Studies on physical, thermal and hydrodynamic properties of interesterified oils

Oils and fats are vital constituents in our daily diet, which provide energy,
essential fatty acids, and serve as a carrier of fat soluble vitamins. In India, about 80%
of the edible oils such as ground nut, sunflower, safflower, mustard, rice bran and
coconut oil as well as hydrogenated fats are used for cooking and frying. During frying
several undesirable physical and chemical changes occur in oils/fats such as
hydrolysis, oxidation as well as thermal decomposition and thermal polymerization.
Extensive research has been reported in literature to describe the chemical changes in
frying oils, but very few have attempted to relate these chemical changes to the
physical and thermal properties of the oil. Physical properties of oil influence its heat
transfer characteristics during immersion frying. There is an awareness regarding the
utilisation of blended oil for culinary uses. The blended oil was reported to show higher
oxidative stability, less free fatty acid and less polar compound formation as well as
higher heat stability during frying operations. However, biotransformation of edible oil
through enzymatic interesterification holds further promise as such modifications
produce clear, transparent, homogeneous, highly stable oils with improved physical
and/or thermal characteristics. These various aspects is addressed in this investigation.