The Detection of Agricultural Products and Food Using Terahertz Spectroscopy: A Review

Abstract

Demand for high levels of quality and safety in agricultural products and food requires appropriate analytical techniques for analysis both during and after production. Desirable techniques should be quick, easy, and safe to use; require minimal or no sample preparation; avoid sample destruction; and be accurate. In this study, the recent technical applications of terahertz spectroscopy to identify and classify, qualitatively and quantitatively analyze, evaluate, and safely control agricultural products and food are reviewed. The challenges and future outlook of terahertz spectroscopy are discussed.

Biomedical Applications of Terahertz Spectroscopy and Imaging

“…Excited by low-frequency molecular vibrations from intra/intermolecular domains connected by weak and conformation-related interactions, including hydrogen bonds, van der Waals, and nonbonded (hydrophobic) interactions, THz radiation has unique properties that are well suited to biomedical research (Box 1) [2]. According to the underlying detection and signal processing method, THz technologies can be classified into two categories: THz spectroscopy and THz imaging.…”

“…Due to the lack of effective sources and detectors, this 'THz gap' between electronics and photonics remained unexplored until advances in physics during the 1980s [1]. Specifically, the rapid development of ultrafast lasers contributed to the establishment of modern terahertz time-domain spectroscopy (THz-TDS), which has been widely utilized in applications such as astronomy, microelectronics, and biomedical science.Excited by low-frequency molecular vibrations from intra/intermolecular domains connected by weak and conformation-related interactions, including hydrogen bonds, van der Waals, and nonbonded (hydrophobic) interactions, THz radiation has unique properties that are well suited to biomedical research (Box 1) [2]. According to the underlying detection and signal processing method, THz technologies can be classified into two categories: THz spectroscopy and THz imaging.…”

Terahertz spectroscopy for bacterial detection: opportunities and challenges

“…Terahertz (THz) radiation generally refers to 0.1 to 10 THz of the electromagnetic spectrum, 3.33 to 333 cm -1 in wavenumbers or 30 to 3000 μm in wavelength (Qin et al 2013). Historically, this BTHz gap^between photonics and electronics remains unexplored, until the advent of efficient THz sources and detectors in the 1980s (Auston and Nuss 1988;Pickwell and Wallace 2006).…”

Applications of Terahertz Spectroscopy in the Field of Construction and Building Materials

“…In the last few years, the rapid development of novel THz sources and detectors has opened additional possibilities of creating innovative imaging and sensing systems, allowing in situ measurements and real-time analysis of different materials. Advances in the field have encouraged new research in various disciplines, including chemistry, pharmacy, physics, materials science, medicine, archaeology, and biology (2)(3)(4)(5)(6)(7)(8). Several advantages of THz systems over other technologies-for example, X-ray tomography, gamma rays, IR imaging, and millimeter-wave imaging (6,(9)(10)(11)-have attracted interest in industry and led to the development of compact, relatively inexpensive, and even portable THz systems, which are now commercially available on different markets.…”