Separation of Butterfat from Waste Ice Cream Using Enzymatic Digestion and Disc Bowl Centrifugation

Wasted ice cream products contain many valuable food components, most notably butterfat, which has potential for recovery. Disk bowl centrifugation, widely used in milk processing, has not been previously used with ice cream. In comparison to milk, ice cream has larger variations in fat content, smaller fat globule sizes, and the presence of additives and emulsifiers. An Armfield FT15 lab-scale disk bowl centrifuge was used to separate samples of five ice creams containing 1.25 kg melted ice cream each at temperatures ranging from 30 °C to 80 °C, while incorporating enzymatic digestion from four enzymes to encourage fat separation. Results showed that fat capture from ice cream is aided by enzymatic digestion. Rennet was the most effective enzyme tested. Although some varieties performed better without processing compared to 1 h incubation, all ice creams benefitted from processing after 4 h of incubation, with at least 40% fat (weight basis) and high total recovery. Optimal conditions were found with a 4 h rennet incubation, with four of five ice cream varieties showing greater than 90% fat recovery and a fat concentration of 37% wet basis or higher.