Chemical and enzymatic modification of butterfat and butterfat-canola oil blends

Chemical interesterification (CIE) and 1,3-specific enzymatic interesterifi cation (EIE) of butterfat lead to decreases in the 32-42 carbon number trig lycerides (TAGs) and increases in the 44-54 TAGs. The solid-fat-content (SF C) of butterfat and the 80% blend dropped upon EIE at all temperatures. The SFC for CIE butterfat dropped 2-3% below 15 degrees C and increased ca 5% above 20 degrees C, while for the 80% blend, SFC dropped ca 5% only below 1 5 degrees C. The hardness index (KI) and storage modulus (G') of butterfat and blends above 70% butterfat decreased upon interesterification. The drop ping point (DP) of butterfat increased by 3 degrees C upon CIE. The DP of b lends above 60% butterfat did not change significantly upon CIE. The DP of EIE butterfat and blends above 60% decreased 2-5 degrees C. The relative pr oportion of the beta' polymorph decreased slightly upon CIE and EIE and ble nding with canola oil. CIE of butterfat lead, however, to a complete conver sion to the beta' polymorph. Sensory evaluation of spreads made using these modified fats showed that interesterification improved spreadability signi ficantly, however, at the expense of some of the butter-like flavor. (C) 19 99 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.