Butterfat recovery from waste ice cream via churning and clarification – Proof of concept

• Churning is an effective process for recovering butterfat from waste ice cream. • Churning duration and temperature impact the composition of the butter produced. • Churning seems to be generally applicable to commercial American ice cream. • Fat quality is preserved through the churning and clarification processes. Ice cream plants generate some product which will not be sent to retailers for a wide variety of reasons such as packaging or quality defects. This imperfect product is typically fed to animals or discarded. To minimize human food loss and recapture economic value, a practical means to recover the butterfat from this waste material is sought. The present study explores the concept that waste ice cream (WIC) could be churned, just as ordinary cream is churned, to separate the fat as a solid mass. Laboratory scale churning was conducted using baffled flasks and shakers inside of incubators; melted ice cream was used in place of WIC. Three differently formulated varieties of ice cream each produced butter when churned. One of these varieties was studied in more detail; it yielded 88–97 % of its total fat as butter when churned at 12–24 °C for 240 min. Churning duration and temperature had important effects on the composition of the butter produced; depending on the choice of these parameters, butters produced were 21–59 % water. Butter with water >43 % was qualitatively very soft. Experimental churning was also conducted in a more traditional churn, at 70 times the scale of the laboratory churns, and it was shown that the process performed similarly. Removing water and solids from the butter through a clarification process yielded product that was >99 % fat, with very limited oxidative or hydrolytic damage.