How far can we go with fibre?

March 31, 2019

Food and drink expert, Carol Raithatha, discusses developments in the use of fibre in unanticipated areas of food and drink formulation.

It’s a sign of the times that I’ve substituted my bed time biscuit for a handful of high fibre bran cereal. The benefits of adding fibre to our diets are becoming clearer by the day, but do we really need to give up on little indulgences to stay healthy? Maybe not – fibre is turning up where you might least expect it as manufacturers get creative and explore novel ways to use this constituent to transform ‘unhealthy’ foods.

Fibre in unexpected places

Fancy some fibre with your ice cream? It’s now possible with products such as a Dutch start-up brand Koupe, an alternative to ice cream that’s high in fibre and high in protein. It is claimed there is more fibre in one serving of Koupe than can be found in a serving of broccoli. Similarly, Halo Top ice cream, which is available in the UK, contains fibre, and claims to be high in protein and only contain 280-360 calories per tub. Thirsty? How about some fibre in your favourite fizzy drink? Coca-Cola Plus, is a calorie and sugar free beverage containing a fibre referred to as indigestible dextrin (a type of starch that resists digestion). Offered in striking white packaging, the drink was launched in Japan in 2017 and is marketed towards consumers over forty years old. Coca-Cola Plus is claimed to help suppress fat absorption and moderate tri-glyceride levels post-meal. The fact that Japan is known to be ahead of the curve when it comes to new ideas for functional food and drinks, is demonstrated by this product.

Forms of fibre can help reduce sugar and fat in traditional recipes, while still allowing for acceptable taste and texture. The confectionery sector is a case in point. For example, this year Cadbury UK will be launching a 30% reduced sugar version of their classic Cadbury Dairy Milk bar. According to the company, the new bar has been “two years in the making”; has been developed by a team of scientists, nutritionists and chocolatiers; and successfully replaces the physical functionality of sugar with fibre. Formulation development consultant, Lindsey Bagley says adding fibre works in many confectionery applications (including chews and gums) because the standard sugar level in traditional recipes is typically above the terminal sweetness threshold (the point at which increasing sugar concentration no longer results in increased sweetness perception). But take note, these products are not likely to be directly marketed as a source of fibre due to their overall nutritional profile and actual fibre content.

According to Bagley, when creating a reformulated product, the fibre should be chosen to match the requirements for taste, nutritional benefits, and positioning of the product. Not all fibre is created equally. “The sensory profile of fibre products has limited the inclusion of fibre in a lot of food products to date, but certainly in the last five, possibly ten years, there has been much more choice and that has enabled formulation to be very much more palatable than it once was,” says Bagley. She gives an example; wheat fibre that could be added to a food such as bread can now range from white and tasteless (cellulose), to brown and coarse with strong flavours and aftertastes (bran). Some of the newer fibre products that Bagley mentions include inulin (derived from chicory root), Promitor (a Tate & Lyle product made from corn), and acacia fibre. These three all happen to be soluble (see the Facts about Fibre box for more information about soluble vs. insoluble dietary fibre) and claiming prebiotic effects.

Newer ingredients offering cleaner sensory profiles can be more expensive, and therefore Bagley feels that products reformulated with these will require complete repositioning and repackaging to communicate the added value to consumers. When asked about which future sectors may go the added fibre route, Bagley says, “I think we can start getting fibre into flavoured milks and other drinks … if the industry could spend a bit of money on their ingredients and develop a story around some of these things than I think there are real opportunities there: I think it just needs manufacturers to start thinking outside the box.” But again, because labelling rules specify minimal levels of fibre to be able make claims such as ‘Source of fibre’ or ‘High Fibre’, the likelihood is that only some of these new products would actively promote themselves based on fibre content.

Why do we need to eat more fibre?

Although the recommended daily adult intake for dietary fibre is 30g per day, on average in the UK, women only consume 17.2g per day and men 20.1g. Experts seem to agree that increasing fibre in our diets could lead to many benefits. Gut health, blood sugar control, lowering of cholesterol, and even dental health are some of the areas where positive effects of fibre consumption have been investigated or claimed. Many newer fibre products claim to act as prebiotics, providing a food source for the growth of beneficial microorganisms within the digestive system. But some fibres can also have low digestive tolerance, making it necessary to limit their dosage in common food and drinks.

The focus in the nutritional world has been steadily turning towards dietary fibre, with an acceptance of its importance extending to related health professionals. A series of systematic reviews and meta-analyses looking at carbohydrate quality and human health published recently in The Lancet, found “striking” evidence to support causal links between higher intakes of dietary fibre and whole grains and reduction in mortality and/or incidence of several non-communicable diseases (cardiovascular-related disease, Type II diabetes, and bowel cancer). The authors suggest that increasing dietary fibre intake and replacing refined grains with whole grains will benefit human health.

Many believe eating a diet high in fibre will tend to make you feel fuller and more satiated, which in turn can decrease the total number of calories ingested, and this should help with reaching or maintaining a healthy weight. A research programme in The Netherlands aptly called ‘Satiety and Satisfaction’ found that high fibre food does provide a full feeling for longer, and this is probably why it appears to reduce snacking behaviour. But the researchers say that in practice there is not much difference in total calories ingested between people who eat more or less fibre, and demonstrating a long-term effect such as weight loss is difficult. This illustrates that the relationship between what we like to eat, what we choose to eat, how much we eat, and how full we feel is very difficult to understand. Focusing on a single constituent or one need state only can give an overly simplistic solution to what is a very complex issue.

Is that fibre in my food?

Adding dietary fibre to commonly consumed products could have an important impact on improving population health, but fibre can also change the sensory profile of food and drinks, with varying impacts on consumer acceptance. For example, a study carried out by the Centre for Food and Flavour in Dijon, France, showed that enriching standard and traditional recipe French bread (baguettes) with dietary fibre from wheat shorts (a mainly insoluble by-product of milling) decreased expected and perceived liking. Addition of the fibre led to an unconventional appearance with a darker and denser crumb structure, as well as an increase in flavour attributes such as coffee, cereal, malt and bitterness; characteristics often found in ‘country-style’ breads. Enrichment with fibre decreased liking more for the standard compared to traditional bread making process.

When it comes to adding fibre to food, it seems it’s about the story and the added value created. If the fibre fits, consumers will accept a range of new sensory characteristics. Like the baguette in France, pasta is a very familiar and commonly eaten food in Italy. Researchers have found that giving information about the fibre content of wheat bran-enriched spaghetti to a sample of pasta consumers in Milan increased acceptability of the spaghetti, particularly for participants who were not already consumers of bran enriched pasta. According to the authors; “Establishing the right balance between the expected health benefit of eating fiber and perceived product liking might be useful to food developers to increase fiber content in pasta formulations without sacrificing sensory attributes and pleasure.” So, if you like pasta, the future may look like a bit of bran in your plate of bucatini! 

In fact, we’re all familiar with many foods, some we consider treats, that add fibre to our diets. Given my bed time snacking habits, I was interested to learn that digestive biscuits contain wholemeal wheat flour and sodium bicarbonate and are said to have been originally developed to aid digestion. One Mcvitie’s Original Digestive contains 0.5g of fibre, which is 2.5 times more than a McVitie’s Classic Rich Tea biscuit. Oatmeal is another source of fibre that many people enjoy as a tasty breakfast. The evidence for beneficial effects of oat fibre is strong enough that in the EU foods that provide at least 3g of oat beta-glucan per day can carry the claim: “Oat beta‐glucan has been shown to lower/reduce blood cholesterol. Blood cholesterol lowering may reduce the risk of (coronary) heart disease. Professor Chris Seal from Newcastle University has even been quoted in the Daily Mail as saying; “I believe that if everyone started the day with porridge, it would have a significant impact on public health”.

Even the most iconic ‘fast food’ can undergo a transformation. For instance, McDonald’s restaurants in France, offered the Big Mac for a period of time with the option of pain complet (whole grain bread). Loyal consumers voiced their disappointment on social media when this option was mysteriously withdrawn. Luckily, convenience food available now in the UK can offer higher fibre choices. For example, if a customer pops into their local Subway for lunch and opts for a 6-inch Veggie Delite on 9-Grain Wheat bread, they will be consuming about twice the amount of fibre (5.7g) compared to the same sandwich made with White bread (3.0g). And back to McDonald’s, this time in the UK, where The Spicy Veggie One (a wrap) will provide 6.4g of fibre compared to the 3.6g found in a Big Mac.

A future fibre rich world

The challenge of providing the growing global population with healthy food and drink without damaging the environment, means that dietary trends of the future will be driven by environmental and sustainability issues, as well nutritional and physical well-being considerations. Vegetarian and vegan diets are becoming more widely followed and accepted. A recently published report advised the ‘Planetary health diet’ which would optimise human health within sustainable food systems. The diet would require 50% reduction in consumption of ‘unhealthy’ foods such as red meat and sugar, and a greater than 100% increase in consumption of ‘healthy’ foods such as nuts, fruits, vegetables and legumes. It’s not just coincidence that this list of ‘healthy’ foods can all provide fibre.

As discussed above, when it comes to sugar reduction, formulation with soluble fibre is becoming a common approach. “If you take the sugar out, what are you going to replace it with? Fat? If you’re looking at something like a cake and want to reduce the sugar, if you don’t do anything else, automatically the percentage of fat goes up. And that’s not good. So, you have to replace it with something. You can’t replace it with a sugar because that is what you are striving to take out. These fibres are actually, a very good way to work to a neutral calorie offering when you are taking the sugar out,” says Bagley. There are many new ingredients available and there are likely to be even more interesting sources of fibre in the future. Some could even help in the struggle to reduce waste: For example, as veganism and the use of various plant sources for protein becomes more and more popular, dietary fibre is often created as a by-product.

It seems that as well as proposing big changes to our diet, nudging behaviour, such as adding small amounts of fibre to snacks, could be helpful in the fight to fulfil our fibre requirement. Every consumer has their own needs and preferences, so using many approaches to improve diet while retaining the pleasure from food and drink seems sensible. Expecting to get all your fibre from ice cream, confectionery or convenience food is probably not the best (or most responsible) way towards a healthy diet, but if you are going to indulge yourself anyway…

Carol Raithatha is the director of Carol Raithatha Limited, a UK-based consultancy specialising in sensory evaluation and food and drink research.