Color and gelling properties of dried egg white: Effect of drying methods and storage conditions

Figures & data

Table 1. Gelling properties (gel hardness and %WHC), protein denaturation enthalpy (∆H), water content, and midpoint T_g of unstored and stored FDEW and HDEW.

Sample	Storage temperature (°C)	Storage time (months)	Gelling properties		∆H (J/g dry basis)	Water content (g H2O/100 g dry samples)	Midpoint Tg (°C)
			Hardness (N)	WHC (%)
Fresh egg white			29.46 ± 1.41^de	50.07 ± 0.58^h	22.7 ± 0.3^a	87.78 ± 0.02*	—
FDEW	Unstored		28.62 ± 0.07^de	52.94 ± 1.57^fgh	22.5 ± 0.3^a	3.31 + 0.07^f	54.9 + 0.8^d
	25	1	28.27 ± 0.05^de	56.41 ± 2.03^ef	18.4 ± 0.4^bc	—	—
		2	29.38 ± 0.25^de	55.48 ± 1.13^fg	18.2 ± 1.4^bc	—	—
		4	32.95 ± 1.39^d	56.50 ± 2.31^e	16.9 ± 0.0^cd	3.65 + 0.04^e	56.9 + 0.8^c
	40	1	28.76 ± 1.02^de	66.42 ± 1.22^d	17.1 ± 0.7^cd	—	—
		2	32.14 ± 2.18^d	64.26 ±1.22^d	16.9 ± 0.6^cd	—	—
		4	53.49 ± 3.38^c	80.00 ± 0.72^c	14.1 ± 1.1^e	3.62 + 0.01^d	57.8 + 0.8^c
HDEW	Unstored		26.40 ± 0.55^e	52.47 ± 2.96^gh	22.3 ± 0.5^a	10.16 + 0.15^a	52.0 + 0.5^e
	25	1	29.14 ± 0.78^de	65.51 ± 0.43^d	19.2 ± 1.0^b	—	—
		2	55.25 ± 0.92^c	83.94 ± 0.26^b	19.4 ± 1.4^b	—	—
		4	88.73 ± 2.32^a	88.61 ± 0.52^a	16.2 ± 1.0^d	9.91 + 0.02^b	60.9 + 1.2^b
	40	1	75.48 ± 5.15^b	86.83 ± 1.68^ab	17.9 ± 0.2^bcd	—	—
		2	Nd	Nd	16.2 ± 0.2^d	—	—
		4	Nd	Nd	13.1 ± 0.8^e	9.72 + 0.02^c	63.5 + 1.4^a

Note: Data are shown as mean ± standard deviation (n = 2).

Means with different letters in the same column are significantly different (p < 0.05)

Nd: The hardness value and %WHC were unable to determine.

—: The values were not determined.

*Water content of fresh egg white = 87.78 ± 0.02 % wet basis.

Figure 1. The color values L*, a*, b*, and ΔE* of unstored and stored FDEW and HDEW at 25 and 40°C for 1–4 months. Data are shown as mean with standard deviation (n = 2).

Figure 2. A: Exposed SH and B: Total SH contents of unstored and stored (4 months) FDEW and HDEW. Note: SH contents of HDEW stored at 40°C for 4 months could not be determined because it is not soluble. Data are shown as mean with standard deviation (n = 2). Different letters in each graph are significantly different (p < 0.05).

Figure 3. SDS-PAGE patterns of the protein samples: A: SDS-PAGE in the absence of 2-ME; B: SDS-PAGE in the presence of 2-ME; fresh egg white (lane 1), unstored FDEW (lane 2), FDEW storage at 25°C for 1, 2, and 4 months (lanes 3, 4, and 5), FDEW storage at 40°C for 1, 2, and 4 months (lanes 6, 7, and 8), unstored HDEW (lane 9), HDEW storage at 25°C for 1, 2, and 4 months (lanes 10, 11, and 12), and HDEW storage at 40°C for 1, 2, and 4 months (lanes 13, 14, and 15).