Better analysis of specific dietary fibres – whether long-chain or short-chain, for example – will give the food industry, researchers, risk assessors and society as a whole more information about the specific composition of foods. The method involves weighing long-chain insoluble and soluble dietary fibre, while short-chain fibre is identified by chromatography.
Evira is the first Nordic authority to introduce a method to analyse dietary fibre, with results to be published according to their water solubility and size in the Finnish Food Composition Database, Fineli, over the coming year.
Helena Pastell, doctor of food sciences and senior researcher of the Chemistry and Toxicology Research Unit, explained that oligosaccharides (short-chain, very small components of dietary fibre) are found in rye, the basis of rye bread, which is one of the main sources of dietary fibre in Finland.
"Determined with this more specific analytical method, the total dietary fibre in rye has proved to be higher than previously," she said. "Oligosaccharides, in particular, increase the growth of beneficial lactic acid bacteria in the large intestine. It is also important to remember that a product can be promoted as a high-fibre product if it contains at least six grams of fibre per 100 grams of product.”
Most Finns do not consume enough dietary fibre compared to the recommended 25 g per day for women and 35 g per day for men. However, different types of dietary fibre may have different health benefits. Insoluble fibre is important for increasing stool bulk, while soluble fibre has been shown to reduce blood serum cholesterol levels and limit spikes in blood sugar. Fibre is also thought to be protective against bowel cancer.
“A wider use of the method is important in order to produce comparable results on dietary fibre,” Evira said.
The analytical method is based on the definition of dietary fibre adopted by the Codex Alimentarius Commission.