Establishment of a method for determining the origin of glutamic acid in processed food based on carbon and nitrogen stable isotope ratios.

We developed a discriminant method based on the stable isotope ratio of carbon and nitrogen (δC and δN) to evaluate whether monosodium glutamate (MSG) is used in processed food samples. δC measurements were performed by elemental analyzer/isotope-ratio mass spectrometry (EA/IRMS) for on glutamic acid isolated from samples at high purity, and δN measurements were performed by gas chromatography/combustion/IRMS (GC/C/IRMS) following the purification and derivatization steps. By applying these methods, the δC and δN values for glutamic acid present in a wide variety of processed foods were obtained.

Distinguishing glutamic acid in foodstuffs and monosodium glutamate used as seasoning by stable carbon and nitrogen isotope ratios.

Recently, a number of consumers have begun to appreciate more natural ingredients and have become less willing to consume monosodium glutamate (MSG) as a seasoning. By measuring stable isotope ratios (δC and δN) of glutamic acid contained in foodstuffs and MSG used as seasoning, we attempted to distinguish between both using elemental analyzer-isotope-ratio mass spectrometry (EA/IRMS) and gas chromatography/combustion/IRMS (GC/C/IRMS). As a result, seasoning MSG was observed to have a lower δN value than glutamic acid in foodstuffs.

Development of a Method to Isolate Glutamic Acid from Foodstuffs for a Precise Determination of Their Stable Carbon Isotope Ratio.

Recent growing health awareness is leading to increasingly conscious decisions by consumers regarding the production and traceability of food. Stable isotopic compositions provide useful information for tracing the origin of foodstuffs and processes of food production. Plants exhibit different ratios of stable carbon isotopes (δC) because they utilized different photosynthetic (carbon fixation) pathways and grow in various environments.

[Validation of Simultaneous Analytical Method of Veterinary Drugs in Foods Using New Automatic Pretreatment Equipment].

New automatic pretreatment equipment (FASVED; Food Automatic Analytical Systems for Veterinary Drugs) was developed. FASVED consists of ten main units: reagent dispenser, homogenizer, transfer hand, lid opening/closing device, centrifugal separator, pipette, shaker, column purification device, centrifugal evaporator and cooling device, and it is capable of freely combining operations by these units. A validation study was performed on two methods for determination of 178 veterinary drugs in livestock products, swine muscle, egg and shrimp, according to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan.