Different functionalities (nutritional and physical) require specific compositions that are usually not found in a single natural fat or oil. For this reason, fats and oil are often modified in order to achieve these desired compositions and thus physical and nutritional properties. For example; melting behavior, solid fat content are important factors in formulation of shortening and margarine while decreasing poly unsaturated fatty acids (PUFAS) to increase oxidative stability is important in frying oil. Following are the commonly used methods used to modify fats and oil
- Interesterification (chemical / enzymatic )
Fractionation of fat and oil: fractionation is the process to get several fractions of different melting point, hardness and solid fat content from solid or semisolid fat and oil thus makes it possible to extend the application of edible fat and oil in related food products. Fractionation has two stage process
- Partial crystallization (in crystallizer)
- Separation of solid and liquid fraction (filtration/centrifugation)
There are three types of fractionation method
- Dry fractionation
- Detergent fractionation
- Solvent fractionation
Fractionation technique have been used to produce cooking and frying oil from palm oil, soft butter from anhydrous milk and so on. Fractionation is the reversible process of energy saving and less loss in yield and also can easily get both hardened fat without trans-isomer and liquid oils.
Name : Pratiksha Shrestha
Ms. Shrestha holds masters degree in food engineering and bioprocess technology from Asian Institute of Technology (AIT) Thailand. She is currently working for Government of Nepal at Department of Food Technology and Quality Control (DFTQC), Kathmandu. She is also a teaching faculty in College of Applied food and Dairy Technology (CAFODAT) affiliated to Purbanchal university, Nepal.