Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Dairy Science

First Advisor

Robert J. Baer


Today's consumers are demanding food products that are "low-fat", "reduced fat", "high in -unsaturated fatty acids", and "low cholesterol". This trend in food product selection is at the advice of many health professionals. Current health recommendations are to lower the dietary intake of fat, especially saturated fat. In 1992, total dairy sales accounted for over 10% of total food sales (Milk Industry Foundation, 1993). Since dairy products are perceived as being hypercholesterolemic, a market exists for dairy products which are "lower in fat" and/or "lower in saturated fat". It is said that "consumer perception is marketing reality", and because of this the dairy industry may alter consumers views on dairy products by manufacturing perceived "healthier" products. Due to current dietary guidelines, dairy products with higher concentrations of unsaturated fatty acids could include a portion of the dairy market. Coronary heart disease (CHD) risk factors played a major role in setting these new dietary guidelines. Greater than 500,000 deaths are blamed on CHD each year in the United States (Ney, 1991). Atherosclerosis is a disease in which lipids and cholesterol accumulate on the arterial walls causing them to thicken, resulting in CHO. It is important that the dairy industry realizes these concerns and acts on them by capturing a share of the market for foods perceived as being healthier. Evidence suggests that only certain fatty acids are associated with increasing the risks of CHD. Milk fat from dairy cows possesses its own unique fatty acid profile. It contains approximately 66% saturated fatty acids, 30% monounsaturated, and 4% polyunsaturated. Half of the medium-chain (C12:0 to C17:0) and almost all of the long-chain fatty acids (C18:0 and longer) are derived from the cow's diet (Eppard et al., 1985). This last statement suggests that dietary manipulation could be used to alter the fatty acid profile of milk fat. Other factors that may alter the fatty acid content of milk include seasonal variation, genetic variation, stage of lactation, and use of recombinant bovine somatotropin. It has been found that feeding cows supplemental fat increases the concentration of unsaturated fatty acids in milk fat (Grummer, 1991). While this may be appealing to the consumer there are still some potential problems which should be overcome before integration into the industrial market. The first concern is producer economics for buying special feed for their dairy herd. Another potential problem would be the manufacturers economics and logistics regarding keeping the milk separate throughout and after pickup and processing. It has also been reported (Stegeman et al., 1991; Lightfield et al., 1993) that the fat content in milk higher in unsaturated fatty acids is underestimated when analyzed by the mid-infrared spectroscopic method. It is important that these concerns are realized and corrective action is taken. The National Cheese Institute (1992) stated that total retail cheese sales were up 5% in 199.1, reaching in excess of $18 billion dollars. Despite perceived health concerns the nation's cheese market has continued to grow with one-third of the milk supply going towards its manufacture. The largest growth in the cheese industry belongs to the Italian cheese market which went from 2.06 pounds (4.5 kg) per capita in 1970 to 9.36 pounds (20.6 kg) in 1991 (National Cheese Institute, 1992 ). American type cheeses (of which Cheddar makes up the largest portion) increased from 7.02 (15.4 kg) pounds per capita in 1970 to 11.1 pound (24.4 kg) in 1991. Cheeses which meet regulations for reduced fat or low-fat have steadily gained prominence on the dairy shelf. It appears that cheeses which meet both dietary recommendations of being lower in fat and saturated fat would stand an increased chance to succeed in today's marketplace. The objective of this study was to feed supplemental fat from extruded soybeans to lactating dairy cows and to manufacture a reduced fat Cheddar cheese higher in unsaturated fatty acids with acceptable sensory characteristics.

Library of Congress Subject Headings

Cheddar cheese
Dairy cattle -- Feeding and feeds
Unsaturated fatty acids


Includes bibliographical references (pages 35-42)



Number of Pages



South Dakota State University


In Copyright - Non-Commercial Use Permitted

Included in

Dairy Science Commons