Contribution of 2-methyl-3-furanthiol to the cooked meat-like aroma of fermented soy sauce

Figures & data

Table 1. Concentrations of volatile thiols in FSS samples.

Compound	Threshold^11,17^) (ng/L)	Concentration (μg/L)
		Raw soy sauce		Heat-treated soy sauce
		Range^a	Average	Range	Average
2M3F	4	0.4–1.0	0.7	0.5–1.9	1.3
2FM	0.4	0.8–1.9	1.3	1.2–2.8	2.0
ET2MP	500	5.4–27.4	13.6	13.7–40.9	22.8
BM	0.3	0.1–0.8	0.3	0.3–0.7	0.6

^a Range of volatile thiol concentrations in five soy sauce samples.

Table 2. Number of panelists who recorded stronger cooked meat-like aroma soy sauce (N = 34).

Concentration of 2M3F for addition to soy sauce (μg/L)		0.2	0.4	0.8
Number of panelists	Soy sauce	9	2	4
	Soy sauce with the addition of 2M3F	25	32	30
p-value（χ^2-test）		<0.01	<0.001	<0.001

Table 3. Concentrations of 2M3F and 2FM in raw soy sauce A after heating.

Compound	2M3F (μg/L)		2FM (μg/L)
Temperature	5 min^a^, ^d	20 min	5 min^e	20 min
–^b	0.3 ± 0.1^c		0.6 ± 0.1
80 °C	1.2 ± 0.1	2.4 ± 0.3	1.2 ± 0.1	1.4 ± 0.1
95 °C	6.6 ± 0.4	6.8 ± 0.3	5.0 ± 0.3	5.2 ± 0.1
120 °C	11.1^f ± 0.4	18.3^g ± 0.8	9.7^h± 0.7	18.2^i ± 0.6

^a Heating time.

^b Before heat treatment.

^c Values correspond to the mean ± SD (standard deviation) of four analyses.

^d,e Values in the same column are significantly different from each other (p < 0.05).

^f,g,h,i Values with different superscripts indicate significance (p < 0.01).

Table 4. Changes of 2M3F and 2FM in FSS samples at 120 °C for 5 min^a.

Sample		Raw soy sauce (B, μg/L)		Heat-treated soy sauce (BH, μg/L)
Before heating		2M3F	2FM	2M3F	2FM
		0.7^b ± 0.1^d	1.2 ± 0.1	1.3^e ± 0.2	2.4 ± 0.2
After heating	Not added	13.5^c ± 0.3	8.9 ± 0.3	5.6^f ± 0.4	4.4 ± 0.1
	Added ribose + Cys	15.7 ± 1.1	12.1 ± 0.1	6.6 ± 0.2	6.8 ± 0.3
	Added glucose + Cys	12.4 ± 1.4	11.4 ± 0.1	4.3 ± 0.4	6.1 ± 0.5

^a Soy sauce samples (180 mL) were heated in a laboratory autoclave. For these heating experiments, cysteine (1.8 mM) and the corresponding carbohydrate (47 mM of glucose or 7.7 mM of ribose) were added.

^b,c,e,f Values with different superscripts indicate significance in raw or heat-treated soy sauce (p < 0.01).

^d Values correspond to the mean ± SD (standard deviation) of four analyses.