Taste of Water-Soluble Extracts Obtained from Over-Fermented Tempe

Figures & data

TABLE 1 Parameters of water-soluble extracts of over-fermented tempe obtained from the same initial weight of fresh tempe

Over-fermented tempe	Crude protein	Total acid	Total sugar	pH value
(hour)	(g/100 g)	(g/100 g)	(g/100 g)
0	34.94 ± 5.67	13.46 ± 0.98^a1)	6.61 ± 0.21^a	5.4 ± 0.1
24	49.41 ± 5.18	13.13 ± 1.68^ab	3.84 ± 0.54^b	5.6 ± 0.1
48	51.01 ± 8.19	12.20 ± 1.11^ab	4.50 ± 0.02^b	5.7 ± 0.2
72	51.88 ± 9.51	10.47 ± 0.40^bc	1.68 ± 0.38^b	5.9 ± 0.1
96	53.43 ± 4.81	9.24 ± 0.98^c	1.45 ± 0.04^b	6.1 ± 0.3

¹Different letters of within the column indicate significant differences at p < 0.05 level.

TABLE 2 Composition of amino acids in water soluble extracts of over-fermented tempe obtained from 600 g of fresh tempe subjected to prolonged fermentation

Amino acids	Concentrations (g L^–1)										Taste threshold(g L^–1)	Taste
	0^1)		24		48		72		96
	Free	Residue^2)	Free	Residue	Free	Residue	Free	Residue	Free	Residue
Asp	0.4 ± 0.1	9.3 ± 3.3	1.0 ± 0.3	24.6 ± 8.2	1.2 ± 0.3	24.2 ± 7.0	1.1 ± 0.4	25.7 ± 3.1	1.7 ± 0.3	23.8 ± 1.0	1.0	Umami
Glu	0.8 ± 0.4	19.3 ± 6.8	3.3 ± 0.6	49.5 ± 13.7	5.6 ± 1.1	47.9 ± 15.6	4.7 ± 2.5	45.4 ± 3.6	4.2 ± 1.2	40.2 ± 2.6	0.3
Ala	0.8 ± 0.2	2.0 ± 0.7	3.4 ± 1.5	6.1 ± 2.6	3.3 ± 0.9	6.4 ± 1.8	2.6 ± 0.8	8.3 ± 0.4	2.4 ± 0.2	7.3 ± 0.8	0.6	Sweet
Gly	0.4 ± 0.4	2.8 ± 0.8	0.9 ± 0.4	6.6 ± 1.4	0.9 ± 0.3	6.9 ± 1.1	1.2 ± 0.7	7.6 ± 1.5	1.5 ± 0.7	6.4 ± 0.5	1.3
Ser	0.9 ± 0.3	2.4 ± 0.7	1.9 ± 0.3	7.6 ± 2.5	2.0 ± 1.0	7.5 ± 1.1	1.0 ± 0.5	9.2 ± 1.9	1.3 ± 0.8	8.8 ± 0.5	1.5
Thr	0.7 ± 0.3	2.4 ± 0.7	1.0 ± 0.2	7.1 ± 2.2	0.8 ± 0.1	7.0 ± 1.6	0.5 ± 0.3	8.1 ± 1.7	0.7 ± 0.2	7.4 ± 0.4	2.6
Arg	0.6 ± 0.2	4.0 ± 1.4	1.1 ± 0.2	11.3 ± 3.7	1.1 ± 0.0	10.9 ± 2.8	0.6 ± 0.4	12.1 ± 2.3	0.5 ± 0.4	11.6 ± 0.1	0.5	Bitter
His	1.7 ± 0.6	1.4 ± 0.4	2.9 ± 0.3	3.3 ± 0.6	2.6 ± 1.1	3.5 ± 0.2	1.2 ± 0.3	4.5 ± 0.8	0.8 ± 0.2	4.1 ± 0.1	0.2
Ile	0.2 ± 0.1	2.1 ± 1.0	0.9 ± 0.7	7.2 ± 3.7	0.6 ± 0.0	7.4 ± 2.9	0.9 ± 0.5	8.8 ± 0.4	1.6 ± 0.6	8.5 ± 1.0	0.9
Leu	0.3 ± 0.1	2.8 ± 1.0	1.3 ± 0.9	10.0 ± 4.6	0.9 ± 0.1	10.3 ± 3.0	1.3 ± 0.9	12.9 ± 1.9	2.3 ± 0.8	12.8 ± 0.1	1.9
Met	0.1 ± 0.1	1.0 ± 0.2	0.3 ± 0.1	2.8 ± 0.7	0.3 ± 0.0	2.8 ± 0.5	0.1 ± 0.1	3.3 ± 0.8	0.5 ± 0.1	2.7 ± 0.1	0.3
Phe	0.2 ± 0.1	2.6 ± 0.9	1.0 ± 0.8	7.8 ± 3.5	0.7 ± 0.0	8.2 ± 2.5	1.0 ± 0.6	9.9 ± 1.1	1.9 ± 0.7	9.9 ± 0.4	0.9
Val	0.3 ± 0.1	1.9 ± 0.9	1.2 ± 0.9	6.6 ± 3.6	0.8 ± 0.1	6.8 ± 2.5	1.2 ± 0.7	8.5 ± 0.4	2.2 ± 0.9	8.2 ± 0.9	0.4
Tyr	0.4 ± 0.1	1.3 ± 0.4	0.9 ± 0.4	4.3 ± 1.9	0.7 ± 0.0	4.6 ± 1.1	0.8 ± 0.4	5.9 ± 1.0	1.3 ± 0.2	5.8 ± 0.1	0.9
Lys	1.7 ± 0.6	4.7 ± 1.6	2.1 ± 0.2	10.0 ± 2.8	0.6 ± 0.4	10.9 ± 3.1	0.7 ± 0.6	11.6 ± 1.3	0.8 ± 0.7	9.8 ± 2.1	0.5	Tasteless
Total	9.3	60.0	23.3	164.9	22.0	165.4	18.8	181.9	23.9	167.2
	± 3.2	± 20.7	± 7.8	± 55.6	± 2.9	± 46.8	± 9.6	± 22.1	± 5.3	± 8.2

¹Over-fermented tempe (hours).

²Calculated from total amino acids concentration minus free amino acids concentration (total amino acids data not shown).

TABLE 3 Taste activity ratio of umami-sweetness to bitterness taste in water soluble extracts (50 mL) of over-fermented tempe obtained from 600 g of fresh tempe after prolonged fermentation

Taste characteristic	Taste activity value
	0^1)	24	48	72	96
Umami + sweet	5.4	19.8	27.6	23.0	22.2
Bitter	11.8	25.0	20.6	13.8	18.8
Ratio	0.5	0.8	1.4	1.6	1.2

¹Over-fermented tempe (hours).

FIGURE 1 Taste characteristic A: and taste activity value B: of free amino acids in water soluble extract of over-fermented tempe obtained from 600 g of fresh tempe. Amino acids are grouped as follows: Asp and Glu for umami taste; Ala, Gly, Ser, and Thr for sweet taste; Arg, His, Ile, Leu, Met, Phe, Val, and Tyr for bitter taste; and Lys as tasteless. Taste activity values were calculated from the individual amino acid concentrations divided by their corresponding threshold values.

TABLE 4 Dilution factor of umami taste found in water-soluble extracts (WSE) of over-fermented tempe and their fractions. WSE was evaluated at 5 times concentrated

Over-fermented tempe (hour)	Description	Taste	Dilution factor
0	WSE	umami	32
	Fractions
	F1	umami	2
	F2	umami	16
	F3	umami	16
	F4	umami	1
24	WSE	umami	64
	Fractions
	F1	umami	4
	F2	umami	16
	F3	umami	128
	F4	umami	2
48	WSE	umami	128
	Fractions
	F1	umami	16
	F2	umami	128
	F3	umami	4
72	WSE	umami	256
	Fractions
	F1	umami	8
	F2	umami	128
	F3	umami	8
96	WSE	umami	128
	Fractions
	F1	umami	8
	F2	umami	64
	F3	umami	8

FIGURE 2 RP-HPLC profiles of the Sephadex G-25 gel permeation fractions (F1, F2, and F3) of water soluble extract obtained from over-fermented tempe after different fermentation periods. Detection was at UV 241 nm.