Fig 1.
PACE gel showing extracted oat and barley mixed-linkage β-glucan, fingerprinted with specific glycosylhydrolases (‘A’–with α-amylase to analyse starch related impurities; ‘L’–with lichenase to analyse the presence and relative quantity of extracted β-glucan; ‘X’–with xylanase 11 to analyse xylan related impurities and ‘b’–background, non-digested sample) and their separation based on size and structure after derivatization with ANTS. ‘S’ shows starch sample digested with α-amylase and ‘std’ shows (Xyl)1-6 standards used for oligosaccharides identification. Bands marked with blue asterisks are mixed-linkage β-glucan specific oligosaccharides DP ≥ 3. Xyl1 –xylose, Xyl2 –xylobiose, Xyl3 –xylotriose, Xyl4 –xylotetraose, Xyl5—Xylopentaose, Xyl6 –Xylohexaose. Shorter oligosaccharides migrate further in the polyacrylamide gel.
Table 1.
Summary of characterization of the β-glucan extracts from oat and barley.
The table includes purity and composition values, weight-average molar mass, average rrms and mass recovery from the AF4 channel.
Fig 2.
Fractogram of the β-glucan extract from oat, non-filtered and filtered sample.
The signals are: grey solid line—Rayleigh ratio from MALS (a.u., 69.3° - 121.2°) from non-filtered sample, black solid line—Rayleigh ratio from MALS (a.u., 69.3° - 121.2°) from filtered sample, grey dashed line—dRI signal (a.u.) from non-filtered sample, black dashed line—dRI signal (a.u.) from filtered sample, grey crosses—rrms of non-filtered sample, black crosses—rrms of filtered sample. Channel and flow conditions as described in Materials and Methods, part e, except: initial cross-flow of 0.5 mL/ min with an exponential decay with half-life of 2 min, t0 = 6.5 min.
Fig 3.
Fractogram of the β-glucan extract from oat.
The signals are: black line—Rayleigh ratio from MALS (a.u., 69.3° - 121.2°), grey line—dRI signal (a.u.), grey triangles—molar mass distribution [g/mol], black crosses—rrms distribution [nm].
Fig 4.
Fractogram of the β-glucan extract from barley.
The signals are: black line—Rayleigh ratio from MALS (a.u., 69.3° - 121.2°), grey line—dRI signal (a.u.), grey triangles—molar mass distribution [g/mol], black crosses—rrms distribution [nm].
Fig 5.
Differential molar mass fraction of the extracts.
The colors denote: black—oat, grey—barley.
Fig 6.
Fluorescence-fractogram of the β-glucan extract from oat.
The colors denote: black—Rayleigh ratio from MALS (a.u.), grey—fluorescence signal of in-line Calcofluor-labelled β-glucan at λem = 445 nm (a.u.).
Fig 7.
Fluorescence-fractogram of the β-glucan extract from barley.
The colors denote: black—Rayleigh ratio from MALS (a.u.), grey—fluorescence signal of in-line Calcofluor-labelled β-glucan at λem = 445 nm (a.u.).