Fatty acid profiles of in vitro digested processed milk

Authors: Tunick, Michael; Van Hekken, Diane

Submitted to: Foods
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/3/2017
Publication Date: 11/9/2017
Publication URL: https://handle.nal.usda.gov/10113/5859847
Citation: Tunick, M.H., Van Hekken, D.L. 2017. Fatty acid profiles of in vitro digested processed milk. Foods. 6:99.

Interpretive Summary: Milk contains fatty acids, such as omega-3 fatty acids and conjugated linoleic acids, that provide health benefits when consumed, but the ability to digest milkfat to release these and other fatty acids following different processing conditions has not been fully studied. In this study, the release of fatty acids from milkfat subjected to pasteurization, homogenization, or both was determined following a simulated digestion technique, which mimics digestion in the human stomach and small intestine. Pasteurization and homogenization combined were found to enhance the release of healthy fatty acids from milkfat under the controlled digestion conditions compared to the other combinations studied. Findings from this and other studies using animal and human models will aid in understanding the digestion of milkfat and the release of healthy fatty acids when milk and dairy foods are consumed.

Technical Abstract: Digestion of milkfat releases some of the long-chain (18-carbon) fatty acids (FA) that can provide health benefits to the consumer, yet because they are found in small amounts and can be difficult to identify, there is limited information on the effects that common fluid milk processing may have on the digestibility of these FAs. This study provides FA profiles for raw and combinations of homogenized and/or heat treated (high and ultra-high temperature pasteurization) milk, before and after in vitro digestion, in order to determine the effects of processing on the digestibility of these healthy fatty acids. Use of a highly sensitive separation column resulted in improved FA profiles that showed that when milk was subjected to both pasteurization and homogenization, the release of the 18-carbon FAs, oleic acid, linoleic acid (an omega-6 FA), rumenic acid (a conjugated linoleic acid, CLA), and linolenic acid (an omega-3 FA) was higher than with either pasteurization or homogenization or no treatment. Milk is noted for containing the omega-3 FAs and CLAs, which are associated with positive health benefits. Determining how processing factors may impact the components in milk will aid in understanding the release of healthy FAs when milk and dairy foods are consumed.