Sanitation of medical cannabis flowers (Cannabis sativa L., flos): comparing current technologies and non-thermal plasma novelties from safety and quality perspectives

The use of cannabis in medicine has rich historical roots spanning thousands of years before stigmatism surrounding the narcotic use of this plant led to strict regulations on its use. Recently, medicinal and recreational cannabis use has experienced a resurgence in many regions of the world, receiving attention from society and policy as legalization increases availability and necessity of greater mindfulness. Research on cannabis is gaining more traction to better inform the regulations needed to ensure the safe and effective usage of this drug. Owing to cannabis being a natural plant product, there are contamination risks even when it is produced under good manufacturing practices (GMPs), which can pose a health risk to consumers. Several pathogenic bacteria and fungi have been found on cannabis, either causing disease in the plant or causing health issues in people who consume the product. The literature on the microbiological safety of cannabis focuses on identifying the species that exist on the plant and the efficacy of sanitation methods currently used in the food industry for the decontamination of cannabis. Specifically, irradiation methods such as gamma irradiation and electron beams have been applied to effectively lower the microbial load on cannabis. However, these irradiation methods face pushbacks due to cost barriers, regulatory issues, and customer disapproval for irradiated products. Innovative gaseous and non-thermal plasma methods are beginning to gain attention because of their preliminary results in effectively decontaminating food products. Indirect non-thermal plasma methods such as ozone and plasma-processed air present new, possibly better, sanitation options for the complex flower structure of cannabis while maintaining its quality. This review discusses the historical importance of cannabis usage and the need to mitigate microbial contamination while considering the current methods used to sanitize cannabis. Finally, we present innovative gaseous and non-thermal plasma methods that are currently being integrated or are under research for cannabis sanitization to improve the safety and future regulatory aspects of cannabis processing.