Development of a New Isolation Method and Gas Chromatographic Determination of Organic Acids in Soy Sauce

Abstract

A simple and rapid isolation method of organic acid in soy sauce was developed and the simultaneous determination of volatile and non-volatile organic acids was performed by our previously developed gas chromatographic technique .The extraction efficiency by newly developed batch-wise extraction with ether using celite and anhydrous sodium sulfate was discussed in comparison with ordinary methods such as continuous liquid extraction and repeating extraction by Mojonnier tube.Among others, continuous liquid extraction gave the best yield but this method was disadvantageously time consuming. Secondly, the repeating extraction by Mojonnier tube often produced emulsion to make extraction more difficult and gave the lowest yield of the three.The batch-wise extraction was most rapid and advantageous without emulsification and gave relatively high yields-formic 111, acetic 96, lactic 91, glycolic 60, oxalic 94, levulinic 92, benzoic 96, succinic 90, malic 98, pyroglutamic 59, and citric 66% as compared with the yield of a continuous liquid extraction.The application of batch-wise extraction followed by the treatment with cationic ion exchange resin to the gas chromatographic analysis permits the rapid and convenient determination of organic acids in soy sauce. This method was well applied to the quality evaluation of soy sauce as well as the determination of preservatives.

Biological Activity of the Constituents in Roots of Ezo-no-gishigishi (Rumex obtusifolius)

“…The effluent and H 2 0 wash (200 ml) were combined, concentrated in vacuo and made up to 10ml with MeOH. An aliquot of this MeOH solution was treated with excess etherial CH 2 N2 and analyzed by OLC using tridecane as an internal reference according to the method of Yamashita et al 7 ) with a slight modification. Detector: FID; carrier gas and flow rate: N 2 60 mljmin; operating conditions: temp.…”