A Review on the Applications of Portable Near-Infrared Spectrometers in the Agro-Food Industry

Abstract

Industry has created the need for a cost-effective and nondestructive quality-control analysis system. This requirement has increased interest in near-infrared (NIR) spectroscopy, leading to the development and marketing of handheld devices that enable new applications that can be implemented in situ. Portable NIR spectrometers are powerful instruments offering several advantages for nondestructive, online, or in situ analysis: small size, low cost, robustness, simplicity of analysis, sample user interface, portability, and ergonomic design. Several studies of on-site NIR applications are presented: 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; and soil analysis. Chemometrics is an essential part of NIR spectroscopy manipulation because wavelength-dependent scattering effects, instrumental noise, ambient effects, and other sources of variability may complicate the spectra. As a consequence, it is difficult to assign specific absorption bands to specific functional groups. To achieve useful and meaningful results, multivariate statistical techniques (essentially involving regression techniques coupled with spectral preprocessing) are therefore required to extract the information hidden in the spectra. This work reviews the evolution of the use of portable near-infrared spectrometers in the agro-food industry.

Near‐Infrared Spectroscopy for Determination of the Biochemical Methane Potential: State of the Art

“…Near infrared spectroscopy (NIRS) is a useful method for the quantitative determination of compounds of interest in many industries, such as the pharmaceutical, food and agricultural industries, as reviewed by De Beer et al 10, dos Santos et al 11, and Dale et al 12, respectively. According to the American Society of Testing and Materials, near‐infrared (NIR) radiation lies in the region of the electromagnetic spectrum between 780 and 2526 nm, although the NIR region is often described in wavenumbers rather than wavelengths, as the former unit is proportional to the energy of vibration when infrared light interacts with molecular bonds 13.…”

Feasibility of Nondestructive Sugar Content Analysis of Korean Pears by Using Near‐infrared Diffuse‐reflectance Spectroscopy

“…The demand for a reliable nondestructive quality analysis methodology has grown in agricultural food industry because of the continuous improvement in standards for food quality, safety, diversity, and so on . To meet this need, the analysis of chemical and physical properties of agro‐food products should be performed frequently during the growth, storage, and circulation stages.…”

“…Under this circumstance, optical spectroscopic techniques can be considered as alternative fast and reliable nondestructive methodologies. Among the various optical spectroscopic techniques, near‐infrared (NIR) spectroscopy has proven to be the most promising technique for practical nondestructive agro‐food analysis . For this purpose, the NIR spectroscopy, based on absorption spectroscopy, utilizes the NIR light–matter interactions inside the products.…”

“…In this work, we have investigated the feasibility of using NIR diffuse‐reflectance spectroscopy in combination with multivariate calibration as a nondestructive sugar content analysis methodology for Korean pears. For several fruits such as mandarin, tomato, orange, apple, pear, plum, strawberry, blueberry, apricot, mango, and nectarine, the applications of NIR spectroscopy have been reported so far . The physical and chemical properties of fruits such as firmness, soluble solids content (SSC), acidity, and so on, could be analyzed from the NIR spectra.…”

“…The demand for a reliable nondestructive quality analysis methodology has grown in agricultural food industry because of the continuous improvement in standards for food quality, safety, diversity, and so on. [1][2][3] To meet this need, the analysis of chemical and physical properties of agro-food products should be performed frequently during the growth, storage, and circulation stages. However, most of the conventional methods for the agro-food analysis can deal with only a few samples from many products through destructive sample preparation and time-consuming analysis process.…”