Food Testing

Della Pelle, F., Scroccarello, A., Scarano, S., & Compagnone, D. (2019). Analytica Chimica Acta, 1051, 129-137.

Assessing the sugar content in foods is an important issue in food quality control, both during processing and in the final product. Sugar content is a key parameter in defining the sweetness and caloric intake of foods, and it also determines the category of raw materials in many products. Moreover, the production of many foods is sugar-driven (e.g., fermentation, ethanol production, sugar hydrolysis), and the amount of sugar becomes a critical factor in regulating and monitoring the process.

A simple colorimetric method based on the formation of silver nanoparticles (AgNPs) for the quantification of sugars (monosaccharides, polyols, and disaccharides) has been proposed. Sugars are able to form AgNPs, reducing Ag⁺ and stabilizing the suspension. Since the driving force is not only chemical reduction, the optimized method can measure both "reducing" and "non-reducing" sugars with similar reactivity. Detection is performed using the local surface plasmon resonance (LSPR) absorption band centered around ≈430 nm.

Kharbach, Mourad, et al. Foods 12.14 (2023): 2753.

The use of advanced spectroscopic techniques in food analysis is crucial for several reasons. First, techniques such as NIR, Raman, FTIR, and UV-Vis provide non-destructive and non-invasive methods for analyzing food samples, making them an ideal choice for large-scale analysis in the food industry without affecting the quality or safety of the sample. Second, they provide detailed information about the chemical composition and structure of foods, which can be used for classification and identification of different food types, detection of contaminants, and monitoring of food quality changes. Finally, the implementation of advanced chemometric tools can effectively analyze the complex spectral data for food quality assessment.

Spectroscopic Techniques in Food Analysis:

X-ray fluorescence-based methods: Energy-dispersive X-ray fluorescence (EDXRF) is a common technique used to determine the mineral content in food samples.

Hyperspectral and multispectral imaging: Hyperspectral and multispectral imaging combined with chemometric tools can be used for food adulteration detection, food component evaluation, food quality monitoring, and food classification.

Infrared spectroscopy: Infrared spectroscopy includes near-infrared (NIR) and mid-infrared (MIR) spectroscopy. Infrared spectroscopy and chemometrics can be used for quantitative and qualitative analysis of food components (such as carbohydrates, proteins, fats, and moisture content) and for the determination of functional groups, carbon, and nitrogen.

Raman spectroscopy: Raman spectroscopy is a vibrational spectroscopic technique based on the inelastic scattering of monochromatic light.

Nuclear magnetic resonance analysis: Nuclear magnetic resonance (NMR) is a spectroscopic technique used to determine the molecular structure and physical properties of matter, and it can be effectively used to ensure the quality of different food samples.

Ultraviolet-visible: UV-Vis spectroscopy is considered one of the most sensitive techniques for determining low-concentration components in food samples.

Fluorescence spectroscopy: Fluorescence spectroscopy has been used for the analysis of various elements in foods.

Domínguez, I., Frenich, A. G., & Romero-González, R. (2020). Analytical Methods, 12(9), 1148-1162.

Mass spectrometry (MS) is extensively utilized in the realm of food safety and has been fully integrated into everyday analysis and research facilities. In fact, MS is considered an essential tool for monitoring food contaminants. Continuous improvements in instrumentation have led to breakthroughs in analytical chemistry, which in turn have led to breakthroughs in food science. The progress of MS has enabled the development of reliable, reproducible, and powerful new methods, allowing for rapid and accurate screening analyses.

Mass Spectrometry Techniques Used in Food Safety Monitoring

The mass spectrometry techniques commonly used in food safety monitoring include matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), ion mobility spectrometry-mass spectrometry (IMS-MS), atmospheric pressure ionization mass spectrometry (AMS), gas chromatography-mass spectrometry (GC-MS), liquid chromatography-mass spectrometry (LC-MS), capillary electrophoresis-mass spectrometry (CE-MS), supercritical fluid chromatography-mass spectrometry (SFC-MS), and high-resolution mass spectrometry (HRMS).