With consumers slowly absorbing the 5 A DAY message, the fresh produce industry could be headed for a surge in demand across the board. However, these days, it is not just a question of producing higher yields of supremely attractive and tasty crops. As scientists become more aware of the nutritional qualities of produce, we could be moving into an age of nutritional enhancement, where our favourite ‘superfoods’ will be even better for us than before.
New Zealand-based horticultural research centre HortResearch is in the process of conducting a range of programmes aimed at exploring the evolving science of functional foods. According to food business development leader, Karl Crawford, quantifying and improving the nutritional enhancement of food is commanding increasing importance at the institute.
“We currently have NZ$7 million (£2.7m) invested in studies examining different areas where fruit and fruit-based foods affect human health and performance,” says Crawford. “Our main fresh fruit focus at present is on berryfruit, specifically, the health-giving properties berryfruit offer, the scientific reasons for those benefits, and ways in which to breed new berryfruit cultivars that offer enhanced benefits.”
Last year HortResearch began a four-year NZ$6.4m government funded programme to assess the possible link between consumpton of dark-red coloured fruit juices and improved cognitive function. The study, entitled Healthful Berries, tested cognitive responses in 60 people over 65 to determine the anti-aging properties of berry juices and the efficacy of manufacturing products with optimum phytochemical compositions and results are pending.
As the recently reported surge in demand for blueberries in the UK has shown, consumers are very interested in the notion of nutrient-rich ‘superfoods’. Crawford says in New Zealand the demand for blackcurrants and boysenberries, as well as blueberries, has doubled in the last decade as the anti-aging properties of berries have been increasingly highlighted. However, while he is confident berries will continue to provide new and exciting health benefits, with research being conducted all over the world, Crawford suggests it is anyone’s guess as to what the next ‘hot’ product will be.
UK PROJECTS - BLACKCURRANTS
Scientists at the Scottish Crop Research Institute (SCRI) have been collaborating with East Malling Research (EMR) in a bid to enhance the vitamin C content of blackcurrants.
The researchers at SCRI are now into their third season of a five-year project and have been assessing the manner in which Vitamin C is accumulated and transported, and whether it is stored within the blackcurrant plants. This will allow them to establish the possibility of modifying the process, to produce greater concentrations, according to SCRI researcher, Robert Hancock.
The team has also been looking at the effect of geographical location, and, therefore, growing conditions, on different cultivars. “We are mainly finding that there seems to be a correlation between solar radiation, the amount and strength of sunlight, and the capacity to synthesise and accumulate Vitamin C,” says Hancock. “There is evidence the biosynthetic pathway is regulated by light and if that was found to be the rate limiting-factor in vitamin C synthesis, that would inform us agronomically how light might be moderated to have an effect on production. So we could make suggestions to growers, for example, reducing the density of plantings.”
Hancock says the team is now starting to look at the flexibility to agronomical manipulation of individual genotypes in existing cultivars. Given the long process of breeding new cultivars, if the existing strains prove susceptible to manipulation, it will allow them to aid agronomists much more quickly.
Blackcurrant production in the UK is largely dominated by major processing company GlaxoSmithKline (GSK), manufacturer of the Ribena branded cordial drink. At GSK, such is the emphasis placed on acquiring blackcurrants with higher nutritional contents, the company funds much of the relevant breeding research at SCRI.
ONIONS
Recognsing a fairly widespread deficiency in human intake of selenium, the Institute of Food Research (IFR) has commenced work this year, in collaboration with the University of Nottingham, to assess the role of selenium in immune function, and examine the differing effect of acquiring the mineral in supplement form or in moderated food, such as selenium-enriched onions.
Deficiency of selenium has been linked to infertility, depression, heart disease and increased risk of several forms of cancer. And according to IFR researcher, Belinda Clark, while some land areas of the UK are naturally rich in selenium, the national intake of the mineral has decreased over the past 30 years. “This fall in selenium intake is thought to be due to changes in bread-making, and the replacement of selenium-rich Canadian wheat with lower selenium content wheat from Europe,” she says.
“The IFR team have funding from the Food Standards Agency to carry out several 12-week dietary intervention studies using human volunteers over a period of three years.” The volunteers will either be supplied with selenium supplements or meals, such as lasagne, containing onions grown in high selenium soils.
TOMATOES
Scientists at the John Innes Centre (JIC) and IFR have discovered a gene in tomatoes that may help them, as well as humans, combat stress. The gene (HQT) was found to be responsible for producing an antioxidant, chlorogenic acid (CGA). By increasing the activity of HQT, the scientists have managed to raise the levels of CGA in the tomato fruits which has helped protect them against attack from bacterial disease.
“Our tomatoes are doubly special,” says Cathie Martin, project leader at JIC. “They not only protect themselves against disease, but may benefit humans that eat them by protecting against age-related diseases. For us the excitement is that this adds to our understanding of how plants naturally protect themselves against stress and diseases, but in the long term it may be that this discovery leads to fruits that are better for us.”
This discovery may also be applicable to other plants, according to IFR’s project leader, Tony Michael. “Plants possess a whole repertoire of genes involved in producing protective compounds,” he says. “CGA is the main polyphenol in this category in tomatoes. Now we have identified the gene for the enzyme that produces it, we can look for genes that produce similar compounds in other plants, with benefits for agriculture and for human nutrition.”
FISH OILS
According to Peter Shewry, head of crop performance and improvement at Rothamstead Research, there can also be environmental benefits to be gained from functional food research. Researchers at Romthamsted have been involved in a project to reproduce essential fish oils in edible plants. Shewry says since fish oils largely come from the algae which they ingest, it is possible to extract the algae gene responsible for the oil production and transplant it into edible oil crops, such as rape seed, or even brassicas.
While he acknowledges that this type of work would be likely to spark controversy among consumers he claims the positives make it well worth considering. “It does require a GM approach but offers benefits to consumers as well the environment and we can’t harvest fish oils forever.”
BRASSICAS
A Defra-funded research project at Warwick HRI has been set up to establish the possibility of extending the shelf-life of broccoli to maximise its nutritional benefit.
According to project leader Vicky Buchanan-Wollaston, like other members of the brassica family, broccoli is known to contain high levels of beneficial components such as fibre, minerals, vitamins, antioxidants, polyphenols and glucosinolates, which offer health benefits including decreased risks of coronary heart disease and cancer. However, it is plagued with a short and often unpredictable shelf life, which is not only characterised by a loss of colour and flavour, but also a significant reduction in its nutrient value.
“At Warwick HRI we have shown there is both a genetic and an environmental effect on shelf-life quality of broccoli,” says Buchanan-Wollaston. “We have a collection of well characterised, genetically stable, broccoli lines showing a wide variation in shelf life, that can be exploited to investigate further aspects of product quality including nutrient content, rate of nutrient loss during storage and effects of metabolome content on shelf life.”
Her team is now working on different projects to identify the genetic markers affecting the shelf-life trait, which should enable forecasts to be made for broccoli exposed to different stress treatments. In addition, they are looking at the possibility of rolling out the analysis to other brassicas.
Researchers at the Institute of Food Research (IFR) have also been working with brassicas, to assess their anti-cancer properties. The team has been looking at the human synthesis of isothiocyanates, known as ‘mustard oils’ or ITCs, by components, called glucosinolates in broccoli, and examining the possibility of producing ITC-enriched forms of broccoli.
“These novel cultivars have been developed through conventional breeding and are now ready for commercial production, says a spokeswoman for IFR. “We are using these in human intervention studies in collaboration with the Queens Medical Centre, University of Nottingham, and comparing changes in gene expression in the gastrointestinal tract following eating either standard or ITC-enriched broccoli.”
In addition the IFR researchers have been investigating the way in which the biological effect of the JTCs is genetically expressed in different people.
“One aspect of this project is to study the effect of variation at the human GSTM1 gene,” the spokeswoman explains. “Forty per cent of us lack this gene through an ancestral deletion from the genome. Epidemiological evidence suggests we may gain greater protection from cancer following broccoli consumption if we lack this gene. Thus, each of the volunteers are ‘genotyped’ to see if they have GSTM1, and we will correlate these data with the types of ITC metabolites found, the rate at which they are excreted and the types of genes which ITC switch on.”
Future Expectations
Given the novelty of this area of research and duration of many of the projects, it could be some time before any groundbreaking discoveries are reported. However, HortResearch’s Crawford claims by 2008-2010, when the majority of the institute’s current studies will end, his colleagues should at least have a “far greater understanding of how our bodies use compounds found in fruit, and, importantly, how science can track those compounds from the field or orchard, through to a processed product”.
However, despite this overall movement towards functional eating, Crawford does not expect to see a significant change in the way people shop for produce. “The interface between consumers and produce has remained virtually unchanged over hundreds of years,” he says. “Providing new cultivars with added health benefits is never going to change that. Yes, we will certainly see greater choice for consumers, but the mere presence of greater choices is not a fundamental change in an industry that already adopts an ever-greater product offering every year.”
Neither does he anticipate functionality gaining importance over traditional, more cosmetic factors, known to affect purchasing decisions. “In fact, quite the opposite could occur, with flavours and colours becoming ‘brands’ for the particular health and wellbeing benefits offered by functional foods,” he explains. “Already blackcurrants, blueberries and boysenberries are attracting huge attention for their anti-ageing potential. This potential has, in the consumer’s eye at least, become inextricably linked to their deep blue colouring. A similar situation is also occurring with the antioxidant lycopene in tomatoes.” Crawford says this correlation is already being observed in New Zeland with people being encourgaed to eat a range of colours for their 5 A DAY allowance.
“The way in which functional foods will affect consumer behaviour is far more subtle,” Crawford suggests. “Essentially, information on the health benefits of certain foods will become an extra factor in consumer purchase decisions, weighed carefully alongside traditional purchase drivers such as price, quality, taste and colour.” Crawford believes that in this way, functional foods have the potential to affect the first real change in consumer purchase behaviour since the advent of viable long-term produce preservation.
However, whether such discoveries will help to improve overall consumption of fresh produce, remains to be seen. “Obviously, there will be sections within the consumer group who will react to functional foods by purchasing more fruit and vegetables, and certainly fruit and vegetables with added health benefits will take some market share from those that do not,” says Crawford. “However, we already know that fruit and vegetables are good for our bodies, and yet consumption rates in the developed world are static or in decline. If functional foods are going to make a positive impact on produce sales, they will have to be more than just ‘good for you’, they will have to suit changing consumer trends.”
Rothamsted’s Shewry agrees that one of the biggest challenges is reaching the widespread price-sensitive consumers, claiming the people most in need of nutritional enhancement will only benefit if the products are available to them at a price they will be willing to pay. This understanding is also central to an EU-funded international project Shewry is involved in to raise the fibre content of white bread.
Crawford suggests innovation and presentation will be fundamental in targeting new consumers. “Where functional foods may be able to boost fruit and vegetable consumption is through presenting these foods, or the health benefits they offer, in new and exciting ways. If we can isolate the compounds within fruit and vegetables which are especially good for us, and present them as a snack food or drink, then we could indirectly increase produce sales.”
SPOTS THE DIFFERENCE FOR CALIMAN
Spotted papaya are set to change the way we look at fruit, according to Brazilian producer, Caliman Agricola SA.
After research with the food technology laboratory of the North Fluminense State university in Brazil, Caliman has discovered its spotty papayas contain up to 16 per cent more vitamin C than conventional varieties.
And following its successful uptake on the domestic market, the company is planning to launch the vitamin-enriched Leopard papaya into Europe later this summer.
According to Ana Köbig, marketing director at Caliman International, thanks to the cartoon leopard on the label, detailing its nutritional selling point, consumers have been increasingly drawn to the unconventional looking fruit.
Contrary to popular belief the spots are not signs of disease or damage. Rather, in this instance they are a pure concentration of L-ascorbic acid, the main active variant in vitamin C, which is beneficial to both the consumer and the papaya itself.
Vitamin C has been proven essential for a number of reasons: it combats free radicals, which helps delay the aging process; it reduces infections; enables better protection and reconstitution of the body cells, by urging the body to produce more collagen and protein; enables better iron absorption; helps rid arteries of fatty deposits and protects against several types of heart disease and cancer.
Meanwhile, the spots of L-ascorbic acid protect the fruit against exposure to extreme temperatures as it grows, which helps it to combat oxidation.
The spotted fruit of both Golden and Formosa varieties have presented higher levels of vitamin C than spotless ones at all stages of maturation. The spotted Caliman Formosa papayas are 12.31 per cent higher in Vitamin C, while the Golden variety are 9.18 per cent higher than standard types. The difference amounts to an average of 10mg, representing 15 per cent of the recommended daily intake.
Calimam’s spotted papayas are harvested from June to November, depending on weather.
Wealmoor Ltd has been Caliman’s sole commercial representative for papaya in the UK for 14 years, supplying them to Tesco and Sainsbury’s, as well as the wholesale and foodservice sectors.
Paul Bailey, business unit manager at Wealmoor Ltd, says this nutritional discovery should help to raise the profile for papaya. “Caliman has been at the forefront of papaya R&D for over 20 years now, introducing the now industry-standard ‘Golden’ variety to the UK and then a stream of first-to-market initiatives, such as organic, Formosa & Calimosa varieties, as well as countless packaging initiatives which have helped to bring papaya increasingly into the mainstream,” he says. “This latest work on the health benefits associated with Papaya re-emphasises why Caliman is the UK’s market leader.”
Wealmoor’s new product development and design manager, Bina Shah agrees the spotted papaya could make a big impact among a specific group of the market. “The cartoon leopard label is an excellent idea, and I believe an ideal way to entice the younger generation from the inhibitions of eating unconventional fruits,” says Shah. “Breakfast cereal companies have long used such marketing strategies to appeal to children. The papaya could be effectively promoted in a similar fashion, allowing young people to discover the unique and delicious taste of the fruit whilst enjoying its health benefits. Already established as an integral part of a typical Brazilian breakfast, the papaya has the potential to be the perfect compliment to any breakfast table - delicious, refreshing and packed full of goodness...what a ‘purrrrrrfect’ way to start your day!”
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