Gastrointestinal conditions influence the solution behaviour of cereal β-glucans in vitro

► We studied the β-glucan solution behaviour along an in vitro gastrointestinal tract. ► Calcofluor labelling coupled to field-flow fractionation was successfully monitored. ► β-Glucan aggregates are disrupted in gastric pH but re-form in small intestinal pH. ► The aggregation of pure β-glucans in intestinal conditions reflects the onset of gel formation which may add to health effects. ► It is difficult to predict β-glucan intestinal activity by analysing food products.