Glycine max (L.) Merr. - syn. Glycine soja (L.) Merr., Phaseolus max L., Glycine hispida Maxim., Glycine hispida (Moench) Maxim. - Fabaceae
soybean, soya, Sojabohne, Soja (-pflanze)
Erect brown-hairy bushy annual, 0.50-1.50m tall, native in Eastern Asia (?, only known in culture), cultivated in China, Japan, India, USA, Brazil; leaves usually pinnately 3-foliolate, leaflets papery, broadly ovate, entire, long petioled; flowers purple, light purple, or white, small; pod hanging on very short stalk, brown, hairy; seeds 2-5, green, yellow, brown or black with small hilum, 5-8mm across; germination epigeal. http://www.efloras.org/florataxon.aspx?flora_id=2&taxon_id=242323602
„Soy sauce (also called soya sauce) is a condiment made from a fermented paste of boiled soybeans, roasted grain, brine, and Aspergillus oryzae or Aspergillus sojae molds… Soy sauce has a distinct yet basic taste of umami, due to naturally occurring free glutamates.“ https://en.wikipedia.org/wiki/Soy_sauce
„Application of aroma extract dilution analysis (AEDA) to the volatiles isolated from a commercial Japanese soy sauce revealed 30 odor-active compounds in the flavor dilution (FD) factor range of 8−4096, among which 2-phenylethanol showed the highest FD factor of 4096, followed by 3-(methylsulfanyl)propanal (methional), the tautomers 4-hydroxy-5-ethyl-2-methyl- and 4-hydroxy-2-ethyl-5-methyl-3(2H)-furanone (4-HEMF), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (4-HDF), and 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolone), all showing FD factors of 1024. Thirteen odorants were quantified by stable isotope dilution assays, and their odor activity values (OAVs) were calculated as ratio of their concentrations and odor thresholds in water. Among them, 3-methylbutanal (malty), sotolone (seasoning-like), 4-HEMF (caramel-like), 2-methylbutanal (malty), methional (cooked potato), ethanol (alcoholic), and ethyl 2-methylpropanoate (fruity) showed the highest OAVs (>200). An aqueous model aroma mixture containing 13 odorants, which had been identified with the highest OAVs, in concentrations that occur in the soy sauce showed a good similarity with the overall aroma of the soy sauce itself.“
[Characterization of the key aroma compounds in soy sauce using approaches of molecular sensory science., Steinhaus, P., Schieberle, P., Journal of agricultural and food chemistry, 55(15), 2007, 6262-6269]
The odor activity values(OAV) of (E,E)-2,4-decadienal, dimethyl disulphide, 3-methylbutanal, ethyl butyrate, and 2-methylbutanal showed that these compounds contribute to the characteristic odor of tofu (made by coagulating soy milk).
[Volatile Flavor Compounds of Tofu [J]., Qi, S.P., Weng, X.C., Journal of Shanghai University (Natural Science Edition), 1, 2008, 25]
„Whereas 3-(methylthio)propanal (methional) and 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon) were detected in all of the soy sauce aroma concentrates as having high flavor dilution (FD) factors, 4-ethyl-2-methoxyphenol was detected as having a high FD factor in only four of the soy sauces (KS, US, TS, and SSS). Furthermore, 5(or 2)-ethyl-4-hydroxy-2(or 5)-methyl-3(2H)-furanone (4-HEMF) and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (4-HDMF), which were thought to be the key odorants in KS, were detected in KS, US, TS, and SSS, but the FD factors widely varied among them.“
[Comparison of key aroma compounds in five different types of Japanese soy sauces by aroma extract dilution analysis (AEDA)., Kaneko, S., Kumazawa, K., Nishimura, O., Journal of agricultural and food chemistry, 60(15), 2012, 3831-3836]
The types of odorants occurring in 27 commercial soy sauces produced through three different fermentation processes (high-salt liquid-state fermentation soy sauce, HLFSS; low-salt solid-state fermentation soy sauce, LSFSS; Koikuchi soy sauce, KSS) were similar, although their intensities significantly differed. Of the 41 key aroma-active compounds quantified, 3-methylbutanal (malty, almond, OAV 460), ethyl acetate (fruity, 183), HEMF (caramel-like, 181), 2-methylbutanal (malty, almond, 167), 3-(methylthio)propanal (cooked potato, 101), 2-methylpropanal (malty, nutty, 80), 2-methyl-1-butanol (malty, 35), phenylacetaldehyde (honey-like, 31), ethyl 2-methylpropanoate (fruity, 25), ethanol (alcoholic, 12), 3-methyl-1-butanol (malty, rancid, pungent, 9), 1-octen-3-ol (mushroom-like, 7), 5-methyl-2-furancarboxaldehyde (almond, spicy, caramel-like, 7), dimethyl trisulphide (cooked onion, 4), dimethyl disulphide (onion, cooked cabbage, 2), guaiacol (smoky, burnt, 2), scetic acid (sour, 1), 2-phenylethanol (floral, sweet, 1), 3-(methylthio)-1-propanol (cooked potato, 1), ethyl propionate (fruity, 1), 4-ethylguaiacol (smoky, bacon, 1), 4-vinylguaiacol (spicy, burnt, 1), and maltol (caramel, sweet, 1) had the highest odor activity values.
„There were 26 compounds in common for all the testing soy sauces… They are important characteristic aroma compounds for soy sauce, including ethanol, 2-methyl-1-propanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 1-octen-3-ol, 2-phenylethanol, 2-methylpropanal, 2-methylbutanal, 3-methylbutanal, benzeneacetaldehyde, acetic acid, ethyl acetate, guaiacol, 4-ethylguaiacol, 2-methylpyrazine, 2,5-dimethylpyrazine, 2,3,5-trimethylpyrazine, 2,5-dimethylfuran, furfural, 2-furanmethanol, 5-methyl-2-furancarboxaldehyde, 3-phenylfuran, dimethyl disulphide, dimethyl trisulphide, 3-(methylthio)propanal and maltol. The five most abundant compounds were ethanol > acetic acid > 3-methyl-1-butanol > 2-furanmethanol > maltol…
The data showed that the panels could detect the omission of any ethyl ester volatiles of high significance (i.e. ethyl acetate, ethyl 2-methylpropanoate, ethyl propionate, and ethyl isovalerate). This result indicates the important role of these fruity-smelling compounds in the overall soy sauce aroma. Thus, fruity note was often used as an aroma index for sensory evaluation of soy sauce (Feng et al., 2014 and Kaneko et al., 2012)…
Eight key volatiles were identified from the 26 potent aroma compounds in the original aroma model mixture, showing significant difference in the omission experiments of the three groups… These 8 volatiles included 3-methylbutanal, ethyl acetate, 3-(methylthio)propanal, benzeneacetaldehyde, ethyl 2-methylpropanoate, ethanol, dimethyl trisulphide and acetic acid, among which 7 could be detected in all soy sauce samples of this study and 6 were previously considered as key characteristic aroma compounds for model soy sauce (Kaneko et al., 2012).“
[Characterisation of aroma profiles of commercial soy sauce by odour activity value and omission test., Feng, Y., Su, G., Zhao, H., Cai, Y., Cui, C., Sun-Waterhouse, D., Zhao, M., Food chemistry, 167, 2015, 220-228] http://www.sciencedirect.com/science/article/pii/S0308814614009431
„The high-performance liquid chromatography (HPLC) fractions containing peptides with glutamic acid residue from koikuchi-shoyu and tamari-shoyu have a much lower umami taste intensity (taste dilution factors found <1 to 4) compared to those containing free amino acids and salt (taste dilution factors found 16 to 32). Therefore, the contribution of peptides in eliciting an intense umami taste was clearly not significant, on the other hand, free amino acids and sodium salt are the key components of the intense umami taste of soy sauce. Interestingly, the free amino acids present in the fractions consisted of umami tasted and sweet tasted amino acids. The concentrations of umami tasted amino acids were actually much lower than their supposed concentrations for exhibiting the equal umami intensities found in their fractions (Lioe and others 2006). This fact give an insight that the intense umami taste in soy sauce is also resulted from the interaction between umami components and other tastants.“
[Soy sauce and its umami taste: a link from the past to current situation., Lioe, H.N., Selamat, J., Yasuda, M., Journal of food science, 75(3), 2010, R71-R76] http://onlinelibrary.wiley.com/doi/10.1111/j.1750-3841.2010.01529.x/full
As shown on the basis of an umami intensity of a 6.0 mM monosodium L-glutamate (MSG) solution, the umami enhancing fractions of a typical Japanese soy sauce, Koikuchi Shoyu, led to the identification of N-(1-deoxy-D-fructos-1-yl)pyroglutamic acid (Fru-pGlu), N-(1-deoxy-D-fructos-1-yl)valine (Fru-Val), N-(1-deoxy-D-fructos-1-yl)methionine (Fru-Met), pyroglutamylglutamine (pGlu-Gln), and pyroglutamylglycine (pGlu-Gly). „Although all the compounds identified were at sub-threshold concentrations in the soy sauce, a taste reconstitution experiment revealed that they contributed part of the umami taste of the soy sauce.“
[Isolation and identification of the umami enhancing compounds in Japanese soy sauce., Kaneko, S., Kumazawa, K., Nishimura, O., Bioscience, biotechnology, and biochemistry, 75(7), 2011, 1275-1282]
Some foods own a „continuity, mouthfulness and thick flavour“, which cannot be explained by the five basic tastes alone. These sensations are evoked by kokumi substances.
„The kokumi peptide γ-Glu-Val-Gly in soy sauces was determined and quantified by LC/MS/MS. Soy sauces contained γ-Glu-Val-Gly at 0.15-0.61 mg/dl. This is the first report to confirm the existence of this peptide in vegetable foods.“
[Kuroda, Motonaka, et al. „Determination and quantification of the kokumi peptide, γ-glutamyl-valyl-glycine, in commercial soy sauces.“ Food chemistry 141.2 (2013): 823-828]
Glycine max (L.) Merr. as Dolichos soja L., Jacquin,N.J. von, Icones plantarum rariorum, vol.1, t.145 (1781-1786)
© Rolf Marschner (20007), www.botanische-spaziergaenge.at