NEWS
Study shows sucrose decomposes
Sucrose does not melt; it decomposes, and this discovery means that food scientists can manipulate sugars to improve their products’ flavor and consistency, according to researchers at the University of Illinois–Urbana.
In their research, the researchers could not achieve a constant melting point for sucrose. They received different results depending on how quickly the sucrose was heated, which led them to determine that the melting point was heating–rate dependent, reported Shelly J. Schmidt, a professor of food chemistry at the university.
“In the literature, the melting point for sucrose varies widely, but scientists have always blamed these differences on impurities and instrumentation differences,” said Schmidt. “However, there are certain things you’d expect to see if those factors were causing the variations, and we weren’t seeing them.”
A true or thermodynamic melting material melts at a consistent, repeatable temperature, retaining its chemical identity from the solid to the liquid state, added Schmidt. The researchers used liquid chromatography to show that sucrose was not the same before and after it transitioned from a solid to a liquid. The researchers called this “apparent melting,” and they have already shown that glucose and fructose are apparent melting materials.
Natural born bacteria killer
A newly discovered naturally occurring lantibiotic kills foodborne bacteria like Salmonella, Escherichia coli, and Listeria and may one day be used as an additive to prevent the growth of harmful bacteria, reported University of Minnesota researchers.
The lantibiotic, a peptide produced by a harmless bacterium, kills Gram-negative bacteria and could be used in meat, processed cheeses, egg products, dairy products, canned foods, seafood, salad dressing, fermented beverages, and other foods. Most important is that it is difficult for pathogens to develop resistance against lantibiotics.
The researchers hold a patent for the lantibiotic, which they discovered while researching the genome of bacteria. The university’s Office for Technology Commercialization is searching for a licensee for the technology.
Single method detects umami
An ion-pair liquid chromatography–mass spectrometry method developed by Dutch researchers successfully quantified several known umami compounds in foods and may help scientists discover new umami compounds by using a single method rather than multiple ones.
Scientists use two different methods for two classes of compounds (glutamic acid and 5’-ribonucleotides) when analyzing umami taste in food, according to the researchers from TNO, Zeist, the Netherlands. They developed the single method to replace several steps in the analysis of these compounds. They also demonstrated the use of the method in discovering new umami compounds by using multivariate statistics to correlate complete peak patterns to relevant sensory attributes.
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The study, “Comprehensive Analysis of Umami Compounds by Ion-Pair Liquid Chromatography Coupled to Mass Spectrometry,” appeared online early in Journal of Food Science, doi: 10.1111/j.1750-3841.2011.02306.x.
Cooling eggs may improve safety
A new cooling system may help improve eggs’ natural defenses against harmful bacteria such as Salmonella.
Kevin Keener, Associate Professor of Food Science at Purdue University, developed the process that rapidly cools eggs with carbon dioxide (at -110°F) and alters pH levels to increase the activity of lysozymes, which break down the cell walls of Gram-positive bacteria. Eggs are placed in a cooling chamber while the cold gas circulates around the eggs, forming a thin layer of ice inside the eggshells. As the ice layer melts after treatment, the eggs’ internal temperature lowers to less than 45°F. Studies conducted by U.S. Food and Drug Administration scientists have shown that if eggs were cooled and stored at 45°F or less within 12 hours of being laid, there would be an estimated 100,000 fewer cases of salmonella illness from eggs in the United States each year, said Keener.
Controlling E. coli in meat
Certain antimicrobials formulated in brine solutions may be effective at controlling Escherichia coli O157:H7 in meat injected with the solutions, according to researchers at Colorado State University.
Injecting brine solutions into beef contaminated with E. coli O157:H7 on its surface may introduce the pathogen into the internal structure of the meat. The researchers sought to evaluate the survival of E. coli O157:H7 in brines formulated with and without antimicrobials, and in the absence (simulating freshly prepared brines) or presence (simulating recirculation of brines) of meat residues and meat microflora. The results showed an immediate reduction of pathogen levels in brines formulated with cetylpyridinium chloride (CPC) or sodium metasilicate. There was a reduction of pathogen levels during storage in brines formulated with lactic acid, acetic acid, citric acid, nisin + ethylenediamine tetraacetic (EDTA) acid, pediocin + EDTA, CPC, sodium metasilicate, or hops beta acids, but the reductions depended on the antimicrobial, brine type, and storage temperature and time. More research needs to be conducted on the physicochemical and sensory characteristics of meat products injected with antimicrobial-containing brines, reported the researchers.
The study, “Survival of Escherichia coli O157:H7 in Meat Product Brines Containing Antimicrobials,” appeared online early in Journal of Food Science, doi: 10.1111/j.1750-3841.2011.02300.x.
IFSH receives USDA grant
The U.S. Dept. of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) has awarded a grant to the Institute for Food Safety and Health (IFSH) at the Illinois Institute of Technology to study human noroviruses across the food supply chain.
IFSH is one of more than 30 institutions that will collaborate in designing effective control measures to reduce the number of foodborne illnesses caused by viruses. The $25 million grant will fund the development of a research team to create the USDA–NIFA Food Virology Collaborative to conduct scientific studies on and produce education initiatives about foodborne viruses.
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“IFSH is contributing to the grant its specialized capabilities in developing and validating processing technologies, in particular high pressure processing and high power ultrasound technologies to control foodborne viruses,” said Alvin Lee, IFSH Director of Microbiology and a consortium co-project director and theme leader for preventive controls.
Noroviruses spread from person to person, through contaminated food or water, or by touching contaminated surfaces. The foods at greatest risk for contamination are oysters, clams, mussels, fresh produce, and foods that are handled very much just prior to consumption.
Detecting bacteria quickly
A new technology is a more improved method for detecting Escherichia coli than conventional methods, providing results in five hours rather than 8–24 hours, according to scientists at the University of Arkansas’ Center for Food Safety and the U.S. Food and Drug Administration’s Food Emergency Response Network. Litmus Rapid-B LLC developed the test as part of a new public–private collaboration with the university. The partnership allows both parties to share resources to help combat consumer sickness and death from food contamination by improving the identification of and pinpointing foodborne bacteria such as E. coli and Salmonella at processing and distribution points as quickly as possible.
What’s new with food companies
• AAK has acquired Golden Foods/Golden Brands.
• Bay State Milling Co. is constructing a 4,000-sq-ft innovation center at its headquarters in Quincy, Mass.
• Bell Flavors & Fragrances has acquired an 85,000-sq-ft warehouse next to its corporate headquarters in Northbrook, Ill., and has plans for expansion.
• Cargill has opened a technology and innovation center in Campinas, Sao Paulo, Brazil.
• Chiquita and Walt Disney World Resort have formed a multi-year alliance to offer Chiquita® and Fresh Express® products at various retail points at Walt Disney World in Lake Buena Vista, Fla.
• Cott Beverages Inc. has licensed pTeroPure® technology from ChromaDex.
• DSM has opened a Nutrition Innovation Center in Parsippany, N.J.
• ICL Performance Products has acquired Cosmocel Quimica S.A. de C.V.
• Kraft Foods Inc. announced plans to split into two independent public companies: a global snacks company and a North American grocery business.
• Lane Southern Orchards has selected YottaMark Inc.’s HarvestMark fresh food traceability program for its PTI compliance needs.
• National Starch Food Innovation has appointed Azelis its exclusive distributor in Greece.
• NSF Davis Fresh, a unit of NSF International, has changed its name to NSF Agriculture.
• Olam Spices & Vegetable Ingredients has opened the Olam Global Tomato Innovation Center in Lemoore, Calif.
• Provexis and DSM Nutritional Products will partner to develop and commercialize a new naturally derived casein ingredient.
Karen Nachay,
Associate Editor
[email protected]