Optimization of extraction using surface response methodology and quantification of cannabinoids in female inflorescences of marijuana (Cannabis sativa L.) at three altitudinal floors of Peru

Abstract The aim of this study was to extract and quantify cannabinoids from female inflorescences of Cannabis sativa L. from three altitudinal floors of Peru, by optimizing the amplitude, time, and methanol concentration in the ultrasound-assisted extraction required to maximize cannabidiol (CBD), delta-9-tetrahydrocannabinol (Δ9-THC) content, and yields. Optimal extraction conditions were determined by response surface and the central composite design was used. The quadratic model was adequate for yield, Δ9-THC, and CBD with R 2 values of 0.998, 0.985, and 0.991 respectively. Optimal conditions were 99% radiation amplitude, 20 min extraction time, and 96% ethanol concentration. The optimized extract of C. sativa L. inflorescences had a yield of 24.12%, 0.62% CBD, and 5.973% THC. The content of cannabinoids studied in the Junín Region at altitudes between 2,070 and 3,274 m above sea level (m asl) had a CBD content between 0.1 and 0.4%, THC between 2.2 and 6%, and yield of 10–24%; in the Ayacucho region at an altitude of 2,627 m asl the CBD content was between 0.62 and 0.65%, THC was 6.21–6.72%, and yield of 23.8–24%; and in the Huánuco region at altitude of 660–711 m asl it had a CBD content between 0.55 and 0.65%, THC from 8.11 to 8.92%, and yield from 24.3 to 29.7%. It was concluded from the present work that the parameters such as amplitude, time, and solvent directly influence the extraction yield, in the same way the altitude influences the content of cannabinoids, being lower yields at higher planting altitude.