Near-Infrared Transmittance Spectral Imaging for Nondestructive Measurement of Internal Disorder in Korean Ginseng

Authors: KANDPAL, LALIT - Chungnam National University; LEE, JAYOUNG - Chungnam National University; BAE, HYUNGJIN - Chungnam National University; Kim, Moon; BAEK, INSUCK - Orise Fellow; CHO, BYOUNG-KWAN - Chungnam National University

Submitted to: Sensors
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/2/2020
Publication Date: 1/3/2020
Citation: Kandpal, L., Lee, J., Bae, H., Kim, M.S., Baek, I., Cho, B. 2020. Near-Infrared Transmittance Spectral Imaging for Nondestructive Measurement of Internal Disorder in Korean Ginseng. Sensors. 20:273. https://doi.org/10.3390/s20010273.
DOI: https://doi.org/10.3390/s20010273

Interpretive Summary: Quality grading of ginseng root (Panax ginseng) includes assessment for inner whitening, a major internal disorder. Conventional assessment methods are time-consuming and sometimes inaccurate for detection of inner whitening. This study developed a new method to evaluate ginseng samples using transmittance spectral imaging and demonstrated that the method could effectively detect inner whiting using only a few different wavebands of light. This method provides a rapid and cost-effective non-destructive method to evaluate internal quality of ginseng that could be incorporated into online real-time inspection system to help producers and processors ensure effective automated sorting and distribution of ginseng for product quality and safety.

Technical Abstract: Grading of ginseng (Panax ginseng) including evaluation evaluation of internal quality attributes is essential for quality control. Assessment for inner whitening, a major internal disorder, must be conducted when identifying high quality ginseng. Conventional methods for detecting inner whitening use manual inspection, which is time-consuming and inaccurate. This study developed an internal quality measurement technique using transmittance spectral imaging to evaluate inner whitening in ginseng samples. Multivariate analysis was used on ginseng hypercube data to evaluate the technique. The transmittance spectra and spectral images of ginseng samples exhibiting inner whitening showed weak intensity characteristics compared to normal ginseng, owing to the presence of whitish internal tissues of higher optical density. Based on the multivariate analysis, even a simple waveband ratio image has the great potential to quickly detect inner whitening in ginseng samples, since these ratio images showed a significant difference between whitened and non-whitened regions. It is possible to develop an efficient spectral imaging system for real-time detection of inner whitening in ginseng, using minimal wavebands. This novel strategy for rapid, cost-effective, non-destructive detection of ginseng inner quality can be a key component for the automation of ginseng grading.