Location: Dairy and Functional Foods ResearchTitle: Cross-linking of bovine and caprine caseins by microbial transglutaminase and their use as microencapsulating agents for n-3 fatty acids Author
Submitted to: International Journal of Food Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2013
Publication Date: 6/1/2014
Publication URL: http://handle.nal.usda.gov/10113/59502
Citation: Mora-Gutierrez, A., Ataie, R., Kirven, J.M., Farrell Jr, H.M. 2014. Cross-linking of bovine and caprine caseins by microbial transglutaminase and their use as microencapsulating agents for n-3 fatty acids. International Journal of Food Science and Technology. 49(6):1530-1543. DOI: 10.1111/jifs.12450. Interpretive Summary: Polyunsaturated fats are essential for human growth and development, but they are not always abundant in the average American diet. Fish and algal oils represent potentially excellent supplements in milk and dairy products, but they are may produce off-flavors on standing. This research is aimed at finding ways to prevent this deterioration using the milk proteins, the caseins as protective agents. The proteins were used to form a protective coat around the fats. It was discovered that treatment of the caseins with an enzyme that produces cross links in the proteins provided the best protection from deterioration. Interestingly, one type of goat casein was best before or after cross-linking. This research may lead to new supplements for milk and dairy products, and will yield new uses for caseins.
Technical Abstract: Bovine and caprine caseins were cross-linked with microbial transglutaminase (mTG). The mTG-cross-linked bovine or caprine casein dispersion, mixed with 14.5% maltodextrin (DE = 40), was used to prepare emulsions with 10.5% algae oil. Oxidative stability of emulsions was evaluated by peroxide values (PV) and anisidine values (AV). Adding liposoluble rosemary extract rich in carnosic acid and delta–tocopherol lowered the formation of hydroperoxides and their subsequent decomposition products in emulsions. Emulsions stabilized with liposoluble rosemary extract rich in carnosic acid and delta–tocopherol were spray-dried with inlet and outlet temperatures set at 180 and 95 deg C. After 4 weeks of storage at 30 deg C, the algae oil microencapsulated with mTG-cross-linked bovine casein reduced AV and PV by 19 and 34% respectively, while the algae oil microencapsulated with mTG-cross-linked caprine casein with low levels of alpha s1-casein reduced AV and PV by 24 and 42%. The above results clearly indicated that the choice of milk caseins (bovine vs. caprine) cross-linked with mTG impacts the oxidative stability of spray-dried algae oil emulsions (microcapsules) enriched with n-3 fatty acids.