NEWS
New insights into impulsive eating
Keeping glucose levels in check by more frequently eating small servings of healthy foods might curb your appetite for high-calorie foods by affecting the part of the brain that promotes eating, reported researchers at Yale University and the University of Southern California.
The subjects underwent functional MRI scans as they were shown pictures of high-calorie food, low-calorie food, and non-food while the researchers manipulated glucose levels intravenously and examined changes in blood sugar levels. The scans showed that the area of the brain that regulates emotions and impulses—the prefrontal cortex—is unable to stop signals to eat high-calorie food when blood glucose levels drop. The response was incredibly strong in obese subjects shown pictures of high-calorie food.
“Our results suggest that obese individuals may have a limited ability to inhibit the impulsive drive to eat, especially when glucose levels drop below normal,” said Kathleen Page, Assistant Professor of Medicine at the University of Southern California and one of the lead authors of the paper.
The study, “Circulating Glucose Levels Modulate Neural Control of Desire for High-calorie Foods in Humans,” appears online early in Journal of Clinical Investigation, doi: 10.1172/JCI57873.
A laser focus on freshness
New laser technology may help maintain the freshness of packaged foods by monitoring gas levels inside packaging, according to researchers in Atomic Physics and Packaging Logistics at Lund University, Lund, Sweden.
The researchers developed the laser instrument, which measures the amount of oxygen in the packaging by shining a laser beam into the packaging, reading the light with a handheld detector, and analyzing the reading with a computer. During the packing process, carbon dioxide or nitrogen is pumped into the packaging to surround the product and extend its shelf life. Initially, little or no oxygen is in the packaging but since no packaging is completely airtight, some air can enter through the packaging material or package seal and accelerate the spoilage of the product. The laser reportedly can measure through just about all packaging materials.
The researchers anticipate that manufacturers can use the technology to check and improve how airtight packaging is, and store employees can use it to check the shelf life of foods. Gasporox is commercializing the technology.
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Bacterium substance may preserve food
An antimicrobial substance produced by intestinal bacteria is effective against several microorganisms and may be used as a food preservative, reports a study in Journal of Food Science.
The bacterium, Lactobacillus plantarum vN, which researchers isolated from the gastrointestinal tract of healthy chickens, produced an antimicrobial substance designated vN-1 that inhibited the activity of Pseudomonas spp., Staphylococcus aureus, Micrococcus luteus, Salmonella Typhimurium, Erwinia amylovova, and others; was active at wide pH range; was thermostable; and was resistant to several organic solvents and to enzymatic inactivation. Other studies have found that antimicrobial substances isolated from non-Lactobacillus bacteria inhibit certain pathogenic bacteria, but the researchers of this study wanted to investigate a substance isolated from L. plantarum that could inhibit Pseudomonas spp. The researchers emphasized the importance of inhibiting Pseudomonas spp. as they are the main spoilage microorganisms of refrigerated poultry meat under aerobic conditions.
The study, “Antagonistic Intestinal Microflora Produces Antimicrobial Substance Inhibitory to Pseudomonas Species and Other Spoilage Organisms,” appeared in the October 2011 issue of Journal of Food Science.
Measuring oxidation in fresh fish
Oxidation of lipids may be slower in white-colored flesh fish than in red-colored flesh fish and blue-black–colored flesh fish, reported Japanese researchers studying the development of off-flavors in fresh fish.
The researchers used an electronic nose system and gas chromatography–mass spectrometer with headspace solid-phase micro-extraction to analyze the changes in volatile compounds in a number of different species of fresh fish in ice storage for 3–4 days. Some of the fish samples like jack mackerel and chub mackerel had darker-colored flesh and others like red sea bream and Japanese sea bass had white-colored flesh. In the fish species that had the most oxidation, there were increased levels of aldehydes and alcohols. The results might be used to help prevent off-flavors in fish, said the researchers.
The study, “Change of Volatile Compounds in Fresh Fish Meat during Ice Storage,” appeared in the November/December 2011 issue of Journal of Food Science.
Clean seeds help sprout safety
To keep sprouts free of foodborne pathogens like Escherichia coli, the food industry needs to ensure the cleanliness of the seeds, according to researchers at the University of Illinois.
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“Once seeds have germinated, it’s too late” said Hao Feng, an associate professor of food and bioprocess engineering. “Sprouts are extremely complex structures with a forest-like root system that conceals microorganisms. Just a few E. coli cells can grow to a substantial population during germination and sprouting, and it’s very difficult to get rid of them all.”
For some of the experiments on various sprout seeds, the researchers used both the U.S. Food and Drug Administration-recommended dose of chlorine to kill microorganisms and a new sanitizer (combination of surfactant and organic acid). The analysis of the seeds after treatment showed that E. coli was eliminated on the alfalfa seeds. Because broccoli and radish sprout seeds have a rough surface, low doses of irradiation were needed.
Particle interaction affects solubility
The formation of a “crust” on the surface of milk protein concentrate powder particles may contribute to the decrease in the solubility of the powder during storage, according to research published in Journal of the Science of Food and Agriculture.
The researchers used scanning electron microscopy to analyze the surface composition and structural changes in high-protein (80%) milk protein concentrate powder that was stored for 90 days at temperatures of 25°C and 40°C and relative humidities of 44%, 66%, and 84%.
The results showed no significant changes to the surface composition (fat, protein, and lactose) of the powder samples but did show some changes in the microstructure. More specifically, the researchers noted that the crust that formed on the surface of the powder was made of a thin layer of fused casein micelles that exhibited hydrophobic properties.
The study, “Storage Induced Changes to High Protein Powders: Influence on Surface Properties and Solubility,” appeared in the November 2011 issue of Journal of the Science of Food and Agriculture.
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What’s new with food companies
• Anheuser-Busch InBev and GE are partnering to develop manufacturing solutions to achieve energy and water usage savings at InBev facilities in China.
• Blue Diamond Growers will build a manufacturing plant in Turlock, Calif., and will upgrade facilities in Sacramento and Salida, Calif.
• Cargill has received a patent to improve its novel glucosamine production process.
• Danisco has launched a new website, www.danisco.com/health.
• DSM Nutritional Products has formed Nutritional Lipids business to focus on developing nutritional lipid ingredients.
• Frontera Produce has selected HarvestMark for its pineapple traceability.
• Frutarom has acquired Flavor Systems International Inc.
• Frutarom Switzerland Ltd. will begin marketing its Red Vine Leaf Extract EFLA® 945 in Germany. The ingredient reportedly has vascular health benefits and can be used in beverage applications.
• NutraCea and BENEO-Remy have formed a co-branded sales and marketing agreement.
• Silliker is building a new laboratory in Crete, Ill. It will consolidate its Chicago Heights and South Holland, Ill., operations at the new lab.
• Takasago has opened a new culinary center in Rockleigh, N.J.
• TIC Gums has earned the first annual Ingredients/Flavorings/Seasonings/Additives Innovation Award from the International Dairy Foods Association for its Dairyblend SC-ASC ingredient.
• Turtle Island Foods is building a food processing facility to achieve Leadership in Energy and Environmental Design (LEED) certification.
• Wild Flavors has acquired the mint flavors and ingredients business of A.M. Todd Group.
Karen Nachay,
Associate Editor
[email protected]