A review of the use of scraped surface heat exchangers to crystallize fats and fat-based products

Abstract

Scraped surface heat exchangers (SSHE) are very important in many industriesincluding chemical, cosmetic, pharmaceutical, and food. Some of the applica-tions of SSHE in the food industry are to control the crystallization process in fatsand frozen desserts, among other applications. This can be achieved because ofthe scraping action of the fixed blades that continuously rotate within the coolingsurface removing the crystallized product from the surface, improving heat trans-fer, preventing crystal build-up on the wall, and accelerating the crystallizationprocess. There are many process parameters that can be controlled in the SSHEto control and tailor the fat crystallization process, and many fat-based productscan benefit from this machine, such as shortenings, spreads, and chocolates.Moreover, SSHE have recently been coupled to other processing devices suchas high intensity ultrasound (HIU), high pressure homogenizers, and others toimprove the crystallization process even further. This review focuses on theimportance of SSHE in fat and fat-based products and discusses the importanceof the parameters of the SSHE in the crystallization process, as well as how theyaffect the physical properties of different fat sources and spreads.