Mid-Infrared Spectroscopy Coupled with Chemometrics: A Tool for the Analysis of Intact Food Systems and the Exploration of Their Molecular Structure-Quality Relationships - A Review

Public interest in food quality and methods of production has increased significantly in recent decades, due in part to changes in eating habits, consumer behavior, and the increased industrialization and globalization of food supply chains.1 Demand for high levels of quality and safety in food production obviously requires high standards in quality assurance and process control; satisfying this demand in turn requires appropriate analytical tools for food analysis both during and after production. Desirable features of such tools include speed, ease-of-use, minimal or no sample preparation, and the avoidance of sample destruction. These features are characteristic of a range of spectroscopic methods including the mid-infrared (MIR). While it is true that near-infrared (NIR) spectroscopy has achieved greater uptake by the food industry,2 reported applications of MIR in this sector have increased over the past decade or more.
Foods represent significant analytical challenges. They are highly complex, variable and can be found in a number of different physical states: these include solids, dilute solutions, emulsions, foams, highly visco-elastic forms, and glassy