Preparation and physical properties of bloom-resistant chocolate using no-trans CBR made of palm-based triacylglycerols

Abstract: Cocoa butter replacer (CBR) is employed for compound chocolates that do not require any tempering process. Conventional CBRs consist of triacylglycerols (TAGs) with trans fatty acids and their compatibility with cocoa butter is < 20%. In 2015 the FDA decided to exclude Partially Hydrogenated Oils (PHOs) from GRAS and high attention has been paid to prepare trans-free CBRs. In the present study, we prepared 2 types of no-trans CBRs (Fat A and Fat B) and evaluated their applicability to replace the conventional trans-fat based CBRs.

Fat A and Fat B were prepared by inter-esterification and solvent fractionation. Fat A was composed with palm oil (PO) and fully-hydrogenated palm oil (FHPO), Fat B was composed with PO, FHPO and palm kernel oil. The melting points of Fat A and Fat B are 39.0°C and 38.6°C, respectively. Both fats were stored under thermal thawing condition (17↔28°C), and their polymorphic structures were determined. Then, compound chocolates were prepared using the two fats, and bloom resistance was observed.

In the presence of 20% cocoa butter, Fat A maintained beta-prime form for 1 month, while Fat B sustained beta-prime form for more than 2 months. Compound chocolate with Fat A showed fat bloom after 2 months storage, while fat bloom did not occur in compound chocolate with Fat B for 3 months. From this study, we found that both fats are suitable as the alternative fats of conventional trans-fat-based CBRs. Furthermore, it was found that the no-trans CBR with partially lauric acid has high stability of beta-prime form containing 20% cocoa butter. Therefore, we consider that the no-trans CBR with partially lauric acid is the solution to replace trans-fat based CBRs.