Human olfactory discrimination of genetic variation within Cannabis strains.

Cannabis sativa L. is grown and marketed under a large number of named strains. Strains are often associated with phenotypic traits of interest to consumers, such as aroma and cannabinoid content. Yet genetic inconsistencies have been noted within named strains. We asked whether genetically inconsistent samples of a commercial strain also display inconsistent aroma profiles. We genotyped 32 samples using variable microsatellite regions to determine a consensus strain genotype and identify genetic outliers (if any) for four strains. Results were used to select 15 samples for olfactory testing. A genetic outlier sample was available for all but one strain. Aroma profiles were obtained by 55 sniff panelists using quantitative sensory evaluation of 40 odor descriptors. Within a strain, aroma descriptor frequencies for the genetic outlier were frequently at odds with those of the consensus samples. It appears that within-strain genetic differences are associated with differences in aroma profile. Because these differences were perceptible to untrained panelists, they may also be noticed by retail consumers. Our results could help the cannabis industry achieve better control of product consistency.

Human olfactory detection of packaged cannabis.

Olfactory detection of cannabis aroma by police officers can be the basis for warrantless searches of motor vehicles in many jurisdictions in the United States. The odor source in these cases is often dried cannabis flower contained in various casual wrappings as well as in more elaborate packaging. Here we investigate whether packaging format alters the detectability of the cannabis. Two cannabis strains and five packaging formats were evaluated. Untrained observers were presented with two containers and asked to identify, based only on smell, the container that held a sample of packaged cannabis (the other container held identical, but empty, packaging material). The results showed that open and casually packaged cannabis was identified with high accuracy, while material packaged in doubly vacuum-sealed plastic was correctly identified at rates no different from chance. The results may help address issues involving the detectability of cannabis aroma in law enforcement and other scenarios.

Consumer perceptions of strain differences in Cannabis aroma.

The smell of marijuana (Cannabis sativa L.) is of interest to users, growers, plant breeders, law enforcement and, increasingly, to state-licensed retail businesses. The numerous varieties and strains of Cannabis produce strikingly different scents but to date there have been few, if any, attempts to quantify these olfactory profiles directly. Using standard sensory evaluation techniques with untrained consumers we have validated a preliminary olfactory lexicon for dried cannabis flower, and characterized the aroma profile of eleven strains sold in the legal recreational market in Colorado. We show that consumers perceive differences among strains, that the strains form distinct clusters based on odor similarity, and that strain aroma profiles are linked to perceptions of potency, price, and smoking interest.

An olfactory demography of a diverse metropolitan population.

BACKGROUND: Human perception of the odour environment is highly variable. People vary both in their general olfactory acuity as well as in if and how they perceive specific odours. In recent years, it has been shown that genetic differences contribute to variability in both general olfactory acuity and the perception of specific odours. Odour perception also depends on other factors such as age and gender. Here we investigate the influence of these factors on both general olfactory acuity and on the perception of 66 structurally and perceptually different odours in a diverse subject population. RESULTS: We carried out a large human olfactory psychophysics study of 391 adult subjects in metropolitan New York City, an ethnically and culturally diverse North American metropolis. 210 of the subjects were women and the median age was 34.6 years (range 19-75). We recorded ~2,300 data points per subject to obtain a comprehensive perceptual phenotype, comprising multiple perceptual measures of 66 diverse odours. We show that general olfactory acuity correlates with gender, age, race, smoking habits, and body type. Young, female, non-smoking subjects had the highest average olfactory acuity. Deviations from normal body type in either direction were associated with decreased olfactory acuity. Beyond these factors we also show that, surprisingly, there are many odour-specific influences of race, age, and gender on olfactory perception. We show over 100 instances in which the intensity or pleasantness perception of an odour is significantly different between two demographic groups. CONCLUSIONS: These data provide a comprehensive snapshot of the olfactory sense of a diverse population. Olfactory acuity in the population is most strongly influenced by age, followed by gender. We also show a large number of diverse correlations between demographic factors and the perception of individual odours that may reflect genetic differences as well as different prior experiences with these odours between demographic groups.

Dollars and scents: commercial opportunities in olfaction and taste.

Research successes over the past decade have provided a broad outline of the neuroscience of olfaction and taste. Our understanding of these systems now spans the molecular to the psychological. It will soon reach critical mass and begin to generate a variety of practical applications with commercial potential. Given the ubiquity of smell and taste and their importance to health, nutrition and quality of life, these applications could have a major impact on consumer product markets and create entirely new ones. Sensory biotechnology could be the first post-genomic application to break through to the consumer market. We describe odor modulation technologies with implications for food intake, health care and other arenas. Our deeper understanding of olfaction and taste in animal behavior and reproduction provides opportunities in pest control and animal husbandry, where environmentally neutral interventions are much in demand.