Structure of Hyla rabbit skin gelatin as affected by microwave-assisted extraction

Figures & data

Figure 1. Yield of gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with extraction time of 5, 15, 30, 60, and 90 min, respectively

Figure 2. Gel strength of gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with extraction time of 5, 15, 30, 60, and 90 min, respectively

Table 1. Amino acid composition of rabbit skin gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with extraction time of 5, 15, 30, 60, and 90 min, respectively

Amino acid	WBE(g/1,000 g)	MAE-5(g/1,000 g)	MAE-15(g/1,000 g)	MAE-30(g/1,000 g)	MAE-60(g/1,000 g)	MAE-90(g/1,000 g)
Aspartic acid	58.31 ± 0.75	60.64 ± 2.72	60.98 ± 5.56	59.00 ± 0.20	60.06 ± 3.13	61.71 ± 0.72
Threonine	22.28 ± 0.63	23.76 ± 1.27	23.32 ± 1.86	22.68 ± 0.31	23.25 ± 1.45	24.06 ± 0.36
Serine	33.55 ± 0.25	33.55 ± 0.20	33.41 ± 0.07	34.15 ± 0.08	34.09 ± 0.23	34.08 ± 0.04
Glutamic acid	94.85 ± 1.50	92.55 ± 4.81	89.82 ± 11.51	99.17 ± 1.60	96.50 ± 4.08	91.82 ± 1.50
Glycine	232.29 ± 3.40	233.53 ± 0.81	230.45 ± 3.45	235.61 ± 2.03	235.13 ± 2.39	235.94 ± 1.23
Alanine	97.10 ± 1.15	99.50 ± 0.29	97.46 ± 2.71	97.51 ± 1.72	98.05 ± 0.50	98.77 ± 0.27
Cysteine	0	0	0	0	0	0
Valine	24.92 ± 0.59	26.34 ± 0.36	26.16 ± 1.07	26.21 ± 0.26	26.03 ± 0.80	26.22 ± 0.48
Methionine	6.06 ± 3.11	7.18 ± 1.03	5.76 ± 2.60	8.13 ± 1.00	7.36 ± 1.07	5.25 ± 1.12
Isoleucine	15.03 ± 1.13	15.24 ± 1.22	15.37 ± 1.70	15.07 ± 1.14	15.29 ± 1.31	16.42 ± 0.32
Leucine	30.83 ± 0.38	32.10 ± 0.13	31.76 ± 0.40	31.49 ± 0.55	31.61 ± 0.49	32.15 ± 0.30
Tyrosine	2.70 ± 0.05	2.76 ± 0.35	3.41 ± 1.41	2.68 ± 0.22	2.74 ± 0.42	2.85 ± 0.47
Phenylalanine	23.61 ± 0.24	24.52 ± 0.40	25.39 ± 1.09	24.69 ± 0.35	24.56 ± 0.40	24.63 ± 0.22
Lysine	42.71 ± 0.49	43.19 ± 0.29	44.70 ± 1.16	43.63 ± 0.80	43.57 ± 0.90	44.24 ± 0.63
Histidine	9.19 ± 1.36	8.01 ± 0.10	11.14 ± 0.38	9.58 ± 1.68	9.69 ± 1.54	9.07 ± 1.47
Arginine	93.80 ± 15.43	87.74 ± 2.26	87.38 ± 3.10	86.32 ± 0.56	85.94 ± 0.94	86.31 ± 0.72
Proline	108.93 ± 2.14	111.61 ± 1.35	109.60 ± 2.52	111.15 ± 1.20	111.33 ± 1.25	111.32 ± 0.73
Hydroxyproline	103.84 ± 7.29	97.78 ± 2.42	103.88 ± 8.90	92.93 ± 7.83	94.81 ± 8.52	95.17 ± 3.24
Imino acid	212.77 ± 7.60	209.39 ± 2.76	213.48 ± 9.25	204.08 ± 7.92	206.14 ± 8.61	206.48 ± 3.32

Figure 3. SDS-PAGE patterns of rabbit skin gelatin extracted by WBE and MAE. M: marker; 5, 15, 30, 60, and 90: gelatin obtained by microwave-assisted extraction with an extraction time of 5, 15, 30, 60, and 90 min, respectively. WBE: gelatin obtained by water bath extraction

Figure 4. Rheological properties of rabbit skin gelatin: (a) elastic modulus (G’) and loss modulus (G″) and (b) gelling and melting temperatures. The temperature was cooling from 5°C to 40°C and heating from 40°C to 5°C. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with an extraction time of 5, 15, 30, 60, and 90 min, respectively

Table 2. The major peaks in the amide region of rabbit skin gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with extraction time of 5, 15, 30, 60, and 90 min, respectively

Gelatins	Amide A (cm^–1)	AIII/1,454 cm^–1
WBE	3,433.91	0.80
MAE-5	3,444.41	0.85
MAE-15	3,435.15	0.91
MAE-30	3,436.24	0.78
MAE-60	3,442.63	0.80
MAE-90	3,442.98	0.77

Figure 5. FTIR results of rabbit skin gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with an extraction time of 5, 15, 30, 60, and 90 min, respectively

Figure 6. SEM images of rabbit skin gelatin extracted by WBE and MAE. WBE: gelatin obtained by water bath extraction; MAE-5, MAE-15, MAE-30, MAE-60, and MAE-90: gelatin obtained by microwave-assisted extraction with extraction time of 5, 15, 30, 60, and 90 min, respectively