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Biomedical subjects

Y Uematsu

Publications and source records attributed to Y Uematsu.

95 records · Page 6Linked to original sources
PubMedDate not supplied

Spectrophotometric determination of saponin in Yucca extract used as food additive.

A spectrophotometric method was developed for the determination of saponin in Yucca extract or its preparation for food additive use. A saponin fraction of Yucca extract was prepared by column chromatography with porous polymer, and hydrolyzed with a 2 mol/L mixture of hydrochloric acid-ethanol (1 + 1) to generate sapogenin. Sapogenin amounts were determined by measuring absorbance at 430 nm, based on the color reactions with anisaldehyde, sulfuric acid, and ethyl acetate. Recoveries from Yucca extracts were 91.5-95.1%, and the detection limit was 10 microg/kg. Commercial Yucca extracts for food additive use were composed of 5.6-6.4% (w/w) saponin, making it a minor component.

Food Additives↗
PubMedDate not supplied

Determination of sucrose esters of fatty acids in food additive premixes by gas chromatography and confirmation of identity by gas chromatography/mass spectrometry.

A gas chromatographic (GC) method was developed for the determination of sucrose monoesters of fatty acids (mono-SuE) and sucrose acetate isobutyrate (SAIB) in food additive premixes. Mono-SuE and SAIB fractions were prepared by column chromatography with either a C8 or a silica gel solid-phase extraction column. The mono-SuE fraction was acetylated and applied to a wide-bore GC column (0.53 mm x 15 m) by splitless injection for determination. The SAIB fraction was applied to the GC column without derivatization. Gas chromatography/mass spectrometry was used to confirm the identity of GC peaks. The detection limits for mono-SuE and SAIB were 0.005 and 0.01%, respectively. Mono-SuE (C12, C14, C16, C18, and C18:1) and SAIB were found in commercial food additive premixes and some foods.

Chromatography, Gas↗