Validation of the Soleris®Enterobacteriaceae Method for Detection of Enterobacteriaceae in Dried Cannabis Flower: AOAC Performance Tested MethodSM 121901

Abstract: Background The Soleris®Enterobacteriaceae vial is a growth-based, automated method for detection of bacteria of the family Enterobacteriaceae in foods and other sample types including nutraceuticals and cosmetics. The Soleris method is used in a “dilute-to-specification” or threshold manner, in which a result is scored as positive or negative around a predetermined cutoff (in CFU/g) established by the dilution and volume of sample homogenate tested. The Soleris method was granted AOAC Performance Tested MethodSM (PTM) status for select foods after successful completion of a validation study (PTM 121901). Objective The objective of this study was to validate the method for the detection of Enterobacteriaceae in dried cannabis flower [>0.3% delta-9-tetrahydrocannabinol (THC)]. Methods The matrix study included comparison of Soleris method presumptive results to confirmation from the Soleris vials, and comparison of the Soleris confirmed results to those of the ISO 21528-2:2017 colony count method. Test materials at four different levels of contamination ranging from 7.8 to 3500 CFU/g were tested at three dilutions, corresponding to test thresholds. Results Probability of detection analysis at P < 0.05 showed there were no significant differences between Soleris presumptive and confirmed results, and no significant differences between Soleris confirmed and ISO 21528-2:2017 results. Conclusion The results provided evidence that the Soleris Enterobacteriaceae test is an accurate method for detection of Enterobacteriaceae in dried cannabis flower. Highlights The Soleris Enterobacteriaceae method provides cannabis industry QC personnel with an effective method for analysis of dried cannabis flower and produces results in 20–24 h.