoon period 🔗

During and after the monsoon, green fodder and fresh pasture are abundantly available. Animals graze more, consuming higher quantities of fresh grass. This increases the proportion of short-chain fatty acids in milk, which translates to higher RM and Polenske values in ghee. The ghee produced during this period tends to be softer and may have a more intense yellow colour (in cow ghee) due to higher carotene intake from fresh greens.

Summer months 🔗

In summer, green fodder becomes scarce. Animals are fed dry straw, silage, and fibrous feeds – often supplemented with concentrates and oil cakes. This dietary shift typically increases long-chain and unsaturated fatty acids in milk fat, resulting in ghee that may be harder and have different analytical values. A study on Murrah buffaloes found that milk fat percentage was significantly higher in winter, while RM and Polenske values of ghee were elevated during summer – reflecting the complex interplay between ambient temperature, feed intake patterns, and rumen digestion efficiency.

Winter months 🔗

Winter often brings better-quality berseem and other fodder crops in many parts of India. BR readings for cow ghee have been reported to peak around February-March (42.89) and dip during December-January (42.18), showing that even within a single cool season, small dietary and physiological shifts produce measurable changes in ghee constants.

Effect of method of preparation 🔗

The method used to manufacture ghee does not significantly alter the fatty acid profile or major analytical constants like RM value, Polenske value, or iodine value – provided the raw material quality is good. A recent study comparing three ghee-making processes (curd-butter, cream-butter, and fermented cream-butter methods) across two cow breeds confirmed that processing had no significant impact on fatty acid composition.

However, the method of preparation does affect minor but important constituents – particularly carotene, vitamin A, vitamin E, and phospholipids.

Traditional (desi) method 🔗

In the traditional Indian method, whole milk is first converted into dahi (curd), then churned into makkhan (butter), which is finally clarified into ghee. This method tends to preserve more vitamin A because a large portion of the fat-soluble vitamin transfers into the fat phase during the souring and churning stages. The slow heating also tends to preserve heat-sensitive compounds better.

Creamery butter method 🔗

In modern dairy processing, cream is separated mechanically, pasteurised, and churned into butter before clarification. Each processing step – cream separation, pasteurisation, butter making – results in some loss of carotene and vitamin A. The more steps involved, the greater the cumulative loss of these micronutrients. Notably, phospholipid levels differ between these methods: creamery cow butter contains 75-218 mg/100g of total phospholipids, compared to 61-67 mg/100g in cow makkhan and 46 mg/100g in buffalo makkhan. However, converting butter or makkhan into ghee does not cause further phospholipid loss.

Impact of clarification temperature 🔗

The temperature at which butter is clarified into ghee is critical. Raising the temperature above 125°C drastically reduces vitamin A content and nearly destroys all carotene. However, tocopherol (vitamin E) in ghee is quite heat-stable and remains in a close range regardless of the method used. Clarification temperature also affects the formation of flavour compounds – the traditional desi method ghee tends to have more volatile carbonyl compounds and lactones than cream-method ghee, contributing to its distinctive aroma.

Key analytical constants and how they respond to these factors 🔗

For quality control and adulteration detection, ghee is tested against a set of physico-chemical constants. Each of these constants responds to the factors discussed above in predictable ways.

Butyro-refractometer (BR) reading 🔗

The BR reading measures the refractive index of ghee and reflects the overall fatty acid composition. As per FSSAI standards, the acceptable BR reading for ghee ranges from 40.0 to 44.0. Oil-rich feed increases the BR reading, while species differences cause minor variations (buffalo ghee averages about 42.0, cow ghee about 42.3).

Reichert-Meissl (RM) value 🔗

The RM value measures volatile, water-soluble fatty acids – primarily butyric acid. Green fodder feeding raises the RM value; oilseed feeding lowers it. Buffalo ghee typically has a higher RM value than cow ghee due to its greater concentration of short-chain fatty acids like butyric and caproic acids. The FSSAI minimum for normal ghee is 24.

Polenske value 🔗

This measures volatile, water-insoluble fatty acids (caprylic and capric acids). Cow ghee typically shows a slightly higher Polenske value than buffalo ghee. Like RM value, it increases with green fodder feeding and decreases when animals are fed on oil-rich diets.

Iodine value 🔗

The iodine value indicates the degree of unsaturation in the fat. Higher unsaturated fatty acid content – from pasture feeding or oilseed diets – increases this value. FSSAI sets the acceptable range at 25 to 38 for ghee.

Saponification value 🔗

This reflects the average molecular weight of fatty acids present in ghee. FSSAI prescribes a range of 205 to 235. Oilseed feeding, which increases longer-chain fatty acids, tends to lower the saponification value.

Practical significance for the dairy industry 🔗

These variations are not just academic – they have real-world consequences. Quality inspectors must account for species, regional feeding practices, and season when interpreting analytical results. A ghee sample from Gujarat’s cotton tract area with an RM value of 22 might be perfectly genuine, while the same value in a ghee sample from Punjab could signal adulteration. This is exactly why FSSAI maintains separate standards for cotton tract area ghee, with adjusted BR reading and RM value limits.

For producers, understanding these factors means better control over product consistency. Choosing specific feed compositions during certain seasons, selecting the right processing method, and understanding species-level differences all contribute to producing ghee that consistently meets both consumer expectations and regulatory standards.

What do you think? If feed has such a strong influence on ghee quality, should dairy producers standardise animal diets more strictly to achieve uniform ghee – or does the natural variation across seasons and regions actually add to ghee’s appeal and diversity?

References

1. https://pmc.ncbi.nlm.nih.gov/articles/PMC9579228/
2. https://www.sciencedirect.com/science/article/abs/pii/S0958694622000267
3. https://www.agriculturaljournals.com/archives/2025/vol7issue9/PartA/7-9-4-411.pdf
4. https://www.foodinfotech.com/fssai-announces-standards-for-ghee-in-the-official-gazette/
5. https://niftem.ac.in/newsite/pmfme/wp-content/uploads/2022/08/ppt_ghee-processing.pdf
6. https://www.academia.edu/89885267/Factors_affecting_milk_yield_milk_composition_and_physico_chemical_parameters_of_ghee_in_Murrah_buffaloes_of_Punjab_region
7. https://www.sciencedirect.com/science/article/pii/S2590157525003360
8. https://www.fssai.gov.in/upload/uploadfiles/files/Compendium_Food_Additives_Regulations_21_10_2022.pdf