Comparative investigation of various protein or protein-based powders addition on texture properties of egg white and yolk gels

Figures & data

Figure 1. Visual images of (a) control, (b) WPC, (c) SPI, (d) BSA and (e) hemoglobin-treated egg white gels and (A) control, (B) WPC, (C) SPI, (D) BSA and (E) hemoglobin-treated egg yolk gels. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Table 1. Changes in color attributes of egg white and egg yolk gels treated byWPC, SPI, BSA and hemoglobin.

		Control	WPC	SPI	BSA	Hemoglobin
L*	EW	96.83 ± 0.18^c	96.14 ± 0.38^bc	95.77 ± 0.45^bc	95.17 ± 0.55^b	62.28 ± 0.58^a
	EY	89.59 ± 0.69^b	89.42 ± 0.76^b	89.67 ± 1.04^b	89.51 ± 0.76^b	66.05 ± 1.90^a
a*	EW	0.29 ± 0.11^a	0.82 ± 0.13^b	0.45 ± 0.13^a	0.40 ± 0.12^a	7.15 ± 0.05^c
	EY	13.49 ± 0.75^b	12.68 ± 0.63^b	11.44 ± 0.80^b	12.96 ± 0.48^b	7.68 ± 0.09^a
b*	EW	18.65 ± 0.15^b	19.52 ± 0.10^c	19.71 ± 0.18^c	17.07 ± 0.16^a	20.73 ± 0.16^d
	EY	73.38 ± 1.63^d	64.37 ± 0.76^b	62.51 ± 1.36^b	69.79 ± 0.72^c	33.66 ± 0.66^a
Whiteness	EW	81.07 ± 0.18^c	80.08 ± 0.07^bc	79.83 ± 0.27^b	82.25 ± 0.31^d	56.37 ± 0.57^a
	EY	75.34 ± 1.79^c	66.46 ± 0.96^b	64.40 ± 1.58^b	71.76 ± 0.87^c	48.48 ± 1.16^a

Values are means ± SE of three replicates. a-g in the same row with different superscripts indicate significant differences (p < .05). Means having no letter do not significantly differ at p < .05. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Table 2. Changes in texture attributes of egg white and egg yolk gels treated by WPC, SPI, BSA and hemoglobin.

		Control	WPC	SPI	BSA	Hemoglobin
Hardness (N)	EW	26.07 ± 0.63^a	33.89 ± 0.30^c	30.13 ± 2.00^b	38.54 ± 0.58^d	31.71 ± 0.89^bc
	EY	56.47 ± 0.43^b	61.82 ± 1.58^b	59.42 ± 1.74^b	57.66 ± 6.33^b	46.59 ± 0.51^a
Adhesiveness (g·sec)	EW	−4.11 ± 0.65^b	−10.49 ± 0.99^a	−8.68 ± 1.16^a	−9.75 ± 2.29^a	−2.32 ± 0.72^b
	EY	−162.68 ± 14.45^a	−157.65 ± 16.03^a	−54.15 ± 6.04^c	−104.85 ± 16.81^b	−6.06 ± 1.03^d
Resilience (%)	EW	39.94 ± 0.82^a	39.38 ± 0.32^a	44.65 ± 1.05^b	41.52 ± 0.30^a	40.39 ± 0.33^a
	EY	29.36 ± 0.19	29.38 ± 0.34	29.49 ± 0.45	29.83 ± 1.52	29.97 ± 0.06
Cohesion	EW	0.71 ± 0.01^a	0.72 ± 0.00^a	0.76 ± 0.01^b	0.73 ± 0.00^a	0.73 ± 0.01^a
	EY	0.64 ± 0.00	0.65 ± 0.01	0.66 ± 0.01	0.65 ± 0.03	0.66 ± 0.00
Springiness(%)	EW	95.38 ± 0.95^b	92.52 ± 0.62^ab	92.56 ± 0.81^ab	91.98 ± 1.25^a	93.89 ± 1.05^ab
	EY	82.93 ± 0.51	82.55 ± 0.22	85.09 ± 0.80	86.98 ± 2.76	83.18 ± 0.62
Gumminess	EW	18.54 ± 0.28^a	24.26 ± 0.32^b	22.93 ± 1.40^b	28.17 ± 0.58^c	23.10 ± 0.47^b
	EY	36.31 ± 0.28^ab	40.33 ± 1.35^b	39.06 ± 0.83^ab	37.96 ± 5.69^ab	30.84 ± 0.31^a
Chewiness	EW	17.68 ± 0.12^a	22.45 ± 0.25^b	21.21 ± 1.22^b	25.90 ± 0.28^c	21.68 ± 0.38^b
	EY	30.11 ± 0.18^ab	33.29 ± 1.18^b	33.22 ± 0.55^b	32.73 ± 4.15^b	25.65 ± 0.44^a

Values are means ± SE of three replicates. a-g in the same row with different superscripts indicate significant differences (p < .05). Means having no letter do not significantly differ at p < .05. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Figure 2. Changes in the WHC of (a) liquid egg white gels and (b) liquid egg yolk gels treated by WPC, SPI, BSA and hemoglobin. Values are means ± SE of three replicates measurements. Error bars represent positive standard errors of the mean. Different lowercase letters (a-e) donate significant difference in these treatment group gels (p < .05). Means having no letter do not significantly differ at p < .05. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Figure 3. Changes in the free sulfhydryl group of (a) liquid egg white and (b) liquid egg yolk, surface hydrophobicity of (c) liquid egg white and (d) liquid egg yolk, protein solubility of (e) liquid egg white and (f) liquid egg yolk samples treated by WPC, SPI, BSA and hemoglobin. Values are means ± SE of three replicates measurements. Error bars represent positive standard errors of the mean. Different lowercase letters (a-e) donate significant difference in these treatment group samples (p < .05). Means having no letter do not significantly differ at p < .05. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Figure 4. SDS-PAGE profiles of (a) liquid egg white and (b) liquid egg yolk samples treated by WPC, SPI, BSA and hemoglobin. 1, control; 2, WPC; 3. SPI; 4. BSA; 5. hemoglobin; HDL, high density lipoprotein, LDL, low density lipoprotein. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Table 3. Changes in secondary structure percentage of egg white and egg yolk gels treated by WPC, SPI, BSA and hemoglobin.

		Control	WPC	SPI	BSA	Hemoglobin
α-helix/%	EW	18.99 ± 0.41^ab	21.95 ± 1.85^bc	17.44 ± 1.19^a	20.78 ± 0.78^abc	23.92 ± 0.78^c
	EY	14.43 ± 4.49^ab	19.59 ± 2.51^b	11.34 ± 0.94^ab	9.67 ± 0.43^a	17.89 ± 3.63^ab
β-sheet/%	EW	19.90 ± 1.79^b	24.66 ± 2.10^c	14.24 ± 0.95^a	14.10 ± 0.35^a	19.85 ± 1.16^b
	EY	31.61 ± 2.51^b	32.03 ± 0.76^b	26.20 ± 0.88^a	31.47 ± 0.65^b	32.23 ± 0.47^b
β-turn/%	EW	31.35 ± 0.34^b	23.52 ± 1.06^a	32.08 ± 1.39^b	22.26 ± 1.91^a	31.53 ± 1.26^b
	EY	15.18 ± 0.34^a	16.06 ± 0.25^b	15.01 ± 0.10^a	16.10 ± 0.05^b	15.44 ± 0.11^ab
irregular curl/%	EW EY	20.12 ± 1.72^ab 41.40 ± 7.63^b	23.47 ± 2.67^bc 20.42 ± 3.49^a	26.52 ± 1.53^cd 43.73 ± 2.98^b	30.51 ± 0.69^d 39.49 ± 1.23^b	16.86 ± 1.22^a 31.70 ± 3.13^ab

Values are means ± SE of three replicates. a-g in the same row with different superscripts indicate significant differences (p < .05). Means having no letter do not significantly differ at p < .05. WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.

Figure 5. SEM micrographs of (a) control, (b) WPC, (c) SPI, (d) BSA and (e) hemoglobin-treated liquid egg white gels, and (A) control, (B) WPC, (C) SPI, (D) BSA and (E) hemoglobin-treated liquid egg yolk gels. 500× (scale bars, 200 μm) and 2000× (scale bars, 50 μm). WPC, whey protein concentrate. SPI, soy protein isolate. BSA, bovine serum albumin.