Food Metabolome Repository

Food Metabolome Repository is a repository for food metabolome data obtained using liquid chromatography-mass spectrometry (LC-MS).

The Aim

Food Metabolome Repository is constructed as a reference of unknown peaks for discovering unutilized chemicals from a huge number of peaks which is detectable but hardly annotatable in samples surrounding us, such as foods, environments, wastes, and so on. A comparable metabolome dataset with a wide variety of samples obtained using high-resolution MS gives us a hint to prioritize the unknown peaks for further detailed investigation and identification spending large costs.

Feature 1: Visualization of Compound Diversity

A two-dimensional mass chromatogram shows an overview of detected food metabolites.

MassChroBook

2D images of all foods are available in PowerPoint files.

Feature 2: Precursor Search

The sample-specific localization of the unknown peaks you focusing on is available using precursor search function.

This information should help you for prioritizing the unknown peaks for further investigation.

Feature 3: Mass Spectrum Search

Information about sample-specific localization of the MS spectrum is useful for structural prediction of the unknown peak. It is also helpful for distinguishing constitutional isomers.
MS3 spectra, available in this repository, are powerful for prediction of aglycones and their glycosides.

Feature 4: Netural Loss Mass Search

The information is also helpful for structural prediction of the unknown peaks.

Target Foods

Approximately 2000 items of foods are listed in the Standard Tables of Food Composition In Japan - 2015 - (Seventh Revised Version). Among them, 222 representative items were selected as the initial target of this repository.

is available here.

Analytical Methods

All foods were analyzed by an uniform method which is suitable for detecting metabolites with molecular weights ranged from 100 to 1500 Da and with medium polarity. Volatiles, highly-hydrophobic compounds and highly-hydrophilic compounds will not be detected in the condition. The metabolites were extracted in methanol, separated by a reversed-phase liquid chromatography using C18 column and water-acetonitrile solvents, and detected using a high-resolution mass spectrometry in positive and negative modes in electrosplay ionization. MS2 and MS3 spectra were obtained for compounds detected with higher intensities.

Data Analysis

The results of compound database search using the measured accurate mass value were attached to the peak information. Also, the predicted flavonoid aglycones which were obtained using measured MS2/MS3 spectra and the FlavonoidSearch system (Akimoto et al., 2017) were attached.

Caution for compound annotations

The compound information provided in this repository is NOT the one that qualified and quantified by authentic methods.

It is not guaranteed that the compounds listed for the peak is present in the food.
It is not guaranteed that the compounds not listed for the peak is absent in the food.

We just provide the candidate compounds that were found in the compound database searching based on the mass value similarities to the detected peaks. Therefore, the results contain many false positives and false negatives. Please use the data with appropriate knowledge for untargeted metabolome analyses using LC-MS.