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Volume III Number 1 Winter 2006/ 07

O F F I C I A L P U B L I C AT I O N O F T H E A D VA N C E D F O O D S A N D M AT E R I A L S N E T W O R K

Teaming up to fight diabetes

André Marette and Hélène Jacques (front), Jérôme Ruzzin and Charles Lavigne of l’Université Laval, are researching how fish nutrients may affect diabetes and heart disease. See page 8.

INSIDE: Connecting coffee and health... page 6


Dr. Rickey Yada

Welcome to our third edition of Advance, the official publication of the Advanced Foods and Materials Network (AFMNet). Advance will help you understand our new projects and how our researchers are helping drive toward a healthier Canada. If you’ve read our previous issues, you’ll recognize a few updates in this edition. Read on for the latest on biofilms, our cutting-edge research in nutrigenomics and how natural health product regulations continue to affect suppliers and consumers. You’ll also notice many other new and exciting areas of research being explored by AFMNet. For example, after two successful years of innovative research, AFMNet has refocused its program to include 20 larger collaboration-rich projects. Also, in this issue of Advance, you’ll learn how AFMNet researchers are determining the properties that make breast milk beneficial and why this knowledge is so important. And you’ll see how plant-derived proteins and carbohydrates are being used to improve the quality of frozen food. Finally, you’ll read how the effects of caffeine consumption vary with each person’s genetic makeup. So grab a coffee, sit back and enjoy this issue of Advance. As always, we welcome your feedback and ideas.

Dr. Murray McLaughlin

Rickey Yada Scientific Director, AFMNet

As you read through this issue of Advance, you’ll realize how AFMNet creates a convergence within the science community, clearly demonstrating how networks across science disciplines and among universities can enhance and strengthen research. After all, research shouldn't happen in isolation. Without the interaction of many scientists and interests at various locations across the country, reactions lack vigour and results cannot catalyze. With many successful connections and results within the AFMNet community, we are now working to get our research out to Canadians. This is where AFMNet’s Research to Business (R2B) program comes in. It aids and encourages knowledge transfer and the commercialization of Canadian science. Drawing from the wealth of AFMNet research, the R2B program aims to increase the pursuit of commercialization activities, challenges barriers to commercialization, increases the profile of university industry liaison offices, boosts investment in commercialization and increases the return on investment in Canadian academic research. I’m pleased to report that we are beginning to see results with the protection of intellectual property and the discussion and development of business opportunities. I trust you’ll find this issue of Advance informative, and we look forward to your inquiries and feedback. Murray McLaughlin Chair of the Board of Directors, AFMNet

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Volume III Number 1 Winter 2006/07 The official publication of the Advanced Foods and Materials Network A publication to promote dialogue and understanding about sophisticated foods and materials research across Canada Executive Editors Rickey Yada Allan Paulson Project Co-ordinator Kate Roberts Editor Owen Roberts Associate Editor Kim Waalderbos Copy Editor Barbara Chance Design JnD Marketing Financial Manager Jan Smith Address correspondence to: Louise Jessup, Communications Manager 150 Research Lane, Suite 215 Guelph, Ontario, Canada N1G 4T2 E-mail: louise.jessup@afmnet.ca Visit the AFMNet website: www.afmnet.ca This publication was written by students in the SPARK program, Students Promoting Awareness of Research Knowledge, at the University of Guelph in Ontario, Canada.


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CONTENTS

Foods and Health

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Healthy from the inside out

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Fish that fight disease

8

Breast is best, but why?

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An enigmatic molecule

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People-friendly peptides

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Connecting coffee and health

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Consumer and Ethical Issues

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Clearing the air on new natural health product laws

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A case for more regulations?

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Understanding public concerns about animal biotech

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Materials The peptide and the pea

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Bright minds versus biofilms

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Towards better frozen food

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What makes proteins stick

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Surviving an incredible journey

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Harnessing a new weapon to battle food-borne bacteria

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Cover photo by Marc Robitaille

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CONTRIBUTORS Alicia Robert s

Fourth-year drama student Alicia Roberts has been writing research stories with SPARK for three years and has enjoyed expanding that experience to the Advance magazines. Her writing has led to learning about biotechnology ethics and enhanced foods, including eggs with health benefits and milk powered by small proteins called peptides. For more information on peptide-powered foods, check her story on page 12.

Christine Eisler

In addition to milking cows, fourth-year agricultural science student Christine Eisler enjoys learning about the research side of agriculture. Through writing for the SPARK program, she has been able to use her “hands-on” farm knowledge to communicate pertinent issues to the public. Read Christine’s story about new developments to enhance proteins on page 24.

Lindsay Brow n

As a sports enthusiast, second-year biomedical science student Lindsay Brown stays active by running and playing soccer. During her first year as a SPARK writer, she combined her education and research knowledge to write about a variety of health and food research, including natural health product regulations on page 16 and protein modifications in frozen foods on page 23.

Leslie Irons

All contributors to Advance are part of the University of Guelph research writing program called Students Promoting Awareness of Research Knowledge (SPARK).

Leslie Irons just can’t satisfy her itch for writing.With a zoology degree under her belt, she is heading towards a high school pre-service science teacher position. Spending time in the classroom and around students makes her mindful about keeping her own health in tip-top shape. She writes about the health benefits of CLA on page 10.

Photos by Martin Schwalbe

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Kate Robert s

Three’s a charm for marketing major Kate Roberts as she completes her threeyear-long adventure as inaugural writer and co-ordinator for Advance. Now in her graduating year, she still tries to find time for sports and playtime with her nephew, Keegan. With a palate keen on seafood, Kate was interested to learn about fish nutrients and their effect on human diseases. See her story on page 8.

Eamon O Flynn

An undergraduate history student, Eamon O’Flynn enjoys his studies and time spent writing and reading. As a SPARK writer, he has been able to use his journalistic skills to examine and explain new research in food science. Check out his story on encapsulated probiotics and how they enhance human health on page 25.

Robert Fieldhouse

Robert Fieldhouse is in his second year of a biophysics master's program. In his own research, he is hard at work tracking down harmful bacterial proteins to explore the link between toxin structure and function. But his interest in research doesn't end there.Turn to page 20 to read his story on how scientists are using pea proteins to fight hypertension.

Amanda Ansell

Fourth-year political science and English literature major Amanda Ansell is an avid music fan and guitar player who hopes to one day pursue a career in news writing. As a self-proclaimed caffeine addict with two part-time jobs, she was interested in finding out what effect those midnight javas might be having on her system. Check out her story on individual responses to caffeine on page 14.

Arthur Churchyard

Questions of food safety are on the mind of Arthur Churchyard, a second-year arts and sciences major. Antibacterials protect much of our food from contamination — good news for Arthur and other university students, who are prone to eat almost anything, whether it’s week-old pizza or fresh squid. Turn to page 26 to learn how bacteria could be destroyed using bits of protein called peptides wrapped in a hard substance found in lobster claws.

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Foods and Health

Healthy from In the 1980s, gut communities were researched using classical culture techniques.That meant samples were removed from the host and spread out on a medium, then colonies were isolated and purified to try to obtain information on each specific organism. But this technique didn’t represent the high numbers of gut organisms because some organisms are unable to grow in isolation. In addition, it’s impossible to replicate in a medium all aspects of the host, such as pH, temperature and oxygen. The method was also cumbersome and expensive because pure cultures of all the gut species had to be prepared manually, then stored in freezers, requiring extensive personnel and storage resources. But researchers have begun using more advanced techniques that are faster, automated and highly accurate. These include comparative DNA sequence analysis, cloning and polymerase chain reaction. Both old and new techniques can be used to obtain as much information as possible. ~ KR

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By Kate Roberts The microbial community inside the digestive tract is a mysterious part of the human body. Researchers have tried to study it in the past, but old techniques have been expensive and laborious and presented an incomplete picture of the complexity of this community. Now, with help from advanced molecular techniques, AFMNet researchers are hoping to better understand the interactions of fibre with the complex gut environment. “What is driving us is lack of information and the desire to learn,” says team leader Martin Kalmokoff, a research scientist with Agriculture and Agri-Food Canada (AAFC) and an adjunct professor at Dalhousie University. Along with Prof. Brent Selinger of the University of Lethbridge’s Department of Biological Sciences, Kalmokoff is investigating how dietary fibre affects the community structure and the growth and activity of certain gut species. It has become widely accepted that gutassociated microbial populations are important to the health of the host. Emerging evidence supports a role for this community in several medical conditions, including late-onset autism, skin conditions, colon cancer, Type 2 diabetes, irritable bowel syndrome, Crohn’s disease and colitis. It’s also believed that certain types of dietary fibre may be useful to stimulate the growth of beneficial bacteria, which may help with such activities as lactose digestion and limit pathogenic bacteria, yeasts and viruses from colonizing the gut. Selinger hopes that, by learning more about gut communities and their responses to certain foods, humans can derive long-term health benefits such as developing disease-specific diets. For their study, the researchers used animal models to first characterize the gut bacterial

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community with well-defined control diets. These diets can be modified using different fibre sources to study how they affect the gut bacterial community. The team hopes to determine if these responses to the nutrients can be reproduced. Kalmokoff ’s research over the last three years has focused on inulin, a plant fibre commonly referred to as a prebiotic (a compound that is claimed to nourish the good bacteria already in the digestive system, causing them to grow). Many health claims are associated with the ingestion of this and related fibres. Humans are unable to digest inulin, so it passes through into the colon, where fibre-digesting bacteria break it down. Kalmokoff has found that the enzymes bacteria use to break down this fibre create a huge response in gut activity. “Introducing the fibre produced profound changes in the community, and we are now trying to interpret the response,” he says. With AFMNet supporting this project, Kalmokoff and Selinger can work with a much larger and diverse research team and access top-notch facilities and equipment to look at more dietary fibres and how they affect the gut population. Also involved in this project are Steve Brooks and John Austin of Health Canada; Doug Inglis of the AAFC Lethbridge Research Centre; Prof. Julia Green-Johnson of the University of Ontario Institute of Technology; Prof. Lisbeth Truelstrup Hansen of Dalhousie University; post-doctoral researcher Jayadev Raju of Lethbridge; and graduate student Lisa Waddington of Dalhousie.  Dave Peleschak

Taking a new approach

Researchers look at gut activity to help determine the impact of certain foods


the inside out

Certain fibres may have a greater impact on the gut community, affecting diseases such as Type 2 diabetes, Crohn s disease and irritable bowel syndrome.

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Foods and Health

Fish that fight disease Researchers consider beneficial effects of fish nutrients on human diseases By Kate Roberts Cover Story

R.D. Moccia, University of Guelph

Fish like these may contain nutrients that could help control diabetes and heart disease.

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Fish — fish oils, protein and omega-3s — have the nutritional world buzzing. The excitement has caught on with Université Laval professor André Marette, who’s leading a team that will study nutrients found in fish and their effects on the metabolic and genetic profile of humans. Marette hopes this research will lead to strategies to control diabetes, heart disease, cardiovascular disease and insulin resistance (a prediabetic condition in which the body does not respond normally to the action of insulin). “Independent studies have shown that diets including fish oil and fish protein have beneficial effects on these metabolic diseases,” says Marette,” but the combined effects of these nutrients have not been tested in humans, and little is known about their effects at the molecular level.” This research project will be approached as two separate studies. The first involves feeding fish oil, fish proteins or both to laboratory animals that have wavering insulin resistance upon induction of dietary obesity, to study the effects of those fish nutrients on the animals’ overall metabolic profile. The researchers will also examine blood lipid levels, insulin sensitivity (the degree to which cells respond to a particular dose of insulin), inflammation markers and vascular function, to see if the fish oil and proteins have any influence on the incidence of diabetes and cardiovascular disease. Tissue samples from the muscle, fat and liver will be studied to learn whether the animals’ genetic profile changed as a result of the fish nutrient intake. The researchers can use this information to begin pinpointing which genes are turned on or off with the help of the fish ingredients. “We want to see which genes can be regulated by diet,” says Marette.

The second study is human-focused. People with moderate obesity and insulin resistance will eat a diet enriched with either fish oil or fish oil plus fish protein for three months. The researchers will then measure the subjects’ lipid, glucose and blood hormone levels, along with inflammatory markers and cardiovascular risk factors. Muscle biopsies will also be taken to assess the effects of the fish nutrients on the gene profiles. This study will show whether fish proteins enhance the effect of fish oil to improve the metabolites that affect cardiovascular health and to further lower the risk of developing diabetes and cardiovascular disease. The team Participants in this multidisciplinary research include Université Laval nutritionist Hélène Jacques, geneticist MarieClaude Vohl and clinical researcher and diabetologist John Weisnagel. University of Guelph nutritional scientist Bruce Holub will help with the human studies of fish oil. Prof. Jiri Frohlich of the University of British Columbia will assist with the determinations of inflammatory markers and the lipid profile in humans. Prof. Roger McLeod of Dalhousie University will contribute his unique expertise in lipoprotein metabolism. This team also has an academic partner — Institut des nutraceutiques et aliments fonctionnels (INAF) at Laval — and two industrial partners — Ocean Nutrition Canada, which provides the fish oil, and Marine Harvest Ingredients in Norway, which provides the fish protein. Charles Lavigne from INAF also joins the team as lab group leader. The National Institute of Nutrition and Seafood Research in Norway is the government partner on this project that ensures proper research is occurring to protect potential consumers. This research has been funded by AFMNet, the Canadian Institutes of Health Research, the Canadian Diabetes Association, the Canada Foundation for Innovation and Fonds de la recherche en santé de Québec. 


Breast is best, but why? Molecular components in breast milk could help treat human diseases Intuitively, people know that breast milk is best for babies. It helps reduce gastrointestinal problems, it contains loads of antioxidants, and some studies claim it increases intelligence. But what makes breast milk so much better than formula? That’s the question human nutritional sciences professor James Friel of the University of Manitoba hopes to answer. Using a diverse group of researchers, Friel plans to analyze breast milk by breaking it down into its components, then isolating and identifying specific molecules. He wants to study the antioxidant properties of human milk and compare it with formula and other baby food. Eventually, if the beneficial molecules can be successfully isolated, they could be used to boost other food products. “Ultimately, we would like to add these molecules to formula, baby food or even to adult food to treat adult diseases such as Crohn’s disease or ulcers,” says Friel. A key component of the project will include investigating the effects breast milk has on oxidative stress, the reaction of a baby’s tissue once it is exposed to oxygen. Early in life, newborn infants are exposed to oxidative stress because there is five times more oxygen in the air than in the womb. Oxygen can be a potential toxin because it’s a free radical, always looking to complete the outer ring of its electrons, which can damage tissue. Friel and his team believe human milk is a radical scavenger, completing oxygen’s outer ring and protecting the tissues. The team To carry out this research, Friel has assembled a team of experts. U of M human nutritional scientist Rotimi Aluko is known for his work with peptides and will be looking at the breakdown of milk. It’s been thought that digesting protein builds tissue, but research is starting to show that digested protein molecules can have

Dave Peleschak

By Kate Roberts

Adding breast milk compounds to baby formula and food could help reduce gastrointestinal problems.

potent activity, including some that end up acting like hormones. Miyoung Suh of U of M has a long history of research with lipids and is focusing on the unique lipid molecules in breast milk. U of M physiologist William Diehl-Jones is an expert on premature infants and cell cultures. He will help test molecules for antioxidant activities and will perform many infant intestinal cultures. He also contributes his model knowledge of infant intestines to the team. Nutraceutical specialist David Kitts of the University of British Columbia brings his experience with blueberries and bioactive molecules (isolated from plants) to the project in hopes of helping to isolate molecules from milk. Jean-Claude Lavoie, a researcher at Centre hospitalier universitaire Sainte-Justine, a pediatric health centre in Montreal, is using animal models to test the effects of feeding specific breast milk compounds on oxidative stress. After the compounds in the milk have been identified, U of M consumer specialist Benedict Lawlor will set up panels to gauge consumer acceptance of breast milk compounds incorporated into food products.  AFMNet – ADVANCE 2006 / 07

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Foods and Health

An enigmatic mole CLA’s alleged health-enhancing effects are still to be proven By Leslie Irons

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cule Beef Information Centre

Inconsistent research results on conjugated linoleic acid (CLA), a popular but mystifying nutraceutical, have left many scientists scratching their head. One research team is wiping the slate clean and heading back to basics for a simpler look at the molecule, which has been available to consumers since 1998. CLA, a fatty acid found in some meat and dairy fats, has been publicly heralded as having significant health benefits associated with weight loss, an enhanced immune system and reduced risk of heart disease and cancer, among myriad other advantages. But a recent study led by McGill University professor Peter Jones was unable to support earlier findings that CLA fuels weight loss in humans. So his team is taking CLA back to the drawing board at Manitoba’s Richardson Centre for Functional Foods and Nutraceuticals to look at basic regulators — inflammatory markers linked to heart disease and cancer, and cellular regulators of metabolism — to determine CLA’s efficacy, safety and biological mechanisms of action. “CLA is one of the most enigmatic molecules out there,” says Jones. “And because it’s already on the market, we need to be sure that its suggested benefits are supported and that it’s safe for consumers.” His previous study on human diets supplemented with CLA used magnetic resonance imaging to measure the most minuscule body mass changes. To his surprise, no significant differences were discerned in body weight or fat deposition. Now he’s returned to animal models to track several basic cellular functions in hamsters and mice supplemented with CLA, to see what primary mechanisms are at work.

So far, Jones and his team have found that CLA may play an important role in modifying gut bacteria. But it’s still unclear what effects it has on digestive processes such as intestinal nutrient absorption and nutrient availability. These are factors that could play a role in CLA’s weight-loss claim. This new study will track cellular metabolic regulators called peroxisomal proliferators to gain deeper insight into CLA’s role in metabolism. The study will also look for indications of health benefits related to reduced risk of heart disease and cancer. Reducing eicosanoid production (eicosanoids are inflammatory markers that have been associated with these and other chronic diseases) or altering eicosanoid profiles has been used to reduce the risk of such diseases. “CLA has previously demonstrated the ability to alter eicosanoid production in rodent models,” says Jones, “so it has great potential to mediate these benefits in humans.” With continued help from Prof. Hélène Jacques of l’Université Laval, who’ll be looking at plasma lipoprotein and lipid metabolism and systemic inflammatory markers, Prof. Catherine Field of the University of Alberta, who will be measuring intestinal inflammatory response to CLA, and numerous other collaborators, Jones hopes to piece together a clear understanding of CLA’s primary mechanisms of action, how it might achieve its suggested health benefits and what is causing the discrepancies between studies. This research has received support from the Canadian Institutes of Health Research and the Heart and Stroke Foundation. Lipid Nutrition North America is supplying the CLA for the study. 

Some dairy and meat fats, such as this beef, contain CLA, a mysterious nutraceutical currently being explored by AFMNet researchers. AFMNet – ADVANCE 2006 / 07

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Foods and Health

Peoplefriendly peptides New food science technologies involving phosphopeptides could take stress off cells By Alicia Roberts

People with chronic fatigue syndrome (CFS), a degenerative disease that attacks cells in the small intestine, and other cellular stress-related health problems may soon get help from small protein particles called phosphopeptides found in milk and eggs. AFMNet researcher Yoshinori Mine of the University of Guelph’s Department of Food Science is leading a project to home in on the ability of phosphopeptides to reduce degenerative diseases such as CFS. Mine says certain peptides in foods may react with genes in the body to reduce the stress on cells, warding off degeneration. Typically these peptides are inactive, but when they’re digested in the body or exposed to enzymes in the lab, they become active and can have various functions, he says. They can reduce hypertension, influence immunity, act as antioxidants and have hormone-like functions.

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“We’re looking at food not just as a way to satisfy an appetite or for traditional nutrients,” he says. “We’re looking at how such bioactive peptides are released from foods and how certain components of foods react with genes to bring out specific health benefits.” One such benefit could be stress relief for problems such as CFS. Through natural processes, cells become unstable, leading to degradation and accelerated aging. This complicates various chronic diseases. Normally, cells can detoxify themselves with a built-in antioxidant called glutathione (GSH). But when factors such as excessive alcohol consumption and smoking enter the picture, GSH is less effective. That leads to degenerative health problems. Mine and his team have found that a peptide in eggs and milk has the ability to help reduce the stress load. They’re studying its


interactions through two food science approaches: nutrigenomics and proteomics. The nutrigenomic approach helps the team understand the peptide’s interactions at a genetic level. So far, they’ve found it can influence a specific gene to synthesize GSH, ultimately helping to fight stress. Mine says he’s now trying to understand how and why this occurs. In the proteomic approach, the focus is on the specific characteristics of the peptide and why it has the ability to react with genes. The team is studying pigs with CFS to learn more about the peptide’s effects on cellular stress. Through tissue and blood samples, the researchers can assess the peptide’s influence. Mine’s goal is to better understand why people have CFS, to improve diagnosis and to offer preventive and treatment measures

Paula Bialski

Food science professor Yoshinori Mine holds what may be the secret to reducing the impacts of degenerative diseases such as chronic fatigue syndrome. He s using peptides from eggs and milk to slow the disease effects.

using the peptide. He says the peptide could be used in developing specific foods with antioxidative stress qualities or to make supplements that could help expel stress. He notes that AFMNet enables him to bring many experts together for this research. “This is an exciting interdisciplinary project. We’re developing a cross-linked partnership with other AFMNet research projects, industry partners and medical sectors to gather our ideas for cuttingedge research of chronic fatigue in Canada.” Also involved in this research are University of Guelph professors Ming Fan of the Department of Animal and Poultry Science and Gordon Kirby of the Department of Biomedical Sciences, University of Toronto nutritional scientist Ahmed El-Sohemy and Rong Cao of Agriculture and Agri-Food Canada.  AFMNet – ADVANCE 2006 / 07

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Foods and Health

Connecting coffee and consumers Study examines why some people crave caffeine and others avoid it By Amanda Ansell

Office of Research

Genetic makeup may explain how individuals respond to caffeine.

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Caffeine is the most widely consumed stimulant in the world. Some people like the pick-me-up it provides, but others shun it because it puts their nervous system into overdrive and causes undesirable side effects. University of Toronto researchers say these reactions may have to do with genetic makeup and how individual bodies experience the caffeine buzz differently. Prof. Ahmed El-Sohemy and master’s student Stephan Ozsungur of the Department of Nutritional Sciences are studying why some people actively seek out caffeinated substances while others avoid them. They’re looking at how genetics may influence food preferences. “A small amount of caffeine can elicit pleasurable effects in some people, elevate their mood and give them more energy, yet for others, just the smell can bring on feelings of anxiety or jitteriness,” says El-Sohemy. “We want to understand why this is.” The research team used two studies to understand the motives behind consumer caffeine choices — a food frequency questionnaire and a health and lifestyle survey. If the decision is based more on physiology (“I consume caffeine to ease anxiety or increase energy”) than social or economical factors (“Coffee is too expensive”), it might be possible to discover if that individual has genetic reasons for different patterns of caffeine consumption, ElSohemy says. Already, the team has identified genes that code for certain receptors that might influence humans’ response to caffeine. A receptor is a protein on the cell membrane that initiates a cellular


response when provoked by contact with molecules from an outside substance (in this case, caffeine). The cellular response will then pass the caffeine influence on to the whole body. El-Sohemy has found that this particular gene comes in two forms. Which gene variation is expressed will tell researchers about a person’s genotype and, in turn, whether or not he or she is likely to enjoy the effects of caffeine. The results of this study might help researchers understand why some people are more vulnerable to becoming dependent on caffeine and why some are more prone to experiencing heightened symptoms of withdrawal, such as headaches and irritability. “Knowing the genetic basis for consumer food preferences could have a significant effect on how the industry markets its products in the future,” says ElSohemy. “Some foods might be more appealing to certain subsets of the population based on their genetic makeup.” He hopes his research might one day be used to make personalized dietary recommendations for people and help them make healthier nutritional choices. Other Toronto researchers involved in this study include Profs. David Jenkins, Thomas Wolever and Paul Corey and master’s students Leah Cahill and Karen Eny. They are joined by Prof. Timothy Caulfield and research associate Nola Ries of the University of Alberta, Prof. Marica Bakovic of the University of Guelph, Prof. David Castle of the University of Ottawa and Prof. Edmond Kabagambe of the University of Alabama. This work is sponsored by AFMNet. El-Sohemy holds the Canada Research Chair (CRC) in Nutrigenomics, the study of gene-diet interactions; Jenkins holds the CRC in Metabolism and Nutrition; and Caulfield holds the CRC in Health Law and Policy. 

AFMNet is proud to be in partnership with these forward-thinking companies and organizations: Federal Governments Agriculture and Agri-Food Canada Canadian Food Inspection Agency Environment Canada Health Canada National Consumer Research Centre National Research Council Canada Networks of Centres of Excellence United States Department of Agriculture Hospital The Hospital for Sick Children Industry 3M Canada A.M.Todd Company Advanced Foods and Materials Network Axcelon Biopolymers Corp. Bioriginal Food & Science Corp. BioSyntech Canada Inc. Bowater Canadian Forest Products Inc., Thunder Bay Operations Burnbrae Farms Canadian Health Food Association Cargill, Inc. CNKonsulting Danone Vitapole Food and Consumer Products of Canada Forbes Medi-Tech Inc. Fuji Vegetable Oil Inc. Inimex Pharmaceuticals Incorporated Life Science Advisors Lipid Nutrition North America Loblaw Brands Limited Maple Leaf Canada Maple Leaf Foods McCain McLaughlin Consultants Inc. Miller Thomson LLP Nestlé Research Center

Nestlé USA New Era Nutrition Nexia Biotechnologies Inc. Nutri-Pea Ltd. Ocean Nutrition Canada Limited Parrheim Foods Protein Fractionation Inc. Senomyx, Inc. Specialty Biopolymers SUN Microsystems SynGene Biotek Inc. Taiyo Kagaku Co., Ltd. The Coca-Cola Company Wrigley Science Institute Yulex Inc. Other Canadian Institute for Photonic Innovations Canadian International Grains Institute Dietitians of Canada FEAST Enterprises Institute for Glycomics Joint Institute for Food Safety and Applied Nutrition Lochend Luing Ranches Manitoba Institute of Child Health MaRS Landing National Water Research Institute Richardson Centre for Functional Foods and Nutraceuticals Provincial Governments B.C. Department of Fisheries and Oceans Fonds Québécois de la Recherche sur la Nature et les Technologies Government of Manitoba Ontario Ministry of Agriculture, Food and Rural Affairs Ontario Ministry of Health and Long-Term Care

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Consumer and Ethical Issues

Clearing the air on new natural health product regulations By Lindsay Brown Since 2004, Canada has required that natural health products be labelled with standard information such as quantity, dosage, route of administration, possible adverse reactions and storage conditions. Although this puts more information at consumers’ fingertips, an AFMNet research team is studying just how effectively the knowledge is being used. Led by Prof. Heather Boon of the Leslie Dan Faculty of Pharmacy at the University of Toronto, the team is studying consumers’ awareness of the new regulations and how they’re making use of the information. Boon is also gauging how well pharmacists are trained to help consumers with natural health products. “We want to know how the new health product regulations are affecting Canadians — not only consumers but also practitioners, pharmacists and natural health product companies,” she says. The study is looking at over-the-counter herbal and homeopathic remedies, vitamins, minerals and essential fatty acids. The research team has already assessed how the new regulations have affected complementary medicine practitioners (such as herbalists and naturopaths) and companies that manufacture, import and sell natural health products. Data analysis is now under way. Next, they’ll study the impact on consumers and pharmacists. Focus groups held across Canada asked questions such as how pharmacists were expected to give advice on natural health products. Boon says that, although pharmacies are carrying abundant amounts of natural products, pharmacists may not be trained in natural medicine and may be unable to answer consumer inquiries. A survey will be sent to pharmacists in early spring to determine their level of natural product knowledge

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and customer support. It will focus on their current knowledge of natural health products, what they’re doing and what other support they need to improve their service abilities. Boon hopes to use the gathered information to enrich pharmacy training programs and initiate changes to the educational system that include more information on natural health products. “We plan to work to change the educational system and training so pharmacists can better meet the needs of consumers.” Researchers involved in this project include Profs. Tracey Bailey, Tania Bubela, Timothy Caulfield, Glenn Griener and Shirley

Heschuk of the University of Alberta; Prof. Lynda Eccot of the University of British Columbia; Prof. Tannis Jurgens of Dalhousie University; Profs. John Cranfield, Spencer Henson and Getu Hailu of the University of Guelph; Prof. Peter Jones of the University of Manitoba; and Profs. Peri Ballantyne, David Jenkins and Sandy Welsh, graduate students Shade Olatunde, Della Kwan and Teela Johnson, and post-doctoral researcher Kristine Hirshkorn of the University of Toronto. This research is funded by AFMNet and the Canadian Institutes of Health Research.  Vince Filby

With information on labels now regulated, researchers are looking at how it affects Canadian consumers.

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Consumer and Ethical Issues

A case for more regulations? While some trumpet the wonders of nutrigenomics, others suggest society proceed with caution By Eamon O’Flynn

Kate Roberts

Misrepresentation by the media may confuse Canadians about how diets and genetics interact.

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Nutrigenomics — the study of how diets and genetics interact to influence health — is a young research field, but it has contributed to a wide range of products being marketed on the promise that they can offer health benefits based on your genetic makeup. A University of Alberta researcher says this marketing approach raises many questions, including whether such products need an appropriate regulatory system and whether marketing that targets specific races is ethical. Prof. Timothy Caulfield of the faculties of Law and Medicine and Dentistry says the current unregulated system has resulted in product marketing that targets specific races and other identifiable groups. Health magazines, in particular, have been quick to link specific races with supplements, he says. Caulfield is launching a three-year study aimed at understanding the social perspectives around nutrigenomics. “Everyone should be interested in this,” he says. “Everyone eats.” In this study, he’ll look at public understanding of nutrigenomics, how products are represented to consumers and how best to regulate their use and sale. He’ll also examine the role of media in influencing perceptions about nutrigenomics. The approach will be interdisciplinary, using psychology, philosophy, science and sociology as the

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research team maps out ethical issues. Although this study will look at the international regulatory environment, its main focus will be Canada’s regulatory situation, says Caulfield. It will identify what a Canadian regulatory body, if established, would need to cover to oversee nutrigenomics. Based on its current upward trend, the growth of nutrigenomics is likely to continue, he says, so appropriate and timely regulatory responses in Canada will be required. Caulfield says this research could also be used by the Canadian health-care system to determine whether nutrigenomics should be used as standardized treatment of patients or as something accessible to the entire population to promote healthy physical growth. Besides studying marketing and perceptions of nutrigenomics, the researchers will look at genetic predisposition and environmental exposure. To do this, they’ll use available biobanks — collections of human biological material such as cells, biopsy specimens and organs removed during surgery. Others involved in this project are Prof. Tania Bubela and research associate Nola Ries of the University of Alberta, and Prof. David Castle of the University of Ottawa. Funding is being provided by AFMNet, FEAST Enterprises and Dietitians of Canada. 


Understanding public concerns about animal biotech By Alicia Roberts

AFMNet researchers are delving into society s perceptions of cloning and other forms of animal biotechnology.

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Roslin Institute

Biotechnology — particularly genetic modification and animal cloning — is becoming more popular in scientific circles, but what do people really think about it? New risks, ethical concerns and questions are surfacing in society, says a University of British Columbia researcher who’s studying ethical aspects of animal biotechnology. “So far, government stakeholder consultations have focused on the scientific risks of animal biotech,” says Sarah Hartley, who is also an adviser with Genome BC, where she provides input on the ethical, economic, environmental, legal and social issues related to genomics research. “We want to look at the ethical concerns of stakeholders and their implications for public policy.” Animal biotechnology has a wide range of applications that affect society, including food and agricultural production and human health. Research hasn’t really investigated ethical concerns, particularly what people think about specific applications of animal biotechnology, says Hartley, who is working with Conrad Brunk of the University of Victoria. The researchers’ study will involve focus groups with a variety of stakeholders, including animal-welfare groups, religious communities, and the agricultural and health-care industries. These groups will discuss ethical concerns related to animal biotechnology, such as the safety of animals and whether biotechnology will negatively affect humans. These discussions will be analyzed by members of Hartley and Brunk’s diverse research team. The team will be asked to explain differences between their own disciplinary perspective and the focus group responses. This information will then be the focus of a book to help explain the ethics of animal biotechnology. Hartley hopes the information gathered will ultimately feed into public policy addressing the promotion and regulation of animal biotechnology. This research is funded by AFMNet. 

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Materials

The peptide and the pea A hypertension solution isn’t far from your plate, but special processing is key By Robert Fieldhouse The secret to preventing hypertension may lie in everyday foods such as peas, says one University of Manitoba researcher who hopes protein may offer new solutions for those suffering from high blood pressure. Prof. Rotimi Aluko of the Department of Human Nutritional Sciences is working on a collaborative project to develop bioactive peptides from pea proteins by treating them with enzymes that carry out a reaction called hydrolysis (where water splits the proteins into fragments called peptides). He’s studying the structure and function of these peptides, finding ones that fight hypertension by inhibiting enzymes that play a crucial role in the biochemical pathway to high blood pressure. High blood pressure (and the kidney and cardiovascular disorders that can result from it) has been linked to two enzymes: angiotensinconverting enzyme (ACE) and renin. In theory, renin is the ideal target for drugs because it sits at the top of the biochemical pathway leading to high blood pressure, acting like a gatekeeper and exerting its influence on the rate of the ACE-catalyzed reaction that follows. When treating the condition, however, doctors have had to settle for a less effective strategy, which is to stop ACE farther down the pathway simply because there aren’t any drugs that work against renin. But now that’s changing. “Inhibiting ACE is just like cutting off an arm or leg of this giant called hypertension,” says Aluko. “It still lives. But if we produce bioactive peptides that inhibit renin activity, we kill hypertension by cutting off the giant’s head.” Aluko starts with pea proteins and treats them with various enzymes, including alcalase, trypsin and pepsin. All these enzymes fragment the proteins into peptides. The research team optimizes this reaction to get the best set of

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peptides possible, then separates the peptides from each other. This helps determine which peptides are the best candidates for fighting hypertension. Aluko uses a fluorescence method to study the separated peptides’ ability to inhibit renin activity. By using a commercially available substrate — a special molecule that reacts with renin — he monitors renin’s activity by measuring changes in fluorescence light emission. The substrate lights up against a dark background when renin is active, showing researchers which peptides reduce the enzyme’s activity and which ones don’t. Computers are also being used to understand the peptides’ function. Aluko has built a database containing a wealth of peptide information from scientific literature. And in collaboration with Prof. Shuryo Nakai of the University of British Columbia, he is using this database to model how changing the arrangement of the amino acid building blocks in a peptide affects inhibitory activity. Eventually he’d like to predict the activity of totally new peptides from his hydrolysis reaction or laboratory activities. The team has already synthesized some peptides and validated their functions. The job isn’t quite done when Aluko finds a peptide that works. He must then isolate the candidate peptide from the other components of the mixture and determine its sequence and its source in peas. He also sends the peptide to several AFMNet experts for further tests, including animal studies. “With animal work, we can have an idea of the importance of the peptides in actually reducing blood pressure,” he says. Among those involved in this research is Prof. Harold Aukema of the University of Manitoba, who checks that the peptides actually


reduce hypertension in animals with kidney disease, a condition closely associated with hypertension. Another U of M professor, Paramjit Tappia, assesses the effect of peptides on heart enlargement, a common problem that kills many hypertension patients. Prof. Chantal Matar of the University of Moncton makes sure the peptides are safe and accepted by animals’ immune systems. And Prof. Yoshinori Mine at the University of Guelph checks that the peptides can cross the intestines and enter cells. The end goal of this three-year project is to have a prototype that can be developed commercially for large-scale production to make it available to consumers. To that end, U of G professor Spencer Henson is conducting focus groups to see how consumers would prefer to receive the peptides — as a pill, in a beverage or in their food. Aluko also expects to work with an industrial partner (New Era Nutrition) to optimize incorporation of the bioactive peptides into various food formulations such as protein bars and beverages.

Others involved in this project include post-doctoral researcher Jae-Young Je and graduate students Huan Li and Natalie Prairie, all of the University of Manitoba; and Fatou Ndiaye of the University of Moncton. This research is sponsored by the Manitoba Centre of Excellence Fund, the Natural Sciences and Engineering Research Council and AFMNet. Support in kind was received from industrial partners Nutri-Pea Ltd. and New Era Nutrition. 

Dave Peleschak

Proteins in peas may lead to lowered hypertension and blood pressure, according to AFMNet researchers. AFMNet – ADVANCE 2006 / 07

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Materials

Bright minds versus biofilms Researchers are learning a thing or two from the stubborn microbes that contaminate food products Alicia Roberts

By Amanda Ansell and Leslie Irons

Glass and stainless-steel surfaces are tough for biofilms to grip onto, which helps keep food-processing equipment clean.

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In the battle to keep food-processing equipment clean and germ-free, one of the food industry’s biggest challenges stems from some of its smallest adversaries — the tiny micro-organisms that cling to each other and to surfaces, forming biofilms on moist areas, quickly building up in food-processing environments. They’re tough to eliminate. Once a biofilm is formed, it may carry or release pathogens and other potential hazards that could contaminate products, limit shelf life and even damage equipment. Now, AFMNet researchers are collaborating with experts across the country and using some of Canada’s most advanced instrumentation and techniques to investigate the properties and behaviours of these potentially harmful biofilms. “Our goal is to use a number of specialized microscopy techniques to better understand how biofilms are formed and to find ways to slow the growth of microbial species that develop on surfaces within the food-processing industry,” says Prof. Adam Hitchcock of McMaster University. Biofilms are the result of a single bacterium that replicates and lures other bacteria, giving rise to a network of cells that work together to function as an exceptionally resilient microbial community on almost any surface. They can thrive in nutrient-deprived environments such as the stainless-steel equipment in food-processing plants and can develop a variety of defences — including a protective surface secretion — against the antimicrobial sprays used in an attempt to eliminate them. One technique the researchers are using is a new scanning transmission X-ray microscope (STXM), housed at the state-of-the-art Canadian Light Source Inc. research facility in Saskatoon. This relatively new instrument, which Hitchcock helped develop, has a higher

AFMNet – ADVANCE 2006 / 07

spatial resolution — the ability to clearly distinguish small details under the microscope — than conventional optical microscopy. This technology generates information that allows quantitative analysis of both biology and foreign substances such as antimicrobial compounds (which inhibit the growth of micro-organisms, including bacteria, viruses and fungi). STXM also allows the research team to take a close look at how specific cells in biofilms react to antimicrobial substances such as disinfectants, says Hitchcock. In combination with laser and electron microscopy, STXM is creating better understanding of antimicrobial action and why certain agents work better than others. This will help in the development of improved products to control biofilms in food-preparation facilities, he says. Biofilm researchers will also take a close look at the types of surfaces used by industry professionals and their role in forming bacterial films. Less porous materials such as glass or stainless steel might make it harder for microorganisms to get a firm grip on surfaces, says Hitchcock. Choosing the right surface materials can make a big difference in the relative success food processors will have in keeping their stations free of unwanted biofilm buildup, he says. In related research, biophysicist John Dutcher and microbiologist Terry Beveridge, Canada Research Chairs at the University of Guelph, are teaming up at the Guelph Regional Integrated Imaging Facility and the Centre for Food and Soft Materials Science. These facilities house the world-class instrumentation needed to carry out delicate microscopic analyses of biofilm microbes. The team is using atomic force microscopy, which enables a sensor to touch the cell’s surface and analyze its physical properties. In a rare technique called cryo-electron microscopy, cells are flash-frozen before being magnified to a


Towards better frozen food Turned-on proteins may help stop mushiness By Lindsay Brown Frozen food is convenient, but saving time means little if the end product is mushy and unappealing. A key reason for the loss in food quality is dehydration. To help alleviate the problem, a University of Waterloo researcher wants to use the natural ability of plant proteins called dehydrins to bind water. Prof. Barbara Moffatt of the Department of Biology says dehydrins are naturally found in plant tissue. Not much is known about their function, but when they’re able to accumulate in the cell under stresses such as drought and temperature changes, they limit dehydration. Knowing more specifically how dehydrins work, then looking for ways to enhance the natural protein in plant cells, may help in understanding how these proteins can be used to prevent frozen foods from losing their consistency, says Moffatt. “This will provide a novel means of preserving food quality and texture by using natural sources.” In the study, she’s watching how the proteins react with plant cell membranes

under various environmental conditions. She’s using a naturally stress-tolerant weed called Thellungiella salsuginea, commonly known as salt lick mustard. So far, she knows that dehydrins have an unusual structure and can adapt under certain stresses, such as binding to the plant cell membranes in cold temperatures. Now she’s trying to link how this affects the dehydration potential of cells, in hopes that this information can be adapted to produce better food products. Moffatt says dehydrins may protect membranes or preserve water availability. Her team has overexpressed dehydrins in the plant to examine their ability to interact with other cellular components. They’ve also created plants that are deficient in dehydrins to learn how these proteins contribute to plant stress tolerance. The research is now at a critical stage requiring the involvement of biophysicists and experts in metabolite analysis. These essential team members are Prof. Elizabeth Weretilnyk of McMaster University; Profs. John Dutcher, Doug Goff, George Harauz and Rickey Yada and graduate student Scott Allen of the University of Guelph; Prof. Benedict Newling of the University of New Brunswick; and Profs. Gordon Gray and Nicholas Low of the University of Saskatchewan. This multidisciplinary research is sponsored by AFMNet. Earlier support from a Natural Sciences and Engineering Research Council discovery grant led to the isolation of dehydrin genes from Thellungiella salsuginea.  Barbara Moffatt hopes plant proteins will shed light on improving frozen food consistency. Chris Hughes UW Photo Imaging

molecular level, allowing researchers to observe the cells with all their native structure (including molecules) in the proper place. Atomic force microscopy specialist Manfred Jericho of Dalhousie University and Guelph geomicrobiologist Susan Glasauer — an expert in the interaction of bacteria with certain metal ions — are also involved in unravelling the biofilm mystery. Theoretical computer models generated by St. Francis Xavier University physicist David Pink are supporting the investigation. AFMNet biofilm research will help leading food producers enhance food safety in Canada and give them the scientific know-how they need to understand micro-organisms, the factors that contribute to their growth and how they can become resistant to antimicrobial agents. “Our country’s food-safety system already does a great job of protecting consumers,” says Beveridge, “but this research will help regulators stay one step ahead of potential microberelated issues.” And it’s not just the food sector that will benefit. Bacteria can produce an amazing array of nanoscale materials that could be used in diverse applications ranging from new drugdelivery vehicles and novel nanominerals to new industrial materials such as glues, coatings and potential “wonder fabrics.” Other collaborators on this research include Dalhousie University professor Tom Gill; Yuri Gorby of the Pacific Northwest National Laboratory; John Katsaras of the National Research Council lab in Chalk River, Ont.; University of Saskatchewan food science professor Darren Korber; and three members of the National Water Research Institute — John Lawrence and James Dynes in Saskatoon and Gary Leppard in Burlington. The research is sponsored by AFMNet, the Canada Foundation for Innovation, the Canada Research Chairs program, Canadian Light Source Inc., Maple Leaf Foods, the National Science Foundation (U.S.), the Natural Sciences and Engineering Research Council, the Pacific Northwest National Laboratory (U.S.) and the U.S. Department of Energy. 

AFMNet – ADVANCE 2006 / 07

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What makes proteins stick Rethinking how proteins assemble could have multiple benefits

OFAC Animal Agriculture Photo Library

By Christine Eisler

Looking at how proteins bind to surfaces such as this milk tank could help improve sanitation and increase shelf life of products.

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Proteins can bond tightly to surfaces such as stainless-steel tanks, causing sanitation problems for the food-processing industry by creating areas for micro-organisms to reside. A University of Guelph researcher is studying what makes proteins bond this way in hopes of coming up with applications for both the food and health-care sectors. Prof. Jacek Lipkowski of the Department of Chemistry is leading a multidisciplinary team that wants to harness the adsorption capabilities of proteins to help the food industry. Knowing how proteins function could lead to developments such as better cleaning agents, more effective antimicrobial compounds and products that are more shelfstable, he says. “Fouled surfaces in the food and dairy industries can be costly and reduce processing efficiency. Finding ways to reduce fouling and to understand the process would have many benefits.” Using nanotechnology to work at a molecular level, the research team is manipulating the way proteins self-assemble or naturally bond together. Taking advantage of protein aggregation would make it possible to either break up protein particles or further stabilize them, depending on the application, says Lipkowski. This is important to both food processors and retailers. In one application, the research team is harnessing the assembly capabilities of proteins to generate stable processed foods. The common strategy for prolonging a food’s shelf life is to

AFMNet – ADVANCE 2006 / 07

add starches as thickeners to absorb excess moisture. The team has found that when proteins self-assemble, they become hydrophobic or water-repellent. This means they can help keep excess moisture from pooling in the product, which can eventually lead to spoiling. This will be especially beneficial for dairy products, frozen foods and other preserved products. In another area of the team’s research, they’re hoping that better understanding of protein properties will enable them to develop stronger cleaning and antimicrobial agents that are specifically targeted to break up protein assemblies. This three-year project is just getting under way, but Lipkowski is keen about the benefits it will bring to the food industry and others. In particular, using nanostructure techniques will give researchers a better idea of what’s going on at the molecular level in foods. It will also give them an opportunity to work with a cuttingedge technology. “This research has given me the chance to work with some of the best scientists from across the country,” says Lipkowski. “It has also helped train and develop many university students in a multidisciplinary environment, and that will be an invaluable asset to both the Canadian industry and academia in the future.” The team members include Profs. Leonid Brown, John Dutcher and Rickey Yada of the University of Guelph, Profs. Michel Pezolet and Michele Auger of l’Université Laval, Profs. Geraldine Bazuin and Robert Prud’homme of l’Université de Montréal, Prof. Patrick von Aderkas of the University of Victoria, Prof Dérick Rousseau of Ryerson University, Prof. Michael Nickerson of the University of Saskatchewan, Prof. Christopher Yip of the University of Toronto and Dr. Fred Keeley of the Hospital for Sick Children. This project is funded by AFMNet. 


Surviving an incredible journey David Brown

Encapsulation is targeted to helping good bacteria live through digestion and processing By Eamon O’Flynn Good bacteria called probiotics can help improve health and reduce the risk of diseases such as colon cancer. Unfortunately, probiotics don’t survive the harsh digestive environment and are destroyed during food processing and storage. To combat these problems, University of Saskatchewan researchers are working on a means of protecting the bacteria so they can reach the intestines to take effect. Prof. Michael Nickerson is part of a team in the Department of Applied Microbiology and Food Science trying to encapsulate probiotics so they can pass through the body unharmed to reach the intestines. While identifying the most effective way to encapsulate bacteria, the researchers must also find the best prebiotics, nutrients necessary to sustain the probiotic bacteria while encapsulated. “The real challenge is finding a delivery system that both protects and enhances the probiotic so it can work properly in the body,” says Nickerson. This research, which is just getting under way, is divided into three stages. The first involves examining and producing prebiotics (mainly oligosaccharides, which are short chains of sugar molecules) from plant sources. In the second stage, the research team will examine how well commercially available strains

Saskatchewan researchers, from left, Darren Korber, Kimberley Wood, Michael Nickerson, Shuanghui Liu and Nicholas Low are looking for ways to encapsulate good bacteria to improve human health. of probiotics react with the prebiotics collected earlier in the study. Ideally, the oligosaccharides can be fed to the probiotics to promote growth. This means testing different oligosaccharides to determine which ones will react best with the probiotics. Finally, they will investigate the potential of different methods of delivering and protecting the combination of prebiotics and probiotics. To test the different encapsulation possibilities, they will use a model acid-bile gastric system to mimic part of the digestive tract. Peer collaboration is vital to this research, says Nickerson, who counts himself fortunate to be working with specialists familiar with the structure, function and characteristics of oligosaccharides to find those that will best react with probiotics. He also acknowledges his collaboration with Prof. Heather Boon of the University of Toronto, who is surveying customer awareness of and attitudes toward probiotics and encapsulated synbiotics (supplements that contain both a prebiotic and a probiotic) in a supermarket setting in suburban Toronto. Others involved in this project at the University of Saskatchewan are Profs. Nicholas Low and Darren Korber, graduate students Kimberley Wood and Shuanghui Liu and research technician Cindy Wall. This research is sponsored by AFMNet, Bioriginal Food & Science Corp., POS Pilot Plant Corp. and Nestlé.  AFMNet – ADVANCE 2006 / 07

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Materials Brandon Denard

A new weapon to battle foodborne bacteria Peptides could be used to help disinfect food, say researchers By Arthur Churchyard Like microscopic secret agents, tiny proteins called peptides infiltrate bacteria and destroy them by tampering with vital innermolecules. These antibacterial peptides have caught the interest of three AFMNet researchers who say peptides could be used in the battle against food-borne bacteria — they’re more effective than antibiotics and don’t cause allergies. Dalhousie University engineering professor Tom Gill says peptides have been fighting bacteria in animal blood and milk for thousands of years. Now, with interdisciplinary research associates from two other Canadian universities, Gill is studying how peptides could kill bacteria in meat and other food products. “Naturally occurring peptides already help protect many organisms from harmful bacteria,” he says. “We want to understand how peptides get in to damage these bacteria and find new applications of this knowledge in areas such as food safety.” Certain strains of bacteria have become resistant to antibiotics. Allergies are also a concern in the case of antibiotics like penicillin. Gill says peptides are more effective than antibiotics because bacteria don’t evolve fast enough to survive them. He’s especially interested in a peptide called protamine because it’s less expensive than other proteins and non-allergenic. Bacteria suffer from a fatal attraction to protamine because the peptide is positively charged, whereas bacterial cell surfaces are negatively charged. The peptide is drawn to the cell surface, where a special pore on the surface sucks the peptide inside. Gill is working with physics professor David Pink of St. Francis Xavier University to learn exactly how this happens. Using computer models, Pink can show graphically and mathematically how protamine attacks the cell. He’s now working on modelling cell membrane proteins called porins and how they influence the cell’s resistance to attack. Once inside, the protamine can wreak havoc by deforming important enzymes and stopping the translation of genes into proteins, says Gill.

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Peptides act as tiny secret agents infiltrating bacteria and destroying them from the inside out.

University of Guelph microbiology professor Terry Beveridge is also lending his expertise in bacterial cell surfaces to the project. Using microscopic bubbles of fat called liposomes, he is creating an experimental bacteria model by inserting different types of porin proteins on the surface of each bubble. He will then observe which types of porin proteins are susceptible to invasion by protamine. These weak spots could later be used as targets for protamine and other peptides. Understanding the physical and biological properties of peptide uptake in bacteria is helping Gill answer questions about which foods protamine could be used with and how well the peptide works in destroying bacteria. But some challenges remain. Positively charged peptides tend to stick to negatively charged surfaces in food, rendering them useless against bacteria. Another problem is that other proteins in food and bacteria act as scissors to cut peptides into harmless pieces. One way to deal with both these issues is to create what Gill calls a nano-wrap, which protects peptides in a wrap of molecules that are resistant to sticking and scissor enzymes. Over the next three years, he’ll be testing the ability of molecules such as those found in crab and lobster shells to wrap peptides in a protective coating for delivery. Funding for this research is provided by AFMNet. 


Advance Magazine - Winter 2006/2007  

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