Near-Infrared Spectroscopy For Food Quality

Santos et al. (2013) reviewed the the use of portable near-infrared spectrometers in the agro-food industry. We will explore the evolution of NIR spectrometers for food quality in this article.

In the food industry there is a need for cost effective and non-destructive food quality-control analysis systems. As a result, there has been a growing interest in near-infrared (NIR) spectroscopy and the development of handheld devices that can be used in situ. Portable NIR spectrometers are powerful instruments offering several advantages for nondestructive, online, or in situ analysis. In particular, there small size, low cost, robustness, simplicity of analysis, sample user interface, portability, and ergonomic design are all favoured characteristics.

Check out this YouTube video to get a better understanding of how to measure food quality using spectroscopy.

What is Near Infrared Spectroscopy

Near-infrared radiation ranges from 780 to 2500 nm of the electromagnetic spectrum. The measurement of the interaction between this radiation and a sample results in a spectrum characterized by weak absorption bands that are broad and superimposed. The fundamentals of vibrational spectroscopy provide the theory necessary to interpret this characteristic spectrum.

The typically observed bands in NIR spectra correspond to bonds containing the hydrogen atom, such as C–H, N–H,O–H, and S–H, that are frequently present in most organic and some inorganic compounds. A NIR spectrum is essentially composed of overtones and combination bands containing useful chemical and even physical information.

Chemometrics, described as the application of mathematics, multivariate statistics, and computer science, plays a fundamental role in the extraction of all important relevant information hidden in NIR spectra.

NIR Applications

Santos et al. (2013) provided an overview of the applications of portable NIR spectrometers in the agro-food industry. However, it is important to note, many of these studies were performed under laboratory studies, as opposed to under real production conditions. The NIR applications for the agri-food industry include:

• Characterization of internal and external parameters of fruits and vegetables

• Conservation state and fat content of meat and fish

• Distinguishing among and quality evaluation of beverages and dairy products

• Protein content of cereals

• Evaluation of grape ripeness in vineyards;

• Soil analysis

The study concluded that portable NIR spectroscopy is useful in a wide number of applications for the agro-food indsutry. The studies reviewed highlighted the advantages and drawbacks of NIR spectroscopy (Table 1).

Table 1: Advantages and Drawbacks of NIR Spectroscopy in the Food System

You can find the full article by Santos et al. (2013) here.