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

Authors: Garcia, Rafael; BUMANLAG, LORELIE - Retired ARS Employee; Olszewski, Faith; HUYNH, FARAH - Former ARS Employee; LEE, CHANGHOON - Non ARS Employee; Plumier, Benjamin; Renye Jr, John; Tomasula, Margaret

Submitted to: Applied Food Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2024
Publication Date: 12/22/2024
Citation: Garcia, R.A., Bumanlag, L.P., Olszewski, F., Huynh, F., Lee, C., Plumier, B.M., Renye Jr, J.A., Tomasula, M.M. 2024. Butterfat recovery from waste ice cream via churning and clarification – Proof of concept. Applied Food Research. 5:100665. https://doi.org/10.1016/j.afres.2024.100665.
DOI: https://doi.org/10.1016/j.afres.2024.100665

Interpretive Summary: At the plants where ice cream is produced, it is inevitable that some of the ice cream will not be sent to retailers to be sold. Many different things can go wrong, which result in the ice cream being rejected, even in many cases when it is still edible, wholesome food. This ice cream is typically donated to a farmer to feed pigs or disposed of in some other way. Salvaging this ice cream could benefit both the ice cream manufacturers and the public. The research reported here provides a proof of concept for a new method to recover the butterfat from waste ice cream. The method involves churning the liquid ice cream, similar to the way that cream is churned to produce butter. We have demonstrated that this process works, but the substance produced has a higher water content and smells like the ice cream it was made from. Although this “butter” seems appetizing, it contains unknown and varying contamination from various food allergens, which limits its use as a commercial food product. Instead, the intent is that the butter would later be refined, and then recycled by using it in food manufacturing. The research reported here is successful enough that it justifies continued work to further develop this technology and then eventually to integrate it into real ice cream plants.

Technical Abstract: 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 minutes. 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 quality deterioration.