Hard fats as additives in palm oil and its relationships to crystallization process and polymorphism

- Adding hard fats to palm oil improve the crystallization behavior.
- Hard fats containing larger acyl chains proved to be influential additives.
- Hard fats influence changes in the polymorphism of palm oil.
- Hard fats behave as template effects for the induction of β crystals.

The application of palm oil in fat-based product can be inappropriate due to its low crystallization rates and formation of crystalline clusters in post-processing stages. The adjustment of these properties can be achieved with the addition of hard fats, which are low-cost industrial products resulting from the process of total catalytic hydrogenation of liquid oils. During the crystallization of palm oil, these components can act as preferential nuclei in a crystalline ordering process, and may induce or stabilize specific polymorphic habits. The present work evaluated the addition of hard fats from palm kernel (PKO), palm (PO), soybean (SO), cottonseed (CO) and crambe oils (CR), at concentrations of 1 g, 3 g, and 5 g/100 g of oil blend, on the crystallization behavior of palm oil. The study involves the crystallization kinetics, thermal behavior and polymorphism. The addition of hard fats provided a significant decrease of the induction time for nucleation in all blends, except with PKO. All blends showed a preference for crystallization in the polymorphic habit β′, but blends with SO and CR, however, formed a miscellany of β′ + β crystals. Adding hard fats to palm oil increase its compatibility for uses in formulations of cocoa butter alternatives and fat-based products.