In the evolving field of cannabis research, scholars are exploring innovative methods to quantify cannabinoids rapidly and non-destructively. This study evaluates the effectiveness of a hand-held near-infrared (NIR) device for quantifying total cannabidiol (total CBD), total delta-9-tetrahydrocannabinol (total THC), and total cannabigerol (total CBG) in whole cannabis inflorescences. Employing pre-processing techniques, including standard normal variate (SNV) and Savitzky–Golay (SG) smoothing, we aim to optimize the portable NIR technology for rapid and non-destructive cannabinoid analysis. A partial least-squares regression (PLSR) model was utilized to predict cannabinoid concentration based on NIR spectra. The results indicated that SNV pre-processing exhibited superior performance in predicting total CBD concentration, yielding the lowest root mean square error of prediction (RMSEP) of 2.228 and the highest coefficient of determination for prediction (R2P) of 0.792. The ratio of performance to deviation (RPD) for total CBD was highest (2.195) with SNV. In contrast, raw data exhibited the least accurate predictions for total THC, with an R2P of 0.812, an RPD of 2.306, and an RMSEP of 1.651. Notably, total CBG prediction showed unique characteristics, with raw data yielding the highest R2P of 0.806. SNV pre-processing emerges as a robust method for precise total CBD quantification, offering valuable insights into the optimization of a hand-held NIR device for the rapid and non-destructive analysis of cannabinoid in whole inflorescence samples. These findings contribute to ongoing efforts in developing portable and efficient technologies for cannabinoid analysis, addressing the increasing demand for quick and accurate assessment methods in cannabis cultivation, pharmaceuticals, and regulatory compliance.
This study compared the effects of storage time and electron beam (EB) irradiation on microbial counts and chemical stability of dried flowers from two hemp cultivars over 12 weeks. Cannabinoid and terpene content, as well as microbial load, were evaluated at 0, 4, 8, and 12 weeks in EB-irradiated and non-irradiated samples. Microbial count in non-irradiated flowers reached up to 4.1 × 106 colony-forming units (CFU)/g; EB irradiation reduced these levels to <102 CFU/g. Cannabinoid contents were unaffected by EB irradiation and remained stable throughout storage. Terpene content decreased by 8.4% immediately after irradiation, followed by further declines during storage, reaching 22.3% and 24.0% average losses in non-irradiated and EB-irradiated samples after 12 weeks, respectively. EB irradiation caused a higher decrease in monoterpenes (10.8%) than in sesquiterpenes (2.5%). These findings confirm that EB irradiation is an effective sterilization method for hemp flowers that preserves chemical integrity. Storage time also significantly reduced microbial loads in non-irradiated samples; TAMC in cultivar B declined from 20,728 CFU/g to <LOQ (100 CFU/g), and TYMC decreased 16-fold. Cultivar A exhibited a sharp initial TAMC reduction followed by fluctuations and TYMC levels that were 7-fold lower by Week 12, reflecting natural microbial decay during hemp flower storage.