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How to keep foods bursting with goodness
Technology
the use of artificial flavourings by protecting these components until they reach their intended destination within your body, whether that be your taste buds or the depths of your gut. The popularity of “functional foods” containing healthy or supposedly disease-preventing ingredients has grown vastly in recent years (see Graph, opposite). Health-conscious consumers can now buy bread, margarine, cereal, baby food and dairy products stuffed full of added vitamins, minerals, omega-3 oils and
antioxidants, as well as both probiotic bacteria and prebiotics – ingredients supposed to promote the beneficial bugs. There is, however, growing evidence that many of these ingredients fail to deliver whatever benefit they may have, either because they degrade during manufacture and storage of the product, or because our bodies simply break them down before they can do us any good. Up to 90 per cent of some probiotic bacteria used in yogurt drinks for example, including bifidobacteria, do not survive the journey through the stomach to the small intestine. Similarly, omega-3 fatty acids that are believed to boost brain power can become oxidised if exposed to oxygen, which not only makes the oils taste and smell rancid, but produces damaging free radicals. Now the food industry is investigating a range of technologies to protect these vulnerable ingredients. Some involve encasing the ingredients in protective capsules, while others are looking at novel packaging technologies to seal the good stuff separately until the food is opened (see “Delayed reaction”, below). One technique attracting a lot of attention is microencapsulation, developed by the pharmaceutical industry to
cap fitted with a diaphragm to create a sealed compartment where a functional ingredient such as bacteria or vitamins can be preserved for up to 18 months. This can be released into the drink by rupturing the diaphragm with your finger. Since some vitamins degrade under exposure to light, manufacturers often overload their drinks with vitamins, says Rothschild. This is not only more expensive but also makes it difficult to control the dose of vitamins the consumer receives. The caps would instead allow manufacturers to precisely control the amounts of vitamins in any kind of drink. Even more ambitious is the prospect
of coating the inside of packaging surfaces with enzymes to transform the food within. Jose Maria Lagaron of the Agrochemistry and Food Technology Institute in Valencia, Spain, has already used the enzyme beta-galactosidase to transform lactose in dairy products into glucose and galactose. This would allow dairy manufacturers to make varieties of their products for people who are lactose-intolerant, without using an entirely separate production line, he says. And lactose is just the beginning: researchers are also experimenting with the enzyme cholesterol reductase to transform cholesterol into coprosterol, says Lagaron.
How to keep foods bursting with goodness
There’s a new way to keep health-giving additives safe from the ravages of time, oxygen and your hostile gut DUNCAN GRAHAM-ROWE
YOU bite into a cheese sandwich. As you chew the bread, your teeth break open tiny edible capsules, releasing a burst of extra flavour. Once you swallow, even smaller capsules fine enough to survive the chewing will burst open in your gut, releasing probiotic “friendly bacteria” to aid your digestive system. Welcome to the world of bioactive packaging, designed to maximise the benefits of healthpromoting ingredients and limit
DELAYED REACTION A simple way to protect bacteria or other health-promoting ingredients from the environment is to store them in the packaging rather than the food itself. Swedish company Biogaia, based in Stockholm, already sells a drinking straw that releases probiotic bacteria when you drink through it. “The bacteria are in an oil drop that’s attached to the inside of the straw,” says managing director Peter Rothschild. This makes it possible to turn any cold drink into a probiotic, whereas normally heat treatments such as pasteurisation would kill off the good bacteria along with the bad, says Rothschild. Biogaia has also developed a bottle 24 | NewScientist | 2 September 2006
deliver timed release of drugs into the body. Mary Ann Augustin, a chemist at Food Science Australia in Melbourne, has been using a spray-drying technique to coat fish oils in protective edible proteins or carbohydrates, as part of a programme at the Australian national research institute CSIRO. “This has enabled the conversion of fish oil into shelf-stable powdered oil ingredients and liquid emulsions,” she says. Some of these are already available in bread and baby milks. Not only does this prevent the oils oxidising during storage, it should also prevent them altering the texture and flavour of the food, says Jose Maria Lagaron, who is leading a study into using novel materials and nanotechnology in food packaging at the Agrochemistry and Food Technology Institute in Valencia, Spain. This simple encapsulation technique is enough to protect fish oils from the atmosphere, but ingredients such as probiotics and prebiotics need protecting from stomach acids. This means developing a coating to delay their release until they reach the intestine. “It’s a very tall order,” says David Weitz, a material scientist at Harvard University. One simple approach is to encapsulate the ingredients in colloidosomes – porous, crystalline molecules that release their contents gradually. “Just by having tiny pores in the surface you get diffusion over a certain amount of time, so you get a slow release,” says Weitz. However, most progress in this area has been made in encapsulating the bacteria within spheres of digestible “biopolymer”, such as a polysaccharide . A number of labs, including Lagaron’s, are developing biopolymer capsules designed to release their contents in response to different triggers, such as a particular pH or light level, or even the concentration of ions in their environment. Capsules have also been developed that are sensitive to a www.newscientist.com
ICONICA
Extended shelf time means more chance for vitamins and probiotics to perish
THE RISE OF HEALTH-BOOSTING FOODS UK retail sales of “functional” food and drink products such as probiotics and prebiotics 1200 £ millions
1000 800 600 400 200 0 2000 By sector
2001 2001
2002 2003
2003
2004
2005
2005
300 250
£ millions
200 150 100 50
www.newscientist.com
wa ter Ot he B rs e v ( ce inclu erag rea d e l b ing s ar b s & rea ch d, ee se )
SOURCE: MINTEL
ed
Eg gs ttl Bo
Sp rea ds ul ati Ju on d ice , j rink ui s c & e dr di ink lu s ta alt ern So bles y ati a ve da pr iryod uc ts Sti m
Yo gu rts
& dr in Br ks ea kfa st ce rea ls
0
temperature change of just 0.2 °C. All these properties vary throughout the body, says Lagaron. “You can target particular organs and even cells.” Making food healthier is not just about what you put in though, but also what you take out, and encapsulation can help here too. Like other ingredients, artificial flavourings tend to degrade when exposed to light and oxygen while the food sits on the shelf. This means manufacturers must add more flavourings than necessary to ensure the food keeps its taste until it reaches its use-by date. By encapsulating the flavouring in a polymer ball designed to burst only when bitten into, less of the chemical is needed. Hurdles remain, however, not least the cost of encapsulation technologies. Margins in the food industry are extremely low, meaning much of the development in encapsulation so far has been on the back of
research in the pharmaceutical industry. As a result, only those methods that can be put into practice cheaply are likely to succeed. “You can’t put anything expensive in food because the return is so low,” says Weitz. How consumers will take to the technologies also remains to be seen. There have been protests that adding folic acid to bread or fluoride to water amounts to mass medication. What’s more, the industry need only look at how European consumers responded to genetically modified food to see what they might be up against, says Frans Kampers of the Wageningen Bionanotechnology Centre for Food and Health Innovations in the Netherlands – particularly if they are associated with the term “nanotechnology”. If these problems can be overcome, however, such techniques could ultimately improve the nutritional value of foods, and improve their absorption by the body, Kampers says. For example, the industry has started adding flavonoids – oily substances found in vegetables such as broccoli that are believed to act as antioxidants – to a range of foodstuffs, including spreads and drinks. Flavonoids are more easily absorbed by the body as small droplets, but such droplets tend to clump together when added to drinks or spreads, so researchers are attempting to suspend even smaller droplets within an emulsion. The oil is passed through a sieve to create uniform, nanometre-sized droplets. These are then added to the spread or liquid and blended together. “We want to look at adding nutrients to food in such a way that the bioavailability of the nutrients is increased,” says Kampers. If researchers succeed in their efforts, it could bring a new meaning to advertising slogans like “bursting with goodness”. ● 2 September 2006 | NewScientist | 25
the use of artificial flavourings by protecting these components until they reach their intended destination within your body, whether that be your taste buds or the depths of your gut. The popularity of “functional foods” containing healthy or supposedly disease-preventing ingredients has grown vastly in recent years (see Graph, opposite). Health-conscious consumers can now buy bread, margarine, cereal, baby food and dairy products stuffed full of added vitamins, minerals, omega-3 oils and
antioxidants, as well as both probiotic bacteria and prebiotics – ingredients supposed to promote the beneficial bugs. There is, however, growing evidence that many of these ingredients fail to deliver whatever benefit they may have, either because they degrade during manufacture and storage of the product, or because our bodies simply break them down before they can do us any good. Up to 90 per cent of some probiotic bacteria used in yogurt drinks for example, including bifidobacteria, do not survive the journey through the stomach to the small intestine. Similarly, omega-3 fatty acids that are believed to boost brain power can become oxidised if exposed to oxygen, which not only makes the oils taste and smell rancid, but produces damaging free radicals. Now the food industry is investigating a range of technologies to protect these vulnerable ingredients. Some involve encasing the ingredients in protective capsules, while others are looking at novel packaging technologies to seal the good stuff separately until the food is opened (see “Delayed reaction”, below). One technique attracting a lot of attention is microencapsulation, developed by the pharmaceutical industry to
cap fitted with a diaphragm to create a sealed compartment where a functional ingredient such as bacteria or vitamins can be preserved for up to 18 months. This can be released into the drink by rupturing the diaphragm with your finger. Since some vitamins degrade under exposure to light, manufacturers often overload their drinks with vitamins, says Rothschild. This is not only more expensive but also makes it difficult to control the dose of vitamins the consumer receives. The caps would instead allow manufacturers to precisely control the amounts of vitamins in any kind of drink. Even more ambitious is the prospect
of coating the inside of packaging surfaces with enzymes to transform the food within. Jose Maria Lagaron of the Agrochemistry and Food Technology Institute in Valencia, Spain, has already used the enzyme beta-galactosidase to transform lactose in dairy products into glucose and galactose. This would allow dairy manufacturers to make varieties of their products for people who are lactose-intolerant, without using an entirely separate production line, he says. And lactose is just the beginning: researchers are also experimenting with the enzyme cholesterol reductase to transform cholesterol into coprosterol, says Lagaron.
How to keep foods bursting with goodness
There’s a new way to keep health-giving additives safe from the ravages of time, oxygen and your hostile gut DUNCAN GRAHAM-ROWE
YOU bite into a cheese sandwich. As you chew the bread, your teeth break open tiny edible capsules, releasing a burst of extra flavour. Once you swallow, even smaller capsules fine enough to survive the chewing will burst open in your gut, releasing probiotic “friendly bacteria” to aid your digestive system. Welcome to the world of bioactive packaging, designed to maximise the benefits of healthpromoting ingredients and limit
DELAYED REACTION A simple way to protect bacteria or other health-promoting ingredients from the environment is to store them in the packaging rather than the food itself. Swedish company Biogaia, based in Stockholm, already sells a drinking straw that releases probiotic bacteria when you drink through it. “The bacteria are in an oil drop that’s attached to the inside of the straw,” says managing director Peter Rothschild. This makes it possible to turn any cold drink into a probiotic, whereas normally heat treatments such as pasteurisation would kill off the good bacteria along with the bad, says Rothschild. Biogaia has also developed a bottle 24 | NewScientist | 2 September 2006
deliver timed release of drugs into the body. Mary Ann Augustin, a chemist at Food Science Australia in Melbourne, has been using a spray-drying technique to coat fish oils in protective edible proteins or carbohydrates, as part of a programme at the Australian national research institute CSIRO. “This has enabled the conversion of fish oil into shelf-stable powdered oil ingredients and liquid emulsions,” she says. Some of these are already available in bread and baby milks. Not only does this prevent the oils oxidising during storage, it should also prevent them altering the texture and flavour of the food, says Jose Maria Lagaron, who is leading a study into using novel materials and nanotechnology in food packaging at the Agrochemistry and Food Technology Institute in Valencia, Spain. This simple encapsulation technique is enough to protect fish oils from the atmosphere, but ingredients such as probiotics and prebiotics need protecting from stomach acids. This means developing a coating to delay their release until they reach the intestine. “It’s a very tall order,” says David Weitz, a material scientist at Harvard University. One simple approach is to encapsulate the ingredients in colloidosomes – porous, crystalline molecules that release their contents gradually. “Just by having tiny pores in the surface you get diffusion over a certain amount of time, so you get a slow release,” says Weitz. However, most progress in this area has been made in encapsulating the bacteria within spheres of digestible “biopolymer”, such as a polysaccharide . A number of labs, including Lagaron’s, are developing biopolymer capsules designed to release their contents in response to different triggers, such as a particular pH or light level, or even the concentration of ions in their environment. Capsules have also been developed that are sensitive to a www.newscientist.com
ICONICA
Extended shelf time means more chance for vitamins and probiotics to perish
THE RISE OF HEALTH-BOOSTING FOODS UK retail sales of “functional” food and drink products such as probiotics and prebiotics 1200 £ millions
1000 800 600 400 200 0 2000 By sector
2001 2001
2002 2003
2003
2004
2005
2005
300 250
£ millions
200 150 100 50
www.newscientist.com
wa ter Ot he B rs e v ( ce inclu erag rea d e l b ing s ar b s & rea ch d, ee se )
SOURCE: MINTEL
ed
Eg gs ttl Bo
Sp rea ds ul ati Ju on d ice , j rink ui s c & e dr di ink lu s ta alt ern So bles y ati a ve da pr iryod uc ts Sti m
Yo gu rts
& dr in Br ks ea kfa st ce rea ls
0
temperature change of just 0.2 °C. All these properties vary throughout the body, says Lagaron. “You can target particular organs and even cells.” Making food healthier is not just about what you put in though, but also what you take out, and encapsulation can help here too. Like other ingredients, artificial flavourings tend to degrade when exposed to light and oxygen while the food sits on the shelf. This means manufacturers must add more flavourings than necessary to ensure the food keeps its taste until it reaches its use-by date. By encapsulating the flavouring in a polymer ball designed to burst only when bitten into, less of the chemical is needed. Hurdles remain, however, not least the cost of encapsulation technologies. Margins in the food industry are extremely low, meaning much of the development in encapsulation so far has been on the back of
research in the pharmaceutical industry. As a result, only those methods that can be put into practice cheaply are likely to succeed. “You can’t put anything expensive in food because the return is so low,” says Weitz. How consumers will take to the technologies also remains to be seen. There have been protests that adding folic acid to bread or fluoride to water amounts to mass medication. What’s more, the industry need only look at how European consumers responded to genetically modified food to see what they might be up against, says Frans Kampers of the Wageningen Bionanotechnology Centre for Food and Health Innovations in the Netherlands – particularly if they are associated with the term “nanotechnology”. If these problems can be overcome, however, such techniques could ultimately improve the nutritional value of foods, and improve their absorption by the body, Kampers says. For example, the industry has started adding flavonoids – oily substances found in vegetables such as broccoli that are believed to act as antioxidants – to a range of foodstuffs, including spreads and drinks. Flavonoids are more easily absorbed by the body as small droplets, but such droplets tend to clump together when added to drinks or spreads, so researchers are attempting to suspend even smaller droplets within an emulsion. The oil is passed through a sieve to create uniform, nanometre-sized droplets. These are then added to the spread or liquid and blended together. “We want to look at adding nutrients to food in such a way that the bioavailability of the nutrients is increased,” says Kampers. If researchers succeed in their efforts, it could bring a new meaning to advertising slogans like “bursting with goodness”. ● 2 September 2006 | NewScientist | 25