The proximate composition of native barley flours is
shown in Table 1. There were minor differences in protein,
lipid and ash contents of CDC-Candle and Phoenix
flours, whereas their starch, IDF, SDF and b-glucan
contents were considerably different. Compared to
CDC-Candle, Phoenix had higher starch and IDF but
lower b-glucan and SDF contents. Furthermore, the bglucan
contents of CDC-Candle and Phoenix (6.5 and
3.9%, respectively) were higher than SDF contents (5.6
and 2.4%, respectively). This suggests that barley bglucan
contained water-soluble as well as insoluble
fractions. The water-solubility of b-glucan in the native
and extruded flours is given in Table 2. The solubility
(determined at 100 C) of native b-glucan was 79% for
CDC-Candle and 57% for Phoenix, which suggests that
the SDF of native flour might contain a large amount of
b-glucan (91% in CDC-Candle and 93% in Phoenix).
The b-glucan in extruded flours had higher solubility
(determined at 25 C) than its native counterparts
(Table 2), and, at each extrusion temperature, the solubility
increased with an increase in the extrusion-moisture
level. The solubility differences between native
CDC-Candle and Phoenix b-glucans may be attributed
to the variety-dependent molecular variations, while the