[Antioxidant effect of the fibre content of foods]

Antioxidants have some health benefit, but up to now there was less attention paid to the antioxidant properties of dietary fibre. The antioxidant effect of dietary fibre is based on the polyphenol compounds bound to polysaccharide complexes, which are released in the gut and functioning as antioxidants. Another type of antioxidant, calcium fructoborate was also isolated from plant cell wall. It has a marked antioxidant capacity, however, its active component is not a polyphenol, but the boron. There are lots of food plants which have relatively high antioxidant dietary fibre content, thus they support the antioxidant defence of the gastrointestinal tract, and consequently the whole body. The important ones in human nutrition are for instance cereal grains, cabbage, grape pomace, coffee bean or guava. There are different polyphenol compounds in the antioxidant dietary fibres in the plants, therefore their antioxidant capacity varies, but it is approximately equivalent to 50-100 mg DL-α-tocopherol per gram. This antioxidant capacity is considerable, and would be suitable for the prevention of some, oxidative stress-related diseases, such as atherosclerosis or other cardiovascular diseases, and colorectal carcinoma. Orv Hetil. 2018; 159(18): 709-712.