NEWS
Eat less, move more
Less food and more exercise: That is the take-home message from the 2010 Dietary Guidelines for Americans.
In addition to this, the dietary guidelines—released on Jan. 31, 2011, by the U.S. Dept. of Agriculture and the Dept. of Health and Human Services—advise Americans to eat more fruits, vegetables, whole grains, fat-free and low-fat dairy products, and seafood, and to consume less sodium, saturated and trans fats, added sugars, and refined grains. More specific recommendations include avoiding oversized portions; filling half of the plate with fruits and vegetables; examining the sodium levels of processed foods and choosing those that have the lowest numbers; drinking water instead of sugary drinks; and others. The Dietary Guidelines also give recommended amounts of certain nutrients and foods, like sodium and seafood.
The USDA and HHS update the guidelines every five years as mandated by Congress to provide dietary and nutrition advice for people 2 years and older. The agencies will release more advice and tools for consumers, including the new Food Pyramid, in coming months. For more information, visit www.dietaryguidelines.gov.
Sometimes smaller is better
A newly developed nanoparticle can improve an antimicrobial’s ability to fight Listeria monocytogenes and extend the shelf life of foods, according to researchers at Purdue University.
The researchers altered the surface of phytoglycogen, a carbohydrate found in sweet corn. This led to the creation of several forms of a nanoparticle that could attract and stabilize nisin, a foodbased antimicrobial peptide used in the study, reported the researchers. The nanoparticle contained the nisin and was able to release it as needed for up to three weeks to inhibit Listeria. When nisin is used alone, it combats Listeria for only a short period of time, usually up to a few days.
“People have been using nisin for a number of years, but the problem has been that it is depleted quickly in a food system,” said Arun Bhunia, a professor of food science at Purdue and a co-author of the research study. “This nanoparticle is an improved way to deliver the antimicrobial properties of nisin for extended use.”
The researchers are studying ways that other food-based antimicrobial peptides and nanoconstructs can be developed and used to combat Listeria and other foodborne pathogens such as Escherichia coli O157:H7 and Salmonella. The U.S. Dept. of Agriculture and the National Science Foundation funded the research.
The study, “Designing Carbohydrate Nanoparticles for Prolonged Efficacy of Antimicrobial Peptide,” appeared online early in Journal of Controlled Release, doi: 10.1016/j.jconrel.2010.11.024.
Lutein helps cut trans fats
Adding lutein to sunflower oil that was then heated helped to reduce the amount of trans fatty acids that formed during heating better than adding rosemary extract to oil, according to researchers at the University of Ljubljana, Slovenia.
The researchers added rosemary extract or lutein to sunflower oil and heated the samples to 180°C. The amount of trans fatty acids with greater than one trans double bond increased from 0.91% to 1.71% in the control samples. The amount increased to 1.55% in the oil with rosemary extract and 1.43% in the oil with lutein.
The study, which is titled “Influence of Natural Antioxidants on the Formation of Trans-Fatty-Acid Isomers During Heat Treatment of Sunflower Oil,” appeared in the February 2011 issue of European Journal of Lipid Science and Technology.
UC Davis opens winery, lab
The University of California, Davis, on January 28, celebrated the grand opening of the Dept. of Viticulture and Enology Teaching and Research Winery and the August A. Busch III Brewing and Food Science Laboratory, which are part of the university’s Robert Mondavi Institute for Wine and Food Science.
Both the winery and the laboratory are located in the only building on campus that meets the LEED (Leadership in Energy and Environmental Design) Platinum environmental standards, which is the highest certification from the U.S. Green Building Council. The 34,000-sq-ft facility, which, according to the university, will become self-sustainable in energy and water use when all of the features are fully activated, includes an experimental fermentation area, analytical lab, and classrooms (in the winery) and a brewery, milk processing lab, and the California Processing Tomato Industry pilot plant (in the brewing and food science lab).
Roasting boosts AO content
The antioxidants found in dark roasted coffee result from the browning process under high temperatures, or Maillard reaction, reported researchers with the University of British Columbia, Vancouver.
While non-roasted coffee beans have high antioxidant levels, the researchers found that the level of antioxidants was still high in roasted coffee despite a 90% loss of the phenolic chlorogenic acid.
The mechanisms of the antioxidant action associated with the Maillard reaction products formed during coffee roasting involved hydrogen atom transfer and single electron transfer, according to the researchers.
The study, which is titled “Confirmation that the Maillard Reaction is the Principle Contributor to the Antioxidant Capacity of Coffee Brews,” appeared online early in the publication Food Research International, doi: 10.1016/j. foodres.2010.12.037.
Nanoparticles improve films
Research on edible carboxymethylcellulose films containing chitosan nanoparticles shows that the films have the potential for use in food and beverage packaging, according to scientists with the University of São Paulo, Brazil, and EMBRAPA-CNPDIA, São Carlos, Brazil.
The scientists incorporated chitosan/poly(methacrylic acid) nanoparticles into carboxymethylcellulose films and then analyzed the mechanical properties, water vapor permeability, thermal stability, and solubility of the films.
The size of the nanoparticles ranged from 80 nm to 110 nm, and the average thickness of the films was 0.03 mm.
The results showed that the nanoparticles significantly improved the mechanical properties of the films and that these properties were preserved when the films were tested eight months later. Incorporating nanoparticles into the films improved the thermostability of the films by increasing the thermal degradation temperature from 240°C to 266°C. Overall, the films made with nanoparticles of the size 110 nm were most suited for use in food packaging, as they had the lowest water solubility and better mechanical properties, reported the scientists.
The study, which is titled “Highly Stable, Edible Cellulose Films Incorporating Chitosan Nanoparticles,” appeared online early in Journal of Food Science, doi: 10.1111/j.1750-3841.2010.02013.x.
Packaging limits ammonia exposure
Three types of commonly used packaging material were able to defend against ammonia permeability at freezing temperatures, and could be used to help protect meat from ammonia exposure during frozen storage refrigerant leaks, according to a new study published in Journal of Food Science.
Researchers at Kansas State University tested the permeability of low-density polyethylene (LDPE; 2.2 mil), multilayer coextruded polyolefin with high oxygen permeability (MLP; 3 mil), and vacuum film (V-PA/PE; 3 mil, 0.06 mil polyamide/2.4 mil polyethylene).
They made 10x5 cm pouches from the materials and filled them with 50 mL of deionized water. They randomly assigned the pouches to various concentrations of ammonia (50, 100, 250, and 500 ppm) at different exposure times (6, 12, 24, and 48 hours) at -17±3°C and 21±3°C.
At room temperatures, the ammonia levels of the water increased significantly (P<0.05) as time and ammonia concentrations increased, but at freezing temperatures, no ammonia was detected.
The study, “Ammonia Gas Permeability of Meat Packaging Materials,” appeared online early in Journal of Food Science, doi: 10.1111/j.1750-3841.2010.01991.x.
What’s new with food companies
• ADM has acquired the remaining interest in Golden Peanut Co. LLC from Alimenta (USA) Inc., which is ADM’s 50% partner in Golden Peanut.
• Cognis plans to open an ingredients application center in Jacarei, Brazil.
• DeMet’s Candy Co. has acquired the TrueNorth® nut snack brand from Frito-Lay North America.
• Frutarom Industries Ltd. has acquired Rieber Industrial Spices Savory from Rieber & Søn.
• GLG Life Tech Corp. and China Agriculture and Healthy Foods Co. have formed a joint venture to sell food and beverage products sweetened with GLG’s stevia extracts in China.
• Mars Inc. received the U.S. Secretary of State’s 2010 Award for Corporate Excellence for its work in cocoa sustainability and efforts to improve economic development in the Republic of Ghana.
• The European Food Safety Authority has approved the use of Nutrition 21 Inc.’s chromium picolinate in foods in Europe.
• Ocean Nutrition Canada Ltd. and Wilmar International Ltd. have partnered to develop omega-3–based products.
• Omega Protein Corp. has acquired Cyvex Nutrition.
• Riviana Foods plans to build a rice processing plant in Memphis, Tenn.
by Karen Nachay,
Associate Editor
[email protected]