Anhydrous milk fat as a substitute for partially hydrogenated fat: A comparative physico-chemical characterisation

Abstract

Partially hydrogenated fat (PHF) is widely used in the food industry especially as a bakery fat. However, PHF is perceived to have adverse effects on health and hence needs to be replaced by a fat which has similar structural and organoleptic properties without having harmful effects on health. In present study anhydrous milk fat (AMF) was tested for this purpose by comparing the structural aspects of AMF with PHF. AMF from three different sources were characterised for their physico-chemical properties. AMF obtained from commercial sources (Com-AMF) and AMF prepared from cow milk (Cow-AMF) and buffalo milk (Bufl-AMF) was used in this study. The AMF samples contained 4.5-6.2% short chain fatty acids and 17.4-19.4% medium chain fatty acids which were not detected in PHF. The amount of trisaturated triacylglycerols (TAG) in Com-AMF, Cow-AMF and Bufl-AMF was 22.3, 18.8 and 22.5 respectively whereas PHF contained 27.5% trisaturated TAG. The results from DSC studies showed that the total change in enthalpy (∆H) for melting as well as crystallisation for Com-AMF was closer to that of PHF. The SFC pattern for Com-AMF and PHF indicated the plasticity of both the fats. Com-AMF samples showed TAG in β' polymorph similar to that of PHF. Micro-structural analysis showed crystal clusters of comparable size for Com-AMF and PHF with high refraction. The structural studies indicate that PHF can be replaced to certain extent with Com-AMF in the preparation of food products with desirable organoleptic properties.