Emerging thermal imaging techniques for seed quality evaluation: Principles and applications

Abstract

Due to the massive progress occurred in the past few decades in imaging, electronics and computer science, infrared thermal imaging technique has witnessed numerous technological advancement and smart applications in non-destructive testing and quality monitoring of different agro-food produces. Thermal imaging offers a potential non-contact imaging modality for the determination of various quality traits based on the infrared radiation emitted from target foods. The technique has been moved from just an exploration method in engineering and astronomy into an effective tool in many fields for forming unambiguous images called thermograms eventuated from the temperature and thermal properties of the target objects. It depends principally on converting the invisible infrared radiation emitted by the objects into visible two-dimensional temperature data without making a direct contact with the examined objects. This method has been widely used for different applications in agriculture and food science and technology with special applications in seed quality assessment. This article provides an overview of thermal imaging theory, briefly describes the fundamentals of the system and explores the recent advances and research works conducted in quality evaluation of different sorts of seeds. The article comprehensively reviewed research efforts of using thermal imaging systems in seed applications including estimation of seed viability, detection of fungal growth and insect infections, detection of seed damage and impurities, seed classification and variety identification.

A Review of Imaging and Sensing Technologies for Field Phenotyping

“…Thermal imaging has been used by many researchers in agro-food industries, horticultural products, detection of bruises in fruits (Zeng, Miao, Ubaid, Gao, Zhuang, 2020;Kuzy, Jiang, Li, 2018), detection of spoilage by a microbial activity (Chelladurai, Jayas, White, 2010;ElMasry et al, 2020), content volatile compounds (Ding, Dong, Jiao, Zheng, 2017;Dong, Jiao, Li, Zhao, 2019), and food quality evaluation (Ghosh, Rana, Nayak, Pradhan, 2016;Sanchez, Hashim, Shamsudin, Nor, 2020). Several typical sensors are listed in Table 3.…”

Non-Destructive Identification of Naturally Aged Alfalfa Seeds via Multispectral Imaging Analysis

“…The traditional inspection of aged seeds is based on the indicators of color and aroma, germination test, tetrazole staining [ 4 , 5 , 6 ], etc. However, all these methods are time-consuming, and the seed cannot maintain its original state, including when being discarded [ 7 , 8 ]. In recent years, spectroscopic techniques have shown great potential in detecting the seeds.…”

Statistical methods for the analysis of thermal images obtained from corn seeds

“…Typically, the physical characteristics are evaluated considering the size, shape, color, freshness and finally without visual defects [6]. These 172 173 174 171 172 171 173 173 175 172 173 174 171 172 171 173 173 172 173 174 174 172 172 171 171 173 175 173 172 171 171 172 171 173 173 173 algorithms are used by various materials characterization techniques in many knowledge areas of research and industry such as infrared (IR) and charge-coupled device (CCD) cameras, IR, Raman spectroscopy, Fourier transformnear-infrared (FT-NIR), photoacoustic spectroscopy (PAS), among others [8][9][10] [7][8][9] and also with microscopies such as scanning electron microscopy (SEM), photoacoustic microscopy (PAM), image mapping spectrometer (IMS), etc. [10][11][12].…”