Virtually every type of fruit contains substances that confer some kind of health benefit. If the extent of the benefit is proportionate to the publicity it attracts, it appears that the more exotic the fruit, the bigger the hype. So what chance does the humble apple have of entering the superfood stakes?Thanks to its unique combination of bioactive components, a surprisingly good one, according to a growing number of scientists and businesses convinced that the apple can give its Amazonian rivals a run for their money.
But it's not quite as simple as munching on a Granny Smith a day to keep the doctor away.
For a start, most modern dessert apples do not contain significant amounts of the bioactives that have got scientists so excited, while the ancient apple varieties and cider apples that do are too bitter to snack on. So anyone hoping to unlock the commercial potential of these rather astringent-tasting apples has got to find a way of incorporating them into dietary supplements, foods or drinks rather than selling them to be eaten whole in the fruit and veg aisles.
And this means extracting their active components and joining the rapidly growing army of firms jostling for space in the 'functional' ingredients market.
In a market as crowded as this, differentiating yourself from the vast number of fruit extracts sold on an antioxidant platform is therefore critical, says Richard Wood, the boss of Coressence, a UK-based firm hoping to cash in on apples' unique qualities. "This is not about antioxidants. The flavanols such as (-)-epicatechin that we are interested in may act as antioxidants in a test tube using tests such as ORAC (oxygen radical absorbance capacity). However, it is now known that their vascular benefits are the result of other mechanisms, and their effectiveness has little to do with their antioxidant properties."
Unlike some of the high-profile superfruits such as goji and açai, which are primarily sold on a free-radical-busting platform, the ancient apple varieties that Coressence is cultivating contain the kind of polyphenols found in cocoa and green tea, but in even greater concentrations, claims Wood.
While Gallic rivals such as Val de Vire and Diana Naturals are also trying to cash in on other apple bioactives such as quercetin and phloridzin (for inhibiting glucose absorption), and fibres (for satiety and gut health), Coressence is focusing on resurrecting ancient apple varieties that are rich in (-)-epicatechin.
This can quite literally turn back the clock when it comes to the key biomarkers of cardiovascular health, says Wood, who is looking to collaborate with partners in food and drink, dietary supplements and cosmetics to take his company's polyphenols to market.
Although there is some research into how apple fibres can reduce cholesterol, this market is already saturated with soy protein, plant sterols, beta-glucan and omega-3s, says Wood. The biggest USP apples have in terms of heart health is polyphenols, which can significantly improve your 'vascular age' - the biological age of your heart, claims Wood.
"I think this is something we will all be talking about far more in future. As you age, your arteries become damaged. They basically stiffen and fur up, increasing the risk of heart disease or stroke. (-)-epicatechin effectively reverses this process by relaxing your arteries, reducing blood pressure and reducing blood platelet aggregation [which is responsible for blood clots - the trigger for heart attacks and strokes]. We also believe it could help reduce the risk of DVT [deep vein thrombosis], which makes it a very exciting functional ingredient."
Matter over mind
Potentially more exciting, although arguably less likely to make it onto the EU 'positive list' of approved health claims under the Nutrition and Health Claims Regulation, are claims relating to mental functioning. But Wood has high hopes: "Cognition is a major area of development. Epicatechin has already been demonstrated to improve brain blood flow in humans and to dramatically improve learning and memory retention in animal studies."
Coressence has submitted two health claims under article 13 of the Regulation, he says: "The first is an apple flavan-3-ol claim relating to maintaining a healthy circulation and the second is an apple flavan-3-ol claim relating to maintaining cognitive health. We expect both to progress to the positive list. We will also submit a GRAS (generally accepted as safe) application in the US."
Coressence, which owns intellectual property covering both the extraction process for its raw materials and the rights to its specific apple varieties, is in advanced negotiations with a multinational ingredients supplier over a partnership, claims Wood. The company is also exploring collaborations with manufacturers of food and drink, dietary supplements and cosmetics.
Shareholders in Coressence, which brings together plant breeders, horticulturalists, scientists, clinicians, nutritionists and regulatory affairs experts, certainly expect to see some bang for their buck in the near future, says Wood. "We need to be making a return over a reasonable period of time - certainly in the next year or so, as it is now three years since Coressence was incorporated. Our strategy is to create a wide platform backed by strong science so that our brand partners and licensees can deliver high value end products to the market."
Coressence's plant variety rights "are equivalent to patents but last up to 10 years longer", he adds. "We think this forms a double-edged exclusivity which we offer to our licensees and brand partners."
As for breeding, Coressence has seven key varieties at various stages of maturity, says Wood. "The difference in flavanol yield between apples is huge. Modern dessert apples have a very poor amount and distribution of key flavanols. Through our breeding programmes, we seek both to increase the absolute amount of flavanols and their distribution [which is biased towards epicatechin monomers]."
Opportunities exist "throughout the functional foods sectors, in drinks, or as sports recovery drinks, or even sports warn-up drinks, or perhaps long-haul flight drinks to relieve the effects of potential deep vein thrombosis", he adds. "We also see huge potential in beauty-from-within foods, especially those concerned with improved skin tone resulting from increased peripheral skin blood flow. This has the effect of delivering more nutrients and moisture to the skin."
As for applications, he says, "the key thing about polyphenols is that they oxidise. But they work in certain media such as relatively low pH fruit juices, yoghurts, smoothies extremely well. Supplement formulations also work well.
In certain environments, such as cosmetics, it is sometimes necessary to micro-encapsulate them to reduce the oxygen exposure, but this is really only important in very high value formulations. As a pure apple granule, our product is freeze-dried and retains its polyphenol profile for at least two years; the granules also blend well with milk."
Across the Channel, meanwhile, two French companies are also hoping to cash in on the apple's unique properties. The first is Val de Vire Bioactives, a subsidiary of Val de Vire, the cider making arm of French co-op Elle & Vire. The business, which builds on more than a decade of research into extraction methods as well as the health benefits of apples, set up a dedicated manufacturing unit in 2005, but has only just started actively marketing its wares.
Export project manager Sabrina Nicolle says: "We can single out different bioactives, but the most important factor is to have a balanced profile of all phenolic compounds found in cider apple varieties to benefit from synergetic effects existing between them. Our end products are 100% water soluble with good stability at high temperatures and in a wide pH range, which is essential in applications like bakery and pasteurized dairy products. They can have a slightly astringent taste, but this is relatively easy to mask."
Beautiful on the inside
The beauty-from-within market has particular potential, says Nicolle, but the firm also has its eyes on the weight management market via products containing apple fibres and polyphenols that can control blood glucose levels and boost satiety through expanding in the stomach and delaying gastric emptying. Phloridzin is also claimed to reduce the formation of new fat cells by inhibiting the maturation of pre-adipocytes into adipocytes, she argues.
"We have conducted a number of in vitro and rat studies, and are now working on two human intervention trials." Results from the first will be available later in the year, while a second, more wide-ranging study, will look in more detail at the effects of apple extracts on blood lipids, she says.
In vitro and rat studies also suggest that Val de Vire's apple fibres have prebiotic effects as they are selectively fermented in the large intestine, releasing beneficial short chain fatty acids such as butyrate and propionate. By combining fibres with quercetin, bone health claims relating to improved calcium absorption might also be possible in future, she says.
As for more basic communications, apple ingredients tie into 'five-a-day' style messages well, she says. "3.5g of Apple Synergic gives you as many polyphenols and almost twice the soluble fibre you get from one apple."
French rival Diana Naturals is also homing in on the ability of phloridzin to inhibit glucose absorption, following extensive in vitro testing and one human trial. A larger clinical trial is now in progress, says health and cosmetics manager Nathalie Richer, who believes there is most potential in the dietary supplements and cosmetics sectors, at least in the short term.
Perhaps the obvious vehicle for delivering the health benefits of cider apples, however, is cider itself, says Serena Marks, a postgraduate student at Glasgow University, UK, who has been studying the phenolic levels of different ciders and what happens to them once they are ingested.
The fact that health claims on booze are banned in the EU under the Nutrition and Health Claims Regulation doesn't mean cider manufacturers cannot at least try and gain some marketing capital from new research in this area, says Marks. "You can't make hard health claims about red wine under this legislation, but everyone knows that in small quantities, it's good for you. The same could be said about cider."
THE SCIENCE
There is a growing body of research into apple polyphenols, but the focus should now switch from flavanols onto their metabolites - the bioactive substances that actually make it into the bloodstream after we ingest polyphenols, according to experts.
At best, in-vitro cell and gene expression studies are of value only for studying cell structures that are actually exposed to flavanols, such as surface cells in the colon, says Dr Paul Kroon - an academic based at the UK's Institute for Food Research.
"We're interested in compounds that are actually found in the blood, rather than flavonoids in food before it is eaten, as only these compounds will actually come into contact with human tissues and have an effect on arterial health."
Reassuringly for companies such as Coressence, which are marketing their apple ingredients on a cardiovascular health platform, "the metabolites do have a positive effect on the cells that are lining the blood vessels", confirms Kroon.