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A novel method was developed for quantification of bisacuron (BC) and dehydrozingerone (DZ), the functional component of turmeric (Curcuma longa.L) -containing foods, using a relative molar sensitivity (RMS) method based on the combination of HPLC-UV and ¹ H-NMR. The RMSs of BC and DZ using 4-hydroxybenzoic acid ethyl ester (HBE) as the internal standard were calculated to 1.66 and 2.55, respectively. Analysis of fourteen beverage products showed the high correlations between the concentrations of BC and DZ quantified by the RMS method and those quantified by absolute calibration curve method. A collaborative study was conducted by four laboratories on one beverage and one tablet products. The repeatable relative standard deviation (RSDr) of intra-laboratories ranged from 0.7 to 1.7％, and the reproducible relative standard deviation (RSDR) of interlaboratories ranged from 2.0 to 7.3％. The RMS method enabled the quantification of analytes for which difficultly obtain standard materials such as BC and DZ, using an internal standard for which obtain routinely readily available. This RMS method is expected to be applied to quality control for food products containing turmeric. [ABSTRACT FROM AUTHOR]

A novel method was developed for quantification of bisacuron (BC) and dehydrozingerone (DZ), the functional component of turmeric (Curcuma longa.L)-containing foods, using a relative molar sensitivity (RMS) method based on the combination of HPLC-UV and 1 H-NMR. The RMSs of BC and DZ using 4-hydroxybenzoic acid ethyl ester (HBE) as the internal standard were calculated to 1.66 and 2.55, respectively. Analysis of fourteen beverage products showed the high correlations between the concentrations of BC and DZ quantified by the RMS method and those quantified by absolute calibration curve method. A collaborative study was conducted by four laboratories on one beverage and one tablet products. The repeatable relative standard deviation (RSD r ) of intra-laboratories ranged from 0.7 to 1.7%, and the reproducible relative standard deviation (RSD R ) of inter-laboratories ranged from 2.0 to 7.3%. The RMS method enabled the quantification of analytes for which difficultly obtain standard materials such as BC and DZ, using an internal standard for which obtain routinely readily available. This RMS method is expected to be applied to quality control for food products containing turmeric.

In order to validate an HPLC-UV method for the determination of free asparagine, which is a precursor of acrylamide, in grains using dansyl derivatization, an inter-laboratory study was performed in 9 laboratories using 5 kinds of grains (non-glutinous brown rice flour, corn flour, strong flour, whole wheat flour, and whole rye flour), which naturally contain free asparagine. The relative standard deviations for repeatability (RSDr) and reproducibility (RSDr) were in the ranges of 0.5-2.2 and 2.3-5.9%, respectively. The HorRat values ranged from 0.4 to 0.6. These results were within the range of the procedural manual of the Codex Alimentarius Commission, and therefore the method is effective.

Amnesic shellfish poison (ASP) is regarded as one of the shellfish poison groups in the EU, though it is not subject to regulation in Japan. We have developed an analytical method of ASP based on the report by Hatfield et al. and other methods. Validation studies were carried out with certified compositional reference materials (CRM). Performance parameters were estimated based on 17 analytical results. The estimate of trueness was 97.5%, and the estimate of intralaboratory reproducibility (RSD) was 1.5%. The HorRat(r) value was 0.16. These performance parameters meet the criteria in the Codex Procedural Manual. Furthermore, internal quality control was performed by using the CRM. The action limits were set based on the performance parameters of the method. Most of the results of the internal quality control were within the action limit range. The results confirmed that the quality of the analyses was well maintained. The purpose of the analytical method is to confirm that the level of ASP in scallop is less than 4.6 mg/kg. The applicability of the analytical method to scallops was confirmed by using spiked samples.

A novel analytical method was developed for the determination of free asparagine (Asn), which is a precursor of acrylamide, in grains. Asn was extracted from a sample with 5% (w/v) aqueous trichloroacetic acid solution, and the crude extract was cleaned up using a reversed-phase solid-phase cartridge. The cleaned extract was derivatized with dansyl chloride and analyzed by HPLC-UV. HPLC separation was performed by gradient elution on a ODS column using 0.01 mol/L ammonium acetate and acetonitrile mixture as the mobile phase. The calibration curve was linear in the range of 0.5-100 μg/mL. The mean recoveries from potato starch, non-glutinous rice flour and whole wheat flour ranged from 97.7 to 102.6%, the repeatability (RSDs) ranged from 0.8 to 2.0%, and the within-laboratory reproducibility (RSDwr) ranged from 1.4 to 6.2%. Limits of quantitation (LOQs) were 13 mg/kg for potato starch and 4 mg/kg for non-glutinous rice flour. The quantitative values obtained for about 15 kinds of grains using this developed method were approximately equal to those obtained with an automatic amino acid analyzer.