VTT: Use Bilberries to Increase Dietary Fiber Intake

09 Mar 2016 --- Bilberries – a unique part of the Nordic diet – could be utilized in higher amounts in food products to increase our dietary fiber intake, according to VTT Technical Research Centre of Finland Ltd.

VTT Technical Research Centre of Finland Ltd took an interest in bilberry press cake and developed methods to use it as a dietary fiber source in tasty snacks. The findings were published in Food and Nutrition journal.

Kaisa Poutanen, VTT Research manager of food and biomass processing, who also lead the project, told NutritionInsight:"Our idea was mainly to point out the big potential of bilberry press cake as a fiber source, and also note that the quality of bilberry fiber adds variety in diet (it has analogy with e.g. grapefruit fiber which also is 'phenolic' and insoluble)."

VTT studied the dietary fiber content, carbohydrate composition, and non-carbohydrate fiber content of Finnish bilberries (Vaccinium myrtillus) and bilberry press cake - a side product from juice processing. The results indicate that bilberries contain plenty of dietary fiber: fresh bilberries have 3%, freeze-dried bilberries 24% and dry bilberry press cake 59%.

The content can be explained by the high relative proportion of peels and seeds in the berries due to their small size. The dietary fiber was mostly insoluble, which means it has excellent bulking effects and therefore increases intestinal mobility and removal of digestion residue from the body.

Press cake in snacks and muffins
The berry juice industry produces large amounts of press cake, which is currently under-utilized. It is a low-cost raw material with a healthy status and it can be used to substitute all or part of whole berries in health-promoting products.
Bilberry press cake can be used as a substitute for whole berries in berry-striped muffins when it is milled according to VTT’s patented wet milling method. Thanks to bilberry press cake, a fiber content of over 6% in the muffins can be easily achieved without compromising the sensory quality.

It is possible to add bilberry press cake also to extruded snacks. Extrusion processing is a high temperature short time process, where both expanded puffs and flakes can be produced. A nice flavor and crispy texture can be obtained by adding dried and milled press cake of up to 30% to the flour mix used during the extruded snack production.

About these applications of press cake, Anna-Marja Aura, Principle Scientist and lead author of the published findings, explained further to NutritionInsight: "Innovations are needed and were created at VTT; they can be utilized by companies, if they are interested. VTT is happy to discuss the terms of using our technique."

High content of anthocyanins

"Forest bilberries are higher in anthocyanins that the 'wild blueberries', which have been so well branded as superfood," Poutanen noted.

Both bilberries and blueberries (Vaccinium corymbosum) are known for their high content of anthocyanins. In contrast to cultivated blueberries, the anthocyanin content in wild bilberries is also high in the flesh part, and is therefore more bioavailable than in blueberries or their peels. Anthocyanins have anti-inflammatory and anti-carcinogenic activity, and they have the potential to reduce the risk of diabetes and cardiovascular diseases - hence there inportance in 'superfood' status.

Aura concluded: "In my opinion the bilberry is more important in the Finnish diet than blueberries, since bilberries are readily available and allowed to be picked from wild forests due to our historical 'everyman´s right,' which allows picking in private forests if pickers do not go near the residences. Some cultivated blueberries are also available. A large amount of bilberries remain in forests, and they should be harvested to a larger extent."

by Kerina Tull