Exploring dark matter

Even by the standards of the food industry, chocolate makers are a cagey lot. Chocolate can be such a tricky substance to handle that they are unwilling to give their secrets away. Yet chocolate-making is one dark art that could turn out to be rather better for us than we imagined.

Once the preserve of diabetics, lower-calorie, low-carb, low-GI (glycaemic index) chocolate is now on the agenda as a way of combating our expanding waistlines. And what was once considered a perfect food to binge on when facing a broken heart is today being touted as a potential source of chemicals to combat heart problems that are rather more physical in origin.

The potential has not been lost on food companies. At the recent launch of the Food and Drink Federation's (FDF's) new Lifestyle and Dietary Trends Industry Group, the FDF said the functional food market had grown by 523% between 1997 and 2003 and is now worth over £1.2bn in the UK alone. The key point for chocoholics to note is that three of the 10 member companies in the group are Cadbury Schweppes, Masterfoods (the European arm of Mars) and Nestlé UK. These three together account for between 75-80% of the British retail market in chocolate.

While these three companies are reticent to reveal their future development secrets in functional chocolate, Nestlé has already taken a first step with the launch of low-carb versions of Rolos and Kit-Kats last summer. As we went to press, Cadbury unveiled three new chocolate bars in a new low-calorie format. The Dairy Milk, Dairy Milk Mint and Bourneville bars come in a 17.5g format, each with under 99 calories. In a separate development, it is also investing £40m at its Bournville factory in a new 20,000t Dairy Milk moulding plant with modern wrapping and packing line, along with a new chocolate making area.

The company says that 50% of consumers surveyed said they would buy chocolate more often if a lower calorie product were available. "No other offering in the confectionery market helps to manage day-to-day consumption whilst offering the same product as enjoyed by generations of chocolate fans in the UK," it says.

Sweet success

Only time will tell whether consumers are convinced the taste is good enough to forego the full calorie version. Mimicking that luxurious mouthfeel and rounded flavour has always been a sticking point, making sugar and fat difficult ingredients to replace.

As well as sweetness, sugar adds bulk and has an important effect on the texture and melting behaviour of the finished product. There are two basic approaches to replacing it. The first is to add certain fibres, such as inulin, fructo-oligosaccharides or polydextrose. Their use is limited, however, because they have a detrimental affect on the texture and flavour of chocolate if used at too high a concentration. In fact, extra fat may be needed to keep the chocolate workable.

Nevertheless, Nestlé managed to use polydextrose as the main replacement sweetener in both the chocolate and filling of its low-carb Rolos, which carry 346 kcal per 100g as opposed to 471 kcal for the standard product. Reviews from consumers visiting low-carb web sites reveals a rather mixed response to the taste of the new version.

The second approach to replacing sugar is to use bulk sweeteners known as polyols, the best-known of which are the polyols such as maltitol or lactitol. Similar compounds have been used in sugar-free gum and mints for decades, but they are a relatively recent innovation in chocolate. The biggest downside of polyols is their laxative effect, which limits how much people can desirably consume.

In general, the polyols can replace sugar on a one-to-one basis although some of them are not actually as sweet. If sweetness is an issue, they can be supplemented by intensive sweeteners, such as sucralose, acesulfame-k or aspartame, which are up to 200 times sweeter than sugar. Maltitol is an especially popular choice in chocolate. It is roughly 90% as sweet as sugar and doesn't require the addition of intensive sweeteners.

Maltitol is finding increasing use in food products touted as low-carb. But Steve Calver, UK sales manager for Belgian chocolate maker Belcolade, says that the difference in carbohydrates between sugar and maltitol is actually quite modest. "A normal chocolate would typically have around 45% carbohydrate, while a chocolate made with maltitol would only reduce this to around 40%. So there is a difference, but it may not be as high as people imagine."

In any case, Calver thinks that the low-carb trend is on its way out. Adverse health claims have led to low-carb diets falling out of favour in the US in the past year and Calver believes that European slimmers will follow suit.

Nevertheless Belcolade has just introduced a range of sugar-free dark chocolate and no-added sugar milk and white chocolate. The aim is to serve the growing market for lower-calorie products, whether they are low-carb or not. Maltitol has only 2.1 calories per gram, as opposed to 4 calories per gram of sugar.

According to Calver, the rising tide of diabetes will also create an increasingly important niche market. Around 1.8m people are already diagnosed with diabetes in the UK, with an estimated 1m more people undiagnosed.

Fat chance

So what are the chances of more traditional dieters getting a boost from low-fat chocolate? It's a tricky area, because the fat is vital for the workability of chocolate. Bake-stable chunks, for example for muffins, are relatively low in fat at around 26%, while chocolate for bars or coatings is as much as 35% fat. Calver says that reducing the fat below these levels is seen as something of a non-starter: "If you cut the fat content too low you just get a thick stodgy mess that's impossible to work with."

So what about the type of fat? Could chocolate be healthier without being calorie controlled? European Union regulations state that the fat in chocolate must be 95% or more pure cocoa butter, with other vegetable fats restricted to those derived from six specific plant oils. This also restricts any changes that chocolate manufacturers could make. But the good news for health is that the vegetable fat portion of chocolate is not permitted to be hydrogenated, which means that the current health concerns over trans fats are not a problem.

However, leading fat consultant Geoff Talbot says that chocolate with a high milk content could become a target in the trans fat debate as other dietary sources of trans fats are phased out and dairy products start to come under scrutiny. "The vegetable fats in chocolate are not hydrogenated but around 5% of milk fat is trans fats. Natural sources of trans fats will increase as a proportion of the total in people's diets as other sources are removed, for example, from spreads. There's no evidence that these natural trans fats are any worse or any better than those made during processing," he says.

According to Talbot, it's chocolate-flavoured coatings that provide real scope for change. Some coatings simply use the same vegetable fats that are permitted in chocolate but at higher proportions. Others, however, use partially hydrogenated vegetable oils and this is a big area for development. "Manufacturers here are definitely moving away from trans fats," he says. "Lots of manufacturers are looking at zero-trans alternatives." A third group of chocolate-flavoured treats use palm kernel oil, which contains no trans fats, but which does contain that other bete noir of the health conscious -- saturated fats.

So the new breed of chocolate may be lower in calories and better for teeth, but it seems it will always remain slightly naughty -- but isn't that why it tastes so good!FM

Cancer-fighting cocoa may Also boost brain power

In April, Zurich-based Barry Callebaut announced that it has developed a new way of processing cocoa beans to preserve more of a group of naturally-occurring chemicals called polyphenols. At the same time the company announced it had funded research at an external laboratory that showed that the polyphenols found in cocoa have a significant ability to inhibit the growth of in-vitro cancer cells. They provided faster results than comparative tests of another plant compound called beta-sitosterol, which has been shown in previous independent studies to combat cancer.

Barry Callebaut is continuing to fund a longer-term study at a second lab into the effect of polyphenols on rats. Although it's too early for the study to confirm an in vivo anti-cancer effect, the rats have been exhibiting a side effect of improved memory, which the company hopes may also be attributed to the polyphenols.

The Acticoa process remains largely under wraps as Barry Callebaut waits for patent protection, but it will say that it covers several processing stages, from harvesting, through processing to the finished chocolate. The greatest loss of natural polyphenols takes place during the fermentation of cocoa beans, so some of the beans in the Acticoa process are unfermented.