A new approach to detecting sugar syrup addition to honey: Stable isotope analysis of hexamethylenetetramine synthesised from honey monosaccharides (fructose and glucose)

Strategies, techniques and applications for food authentication based on carbohydrates: A review

The increasing complexity and ubiquity of food processing and the emergence of fraudulent practices have made effective and reliable methods to authenticate food products of utmost importance. Carbohydrates, with various nutritional functions, are abundant in foods and can serve as potential markers for food authentication. However, the complex and diverse structures and properties of carbohydrates, especially polysaccharides, pose challenges. Nonetheless, significant progress has been made in this area. This paper provides an overview of the utilization of carbohydrates in food authentication since 2000, focusing on strategies involving carbohydrate-based markers, carbohydrate profiles, and carbohydrate-protein interaction-based assays. The analytical techniques, applications, challenges and limitations of these strategies are reviewed and discussed. The findings demonstrate that these strategies offer origin verification, quality assessment, adulteration detection, process control, and food species identification. Notably, oligosaccharide analysis has proven effective in food authentication and remains a promising marker, especially for analyzing intricate matrices. The advances in chromatography separation and mass spectrometry identification of isomers and trace amounts of these compounds have facilitated the discovery of such markers. In conclusion, carbohydrate analysis can play a crucial role in food authentication. Future research and development will make the authentication of carbohydrate-rich foods ever more accurate and efficient.

A new method to analysis synthetic acetic acid to vinegar: Hydrogen isotope ratio at the methyl site of acetic acid in vinegar by GC-IRMS

Acetic acid is the key organic substance used to verify the authenticity of vinegar. A new method for precisely determining acetic acid δDCH3 in vinegar via gas chromatography -pyrolytic-stable isotope ratio mass spectrometry (GC-P-IRMS) was established. The δDCH3 values were obtained via calibration with a series of standards. The optimised method demonstrated a repeatability standard deviation within 3 ‰. The standard deviation of accuracy of the new method compared with that of the SNIF-NMR method was within 2.6 ‰. The synthetic acetic acid δDCH3 values was -136.7 ‰ ± 29.6 ‰, and the δDCH3 value of acetic acid in vinegar was -414.9 ‰ ± 40.5 ‰, with significant isotopic distribution characteristics. This methodology serves as a supplementary method for measuring the δDCH3 value of acetic acid in vinegar. It has advantages over other methods in terms of time, sensitivity and operability. And provides a new idea for solving the problem of analyzing substances in the presence of exchangeable groups.

Mesophilic and thermophilic fermentation of activated sludge for volatile fatty acids production: focusing on anaerobic degradation of carbohydrate and protein

The volatile fatty acids (VFAs) productions, as well as particulate organics decomposition, soluble chemical oxygen demand (SCOD) yield, and the VFAs production pathways from mesophilic and thermophilic anaerobic fermentation in waste activated sludge were investigated. Batch experiments showed that the decomposition rate of volatile suspended solids (VSS), particulate carbohydrate (P-C) and particulate protein (P-P) followed the first-order kinetic model at different temperatures. However, the intermediates, accumulated in the process of protein or carbohydrate digestion had a more significant inhibitory effect on the production of VFAs during the mesophilic anaerobic acidification process. The production of VFAs by thermophilic anaerobic fermentation is 2086.05 mg COD/L, which is about twice the production under mesophilic conditions. Among them, the concentration and proportion of high molecular weight organic acids such as isobutyric acid (320.29 mgCOD/L) and isovaleric acid (745.75 mgCOD/L) are relatively high. Then 13C stable isotope labelling experiment demonstrated that, the decomposition of carbohydrates yields 77% acetic acid and 86% butyric acid, while protein breakdown produces 85% propionic acid and 99% valeric acid. This confirms that carbohydrates are more favourable for the formation of even-carbon organic acids, while proteins tend to yield odd-carbon organic acids. Additionally, this helps refine the pathway for valeric acid formation during anaerobic acidogenesis.