| Interactions between beta-glucan and starch influence the health benefits of barley-based foods and barley brewing performance. Here, we characterized beta-glucans from waxy and normal barley varieties and compared the effects of different beta-glucans on the pasting and degradation of waxy and normal barley starches as well as the filterability of mashes from unmalted waxy and normal barley. Waxy barley Zangqing18 beta-glucan displayed more compact micrographic features, higher molecular weight, larger particle size, higher thermal decomposition temperature and lower rheological viscosity than normal barley Zangqing2000 beta-glucan. beta-Glucan not only significantly decreased the pasting viscosities of waxy and normal starches but also lowered the pasting temperatures and peak times of normal starch, likely by inhibiting granule swelling and disrupting the integrity of the continuous phase. beta-Glucan also decreased in vitro digestion extent of starch and increased the resistant starch. The unmalted waxy barley had a mash filtration rate much faster than normal barley because starch and beta-glucan in waxy barley were rapidly and completely digested and formed more open filter passages. The effects of beta-glucan on starch properties varied with the types and contents of beta-glucans, whilst the types of starches showed more significant effects. |