Wondering plate of ghee

 Source:https://www.behance.net/gallery/50932649/cinemagraphs-5

Hi, have you ever heard about ghee? Are you wondering what is ghee actually? I’m sure you are! Ghee is obtained from a particular source of dairy products that correlated with it definition where ghee means the pure heat clarified fat derived solely from milk or curd or from desi (cooking) butter or from cream to which no coloring matter or preservative has been added.

Ghee made from buffalo milk is whitish with greenish and cow milk is slight golden yellow in color due to presence of carotene which is found in the fat of the cow milk. Whereas buffalo milk lacks the same thus it is not yellowish like cow milk. During metabolism, this carotene gets converted into vitamin A by the enzyme beta, beta-carotene-15, 15 '-monooxygenase (BCO). Beta Carotene is considered as precursor of Vitamin A. Ghee most common appeared in liquid state but you must know that it could be in semisolid and some time in solid state. The storage temperature becomes a factor that making them differ to each other.

Ghee is slightly different with clarified butter, which is cooked  to the point where the water evaporates and the milk solids separate (and sink). For ghee, you just take one step further which continue cooked them until turn golden brown on the bottom of the pan. This golden brown color is due to caramelization. I am glade to say that ghee is cooked until the milk solid begin to caramelize causes by sugar degradation. Caramelization usually occurs when highly concentrated sugar solutions are heated at high temperature. Most dairy products including cream and butter contain significant quantities of lactose, a disaccharide of glucose and galactose. These are all reducing sugars that take place during caramelization process. You know when milk solid caramelize, it becomes very nutty and fragrant.

         

                 Source: http://rudrapurshopping.com/product/desi-ghee/  

                   Flow chart show the processing line of the ghee making

Composition of ghee being mostly a saturated fat inside since it have 62% amount of fat content. It is solid at room temperature.

Nutritional value are different between milk, butter as well as ghee. During ghee making, all water have been evaporated and  all milk component were strained out. Ghee has little to no casein or lactose, meaning even very dairy-sensitive people can usually eat it. Ghee only contain pure butterfat. This is the biggest difference between butter and ghee and might be a game changer for you if you are super sensitive to dairy protein. Butter is mostly fat and water, but it still has trace amounts of casein and lactose, the two compounds in dairy that most often cause allergies and sensitivities. Casein is what gives butter its wonderful creaminess. For milk, it is rich with nutrient and also high water content. It contains high lactose, protein, calcium, and others.

In order to be marketable, ghee product must comply with the Food Regulations 1985, regulation number 105 that stated the ghee shall be the pure clarified milk fat obtained by removal of water and non-fat milk solids from milk, butter or cream. After that, ghee product shall not contain more than 0.3% of water and 3% of free fatty acid as oleic acid. Furthermore, ghee is allowed to contain permitted antioxidant. Then, it also shall have a Reichert value of not less than 23.5, a polenske value of from 1.5 to 4 and lastly butyro number of from 42 to 45 at 40 °C.

                                                

As I mention before, we get the ghee by heating the butter right? During heating process, some problems deal with physical and chemical changes because of this thermal oxidation issues. The first apparent feature characteristics of heated fats, has been the formation of peroxides. We know that, heating process was done until the formation of golden brown on the bottom of the pan. Unfortunately, continues heating subsequently causes the decomposition of peroxide and the scission products starts volatilizing. Carbonyls, hydroxyl and epoxy compounds get accumulated. The fat turns brown in color which is attributed to αα’ and αβ- unsaturated carbonyls.

For your information, higher temperature was not only speed up the reactions but also causes some different reactions take place. Oxidation of fat at higher temperature differs from oxidation of fat at low temperature. This is because the initial oxidation products which form at low temperature are too unstable to exist more than transiently at higher temperature. When fat is heated in air, it first shows gain in weight as oxygen is absorbed, and its peroxide value may increase. But heating continues, the peroxides decompose, leading to loss in weight. The refractive index and ultraviolet absorption of the fat increase owing to conjugation of the double bonds and to the accumulation of oxygenated products.

Physical changes that you need to know is ghee product has a higher "smoke point which means that it can be cooked to a higher temperature before beginning to burn. This unique make them suitable for cooking. The high temperature treatment employed during manufacturing ghee also destroys most of the bacteria, micro-organisms and moisture, making it light, pure and resistant to spoilage. Thus ghee has a long shelf life of six to eight months, even at ambient temperatures and does not require refrigeration.

Finally, the physical change in ghee that we can see is the formation of very nutty and fragrant flavor because of the caramelization that occurred. Actually, emulsion structures in ghee can lead to nutty flavor profiles. Butter is water in oil emulsion. The heating of butter to make ghee generates a phase inversion of the emulsion. Phase inversions occur when the discrete phase and the continuous phase swap so that the discrete phase becomes continuous and the continuous phase becomes discrete. Switching the dispersed phase from oil to water provided a means of altering the ratios of volatile compounds produced in the cooked samples. The ability to generate different volatile compound profiles through the use of inverted emulsion structures. So when these food emulsions are heated to high temperatures to make products such as ghee, it will forms a range of nutty and fragrance volatile flavor compounds.