Texture Profile Analysis and Functional Properties of Gelatin from the Skin of Three Species of Fresh Water Fish

Figures & data

TABLE 1 Proximate composition of gelatin from the skin of porcine and carp’s skin

		Freshwater carp
Parameters	Porcine	Catla catla	C. mrigala	L. rohita
Moisture (%)	9.56 ± 1.06	5.66 ± 0.29	4.05 ± 0.39	4.27 ± 0.466
Protein (%) (N × 5.8)	90.01 ± 0.08	92.89 ± 0.20	94.7 ± 1.66	93.52 ± 0.642
Ash (%)	0.1 ± 0.02	1.49 ± 0.06	1.87 ± 0.040	1.37 ± 0.115

Values are presented as mean ± standard deviation of triplicate samples.

FIGURE 1 Nitrogen solubility index of gelatin from the skin of Indian major carps with distilled water as a solvent in the pH range of 2–12. (a) Porcine; (b) Catla catla; (c) Cirrhinus mrigala; (d) Labeo rohita.

FIGURE 2 Protein solubility of gelatin as a function of molar concentration of NACL in phosphate buffer (50 mm, pH 7.5). (a) Porcine; (b) Catla catla; (c) Cirrhinus mrigala; (d) Labeo rohita.

TABLE 2 Amino acid composition of gelatin from skin of porcine and fresh water fishes

Content (g/100 g protein)
Amino acids	Porcine	Catla catla	C. mrigala	L. rohita
Alanine	7.8	8.3	8.8	13.1
Arginine	ND	ND	ND	ND
Aspartic acid	10	10.0	11.1	16.4
Cystine	ND	ND	ND	ND
Glutamic acid	15.2	14.8	15.9	21.5
Glycine	24.3	23.2	27.8	34.5
Histidine	1.3	1.0	1.1	1.6
Hydroxyproline	16.71	11.6	12.5	10.43
Isoleucine	1.8	1.8	2.2	3.6
Leucine	4.5	3.9	4.5	6.5
Lysine	ND	ND	ND	ND
Methionine	0.7	1.7	0.1	3.0
Phenylalanine	3.2	3.0	3.1	5.0
Proline	15.2	16.9	14.6	16.1
Serine	5.0	5.3	5.7	7.7
Threonine	3.1	3.9	4.4	5.9
Tryptophan	0.05	0.06	0.05	0.08
Tyrosine	0.5	0.3	0.3	1.1
Valine	4.3	3.9	1.8	6.0
Imino acids (Pro + Hydroxypro)	32.05	28.5	27.1	26.44

ND: not detected.

TABLE 3 Bloom strength and texture profile of 6.67% (w/v) porcine and Indian major carp’s skin gelatin

Source
Parameters	Porcine	Catla catla	C. mrigala	L. rohita
Bloom strength (g)	466.40 (36.0)^c	367.66 (4.50)^b	343.0 (1.90)^b	258.0^a (11.22)^a
Hardness (N)	14.40 (1.27)^c	12.84 (2.89)^bc	8.78 (2.31)^ab	7.05 (1.03)^a
Adhesiveness (g.s)	−260.10 (102)^a	−198.72 (197)^a	−325.48 (185)^a	−364.39 (138)^a
Springiness (mm)	0.943 (0.03)^b	0.925 (0.03)^b	0.903 (0.28)^ab	0.846 (0.06)^a
Cohesiveness	0.913 (0.02)^c	0.892 (0.04)^b	0.835 (0.06)^b	0.648 (0.04)^a
Gumminess (N)	13.167 (1.14)^c	11.45 (1.95)^b	7.34 (1.83)^b	4.58 (0.85)^a
Chewiness (N)	12.45 (1.26)^c	10.61 (1.55)^c	6.64 (1.01)^b	3.86 (0.68)^a
Resilience	0.811 (0.01)^ab	0.885 (0.02)^b	0.90 (0.03)^c	0.770 (0.03)^a

Values in parenthesis are standard deviation n = 3. Mean values with the same lowercase superscript letter are not significantly different (p < 0.05) between the column.

FIGURE 3 Texture profile of gelatin gels from fresh water carp’s skin and porcine. (a) Porcine; (b) Catla catla; (c) Cirrhinus mrigala; (d) Labeo rohita. (Hardness: F1; Cohesiveness: A₂/A₁; Springiness: d₂/d₁; Adhesiveness: A₃; Gumminess: Hardness × Cohesiveness; Chewiness: Gumminess × Cohesiveness.)

TABLE 4 Emulsion capacity of gelatin from porcine and Indian major carp’s skin

	Emulsion capacity (mL oil/mg protein)
Concentration of gelatin sample (%)	Porcine	Catla catla	C. mrigala	L. rohita
0.05	1.381 (0.013)^c	1.06 (0.136)^a	1.026 (0.019)^a	1.224 (0.062)^b
0.1	1.097 (0.009)^d	0.87 (0.0175)^b	0.669 (0.0121)^c	0.552 (0.013)^a
0.25	0.601 (0.014)^a	0.715 (0.008)^a	0.557 (0.010)^a	0.425 (0.007)^a

Values in parenthesis are standard deviation n = 3. Mean values with the same lowercase superscript letter are not significantly different (p < 0.05) between the columns.

FIGURE 4 Foam capacity and foam stability of gelatin from porcine and carp’s skin. (a) Porcine; (b) Catla catla; (c) Cirrhinus mrigala; (d) Labeo rohita.