Date of Award

12-2010

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Food Science and Human Nutrition

Advisor

Denise I. Skonberg

Second Committee Member

Beth L. Calder

Third Committee Member

Alfred A. Bushway

Abstract

Food fortification has become a popular and useful way to deliver nutritive health benefits to populations that otherwise may suffer from nutrient deficiencies. One of the fastest growing food fortification trends in recent years has been omega-3 fatty acid fortification of food products. The most commonly seen efforts have been the incorporation of a-linolenic acid (ALA) obtained from flax seed, and to a growing degree incorporation of docosahexaenoic acid (DHA) from algae. Marine sources such as algal oil and fish oil provide high doses of the long chain polyunsaturated fatty acids (PUFA) associated with lowered risk of cardiovascular disease. Fish oil is superior to both flax seed oil and algal oil because of its ability to deliver high doses of both DHA, important for brain and eye health, and eicosapentaenoic acid (EPA), important for cardiovascular health. The limitations of fish oil fortification are its susceptibility to lipid oxidation and distinctive fishy flavor and aroma. The objectives of this research were to 1) incorporate high levels of fish oil into soft cheeses to maximize EPA + DHA content per serving and 2) determine consumer acceptability of the fortified cheeses. The first study investigated the fortification of soft goat cheese with highly purified menhaden oil at levels formulated to deliver 1000, 1300, and 1500 mg EPA + DHA per serving. Most of the fish oil was lost to the whey fraction of the cheese, resulting in an average EPA + DHA content of 126.9 mg EPA + DHA per serving. The lowest level of fortification delivered 79% of the proposed RDI for EPA + DHA and was shown to be 'liked moderately' by consumers who also said they 'might buy' it. The vacuum-packed fortified cheese had excellent shelf-life stability showing little lipid oxidation over the course of a four-week refrigerated shelf-life study. The second study was designed to investigate the fortification of cream cheese with smoked salmon oil and mixed tocopherol, green tea, or no antioxidant. Equal quantities of smoked salmon oil were added to half and half and the cheese was formulated to deliver between 750 and 1000 mg EPA + DHA per serving. Fatty acid analysis revealed actual delivery of between 800 and 900 mg per serving suggesting-very little loss of oil to whey and almost 100% incorporation of the smoked salmon oil into the curd. There were no overall differences in oxidative stability among cream cheese treatments during four weeks of refrigerated storage, likely due to the naturally occurring tocopherol present in the smoked salmon oil. Consumer acceptability of cream cheese was tested using three levels of salmon oil fortification, providing 150, 300, and 750 mg EPA + DHA per serving, but the overall acceptability of all three samples was equivalent with participants indicating they liked the cheeses 'slightly to moderately'. Both studies successfully met the objectives demonstrating that soft cheeses can be fortified with fish oil at levels significant enough to make an 'Excellent Source' claim for EPA + DHA without sacrificing consumer acceptability or purchase intent.

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