Plastic fats and margarines through fractionation, blending and interesterification of milk fat
Milk fat stearins and oleins were blended with high and low melting natural fats to produce plastic fats, vanaspati substitute and confectionery fats. Margarines of improved nutritional value were also formulated. Fractionation was carried out using acetone, hexane, and isopropyl alcohol. The yield (wt of high melting stearin (HMS) from acetone and IPA was 13.0 0.2 to 13.3 0.1 after crystallization for 24 h at 20 degC. The melting point of the products was 49.0 0.5 to 49.8 0.6 degC. However, in hexane the yield of HMS was 12.2 0.2% at 10 degC. The olein fractions were further fractionated at 10 degC from acetone and IPA, and at 0 degC from hexane, to obtain superoleins and low melting stearins (LMS) HMS fractions were blended with rice bran oil and cottonseed oil at the ratio 70 30 (wt/wt) and the superoleins were blended with sal fat and palm stearin at the ratios 40 60, 30 70 and 20 80 (wt/wt) The blends were interesterified (product melting point: 22.7 0.04 to 39.3 0.10 degC) chemically and enzymatically to prepare margarine. The penetration values (in 0.1 mm) of these margarines were noted to be 112 1.52 to 145 0.00.