Benzoic acid (BA) is typically found in natural food; therefore, naturally occurring BA must be distinguished from added BA preservatives. In this study, we investigated BA levels in 100 samples of fruit products and their fresh fruits as raw materials using dialysis and steam distillation approaches. BA was detected in the range (minimum-maximum) of 2.
View Article and Find Full Text PDFIn this study, we simultaneously determined three antioxidants, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tert-butylhydroquinone (TBHQ), using HPLC equipped both with a photodiode array detector and a fluorescence detector in 25 minutes per sample. Due to the combined use of the two detectors, we could achieve improved target selectivity. Further, quantification at the specific wavelengths for each target substance particularly increased BHT detection sensitivity.
View Article and Find Full Text PDFWe studied the efficiency of methylation for analyzing brominated vegetable oil (BVO). In this report, we investigated whether H-NMR is an applicable method for assessing the efficiency of methylation to analyze BVO. H-NMR sufficiently calculated the efficiency of methylation using each integral and the numbers of protons derived from the methyl group, which is characteristic in products, and the methine group, which is characteristic in unreacted substances.
View Article and Find Full Text PDFThe Japanese official analysis method for determination of nitrate ions in food products used as food additives is associated with various challenges. In some kinds of cheese, the extract becomes suspended. The volume of extracted solution is often not accurate owing to the presence of residues in the solution.
View Article and Find Full Text PDFShokuhin Eiseigaku Zasshi
February 2020
The three sweeteners, aspartame, acesulfame potassium, and sucralose, in chewing gum were determined by using dialysis and direct extraction methods. The results revealed that the previously reported dialysis method tended to show poor extraction of aspartame in comparison with the direct-extraction method. The direct extraction also caused operational problems, such as the gum base adhering to the instruments.
View Article and Find Full Text PDFA quantitative determination method of erythritol, maltitol, lactitol and trehalose in foods by HPLC, and confirmation method by LC-MS/MS were developed. HPLC analysis was performed on a separation column packed with amino group-binding polymer with acetonitrile-water (80 : 20) as the mobile phase. The column was operated at room temperature, and the three sugar alcohols and trehalose were quantified.
View Article and Find Full Text PDFA quantitative analysis by HPLC of α-glucosyltransferase-treated stevia in foods was considered. This analysis is the way which hydrolyzed α-glucosyltransferase-treated stevia in the stevioside (SS) and the rebaudioside A (RS) using a glucoamylase. Recovery (%) of α-glucosyltransferase-treated stevia, spiked at 200 mg/kg in various foods, were more than 80% and the relative standard deviations were less than 5.
View Article and Find Full Text PDFAnalysis of L-ascorbic acid (AsA) and erythorbic acid (ErA) in foods is generally performed by HPLC measurement after extraction with metaphosphoric acid solution. But this method can not always measure the concentrations of AsA and ErA precisely due to the presence of interfering compounds, and the reproducibility of retention time is poor. We considered that quantitative analysis by HPLC and confirmation by LC-MS/MS using an identical extraction solvent might be an effective approach for AsA and ErA analysis.
View Article and Find Full Text PDFTwo yellow dyes, together with tartrazine (Y4), were found in cucumbers pickled in soy sauce, for which the use of tartrazine is permitted, by TLC, LC-DAD, and LC-MS. The retention times on LC chromatograms and the maximum absorbance wavelengths measured by LC-DAD of the two dyes were different from those of tartrazine. Mass spectra of the dyes indicated that these dyes lacked one sulfonyl group of tartrazine.
View Article and Find Full Text PDFShokuhin Eiseigaku Zasshi
March 2017
A rapid dialysis method for the analysis of stevioside (SS) and rebaudioside A (RS) in foods was developed. Minced samples (10 g) were packed into 30 cm net length dialysis tubing with 30% methanol to increase the dialysis efficiency. The dialysis tubing was put in a 100 mL centrifuge tube, and the total fluid volume was made up to 100 mL with 30% methanol.
View Article and Find Full Text PDFShokuhin Eiseigaku Zasshi
August 2008
Interactions between grapefruit juice and medications have long been recognized. In recent years, several furanocoumarins (FCs) that inhibit P450 activity in intestinal microsomes have been isolated from grapefruit juice. FCs, i.
View Article and Find Full Text PDFShokuhin Eiseigaku Zasshi
February 2008
Simultaneous determination of three artificial sweeteners, neotame (NE), alitame (AL) and aspartame (APM) in various foods by high-performance liquid chromatography (HPLC) was developed. Chopped or homogenized samples were packed into cellulose tubing with 0.01 mol/L hydrochloric acid containing 10% sodium chloride, and dialyzed against 0.
View Article and Find Full Text PDFShokuhin Eiseigaku Zasshi
April 2006
A survey of vitamin K contents was carried out on 41 aojiru products and 10 vegetable juice products that were purchased from local markets. Aojiru is a health food made from green vegetables such as kale, ashitaba, mulberry leaf, barley grass and the like. The products are usually provided in various forms, such as frozen, powder and tablet.
View Article and Find Full Text PDFA method for the simultaneous determination of stevioside (Stev), rebaudioside A (RebA) and glycyrrhizic acid (GA) in foods was developed. These sweeteners were extracted from foods, except for dried fishes and shellfishes, by dialysis against Tris-HCl buffer (pH 9.0).
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