Submitted to: Journal of Dairy Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2011
Publication Date: 12/20/2011
Publication URL: http://handle.nal.usda.gov/10113/55654
Citation: Estrada, J.D., Boeneke, C., Bechtel, P.J., Sathivel, S. 2011. Developing a strawberry yogurt fortified with marine fish oil. Journal of Dairy Science. 94(12):5760-5769. Interpretive Summary: Fortified dairy products appeal to a wide variety of consumers and have the potential to increase sales in the yogurt industry and contribute to boost the intake of omega-3 fatty acids. Many attempts to add long chain omega-3 fatty acids (DHA and/or EPA) directly to foods have been unsuccessful because they are unstable and rapidly give rise to a fishy odor and taste upon oxidation, making food unpalatable. Microencapsulation is a process by which particles of sensitive oils can be packed into film(s) of a coating material. The objectives of this study were to develop a strawberry yogurt containing microencapsulated salmon oil (2% w/v) and evaluate its characteristics during a 1 month time period. The addition of 2% w/v of microencapsulated salmon oil to yogurt mix prior to pasteurization and homogenization had no effect on the pH and syneresis, when compared to similar samples without added salmon oil. Oxidation of both yogurt samples with and without added emulsified salmon oil increased during the storage period. There were some slight but significant differences in the characteristics of yogurt with the added encapsulated salmon oil; however, it is feasible to manufacture and fortify yogurts with salmon oil omega-3 fatty acids. The fortification of strawberry yogurt with microencapsulated oils from marine fish byproducts offers new market opportunities for the seafood and functional dairy products industry.
Technical Abstract: Fortified dairy products appeal to a wide variety of consumers and have the potential to increase sales in the yogurt industry and contribute to boost the intake of omega-3 fatty acids. The objectives of this study were to develop a strawberry yogurt containing microencapsulated salmon oil (2% w/v) and evaluate its characteristics during a 1 month time period. Oxidation parameters of unpurified, purified and encapsulated salmon oil were measured. Yogurts including a control were produced and acidity, syneresis, thiobarbituric acid, color and lactic acid bacteria were measured at day 1, and weeks 1, 2, 3, and 4. Fatty acid methyl esters were measured by gas chromatography. The experiment was replicated three times and data was statistically analyzed at a=0.05 using the Statistical Analysis System® (SAS Institute Inc., Cary, NC). Total oxidation of unpurified salmon oil, purified salmon oil and MSO was calculated to be 20.7±1.26, 10.88±0.1 and 13.36±0.25, respectively. Free fatty acids contents were 1.61±0.19, 0.59±0.02 and 0.77±0.02% for USO, PSO and MSO, respectively. Eicosapentaenoic acid and docosahexaenoic acid were the predominant fatty acids in MSO. Among polyunsaturated fatty acids in SYMSO, EPA and DHA were the predominant fatty acids and neither was present in SY. Fortification of SY with MSO had no significant effect on yogurt pH and syneresis. A decrease in concentration of LAB was observed during the storage study of yogurts. TBA values increased proportionately to storage period and SY had a lighter red (higher L*) and less yellowish (lower b*) color than SYMSO. Although there were some slight yet significant differences in the characteristics of SYMSO compared to SY, it is feasible to manufacture and fortify yogurts with salmon oil omega-3 fatty acids.