Apparatus used for small-scale volatile extraction from ethanol-supplemented low-salt miso and GC-MS characterization of the extracted flavors.
An extraction apparatus was equipped with a nitrogen-flushing vessel to purge volatiles from a 10-g miso prepared solution at 40 degrees C, a reflux condenser to recover water, a coiled cold-trap to separate ethanol in advance, and a glass-lined stainless (GLS) trap filled with Tenax TA for flavor adsorption. Volatiles in the GLS tube were released with a thermal desorption device and condensed with a Micro-cryo trap prior to connection with GC and GC-MS for characterization. After analysis, a broad volatile profile comprising 9 categories of functional group and 97 identified compounds was achieved. As affected by ethanol supplementation for miso fermentation, most volatiles except alcohols and acetals in the low-salt products fermented with 5% NaCl and 7.5% ethanol were higher than those in the control products fermented with 9% NaCl and 0% ethanol and the high-ethanol supplemented products fermented with 5% NaCl and 15% ethanol. It reveals that supplementation of ethanol in miso at an appropriate level not only enabled a low-salt miso fermentation but also enhanced flavor formation.
Ku
K L
KL
Department of Food Science, National Chiayi University, Taiwan, Republic of China.
Chen
T P
TP
Chiou
R Y
RY
D000431:Ethanol / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D012965:Sodium Chloride; D013025:Glycine max / Q000737:chemistry*; D014835:Volatilization
D000431:Ethanol; D012965:Sodium Chloride