Yukihiro Goda

Acylated anthocyanins from red radish (Raphanus sativus L.)

Twelve acylated anthocyanins were isolated from the red radish (Raphanus sativus L.) and their structures were determined by spectroscopic analyses. Six of these were identified as pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-beta-D-glucopyranosyl]-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-caffeoyl-2-O-(6-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-p-coumaroyl-2-O-(6-(E)-caffeoyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-(6-(E)-caffeoyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), pelargonidin 3-O-[6-O-(E)-p-coumaroyl-2-O-(6-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside), and pelargonidin 3-O-[6-O-(E)-feruloyl-2-O-(2-(E)-feruloyl-beta-D-glucopyranosyl)-(1-->2)-beta-D-glucopyranoside]-5-O-(beta-D-glucopyranoside).

Isolation, identification and determination of a magenta subsidiary colour in Food Blue No. 1 (Brilliant Blue FCF)

A magenta subsidiary colour was isolated from commercial Food Blue No. 1 (B-1; Brilliant Blue FCF). The absorption maximum for this subsidiary colour at 580 nm is outside of the range of 614-628 nm found for other subsidiary colours and m,m-B-1. On the basis of MS and NMR analyses, the structure of the subsidiary colour was elucidated as the disodium salt of 2-[[4-[N-ethyl-N-(3-sulphophenylmethyl)amino]phenyl][4-oxo- 2,5-cyclohexadienylidene]methyl]benzenesulphonic acid. HPLC analyses revealed that 24 batches of commercial Food Blue No. 1 (three manufacturers) contain 0.1-0.8% (average: 0.5%) of the magenta subsidiary colour.

Determination of Chlorides and Sulfates in Food Colors by Ion Chromatography

A non-suppressed ion chromatographic (IC) method with monitoring of conductivity is described for the determination of soluble chlorides and sulfates in food colors and their aluminum lakes (Al-L).Each color dissolved in water was ion-chromatographed directly with eluent containing phthalic acid (2.5mM) and tris (hydroxymethyl) aminomethane (2.4mM). The recoveries of sodium chloride (0.474μg) and sodium salfate (0.562μg) added to food color standards (each 20μg) were in the range of 98.4-103.2% and 100.5-103.7%, respectively.The solution of soluble chlorides and sulfates from each food color Al-L was prepared by a modification of the standard procedure specified in the Japanese Standards of Food Additives 5th ed. (JSFA-V) and applied to IC under the same conditions as used for food colors. The recoveries of sodium chloride (0.292mg) and sodium salfate (0.296mg) added to commercially available food color Al-L (50mg) were in the range of 86.0-96.3% and 71.0-88.2%, respectively.Compared with the standard method specified in JSFA-V, the IC method showed smaller standard deviations and better recoveries. In addition, the IC method is a simple and simultaneous analysis for soluble chlorides and sulfates. Therefore, it appears that the IC method is suitable as a substitute for the standard method, which is time-consuming and requires considerable care in the analysis.