Innovation Through Education…
Crude fat containing non glyceride components like mucilages, gums, hydrocarbons, free fatty acids, pigments, sterols along with oil are prone to rancidity. Therefore, impurities should be removed prior to storage and distribution of fats and oil. Purification steps normally involves
Interesterification is a chemical reaction that induces the rearrangement of fatty acid within and between triacylglycerols. Interesterification of oil changes its molecular composition to achieve following characteristics.
Hydrogenation brings changes on physical and functional properties of fats and oil. it raises the melting point and reduces the iodine value (IV) of triglycerides. Completely hydrogenated fats (IV<1) are solid and brittle at room temperature. An advantage of hydrogenation is that a wide range of physical properties can be achieved. Functional properties of hydrogenated fat can be determined by solid fat index (SFI) and nuclear magnetic resonance (NMR). The parameters describe the relative amount of solid fat and liquid oil at fixed temperature. NMR gives value according to atomic structure and molecular weight of the substances. Read more
Hydrogenation of vegetable oil refers to conversion of unsaturated liquid oil into saturated or partially saturated plastic fat by catalytic addition of hydrogen. Most widely used catalyst is nickel. The main purpose of hydrogenation of vegetable oil is
For successful hydrogenation, crude oil impurities like phosphorous and sulfur compounds, free fatty acids, and residual soap need to be removed before proceeding for hydrogenation. These impurities have poisoning effect on catalyst and reduce its activity. Canola and rapeseed oil are particularly notorious for high level of natural sulfur which can cause problem in hydrogenation. Read more
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 Read more
Ghani technology is the traditional method of extraction of oil from oil seeds like sesame, mustard, rapeseed etc. by use of simple technology. In this technology, oilseeds are held in scoped circular pit in the center of mortar made of stone or wood. In it works a stout upright pestle which descends from tip curved or angled piece. The pestle rests in a scooped out hollow that also permits pestle to rotate. Today the single angled piece takes the form of two shorter pieces chained together. The bottom of lower angled piece is attached to a load beam. One end of load beam rides around the outside of barrel while other is yoked to animal. The load beam is weighted down either with heavy stones or even seated operator. As the animal moves in circular ambit, the pestle rotates exerting lateral pressure on the upper chest of the pit, first pulverizing the oilseed and then crushing out its oil. Read more
Rendering is the process of extraction of fat from animal tissue by application of heat. Rendering is also called trying. During rendering fat cells are ruptured, expelled and water evaporated. The accompanying connective tissues are separated as solid residue called cracklings. Rendering can be done by following two methods;
Wet rendering:
