Keeping greens safe
Scientists with the U.S. Dept. of Agriculture’s Agricultural Research Service are testing new sanitizing methods and investigating ways to improve the safety of leafy greens and provide consumers with safer packaged fresh-cut greens and lettuce. This is particularly important as the food industry faces food safety challenges such as the illnesses and deaths associated with an outbreak in 2006 of Escherichia coli O157:H7 that was traced to bagged spinach.
The methods, which focus on everything from washing produce before bagging to effective storage conditions after bagging, are being examined to determine the optimal ways to keep this produce safe and fresh both at processing facilities and at home.
Yaguang Luo, a food technologist with the ARS Produce Quality and Safety Laboratory, and colleagues at the University of Illinois collaborated to test the effectiveness of sanitizers used with or without ultrasound treatment as a way to help remove contaminants such as E. coli from the greens before bagging. The highest E. coli reduction—4.5 log, or a decrease from about 300,000 colony-forming units to fewer than 10—was achieved by using a newly formulated wash solution with ultrasound treatment.
Scientists are also studying the environment inside the bag once the greens are packaged as well as the gas permeability of the different film packages. Arvind Bhagwat, a microbiologist with ARS PQSL, applied bacteria to lettuce leaves and then sealed the leaves in modified atmosphere packaging that included packaging films that restricted oxygen transmission. While his results showed that the bacteria actually thrived and better survived an application of synthetic gastric juice, he emphasized that this occurred only when the salad bags were left at room temperature or unrefrigerated for an extended period of time.
The research conducted by these scientists is part of Food Safety (#108), an ARS national program. Visit www.nps.ars.usda.gov for more information.
AMA proposes food ratings
Food and diet were among the focal points in new public health policies adopted at the American Medical Association’s Annual Meeting in June.
AMA suggested the implementation of a rating system for processed foods in addition to the current food label.
"Incorporating a simplified rating system to the nutritional label could provide consumers with a better understanding of the product’s nutritional value," said William Dolan, an AMA board member. "A rating system may also encourage manufacturers to increase the nutritional value of food in order to achieve a better rating."
The organization also called on the Food and Drug Administration to re-examine the current Daily Reference Intake value for vitamin D in light of current scientific research that suggests that the Upper Limit for adults is likely overly conservative.
"The health benefits of vitamin D are plentiful, such as strong bones and a reduced risk of breast cancer and cardiovascular disease," said Steven Stack, an AMA board member.
The current DRI values for vitamin D were adopted by the Food and Nutrition Board in 1997.
Temperature’s effects on Starch
Researchers from the University of Nebraska, Lincoln, examined the effects of temperature on resistant starch and learned that changes in temperature can cause changes to the internal structure of certain resistant starch.
They investigated the thermal behaviors of three resistant starch types: RS 2, which includes some types of raw starch granules and high-amylose starches; RS 3, known as retrograded starch, which is either processed from unmodified starch or resulting from food processing applications; and RS 4, which are starches chemically modified to have resistance to enzymatic digestion. They heated the samples in excess water to specific temperatures (35° C–85° C, at 5° C intervals) and then freeze dried them.
The results showed that internal structural changes were temperature dependent and different for the three samples. The RS 2 sample showed the least amount of structural changes. Temperatures from 80° C to 85° C caused slight, internal structural changes in the RS 3 sample. At the highest temperature tested, the RS 4 sample was the only sample that became almost completely amorphous.
The researchers said that information about the structural changes of resistant starch can be used to predict the starches’ thermal behavior in food products during processing.
The study, "Thermal Behavior of Resistant Starches RS 2, RS 3, and RS 4," appeared in the June/July issue of Journal of Food Science. For more information, visit www.ift.org.
FSA revises food terms guidance
The Food Standards Agency, London, UK, has revised its guidance on the use of marketing terms such as "fresh," "pure," and "natural" for food labeling. The revised guidance includes advice on the use of new terms, including "farmhouse pâté," "handmade," "quality," "selected," "premium," "finest," and "best." It also has new advice for some of the terms that were listed in the previous guidance and advises against the use of some terms that can cause confusion.
The guidance, "Criteria for the Use of Terms Fresh, Pure, Natural, etc. in Food Labelling," is available at http://www.food.gov.uk/multimedia/pdfs/markcritguidance.pdf.
Increasing nutrients in noodles
Noodles are widely consumed in many different cuisines, and researchers continue to investigate ways to improve the nutritional content of this popular food.
Researchers from Centro de Desarrollo de Productos Bióticos del IPN, Morelos, México, and Universidad Central de Venezuela, Caracas, prepared noodles with various mixtures of durum wheat flour and isolated plantain starch and tested their proximal composition. The in vitro starch digestibility, indigestible fraction content, and predicted glycemic index were measured in cooked noodles.
The results showed that the protein content declined with the addition of plantain starch. Both total starch level and the content of starch available for digestible enzymes decreased as the plantain starch level increased, a pattern that the researchers said may be related to increased starch lixiviation during cooking of noodles containing plantain starch. The resistant starch content in the control (durum wheat flour) noodles was ≈50% less than in the samples containing plantain starch.
The soluble indigestible fraction content in all samples was higher than the insoluble counterpart. The hydrolysis index and predicted glycemic index of the plantain starch noodles decreased as the plantain starch proportion rose. The researchers said that in spite of the increased starch digestion rate, plantain starch noodles are a better source of indigestible carbohydrates than pure wheat starch pasta, which, in the end, may have dietetic applications.
The study, "Composite Durum Wheat Flour/Plantain Starch White Salted Noodles: Proximal Composition, Starch Digestibility, and Indigestible Fraction Content," appeared in the May/June 2008 issue of Cereal Chemistry.
Sequencing the cocoa genome
Mars Inc., USDA’s ARS, and IBM Research recently announced plans to sequence and analyze the entire cocoa genome, a significant scientific step that may allow more directed breeding of cocoa plants and enhance the quality of cocoa. Mars will make its research results freely available through the Public Intellectual Property Resource for Agriculture, which supports agricultural innovation for both humanitarian and small-scale commercial purposes. The scientists anticipate that it will take about five years to complete the entire sequencing, assembly, annotation, and study of the cocoa genome.
Food companies expand
A number of food companies from around the world have announced plans to expand, have opened new facilities, or have invested in research and development of new ingredients, products, and services. Here is an update on some of these projects.
• Barry Callebaut, Zurich, Switzerland, has opened its first innovation center in the United States. The new, state-of-the-art research and development facility, located in Pennsauken, N.J., will focus on the development of one-of-a-kind chocolate products and applications. The company has one other innovation center in North America, located in St. Hyacinthe, Quebec, Canada.
• Bunge Ltd., White Plains, N.Y., recently announced that it will acquire the international sugar trading and marketing division of Tate & Lyle PLC, London, UK. The company also announced that it will acquire Corn Products International Inc., Westchester, Ill.
• CP Kelco U.S. Inc., a unit of J.M. Huber Corp., Edison, N.J., and Fluxome Science A/S, Copenhagen, Denmark, recently announced that they have entered into an agreement to jointly develop and commercialize fermentation-derived resveratrol for the dietary supplement, food, beverage, and cosmetics markets.
• Ganeden Biotech, Cleveland, Ohio, announced that it will make available for license its patent related to the use of its probiotics to control bacterial infections associated with infant mortality, specifically, Sudden Infant Death Syndrome. As discussed in U.S. Patent number 7,374,753, Ganeden’s probiotic bacteria can be formulated into a variety of delivery mechanisms, including infant formulas and rehydration/electrolyte compositions, because the bacterium is presented as a viable, shelf-stable organism, either as a vegetative cell or as a spore.
• InBev, Leuven, Belgium, and Anheuser-Busch, St. Louis, Mo., have agreed to combine the two companies, forming the world’s leading global brewer. The combined company, which will be called Anheuser-Busch InBev, will make St. Louis the headquarters for the North American region and the global home of the flagship Budweiser brand. Anheuser-Busch will become a wholly owned subsidiary of InBev upon the completion of this transaction.
by Karen Nachay,