- 一般社団法人 日本調理科学会
- 日本調理科学会誌 (ISSN:13411535)
- vol.39, no.6, pp.357-361, 2006-12-20 (Released:2013-04-26)
The oxalate in spinach leaves is believed to be the substance responsible for the unpleasant taste. We have defined the unpleasant sensation remaining after tasting an oxalate solution as the oxalate taste. The water used for boiling spinach had a strong oxalate taste, while the aqueous extract from spinach leaves or the raw spinach leaves themselves had only a slight oxalate taste. The concentration of oxalate found in the water used for boiling spinach was much lower than that in aqueous extract and raw leaves. These results could be interpreted by models that simulated the irritating crystal formation in the mouth between calcium ions from the saliva and oxalate ions from the spinach leaves. The aqueous extract of spinach leaves was separated into water-and ethanol-eluted fractions by the solid-phase extraction technique. The oxalate ions and oxalate taste were recovered in the former fraction, while the bitterness was recovered in the later, implying that the bitter compound (s) in spinach was not oxalic acid.