Researchers make dairy products more ‘functional’

Rick Bogren
LSU AgCenter researchers are testing how incorporating functional food ingredients into manufactured dairy products could improve their health-giving benefits and how these health-beneficial ingredients affect the physical, chemical and sensory characteristics of dairy products.
Milk fat is high in saturated fatty acids, and saturated fats contribute to gradual blockage of the arteries, reducing blood flow. The omega-3 fatty acids – mostly from fish and vegetable products – on the other hand, are known to have beneficial effects on cardiovascular diseases by lowering cholesterol and triglycerides, lowering blood viscosity and decreasing blood pressure.
The focus of one research project is to replace the saturated fatty acids in cheddar cheese with omega-3 fatty acids. One source of omega-3 fatty acids is a commercial product called OmegaPure, a refined fish oil that can be added to a variety of foods. Another commercial product, Benecol, contains a patented ingredient, plant stanol ester. AgCenter researchers have tested these products in cheddar cheese and evaluated them with different ratios of milk fat.
They found that Benecol and OmegaPure did not affect the overall composition or color of the cheese. Low or medium levels of Benecol and OmegaPure didn’t affect the pH, but high levels of the two products lowered the pH. Neither affected protein levels.

Kayanush Aryana, a researcher in the School of Animal Sciences and the Department of Food Science, manufactured yogurt with arabinogalactan – a compound that stimulates the body’s immune defense system and enhances production of natural killer cells which destroy invading microorganisms – and found no effect on many quality characteristics.He also studied how colostrum – another good source of immune and growth factors – influenced the characteristics of yogurt containing Lactobacillus acidophilus and determined it can successfully be added without adversely influencing yogurt characteristics.
Probiotics are live microorganisms that confer a health benefit when consumed in proper amounts. Researchers have manufactured fat-free, no-sugar-added ice creams with probiotics and developed guidelines governing the proper levels of probiotics. This could eventually lead to the commercial manufacture of probiotic ice creams. The researchers also have manufactured probiotic weight-loss ice cream and yogurt.
Aryana evaluated the effect of various commercially available soluble fibers and found that while all did not perform in a similar manner, each had a beneficial effect on at least one characteristic of probiotic yogurt. He also incorporated several vitamins into fat-free yogurt and found that the lactic acid bacteria and sensory characteristics of the yogurts containing heart-healthy nutrients were not affected, so yogurts for improved cardiovascular health can be manufactured successfully.
Prebiotics are nondigestible carbohydrates that resist hydrolysis and absorption in the upper gastrointestinal tract and are metabolized selectively by at least one type of probiotic in the colon. Aryana’s group is studying the influence of a plant sugar called inulin that’s used to improve the flavor and texture of low-fat and low-sugar processed foods.
Lutein, another naturally occurring compound, may provide protection against age-related macular degeneration, but eating lutein-containing foods may not be sufficient to significantly reduce the risk. Aryana’s group has fortified strawberry yogurt with lutein and studied lutein stability over the shelf life of yogurt.
Jack Losso, an LSU AgCenter food scientist, and Aryana also fortified cheddar cheese with lutein extracted from corn grown in Louisiana and studied its stability in cheese. They found lutein remained relatively stable in these dairy foods. The lutein manufacturer that supported the yogurt project shared Aryana’s method with a yogurt manufacturer in Japan.
Chuck Boeneke, assistant professor of dairy foods technology, has been researching homogenizing milk under high pressure – 30,000 pounds per square inch. The result is that high-pressure homogenization makes two percent milk feel more like whole milk in your mouth. According to a test panel, the texture is the same as whole milk.

 (This article was published in the fall 2008 issue of Louisiana Agriculture.)
11/20/2008 11:26:36 PM
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