170
10.4 Metabolic Profiling
The smell of mushroom is one of the main criteria in determining its quality. The
fresh shiitake mushroom releases only a slight odor. However, gradually a characteristic sulfurous aroma is released upon drying and crushing (Yasumoto et al.
1976). The ingredients of edible mushrooms can be influenced by several factors
including type of species, part of and maturity stage of mushroom, methods adopted
for processing, and storage conditions (Gao et al. 2020). In several studies, the volatile metabolites of dried shiitake mushroom have been identified. The
1,2,3,5,6- pentathiepane, also known as “lanthionine,” is reported as a key compound (Hiraide et al. 2004). The other aroma components such as alcohols, ketones,
sulfides, alkanes, and fatty acids have been reported. The presence of calciferol
(vitamin D2) and vitamin-B complex such as B1 (thiamine), B2 (riboflavin), and
B12 (niacin) along with fatty acids and amino acids has been observed. Besides the
characteristic aroma of shiitake mushrooms due to the presence of
1,2,3,5,6- pentathiepane, the other volatile flavor compounds such as matsutakeol
(octen-1-ol-3) and ethyl-n-amyl ketone are also reported (Bisen et al. 2010). The
nutritious compounds such as 5′-guanylic acid and vitamin D2 are also reported in
higher amount in dried shiitake mushroom. Besides this, several other sulfurcontaining metabolites and alcohols are also reported. Researchers have also
reported 1,2,4-trithiolane and 1,2,4,6-tetrathiepane in dried shiitake mushrooms;
the former was identified as indicator of the smell. Lenthionine (C 2 H 4 S 5 ) was initially identified in the late 1960s (Morita and Kobayashi 1967; Wada et al. 1967a,
b), and it was found to decompose during analysis (Charpentier et al. 1986).
Thereafter, other sulfur-containing compounds such as 1,2,4-trithiolane,
1,2,4,6- tetrathiepane, and 1,2,3,4,5,6-hexathiepane were also identified (Morita and
Kobayashi 1967). Other compounds such as dimethyl disulfide, dimethyl trisulfide,
1,2,4-trithiolane, and one sulfur hereafter S-containing compound with molecular
formula C 2 H 4 S 4 are also identified. 1,2,4-Trithiolane was the only cyclic S compound identified in homogenized fresh mushroom (Kameoka and Higuchi 1976;
Chen et al. 1984).
The origin of cyclic S compounds from lentinic acid, derived from γ-glutamyl
cysteine sulfoxide, in shiitake mushroom dated back to late 1970 (Iwami et al.
1975a, b; Yasumoto et al. 1976). The γ-glutamyl transpeptidase and cysteine sulfoxide lyase were found to convert lentinic acid into cyclic compounds containing
S. Later in 1978, it was found in dried mushroom; the pH and temperature affect the
lenthionine biosynthesis (Ito et al. 1978) during rehydration (Chen and Ho 1986b).
Besides lenthionine, the compounds such as 1,2,4,6-tetrathiepane and
1,2,3,4,5,6-hexathiepane (Morita and Kobayashi 1967, Chen and Ho 1986a, b) and
8-carbon alcohols responsible for the smell of fresh shiitake (Chen and Ho 1986b;
Cronine and Ward 1971; Kameoka and Higuchi 1976; Ito et al. 1978) were not
reported in dried shiitake mushroom. The compounds responsible for sensory intensity were found to be linked to S-containing compounds by H 2 S, SO 2 , and other
compounds. The presence of trace amount of methyl β-methyl-thiopropionate and
R. Salwan et al.
10.4 Metabolic Profiling
The smell of mushroom is one of the main criteria in determining its quality. The
fresh shiitake mushroom releases only a slight odor. However, gradually a characteristic sulfurous aroma is released upon drying and crushing (Yasumoto et al.
1976). The ingredients of edible mushrooms can be influenced by several factors
including type of species, part of and maturity stage of mushroom, methods adopted
for processing, and storage conditions (Gao et al. 2020). In several studies, the volatile metabolites of dried shiitake mushroom have been identified. The
1,2,3,5,6- pentathiepane, also known as “lanthionine,” is reported as a key compound (Hiraide et al. 2004). The other aroma components such as alcohols, ketones,
sulfides, alkanes, and fatty acids have been reported. The presence of calciferol
(vitamin D2) and vitamin-B complex such as B1 (thiamine), B2 (riboflavin), and
B12 (niacin) along with fatty acids and amino acids has been observed. Besides the
characteristic aroma of shiitake mushrooms due to the presence of
1,2,3,5,6- pentathiepane, the other volatile flavor compounds such as matsutakeol
(octen-1-ol-3) and ethyl-n-amyl ketone are also reported (Bisen et al. 2010). The
nutritious compounds such as 5′-guanylic acid and vitamin D2 are also reported in
higher amount in dried shiitake mushroom. Besides this, several other sulfurcontaining metabolites and alcohols are also reported. Researchers have also
reported 1,2,4-trithiolane and 1,2,4,6-tetrathiepane in dried shiitake mushrooms;
the former was identified as indicator of the smell. Lenthionine (C 2 H 4 S 5 ) was initially identified in the late 1960s (Morita and Kobayashi 1967; Wada et al. 1967a,
b), and it was found to decompose during analysis (Charpentier et al. 1986).
Thereafter, other sulfur-containing compounds such as 1,2,4-trithiolane,
1,2,4,6- tetrathiepane, and 1,2,3,4,5,6-hexathiepane were also identified (Morita and
Kobayashi 1967). Other compounds such as dimethyl disulfide, dimethyl trisulfide,
1,2,4-trithiolane, and one sulfur hereafter S-containing compound with molecular
formula C 2 H 4 S 4 are also identified. 1,2,4-Trithiolane was the only cyclic S compound identified in homogenized fresh mushroom (Kameoka and Higuchi 1976;
Chen et al. 1984).
The origin of cyclic S compounds from lentinic acid, derived from γ-glutamyl
cysteine sulfoxide, in shiitake mushroom dated back to late 1970 (Iwami et al.
1975a, b; Yasumoto et al. 1976). The γ-glutamyl transpeptidase and cysteine sulfoxide lyase were found to convert lentinic acid into cyclic compounds containing
S. Later in 1978, it was found in dried mushroom; the pH and temperature affect the
lenthionine biosynthesis (Ito et al. 1978) during rehydration (Chen and Ho 1986b).
Besides lenthionine, the compounds such as 1,2,4,6-tetrathiepane and
1,2,3,4,5,6-hexathiepane (Morita and Kobayashi 1967, Chen and Ho 1986a, b) and
8-carbon alcohols responsible for the smell of fresh shiitake (Chen and Ho 1986b;
Cronine and Ward 1971; Kameoka and Higuchi 1976; Ito et al. 1978) were not
reported in dried shiitake mushroom. The compounds responsible for sensory intensity were found to be linked to S-containing compounds by H 2 S, SO 2 , and other
compounds. The presence of trace amount of methyl β-methyl-thiopropionate and
R. Salwan et al.