Chemical and Functional Properties of Food Saccharides

© 2004 by CRC Press LLC
Mass Fraction
Mass Fraction
0.16
0.12
0.08
0.04
0
0.16
0.12
0.08
0.04
0
30 35 40 45
Vret
[mL]
(a)
30 35 40 45
Vret
[mL]
E
640 /
E
525
(b)
FIGURE 22.8 SEC elution profiles of (a) waxy maize starch glucans and (b) wheat starch
glucans with E 640/E 525 (lcb/scb) ratio. indicates kind and homogeneity of branching pattern.
SEC-system: TosoHaas guard PWH + GMPWM + GMPW6000 + 5000 + 4000 + 3000 (150
mm × 7.5 mm), eluent: 0.005 M NaOH; sample volume: 0.4 ml (5 mg/ml), flow rate: 0.80
ml/min.
starch glucans are shown in Figure 22.8(a) (waxy maize) and Figure 22.8(b) (wheat).
Whereas waxy maize gives rather uniform E 640/E 525 values in the range of 0.5,
obviously indicating scb characteristics, wheat glucans represent a mix of highmolecular-weight
scb-glucans with E 640/E 525 values of 0.9–1.0 and a midrange molecular
weight lcb-population with E 640/E 525 values of 1.5–2.0.
Table 22.4 lists the results of destructive branching analysis for waxy maize and
wheat. The data are in good agreement with results from nondestructive analysis:
highly short-chain branched waxy maize with mean DP = 15 for the terminal Achains,
which represent 72% of the molar mass of a mean molecule with DP = 940.
2.4
1.8
1.2
0.6
0
2.4
1.8
1.2
0.6
0
E E
640 / 525