Structural and Functional Properties of Ovalbumin Glycated by Dry-Heating in the Presence of Maltodextrin

Figures & data

TABLE 1 Secondary structure content, surface hydrophobicity (S₀), and solubility of OVAs

	Content of secondary structure (%)^a
Sample	α-Helix	β-Sheet	Random coil	S0^b	Solubility^c(%)
N-OVA	30.5	28.1	30.4	5.2	100.0 ± 0.4^a
DH-OVA	29.6	35.2	29.1	9.5	95.2 ± 1.1^b
G-OVA	28.2	22.6	32.4	12.8	98.2 ± 0.9^a

^aThe data are estimated from the CD spectra shown in Fig. 2a according to Yang’s method.

^bS₀ was expressed as an initial slope of the FI vs. protein concentration plot, with standard deviations of <0.01.

^cEach value is the mean with its SD (n = 3); means in same column with different letters are significantly different (p < 0.05).

FIGURE 1 SEM images of OVAs. All micrographs were 500× magnified.

FIGURE 2 Some structural and functional characteristics of OVAs. (a) CD spectra of N-, DH-, and G-OVA. Samples were dissolved in 20 mM phosphate buffer (pH 7.4) at a concentration of 0.01 g/L. (b) Tryptophan fluorescence spectra of OVAs. The excitation wavelength was 280 nm and the emission was scanned from 300 to 400 nm. Fluorescence spectra of sample were measured at 0.01 g/L in triplicate. (c) Stability against heat-induced insolubility of N-, DH-, and G-OVA at various temperatures. The protein sample was 1 g/L in 50 mmol/L Tris–HCl buffer (pH 7.0), and heated at various temperatures for 10 min. Data shown are the mean value of the two determinations, with a deviation of less that 1%. (d) Emulsifying properties given as turbidity (A500 nm) of N-, DH-, and G-OVA as a function of standing time after emulsification. The turbidity of the emulsion is plotted as the ordinate and standing time after emulsion formation as the abscissa. Each value is the mean with its SD (n = 3).

TABLE 2 Some functional properties of N-, DH-, and G-OVA

Protein	Emulsifying activity^a,b (A 500 nm)	WBC^c,d (ml/g)	OBC^c,e (ml/g)
N-OVA	0.68 ± 0.03^a	2.11	2.51
DH-OVA	0.72 ± 0.05^a	2.62	2.48
M-OVA	1.49 ± 0.10^c	3.58	4.52

^aEmulsifying activity was determined at 500 nm measured immediately after emulsification.

^bEach value is the mean with its SD (n = 3); means in same column with different letters are significantly different (p < 0.05).

^cData shown are the mean value of the two determinations, with a deviation of <0.01.

^dWBC: water binding capacity.

^eOBC: oil binding capacity.