In vitro bioaccessibility assessment of phenolic compounds from selected cereal grains: A prediction tool of nutritional efficiency

•Wild cereal grains found in Zimbabwe were studied for phenolic compounds bioaccessibility using and in vitro model.•The bioaccessibility of phenolic compounds in the small intestines was lower than in the large intestines.•Condensed tannins are released in the colon for potential use by the body hence they are bioaccessible.

The bioaccessibility of phenolic compounds in five wild and two domesticated cereal grains found in Zimbabwe was determined. The wild cereal grains that were used in the study were Amaranthus hybridus, Brachiaria brizantha, Panicum maximum, Rottboellia cochinchinensis and Sorghum arundinaceum. The domesticated cereal grains used were Eleusine corocana and the red variety of Sorghum bicolor. A. hybridus had the highest intestinal bioaccessibility percentage of 95.4 ± 0.01% while the cereal with the least intestinal bioaccessibility was Rottboellia cochinchinensis with 81.85 ± 0.03%. From the bioaccessibility results we observed that generally, the cereal grains with higher fibre content indicated lower bioaccessibility levels. R. cochinchinensis, which contained 24.89% fibre had small intestine bioaccessibility of 20% while P. maximum which contained 26.03% fibre had 26% bioaccessibility. The bioaccessibility of phenolics compounds in the small intestines was lower than in the large intestines. The lower bioaccessibility in the small intestines may indicate that human digestive enzymes are ineffective in digesting most food constituents to which phenolic compounds were conjugated. . The results obtained in this study may assist in understanding the concept of bioaccessibility by all individuals involved in food production and nutritional evaluation as well as for determining diet and health correlations.