Specialty fats - new crystallization and separation technologies to improve melting properties
Dr Veronique Gibon, Consultant, Artemis Lipids by VG, Belgium

In order to overcome the shortage and, at the same time, improve the physical properties of some cocoa butter sources, the confectionery industry is continuously looking for alternatives to either replace cocoa butter in their recipes or improve its melting properties. These alternatives are better known as speciality or confectionery fats. Specialty fats belong to a unique category because they are substitutes for other types of high value-added exotic fats like cocoa butter, typically used in an extensive range of chocolate, confectionery, bakery and ice cream products. Confectionery fats are designed to resemble the functional properties of coca butter and there are three types of cocoa butter alternatives – the cocoa butter equivalents (CBE), the cocoa butter substitutes (CBS) and the cocoa butter replacers (CBR).

From a processing point of view, all vegetable fats used in these applications are mostly fractionated (ideally with dry, optionally with solvent processes), possibly hardened (preferably with full hydrogenation), or even interesterified (chemically or enzymatically) to match the product specifications.

When applied to speciality fats, the term ‘fractionation’ refers to a selective fractional crystallisation of triglycerides, followed by the separation of the solid from the remaining liquid fraction. The fractional crystallisation is carried out by controlled cooling of a melted fat (dry fractionation) or after it has been diluted in an organic solvent (solvent fractionation). Dry fractionation is a sustainable and well proven process as it does not use chemicals, produces no effluent and experiences no oil losses. Different crystalliser types with appropriate and specific designs are commercially available on the market, as well as different separation processes, with the membrane filter press and the vacuum belt filter most widely used in dry and solvent fractionation, respectively.