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Reducing water use in food processing

Home cooks know the secret to peeling tomatoes is a quick dip in hot water to loosen the skins. It takes a lot of water (and heating energy) to peel three million pounds of processing tomatoes in California each year. New UC Davis research is fine-tuning a novel way of peeling all those tomatoes with almost no water — using infrared heat.

Two methods are used to remove skins in processed tomatoes — a hot water/lye dip, or steam. The dip method uses a lot of water, a lot of energy, and creates a lot of salts . . . which presents its own disposal problem. Steam treatment heats too much of the tomato, resulting in reduced yield and quality.

“The tomato processing industry has long been interested in finding a better way of peeling tomatoes,” says Dr. Zhongli Pan, a USDA researcher, and an adjunct professor at UC Davis. He found that peeling tomatoes with infrared heat eliminates lye use, greatly reduces water use, and results in better quality tomatoes.

Infrared heat is similar to heat from the sun and fireplaces. It allows for efficient heat transfer from the source to the product. Infrared heat has promising potential not only for dry-peeling tomatoes, peaches, and other produce, but also for blanching many fruits and vegetables before freezing, such as apples and “baby” carrots.

Pan and his colleagues are building a pilot-scale infrared tomato heating device. The goal is to develop commercial-scale guidelines for peeling tomatoes and other products with infrared heat. As California's water resources dwindle, new technologies such as this should reduce our reliance on water.

Higher-quality pizza and tomato sauces, and many other food products may appear on our tables if infrared heat can be adopted by the food-processing industry. The secondary impact on water conservation will benefit us all.

(This article was condensed from UC Davis’ “CA&ES Outlook” magazine, fall/winter 2009, page 10.)

Posted on Tuesday, April 27, 2010 at 2:05 PM

Hold the salt? Not so fast, say nutrition experts

Last week (April 21, 2010) the Institute of Medicine issued an official report claiming that Americans consume too much salt and urging that new government standards be established for "acceptable sodium content" in foods. Two UC Davis nutrition experts disagree.

In November, Judith Stern, a professor of nutrition and internal medicine, and David McCarron, an adjunct nutrition professor, both at UC Davis, published a study in the Clinical Journal of the American Society of Nephrology that questioned the scientific logic and feasibility of broadly limiting salt intake in humans. (See journal article online.)

After examining data from sodium intake studies worldwide and a critical body of neuroscience research on sodium appetite (innate behaviors that drive us to consume salt), Stern and McCarron found compelling evidence indicating that humans naturally regulate their salt intake within a narrowly defined physiologic range. They found that Americans' average salt intake falls well within this range.

They suggest that government-led attempts to nationally control salt intake are simplistic, misguided, and not based in science and, instead, advise that individuals who are at special risk for high blood pressure and related diseases consult their physicians for nutritional advice, including appropriate levels of salt consumption.

(To view a flash video and UC Davis press release from October 2009, click here.)

Posted on Tuesday, April 27, 2010 at 1:59 PM

Happy cows produce healthy beef

Several studies suggest that grass-fed beef is more nutritious than conventional grain-fed beef, says a research review published in the March 2010 issue of Nutrition Journal.

The review, written by three Chico State professors and UC Cooperative Extension livestock advisors Glenn Nader and Stephanie Larson, says the diet of exclusively grass gives beef a higher amount of Vitamin A and E precursors, boosts cancer-fighting antioxidants and reduces overall fat content.

"However, consumers should be aware that the differences in (fatty acid) content will also give grass-fed beef a distinct grass flavor and unique cooking qualities," the researchers wrote

In addition, the fat from grass-finished beef may have a yellowish appearance from the elevated carotenoid content. However, the slight changes in taste and appearance may be well worth getting used to.

Along with improved nutrients and lower fat in grass-fed beef, the product has a healthier lipid profile than its conventional counterpart. Health professionals worldwide recommend reduced consumption of saturated fat, trans fat and cholesterol. Grass-fed beef helps consumers meet the recommendation.

Raising cattle on the range also results in an improved omega-3/omega-6 fatty acid ratio in the beef, the authors said. A healthy diet should consist of roughly one to four times more omega-6 fatty acids than omega-3 fatty acids. However, the typical American diet tends to contain 11 to 30 times more omega-6 than omega -3, a phenomenon that may be a significant factor in the rising rate of inflammatory disorders in the United States.

Cooking grass-fed beef to perfection requires a few adjustments. For example, because it is low in fat, it should be coated with extra virgin olive oil, truffle oil or another light oil to enhance flavor and improve browning. The high protein and low fat levels mean the beef will usually require 30 percent less cooking time.

More cooking instructions plus information about grass-fed beef's health benefits, niche marketing, labeling and cost of production are available on the Grass-Fed Beef Web page, developed by the UC and Chico State researchers who wrote the research review for Nutrition.

Posted on Thursday, April 15, 2010 at 9:39 PM

UC Davis' Nutributter to go beyond Africa

UC researchers who created Nutributter and tested it successfully in several African nations are now preparing to reformulate and evaluate the dietary supplement for Bangladesh and Guatemala. The research aims to determine whether specially developed Nutributter can prevent stunting and abnormal motor development in a variety of cultures where children are at risk for malnutrition.

The Africa Nutributter studies found that children preferred a sweet paste, but the scientists believe regional flavors may make the supplement more appealing. For Guatemala, they plan a cinnamon-flavored Nutributter; for Bangledesh, the paste will be flavored with cumin and cardamom.

UC Davis nutrition professor Kathryn Dewey, who leads the project, said it remains to be seen whether Nutributter will be adapted for American consumers.

“I personally think it is marketable,” she said.

Each four-teaspoon serving of Nutributter paste, which comes in a ketchup-packet-like pouch, contains 40 essential vitamins and minerals. Unlike most other nutrient supplements, the product also provides 120 calories of energy plus protein and essential fatty acids. Nutributter is not meant as a replacement for local foods or breast milk, but rather to be added to youngsters’ and pregnant mothers’ traditional diets.

"More than 3 million children die each year of malnutrition due not just to a lack of calories, but also to poor diet quality, particularly insufficient intake of micronutrients like zinc and iron, which are so critical to healthy growth and development," Dewey said.

The idea for the nutrition supplement came from the successful use of Plumpy'nut, a peanut-based food developed by French researchers for famine relief. Each Plumpy-nut packet has 500 calories and children can gain 1 to 2 pounds a week by eating it twice daily. Plumpy-nut is meant to temporarily serve as the sole food source in emergency situations.

The UC Davis Nutributter team heads the International Lipid-based Nutrient Supplements Project (iLiNS). Last year, the project won a $16 million Bill and Melinda Gates Foundation grant. A 2008 UC Davis news release announcing the Gates Foundation grant gives more details about Nutributter and its use in African nations. More information is also available on the iLiNS Web site.

Posted on Thursday, March 18, 2010 at 12:00 PM

Strawberry season in California is all year

The combination of UC's successful strawberry breeding program with an array of north-to-south micro-climates allows California producers to harvest strawberries somewhere in the state practically year round.

This year's wet, cool winter, however, is getting some of California's traditional springtime strawberry powerhouses off to a slow start, according to UC statewide strawberry specialist Kirk Larson, based at the UC South Coast Research and Extension Center in Orange County. There haven't been too many frost or freeze events in Southern California, but it has been well below normal temperatures, resulting in uneven ripening.

UC has an undeniably critical role in the success of the state's strawberry industry. UC-developed cultivars are grown on 65 percent of California strawberry acreage. Speaking to the productivity of UC varieties, those plants produce 85 percent of the state's fruit.

"The big beneficiary of all of this is the consumer," Larson said. "Because there is just so much good fruit, the price is usually affordable."

One of the most popular UC varieties, Albion, was selected by Larson and UC geneticist Doug Shaw for its flavorful, sweet berries, productivity and long shelf life. Other popular UC varieties are Palomar, San Andreas, Diamante, Camarosa and Ventana.

Shaw noted that many California place names and plant variety names honor the state's Hispanic heritage. Shaw wanted the new variety to honor California's English heritage, in the person of explorer Sir Francis Drake.

"But I discovered that 'Drake' is a bad name for a strawberry," Shaw said.

Sir Francis Drake dubbed California 'Nueva Albion' when he claimed the territory. Albion, the oldest recorded name for the island of Great Britain, became the label for a strawberry variety now grown on about 15,000 acres in California.

More information on the UC Strawberry Breeding Program is available on its Web site.

Posted on Monday, March 15, 2010 at 11:46 AM

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