Bread high in fibre and protein has a future in weight management
Weight management diets do not have to mean cutting bread out of the diet, according to clinical studies with fibre and protein. On the contrary, consumers may find that a few slices of the right recipe can help them towards improved appetite control.
For bakers, the ability of fibre and protein combinations to promote satiety is a great opportunity for targeted responses to the healthy living trend. The advantage is that consumers can immediately feel the benefit – a sustained sense of fullness that delays the onset of hunger and reduces energy intake during a later meal.
Two nutritional claims
Many DuPont solutions for high-fibre bread make use of polydextrose, a soluble fibre for an improved nutritional profile at no expense to texture and taste. More recently, we have developed concepts that also include soy protein isolate.
When the fibre level reaches 6g/100g and the protein level accounts for 22-25% of the total energy content, bread qualifies for EU-approved high in fibre and high in protein claims – a convincing selling point on supermarket shelves.
Apart from the fact that bread products with this nutritional profile are still appealing and delicious, clinical trials of polydextrose and isolated soy protein (ISP) have documented clear benefits for weight management diets.
Evidence of appetite regulation
Four published clinical studies have found that dietary supplementation with polydextrose gives a longer lasting sense of fullness, resulting in reduced energy intake at subsequent meals during the day.
In another investigation, our own DuPont scientists looked at the impact of polydextrose on gastric peptide secretion, which is widely believed to play a role in appetite regulation. The results revealed a significant increase in gastric peptide secretion in 18 overweight subjects following consumption of a polydextrose-enriched beverage.
Dose-dependent satiety effect
Studies of protein-supplemented diets have shown that the satiety effect of ISP is dose-dependent: the higher the protein level, the greater the effect.
In one clinical research project, scientists measured the hormone cholecystokinin (CCK), a signalling hormone that indicates the level of satiety. Here, the CCK level was significantly higher and remained so for longer in subjects who consumed products enriched with protein such as ISP.
An important point about a high-protein weight management diet is the tendency of protein to support weight loss while preserving lean body mass. As with satiety, the best results are obtained with a high protein intake.
Top quality score
Protein quality is another important factor. According to the internationally recognised method for measuring protein quality – the Protein Digestibility Corrected Amino Acid Score (PDCAAS) – ISP has a top score of 1, on a par with whey protein and egg. An added advantage for the food industry is that soy protein is among the most accessible proteins on the market.
This rough sketch of the clinical evidence gives just an idea of the nutritional potential of polydextrose and ISP in the weight management segment. If you would like to learn more, get in touch for a complete list of references to the clinical studies.
From our trials, we are convinced they are a great combination in bread. So, to put a high-fibre, high-protein claim on your bread products, all you have to do is get the recipe and start baking.
Finding the right fibre balance
Fibre addition to the diet is important, but which kind of fibre is healthiest: soluble or insoluble? Today it is generally agreed that they are of equal value from a health perspective. A more important consideration in the bakery regards their ability to absorb water.
The trick is to add the right amount of fibre for the desired nutritional effect and ensure sufficient water is absorbed. If too much free water is available for absorption by the flour starch, then bread is likely to collapse. Bakers will also experience a longer baking time for their products, reducing their production capacity.
When used in bread formulations, a soluble fibre such as polydextrose normally has a reduced water-absorbing capability, while insoluble fibre is able to absorb more.
In flat breads, the choice of soluble or insoluble fibre is usually not an issue as, either way, the water is quickly baked off in the oven.
For higher volume bread types, though, it can be an advantage to use a combination of soluble and insoluble fibres in the recipe, due to the higher water absorbency of the insoluble fibre. The same applies to recipes with a fibre content above 6%.
Our bakery team has tested the water-absorbing capability of various fibres and come up with the results shown in the table. One of our tasks at DuPont is to help customers find the right balance of fibres and other ingredients for their recipes.
In our concept, we tested Litesse® polydextrose, SUPRO® 661 IP Isolated Soy Protein, PANODAN® DATEM, GRINDAMYL® H120 Bakery Enzyme, GRINDAMYL® A1000 Bakery Enzyme, GRINDAMYL® PR 59 Bakery Enzyme, DIMODAN® Distilled Monoglycerides and GRINDSTED® Cellulose Gum. All part of the DuPont™ Danisco® range.