NEWS
Researchers study phenolics in hazelnuts
Hazelnuts are a good source of several antioxidants, but removing the skin from hazelnuts lowers the individual and total phenolics content, according to researchers at the University of Ljubljana, Slovenia. The researchers also found that roasting hazelnuts had little effect on their phenolics content.
The researchers established phenolics profiles of six European hazelnut cultivars and then compared the individual antioxidant activities of the hazelnuts with or without skin. They also examined how roasting affects the total phenolics content/antioxidant potential of the hazelnuts. The phenolics identified were seven flavan-3-ols (catechin, epicatechin, two procyanidin dimers, and three procyanidin trimers), three flavonols (quercetin pentoside, quercetin-3-O-rhamnoside, and myricetin-3-O-rhamnoside), two hydrobenzoic acids (gallic acid and protocatechulic acid), and one dihydrochalcone (phloretin-2’-O-glucoside).
The results showed a significant decrease in individual phenolics after skin removal, which resulted in lower total phenolics content value and antioxidant potential. Roasting had little effect on this, and the researchers believe that roasting only decreases the content of some individual phenolics, which represents a minor part of total phenolics content. In other words, the content of individual phenolics, with the exception of gallic acid, was the greatest in whole unroasted hazelnuts and was significantly reduced after skin removal, wrote the researchers.
The study, “Roasting Affects Phenolic Composition and Antioxidative Activity of Hazelnuts (Corylus avellana L.),” appeared online early in Journal of Food Science, doi: 10.1111/j.1750-3841. 2010.01898.x.
Detecting deadly pathogens
Botulism is a deadly form of food poisoning caused by consuming small quantities of botulinum neurotoxin produced by Clostridium botulinum. And now researchers with the Institute of Food Research and Nestlé Research Centre have developed a new method for detecting spores of non-proteolytic C. botulinum.
Non-proteolytic C. botulinum can grow and produce toxin at 3°C, and because it can grow at refrigeration temperature, it makes it a hazard in foods like chilled ready meals. Proteolytic C. botulinum, on the other hand, will not grow at temperatures less than 12°C. The new method is quite sensitive, and it has a low detection limit achieved by using a selective enrichment and large test samples, according to the researchers. Another feature of the method is that it is specific and enumerates only non-proteolytic C. botulinum spores. Other available techniques cannot distinguish between non-proteolytic and proteolytic C. botulinum.
Method distinguishes tea leaves
Fortune tellers claim to determine your fate by reading tea leaves.Now scientists from the University of Seville, Spain, can “read” tea leaves to differentiate between the varieties of tea.
The researchers used inductively coupled plasma atomic emission spectrometry to determine the concentrations of elements in tea leaves, the most abundant elements being calcium, magnesium, potassium, aluminum, phosphorus, and sulphur. Then they constructed classification models to highlight significant differences between the types of tea and characterized the samples using linear discriminant analysis and probabilistic neural networks. The overall technique draws from chemometrics, a branch of chemistry that uses mathematics to extract information from data generated from lab experiments. Differentiating between the types of tea leaves is not that easy to do by sight, said the researchers.
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The researchers used white, green, black, Oolong, and red tea leaves for the experiment.
The study, “Characterisation of Tea Leaves According to Their Mineral Content by Means of Probabilistic Neural Networks,” appeared online early in Food Chemistry, doi: 10.1016/j. foodchem.2010.05.007.
Improving food choices
Health Canada and Food & Consumer Products of Canada recently debuted a Nutrition Facts Education Campaign, which provides information to Canadians to help them make healthier food choices. It includes on-package messages, print and television advertising, and an educational website featuring tips and online tools on how to use the % Daily Value to make informed food choices. For more information, visit www.healthcanada.gc.ca/dailyvalue.
Gut reaction to fighting cancer
Bacteria in the lower gut can release the cancer-fighting compound sulforaphane found in broccoli, allowing it to be absorbed into the body, according to researchers at the University of Illinois–Urbana.
“This discovery raises the possibility that we will be able to enhance the activity of these bacteria in the colon, increasing broccoli’s cancer-preventive power,” said Elizabeth Jeffery, a professor of human nutrition at the university.
She added that overcooking broccoli destroys the plant enzyme myrosinase that produces sulforaphane, but the research findings show that bacteria in the gut can trigger reactions to salvage some of the sulforaphane.
Reducing oil uptake in chips
Combining frying with draining under vacuum can significantly reduce the amount of oil in potato chips, reported scientists at the University of Reading, UK.
For the experiment, the scientists wanted to study the ability of vacuum application to prevent surface oil from being absorbed into the potato chips. The results showed that the oil content of potato chips decreased from 68.48 g of oil/100 g of defatted dry matter to 37.12 g of oil/100 g of defatted dry matter when the chips were fried for 3.5 minutes and a vacuum of 13.33 kPa was applied for 3 minutes after frying. The researchers added that the product quality of the potato chips prepared this way was essentially the same as potato chips prepared the conventional way.
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The study, “The Possibility of Lowering Oil Content of Potato Chips by Combining Atmospheric Frying with Postfrying Vacuum Application,” appeared in the November/December 2010 issue of Journal of Food Science.
Examining food allergy risk
Children, non-Hispanic blacks, and males are at increased risk for food allergies, according to research published in the Journal of Allergy and Clinical Immunology. It estimates that 2.5% of Americans (about 7.6 million) have food allergies.
The researchers used specific immunoglobulin E (IgE) or antibody levels to quantify allergic sensitization to common foods, including peanuts, milk, eggs, and shrimp in a nationally representative sample. The body produces IgE antibodies to a specific food protein, and once that antibody is made, continued exposure to the food triggers an allergic response, explained the researchers.
“It is the first study to use specific blood serum levels and look at food allergies across the whole life spectrum, from young children aged 1 to 5, to adults 60 and older,” said Darryl Zeldin, Acting Clinical Director at the National Institute of Health’s (NIH) National Institute of Environmental Health Sciences and senior author of the research paper. The study was funded by NIH, and the data came from the National Health and Nutrition Examination Survey 2005–2006.
The researchers also found an association between food allergy and severe asthma, noting that the odds of those with asthma and food allergies experiencing a severe asthma attack were 6.9 times greater than those without food allergies.
The researchers emphasized that more studies need to be conducted to understand why certain groups are at increased risk for food allergy. The study, “National Prevalence and Risk Factors for Food Allergy and Relationship to Asthma: Results from the National Health and Nutrition Examination Survey 2005–2006,” appeared in the October 2010 issue of Journal of Allergy and Clinical Immunology.
What’s new with food companies
• Herbamed Ltd. has appointed New Products Plus as its exclusive agent for Ultrasome™ CoQ10 in the western region of the U.S.
• Zhejiang Medicine Co.–USA completed an upgrade to its vitamin E manufacturing facility.
• ChromaDex has initiated a clinical study at the University of Mississippi on pTeroPure™ pterostilbene, which is chemically related to resveratrol.
• Glanbia Nutritionals has received a U.S. patent for its Prolibra whey-derived ingredient.
• The Ministry of Health in India has approved additional food categories for which BENEO-Institute’s low-glycemic sugar replacer Isomalt can be used.
• Solbar has launched a corporate rebranding that includes a new logo, new slogan, and a redesign of its communication materials and catalogs.
• The Food and Drug Administration has issued a no objection letter on the GRAS status of Burcon NutraScience Corp.’s Puratein® and Supertein™ canola protein isolates.
• Ohly has opened a yeast extract plant in Harbin, China.
Karen Nachay,
Associate Editor
[email protected]