Fractionation of edible fats—Separation of fat-covered particles by decanter centrifuge

Abstract

This work investigates the feasibility of using a decanter centrifuge to separate solid particles coated with a high melting fat from a liquid oil. The process involves feeding cold silica particles into a melt, upon which the hardstock fat crystallizes, and the particles are subsequently separated using a decanter centrifuge. Being the first attempt for such a design, only the separation step is studied, and a model system is used. It comprised canola oil (CO), fully hydrogenated rapeseed oil a priori crystallized on silica gel particles. Different particle sizes and accelerations of gravity were studied. To measure the success of this separation process, the data from light microscopy, and differential scanning calorimetry of the feed, oleins, and stearins were used. The findings show that the separation of the fatty particles used in this work, and liquid oil in decanter centrifuges is feasible while future research should focus on the crystallization part of the process. The model developed to describe the oil-holding capacity of the cake focuses on the capillary liquid entrapped in the spaces between the particles and sufficiently represents the experimental findings which show that separation efficiencies increase with increasing centrifugal acceleration.

Practical Applications: This work introduces an alternative fat fractionation process by separating a model system of CO, FHRO, and solid entrainers through a decanter centrifuge. The results can be potentially used for the development of a fully continuous dry fractionation process, which can achieve in one step higher SE than the conventional ones and can be tripalmitate-selective.