Reference Number: 57
Year: 2008
Link: Link to original paper
Nutrition: Fibre | Polyphenols
Summary
Summary
Epidemiological studies associate whole grain consumption with a reduced risk of many diseases. This paper focuses on the antioxidant component of cereal dietary fibre starting from its chemical structure, bioavailability and biological meaning. By the critical assessment of the intervention studies performed using cereal bran and whole grains, the hypothesis that the slow and continuous release in the gut of the dietary fibre bound antioxidants determines the health benefits, is illustrated. In the last part of the work, new perspectives and technological possibilities to enhance the health potential of this cereal component are also highlighted.
SIGNIFICANCE OF THIS STUDY
This study provides us with a basic understanding of the amount and prevalence of dietary fibre and phenolic compounds in cereal grains. Dietary fibre is concentrated in bran representing between 18.1% and 86.7% of the weight of cereals. A large range of fibre content was found for the various cereals which differed with different varieties (wild and cultivated) and with the different milling products. Cereal dietary fibre is classified according to its water solubility as soluble DF (SDF) and insoluble DF (IDF). In all cereal bran, the IDF is largely predominant particularly in maize and wheat, while in oat SDF reaches a considerable amount representing up to 16.2% of the dry matter. Insoluble dietary fibres are the fibres that are broken down by our gut microbes releasing beneficial short chain fatty acids. The most abundant phenolic compounds (PC) in cereals belong to the chemical class of hydroxycinnamic acids and the main one is ferulic acid (FA). The amount of FA found in cereals is highly variable both in whole grain and in bran and the final amount in food is strongly dependent on cereal variety and on milling procedure. FA is found chiefly in the outer parts of the grain with the aleurone layer and the pericarp of wheat grain contain 98% of the total FA.
