Melting points, fats palm stearin

These are fats rich in symmetrical disaturated TAGs which behave like cocoa butter in all respects, and are able to mix in all proportions with cocoa butter. The desirable characteristics of cocoa butter are due to the SOS TAGs (S = saturated) which provide suitable melting point and solid fat content to give rapid melt in the mouth and cooling sensations. Palm mid-fraction (PMF), which has high contents of POP, is easily formulated with other SOS fats for chocolate products (Berger 1981). About 70%-80% PMF with 20%-30% shea or sal stearin, or 60%-65% PMF with 20%-30% shea or sal stearin and 15%-20% illipe are suitable for plain and for milk chocolate with 15% milkfat. Compatibility of cocoa butter (CB) and CBE is affected by addition of milkfat and its fractions into the product (Sabariah etal. 1998). Eutectic interactions between anhydrous milkfat (AMF), CBE and CB were noticeable due to different polymorphism encountered in these fats. 

Sellami et al. (2012) in a solvent free system using a Rhizopusoryzae lipase immobilized onto CaCOs to produce a suitable fat for margarine formulation. This ecofriendly approaeh used low value bioresources like palm stearin and palm olein to obtain a healthier product. The triacylglycerol (TG) profile showed a decrease in the amoimts of saturated TG and increased the lower melting point TG ratio, especially triolein (000). 

Of the above the most important from a soap-maker s point of view are stearin, palmitin, olein and lanrin, as these predominate in the fats and oils generally used in that industry. The presence of stearin and palmitin, which are solid at the ordinary temperature, gives firmness to a fat the greater the percentage present, the harder the fat and the higher will be the melting point, hence tallows and palm oils are solid, firm fats. Where olein, which is liquid, is the chief constituent, we have softer fats, such as lard, and liquid oils, as almond, olive and cotton-seed. 

Palm midfraction (PMF), a fraction of palm oil whose melting points are between those of palm stearin and palm olein [77], has been employed for vegetable-fat-based creams as well in the production of cocoa butter equivalent fats (CBEs) used in chocolate [78]. The effects of additions of SOEs and PGEs on the crystallization of PMF in O/W emulsions were studied recently [79]. Figure 13a shows the isothermal crystallization behavior of PMF in oil-in-water emulsion at 10°C without (pure) and with the addition of 1 wt% S-170. It is obvious that the V values of the pure emulsion are always smaller than in emulsions with S-170... 

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