The fruit of most species of Capsicum contains capsaicin . The only Capsicum without capsaicin is the bell pepper , a cultivar of Capsicum annuum , which has a zero rating on the Scoville scale . The lack of capsaicin in bell peppers is due to a recessive gene that eliminates capsaicin and , consequently , the `` hot '' taste usually associated with the rest of the Capsicum family .