Quality predictive models for bovine liver during storage and changes in volatile flavors

Figures & data

Table 1. Sample sampling time at different temperatures.

Temperature(℃)	Oxidation type	Sampling time
−20	Protein oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10, 30d
	Fat oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10, 30, 60, 90d
−10	Protein oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10d
	Fat oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10, 30, 60d
0	Protein oxidation	0, 0.5, 1, 2, 3, 4, 5, 6d
	Fat oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10, 30d
10	Protein oxidation	0, 0.5, 1, 2, 3, 4, 5d
	Fat oxidation	0, 0.5, 1, 2, 3, 4, 5, 6, 10d
20	Protein oxidation	0, 0.5, 1, 2, 3, 4d
	Fat oxidation	0, 0.5, 1, 2, 3, 4, 5, 6d

Table 2. The first-order kinetic exponential equation of carbonyl, TBARS, and POV with storage time at different temperatures.

Temperature (℃)	First-order kinetic equation	R2 (Regression coefficient)
−20	Carbonyl = 1.5749e^.0397t TBARS = 0.7916e^.0103t	0.9931 0.9753
	POV = 0.5209e^.0083t	0.9916
−10	Carbonyl = 1.5958e^.0611t	0.9903
	TBARS = 0.7564e^.0280t	0.9923
	POV = 0.5435e^.0279t	0.9814
0	Carbonyl = 1.5881e^.0935t	0.9897
	TBARS = 0.7619e^.0653t	0.9912
	POV = 0.5133e^.0755t	0.9969
10	Carbonyl = 1.5487e^.1511t	0.9901
	TBARS = 0.7459e^.1661t	0.9772
	POV = 0.5269e^.1685t	0.9983
20	Carbonyl = 1.6144e^.2351t	0.9920
	TBARS = 0.7676e^.3790t	0.9820
	POV = 0.5794e^.3949t	0.9897

Table 3. Verification and predicted values of carbonyl, TBA, and POV in validation tests.

	Temperature (℃)	Storage time(d)	Measured value	Predicted value	Relative error (%)
Carbonyl		2	2.109	2.006	−4.91
	5	4	2.694	2.565	−4.79
		6	3.502	3.281	−6.30
		2	2.184	2.293	5.01
	15	4	3.442	3.325	−3.38
		6	5.149	4.822	−6.36
TBA		2	0.978	0.936	−4.30
	5	4	1.240	1.162	−6.31
		6	1.343	1.443	7.40
		2	1.170	1.244	6.35
	15	4	1.927	2.046	6.20
		6	3.154	3.364	6.66
POV		2	0.673	0.650	−3.47
	5	4	0.783	0.811	3.62
		6	1.047	1.013	−3.18
		2	0.894	0.948	6.03
	15	4	1.713	1.624	−5.22
		6	2.607	2.782	6.69

Table 4. Volatile compounds identified in headspace of bovine liver.

Peak number	compound	retention index	literature
1	Acetone	545	1; 15
2	2-Butanone	688	2;5
3	Isovaleraldehyde	728	3;7
4	2-Methylbutyraldehyde	729	4;8
5	Valeraldehyde	767	4;19
6	Pentanol	876	7;9
7	Hexanal	881	11
8	Nonane	900	7; 15; 29
9	1,2-Xylene	979	13; 29
10	2-Butylfuran	927	10; 24; 29
11	Cyclohexanol	990	7; 15
12	2-Heptanone	975	7; 24
13	Decane	1000	7; 19
14	2-Pentylfuran	1084	10; 15; 19; 29
15	3-(Methylthio)propionaldehyde	1041	19; 29
16	Heptaldehyde	985	10; 29
17	2,3 Octanedione	1082	19; 24
18	1-Octen-3-ol	1079	5; 6
19	Benzaldehyde	1051	13; 15
20	Octanal	1096	7; 9; 11; 15
21	Undecane	1100	15; 25
22	Pentanoic 2-methyl-Pentanoic acid	1115	7; 10; 15
23	2-Acetylthiazole	1136	7; 15; 24
24	(E)-2-Octenal	1164	26
25	Capryl alcohol	1163	26
26	2-Nonanone	1189	25
27	1-Nonanal	1195	19
28	Dodecane	1200	10; 25
29	2-Nonenal	1282	1; 13; 18
30	2-Decanone	1290	11; 15
31	Decanal	1293	3; 25
32	Tridecane	1300	16; 17
33	Octanoic acid	1370	2; 18
34	Benzothiazole	1331	7; 10; 15
35	2-Decenal	1371	6; 7; 15
36	2-Undecanone	1388	6; 7
37	Tetradecane	1400	6; 7
38	2,4-Decadienal	1451	10; 15; 16; 25
39	Decanoic acid	1464	16; 27; 28
40	Dodecyl aldehyde	1500	15; 17
41	Hexadecane	1600	21; 23
42	2-Butanone	1622	15; 17; 28
43	Tridecanal	1594	7; 11; 14; 24
44	Tetradecanal	1683	1; 13
45	Octadecane	1800	15; 19; 29
46	Pentadecanal	1802	29
47	Palmitaldehyde	1896	16; 17
48	2-Hexadecanone	1855	2; 17
49	Margaric aldehyde	1927	2; 10
50	Octadecanol	2143	25
51	Stearaldehyde	2323	26

Table 5. Consumer acceptance of bovine liver paste prepared with bovine liver stored at different temperatures for 10 and 20d, p<0.05.

Storage time(d)	Storage temperature(℃)	Consumer acceptance (n = 90)
		Appearance***	Odor***	Taste***	Texture***	Overall***
0	_	7.13 ± 0.14^a	8.19 ± 0.17^a	7.25 ± 0.25^a	6.68 ± 0.25^a	6.87 ± 0.24^a
10	−20	7.04 ± 0.31^ab	7.78 ± 0.26^ab	7.33 ± 0.14^a	6.57 ± 0.14^ab	6.75 ± 0.27^a
	−10	6.85 ± 0.17^b	7.69 ± 0.35^abc	7.49 ± 0.15^a	6.49 ± 0.15^ab	6.81 ± 0.24^a
	0	6.21 ± 0.20^c	7.17 ± 0.24^bc	6.85 ± 0.11^b	6.24 ± 0.24^ab	6.56 ± 0.43^ab
	10	6.04 ± 0.19^c	7.08 ± 0.35^c	6.14 ± 0.08^c	6.28 ± 0.18^b	6.12 ± 0.15^b
	20	5.63 ± 0.09^d	6.17 ± 0.45^d	5.29 ± 0.14^d	5.33 ± 0.27^c	6.19 ± 0.45^b
20	−20	7.11 ± 0.25^a	7.63 ± 0.27^b	7.38 ± 0.25^a	6.59 ± 0.32^ab	6.65 ± 0.26^ab
	−10	6.91 ± 0.14^ab	7.77 ± 0.12^b	7.27 ± 0.16^a	6.48 ± 0.17^ab	6.78 ± 0.22^ab
	0	6.57 ± 0.11^b	6.89 ± 0.22^c	6.76 ± 0.22^b	6.19 ± 0.25^b	6.28 ± 0.26^bc
	10	5.76 ± 0.24^c	6.52 ± 0.14^c	5.33 ± 0.14^c	5.67 ± 0.17^c	6.07 ± 0.12^c
	20	5.07 ± 0.13^d	5.31 ± 0.16^d	5.07 ± 0.11^c	5.14 ± 0.25^d	5.37 ± 0.11^d

Figure 1. Change total plate count in bovine liver stored at different temperature (black, −20℃; red, −10℃; blue, 0℃; purple, 10℃; green, 20℃).

Figure 2. Change of carbonyl contents in bovine liver stored at different temperature (black, −20℃; red, −10℃; blue, 0℃; purple, 10℃; green, 20℃) for 30 days.

Figure 3. Change of TBA in bovine liver stored at different temperature (black, −20℃; red, −10℃; blue, 0℃; purple, 10℃; green, 20℃) for 90 days.

Figure 4. Change of POV in bovine liver stored at different temperature (black, −20℃; red, −10℃; blue, 0℃; purple, 10℃; green, 20℃) for 90 days.

Figure 5. Arrhenius curve of rate of change of carbony (A), TBA (B) and POV (C) content.

Figure 6. Heat map representing relative peak area of volatile compounds detected by GC-MS in bovine liver stored at different temperatures and periods (green color means low peak area and red color is high in peak area, relatively).

Figure 7. Relative content of different types of volatile compounds in bovine liver at different temperatures during different time (A,-20℃; B,-10℃; C,0℃; D, 10℃; E, 20℃).