Influence of coarse particles on nutritional quality of flour ingredients: A comparison between cereals and pulses

Seeds of cereals (barley and oats) and pulses (pea and lentil) were milled into whole flours, followed by differential sieving to obtain coarse and fine streams. Percentages of coarse particles the portion well preserving the inherent matrix structure of seeds and comprising undivided starch, protein, and fiber of the three flour streams from the same crop followed a descending order of coarse > whole > fine. In vitro starch digestibility of the three streams of cooked cereal flours was comparable; by contrast, the contents of rapidly digestible starch (RDS, dry starch basis) of the cooked pea and lentil flours exhibited a consistent order of fine > whole > coarse, showing a negative correlation (r = -0.954, p < 0.01) with the percentages of coarse particles. The presence of more coarse particles had positive correlations with the contents of total dietary fiber of both cereal and pulse flours but was not well correlated with the in vitro protein digestibility corrected amino acid scores (IV-PDCAAS). Overall, the coarse pea and lentil flours were more nutritionally desirable because of their markedly higher contents of dietary fiber and phenolic compounds, lower starch digestibility, and greater IV-PDCAAS than the other flour streams. • %Total dietary fiber showed coarse > whole > fine in cereal and pulse flour streams. • In vitro starch digestibility of cooked pulse flours showed fine > whole > coarse. • %Coarse particles showed correlation with starch digestibility in pulse flours only. • Three flour streams from the same crop had similar in vitro protein digestibility. • Coarse pea and lentil flours were nutritionally more desirable than the other flours.