Milk for More People

Millions of people worldwide suffer from lactose intolerance caused by a deficiency of the enzyme lactase in their digestive tracts.  As a result, they are unable to digest large amounts of lactose (milk sugar) present in cows' milk without suffering from abdominal discomfort. 

In the 1980's, ARS researchers used lactase from nonhuman sources to break down about 70 percent of milk sugar into simple sugars--glucose and galactose.  Trials showed most lactose-intolerant people could drink this modified milk and digest it without problems.  Scientists also used the treated milk to make other milk products, including ice cream and yogurt.

A private firm, Lactaid, Inc., became the first company to commercialize the research. 

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Canned Milk that Pours

Some 30 years ago, industry preferred to sterilize evaporated milk in 3 to 15 seconds with an efficient high-temperature, short-time (HTST) process. The trouble was that evaporated milk made the HTST way tended to gel in the can if stored too long at room temperature. The thickening was harmless, but consumers understandably wanted milk that poured.

An ARS dairy team in Philadelphia found that the shelf life of the HTST sterilized milk could be extended from two to six times by adding stabilizers already used in processed cheese. The practice was adopted by industry and is still in use today.

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Saving Our Bacon

It's no exaggeration that ARS researchers in Philadelphia helped save the bacon industry. In the mid-1960's, it had been reported that sodium nitrite, an inorganic compound used to cure bacon and frankfurters, could, under certain conditions, form cancer-causing chemicals called nitrosamines. After analysis with sensitive instruments, extremely small amounts of one nitrosamine were discovered in hot dogs. Another was found in minute amounts in bacon after frying it at high temperatures. It was the heat that did it; the chemical wasn't present in raw bacon at all. Consumer organizations promptly called for a ban on nitrites in foods and a similar ban on sales of bacon.

In an effort to save the nation's bacon, Eastern lab researchers first searched for substitutes for nitrites, testing some 500 compounds as curing agents. Unfortunately, none retarded the growth of microbes as well as sodium nitrite. But researchers also found that the addition of vitamins C and E reduced the levels of nitrosamines in fried bacon and in nitrite-cured products. The findings led to changes in Federal regulations and in industry processing to minimize consumer exposure to nitrosamines. The proposed ban on bacon, a favorite breakfast meat, was averted.

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Low-fat Pizza Cheese

ARS researchers developed reduced-fat mozzarella cheese--now used in the USDA National School Lunch Program.  To date, more than $44 million worth has been purchased for the program.  This all-natural cheese contains only 10 percent fat--full-fat mozzarella contains 23 percent fat.  ARS's low-fat mozzarella has melting and texture properties similar to commercial full-fat Mozzarella.  The cheese is manufactured using ordinary cheesemaking procedures, but at reduced temperatures.  This novel treatment produces mozzarella that melts and strings freely when heated in a pizza oven.  Reduced-fat mozzarella cheese allows school children to enjoy pizza--their favorite lunch--while reducing their dietary fat intake and lowering their risk of diet-related diseases as adults.

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Finding Uses for Whey

Agricultural scientists continue to search for new ways to use whey, and they have found a good many. Besides animal feed, whey is used today in a few dairy products--including a popular chocolate drink--in prepared dry mixes, in candy, in baked goods, in pasta fortified with extra protein, and in baby foods. ARS chemists also cut the cost of an expensive noncaloric sugar--lactulose--used to treat a serious liver disease, by making it from whey.

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Beef Today

Many people refer to select-grade beef as "grass-fed," but that's a misnomer. Steers graded either choice or select typically had the same feedlot diet of grain; corn is currently cheap and plentiful. The breed frequently accounts for the difference in grade. Some breeds that do well in hot climates, like Brahmans, are apt to be on the tough side. Angus-Hereford crosses fed in Montana are usually tenderer.

Much of current ARS beef research is directed toward cross-breeding cattle. The most ambitious program, begun in 1970, is carried out at the U.S. Meat Animal Research Center, near Hastings, Nebraska. So far, some 30 breeds of cattle sires from Europe, Africa, India, and South America have been crossbred with Hereford or Angus mothers. The offspring are evaluated on growth rate and size at maturity, lean-to-fat ratio, age at puberty, and milk production. Their meat is also evaluated for marbling, the interwoven fat associated with tenderness.

Center researchers have found, however, that marbling accounts for only 10 percent of the variation in beef tenderness. The biggest factor, controlling 44 percent of the variation in meat tenderness, is a protein called calpastatin. Various forms of a gene for calpastatin have been located on a beef chromosome, and Center scientists hope that further genetic research will help them develop new strategies for producing more tender beef. Meanwhile, they are working on breeding tenderizing traits into cattle.

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Reducing Salt in Meat

Responding to increasing health concerns over salt in the 1980's, researchers at the ARS Philadelphia lab wondered how much salt is really necessary to preserve meat. How much, they asked, is simply added by processors "for good measure." Painstakingly, they replaced traditional formulas with precise information on salt content for product after product. In the mid-1980's, they reported that just about all processed meats could be made with 20 to 25 percent less salt without risking spoilage. Lower-salt franks, they found, compared well with conventional hotdogs in flavor, texture, and shelf life. They also found that refrigeration is more important than salt level in retarding the growth of microorganisms that cause spoilage.

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Cracking an Egg Mystery

It's rare today to break an egg that isn't fresh, but that wasn't always the case. In the 1960's certain kinds of bacterial spoilage in fresh eggs were costing the industry $20 million a year. It was common practice on egg farms to machine-wash all eggs before marketing them. ARS researchers in the Western lab traced the cause of the spoilage to washing eggs in water high in iron. As a result, egg producers had their wash water tested and stopped using water with high iron content. That particular problem of spoilage disappeared.

In other egg research over the years, the San Francisco scientists improved the flavor of powdered eggs, which had been despised by millions of servicemen in World War II; found a way to pasteurize the whites of eggs for use in meringue and angel food cake; and adapted frozen convenience breakfasts originally developed for the Air Force for civilian use in microwaves.

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Pork Has Fewer Calories

Pork is a lower-calorie meat than it was 10 years ago, thanks to a combination of breeding, diet, and better farm management. Pork is 31% leaner, 14% lower in calories, and 29% lower in saturated fat than it was in the mid-1980's.

The most important single reason for production of a leaner pork is selective breeding--the careful selection of leaner hogs generation after generation. The process was begun by ARS in the 1960's, and it has been continued by a number of state agricultural experiment stations. Next in importance in the development of leaner pork is scientific diet. The feed for pigs today reflects a proper balance of amino acids, from which protein is built. Several institutions have contributed to this research, including the University of Illinois. Finally, improved management and better vaccines also have played a major role. The net result has been a steady improvement in pork quality.

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The First Small Turkey

A milestone in turkey breeding was achieved in 1941 with the release of a new breed, the Beltsville Small White. It was the culmination of seven years of research at the USDA farm at Beltsville, Maryland--a project that made use of six breeds of turkey, including the native American wild turkey. Express aim of the project was to breed a small, meaty, full-breasted bird to meet the needs of the modern American family, which also was getting smaller.

Before the Beltsville White, the average weight of an adult tom turkey was 33 pounds, with toms in some breeds reaching 40 pounds. Average weight of young hens was 14 pounds, with hens of one breed topping 25 pounds at nine months. A roast turkey of such formidable size meant endless rounds of leftovers, and some breeds were too big to fit in an apartment-size oven.

A Beltsville White tom averaged only 15 pounds and young hens, 9 pounds. Despite some resistance to raising the new breed by turkey farmers, who preferred the profit from bigger birds, the Beltsville turkey by the early 1960's accounted for more than 20 percent of domestic turkey production in the U.S., and the breed had spread worldwide. It helped make the turkey a year-round staple.

By 1970, the Beltsville White as a breed had disappeared, replaced by other small turkeys. But the strains and knowledge developed in the Beltsville project made a tremendous contribution to breeding the small turkey of the 1990's.

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Updated 7/17/03