Similarity recognition approach to identify zero-added MSG soy sauce using stable isotopes and amino acid profiles

Food Chem. 2024 Dec 15:461:140859. doi: 10.1016/j.foodchem.2024.140859. Epub 2024 Aug 12.

Abstract

Seasonings such as naturally fermented soy sauce without added monosodium glutamate (MSG), are currently a growth market in China. However, fraudulent and mislabeled zero-added MSG soy sauce may cause a risk of excessive MSG intake, increasing food safety issues for consumers. This study investigates stable carbon and nitrogen isotopes and 16 amino acids in typical Chinese in-market soy sauces and uses a similarity method to establish criteria to authenticate MSG addition claims. Results reveal most zero-added MSG soy sauces had lower δ13C values (-25.2 ‰ to -17.7 ‰) and glutamic acid concentrations (8.97 mg mL-1 to 34.76 mg mL-1), and higher δ15N values (-0.27 ‰ +0.95 ‰) and other amino acid concentrations than added-MSG labeled samples. A combined approach, using isotopes, amino acids, similarity coefficients and uncertainty values, was evaluated to rapidly and accurately identify zero-added MSG soy sauces from MSG containing counterparts.

Keywords: Amino acids; Authenticity; Carbon isotope; Fraudulent labeling; Monosodium glutamate; Nitrogen isotope; Similarity method; Soy sauce.

Publication types

  • Evaluation Study

MeSH terms

  • Amino Acids* / analysis
  • Amino Acids* / chemistry
  • Carbon Isotopes* / analysis
  • China
  • Food Additives / analysis
  • Glycine max / chemistry
  • Nitrogen Isotopes / analysis
  • Sodium Glutamate* / analysis
  • Sodium Glutamate* / chemistry
  • Soy Foods* / analysis

Substances

  • Amino Acids
  • Sodium Glutamate
  • Carbon Isotopes
  • Nitrogen Isotopes
  • Food Additives