Paul Bosland and Ivette Guzmán wrote a chapter in the new book Capsaicin and its Human Therapeutic Development titled "A Matter of Taste: Capsaicinoid Diversity in Chile Peppers and the Importance to Human Food Preference" and its a real treat. Its available open access here:
I've also attached the PDF
Chile peppers are valued worldwide for their distinct capsaicinoid compounds that have
been used traditionally in medicine and culinary practices. With 32 known species, five of
them domesticated, they provide unique chemical profiles, when consumed by humans.
Capsaicinoids, the spicy compounds, are alkaloids used to deter herbivory in the wild,
offering protection to the chile pepper fruit seeds. Among the 22 known capsaicinoid
structures, capsaicin and dihydrocapsaicin are normally the most abundant. In humans,
capsaicin binds to nociceptor TRPV1 that generates a heat sensation. Capsaicin also mitigates
inflammation responses in the digestive tract and has the potential to aid in nutrient
absorption. Distinct heat profiles were recently described for the five domesticated
Capsicum species showing a difference in heat sensations specific to species and pod type.
Due to the many capsaicinoid structures, we explore the implications and opportunities
of having a diverse array of heat profiles in genetically diverse Capsicum species.
Keywords: TRPV1 receptors, pain, heat sensitization, desensitization, capsaicinoid,
Capsicum, capsaicin, inflammation, peppers, chile peppers