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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Dairy and Functional Foods Research » Research » Publications at this Location » Publication #408323

Research Project: Reclaiming Value from Coproducts of Dairy Food Manufacture

Location: Dairy and Functional Foods Research

Title: Recovery of milk fat from waste ice cream through ethanol-induced emulsion destabilization

Author
item LEE, CHANGHOON - Oak Ridge Institute For Science And Education (ORISE)
item Garcia, Rafael
item Bumanlag, Lorelie
item LIANG, CHEN - Oak Ridge Institute For Science And Education (ORISE)

Submitted to: International Journal of Dairy Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/12/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Ice cream manufacturers produce imperfect products that are not suitable for sending to retailers, leading to food wastage. To address this issue, this study aimed to extract fats from discarded products. While the conventional method involves ultracentrifugation, it is not cost-effective and practical for the food industry. Therefore, approaches using ethanol as a organic solvent under various temperatures were applied to ice cream, enabling the separation of fats effectively within a short period of time. The optimal condition found in this study is considered a promising first stage in comprehensive fat purification, and may contribute to the reclamation of human food and economic value.

Technical Abstract: Ice cream manufacturers typically generate some imperfect product that is discarded rather than being sent to retailers, resulting in human food loss. Ice cream may be seen as a dispersion of fat globules in water, stabilized by proteins, surfactants, and stabilizers. Addition of a water-miscible organic solvent will decrease the dielectric constant of the continuous aqueous phase, altering the solubility of ice cream components. In particular, proteins are expected to become less soluble, and fats are expected to become more soluble as the organic modifier concentration increases. In the present study, it is proposed that ethanol may be used to “break” the ice cream emulsion and facilitate the recovery of valuable milk fat. Melted ice cream was mixed with varying concentrations of ethanol to achieve a final concentration range of 0 to 50%. Ice cream maintained its uniformity in the absence of ethanol but upon the addition of ethanol concentrations below 20%, a semi-solid, high-fat top layer was formed. When the final ethanol concentration reached 25%, all the fat was successfully retrieved in the separated pellet. Increasing the concentration of ethanol in ice cream emulsion led to its destabilization and separation of liquid and solid components, resulting in an increase in viscosity. Furthermore, elevating the temperature of the ice cream emulsion contributed to destabilization, resulting in enhanced fat recovery and ultimately achieving circa 100% fat retrieval in the separated pellet. Under the experimental conditions, neither ethanol addition nor temperature increase had a negative effect on fat hydrolysis or oxidation. Based on these results, fat from waste ice cream can be recovered through the destabilization method using ethanol.