Litopenaeus vannamei fermentation using selected Lactobacillus spp. to reduce its allergenicity

Figures & data

Table 1. Orthogonal test to optimise fermentation conditions L₉ (3⁴).

Level	A-glucose (g/100 g)	B-shrimp concentration (g/100 g)	C-inoculum level (mL/100 g)	D-NaCl (g/100 g)
1	1%	20%	2.5%	1%
2	2%	30%	15%	2%
3	3%	40%	25%	3%

Table 2. Concentration of lactic acid bacteria in minced shrimp at different fermentation times.

Samples	Lactic acid bacteria concentration/ log CFU/g
	0 h	12 h	24 h	36 h	48 h	60 h	72 h
Control	2.88 ± 0.03*^f	3.42 ± 0.09^e**	4.52 ± 0.04^c	4.82 ± 0.04^a	4.75 ± 0.04^b	3.63 ± 0.06^d	2.92 ± 0.05^f
L. helveticus TS6024	8.37 ± 0.09^c	8.63 ± 0.08^b	8.94 ± 0.04^a	8.98 ± 0.03^a	8.11 ± 0.08^d	7.72 ± 0.07^e	6.87 ± 0.13^f
L. acidophilus 6005	8.23 ± 0.06^b	8.73 ± 0.13^a	8.78 ± 0.11^a	8.20 ± 0.04^b	7.97 ± 0.09^c	6.78 ± 0.12^d	5.71 ± 0.07^e

*Values are presented as the mean ± SD.

**Different superscript letters in the same row show significant difference (P < 0.05).

Table 3. Comparative assessment of supernatant and precipitate allergens of fermented shrimp.

Samples	L. helveticus TS6024		L. acidophilus 6005
	24 h	48 h	24 h	48 h
Supernatant OD492nm	0.343 ± 0.009*^b,1	0.150 ± 0.007^b,2	0.365 ± 0.008^b,1	0.179 ± 0.013^b,2
Precipitate OD492nm	0.406 ± 0.005^a,1**	0.251 ± 0.012^a,2	0.468 ± 0.009^a,1	0.303 ± 0.011^a,2

Note: Positive control 0.585 ± 0.014; Negative control 0.038 ± 0.001 (interval 0.030–0.050).

*Values are presented as the mean ± SD.

** Different superscript letters in the same column show significant difference (P < 0.05). Different superscript numbers between 24 and 48 h for the same strain in the same row mean significant difference (P < 0.05).

Table 4. Orthogonal test results of L. helveticus TS6024 fermentation.

Test No.	A-glucose (g/100 g)	B-minced shrimp (g/100 g)	C-inoculum level (mL/100 g)	D-NaCl (g/100 g)	Average OD492nm
1	1 (1)	1 (20)	1 (2.5)	1 (1)	0.279 ± 0.007*
2	1	2 (30)	2 (15)	2 (2)	0.227 ± 0.013
3	1	3 (40)	3 (25)	3 (3)	0.174 ± 0.009
4	2 (2)	1	2	3	0.280 ± 0.011
5	2	2	3	1	0.279 ± 0.007
6	2	3	1	2	0.211 ± 0.010
7	3 (3)	1	3	2	0.249 ± 0.006
8	3	2	1	3	0.139 ± 0.011
9	3	3	2	1	0.317 ± 0.008
M1	0.680	0.808	0.629	0.875
M2	0.770	0.645	0.824	0.687
M3	0.705	0.702	0.702	0.593
m1	0.227	0.269	0.210	0.292
m2	0.257	0.215	0.275	0.229
m3	0.235	0.234	0.234	0.198
Sj	0.0204	0.0236	0.0255	0.0327
Optimal level	A1	B2	C1	D3

*Values are presented as the mean ± SD.

Table 5. L. helveticus TS6024 fermentation temperature and time.

TEMP (°C)	Time (h)	Average OD492nm
37	48	0.194 ± 0.005*^b
37	60	0.123 ± 0.009^c**
42	36	0.296 ± 0.012^a
42	48	0.281 ± 0.010^a

*Values are presented as the mean ± SD.

**Different superscript letters in the same column show significant difference (P < 0.05).

Table 6. Orthogonal test results of L. acidophilus 6005 fermentation.

Test No.	A-glucose (g/100 g)	B-minced shrimp (g/100 g)	C-inoculum level (mL/100 g)	D- NaCl (g/100 g)	Average OD492nm
1	1 (1)	1 (20)	1 (2.5)	1 (1)	0.302 ± 0.012*
2	1	2 (30)	2 (15)	2 (2)	0.326 ± 0.010
3	1	3 (40)	3 (25)	3 (3)	0.319 ± 0.008
4	2 (2)	1	2	3	0.277 ± 0.005
5	2	2	3	1	0.330 ± 0.015
6	2	3	1	2	0.306 ± 0.007
7	3 (3)	1	3	2	0.318 ± 0.011
8	3	2	1	3	0.434 ± 0.012
9	3	3	2	1	0.344 ± 0.013
M1	0.947	0.897	1.042	0.976
M2	0.913	1.090	0.947	0.950
M3	1.096	0.969	0.967	1.030
m1	0.316	0.299	0.347	0.325
m2	0.304	0.363	0.316	0.317
m3	0.365	0.323	0.322	0.343
Sj	0.00632	0.00634	0.00167	0.00111
Optimal level	A2	B1	C2	D2

*Values are presented as the mean ± SD.

Table 7. L. acidophilus 6005 fermentation temperature and time.

TEMP (°C)	Time (h)	Average OD492nm
37	48	0.274 ± 0.011*^a
37	60	0.210 ± 0.009^b**
42	36	0.211 ± 0.010^b
42	48	0.175 ± 0.006^c

*Values are presented as the mean ± SD.

**Different superscript letters in the same column show significant difference (P < 0.05).

Figure 1. SDS-PAGE analysis on the degradation effects of L. helveticus TS6024- and L. acidophilus 6005-fermentation on TM molecules. M, marker; lane 1, protein extracts from unfermented shrimp; lane 2, protein extracts from the precipitate of L. acidophilus 6005-fermentation, OD_492nm: 0.175; lane 3, protein extracts from the supernatant of L. acidophilus 6005-fermentation, OD_492nm: 0.145; lane 4, protein extracts from the precipitate of L. helveticus TS6024-fermentation, OD_492nm: 0.123; lane 5, protein extracts from the supernatant of L. helveticus TS6024-fermentation, OD_492nm: 0.107.

Data availability statement

Data can be made available upon reasonable request.