Note on pepper pungency and environmental stress

Abstract Background Hot peppers (genus Capsicum , family Solanaceae) are an economically important agricultural and food industry product, and play a large role in many cuisines worldwide where they are prized for their flavor, odor, and color. They also have beneficial health properties of interest to the pharmaceutical and medical communities. The pungency of hot peppers is due to their capsaicinoid concentration. It has been known for some time that peppers cultivated under stressful environmental conditions, particularly high temperatures and low water conditions, produce higher pungency. This study examines the capsaicinoid content of two groups of hot peppers from the literature—one group cultivated under stressful conditions and a second group cultivated under stable conditions. Results The group cultivated under stressful conditions from a variety of locations displays an exponential distribution in capsaicinoid content ( C ) ( r 2  = 0.92; N  = 80), whereas, the second group displays a linear distribution ( r 2  = 0.98; N  = 140). A simple assumption explains the exponential distribution, namely that the change in pungency over time ( t ) is proportional to the C such that d C /d t  = λ C , where λ is an environmental factor. The solution to this equation is C  =  C o exp λt where C o is the capsaicinoid at time zero. Values for λ range over 0.03–0.07/day. Conclusion The distribution pattern of capsaicinoids in peppers cultivated under stressful conditions shows an exponential pattern, whereas those cultivated under stable conditions display a linear pattern. Pepper pungency patterns might therefore be used to identify stressful conditions due to climate change on a global scale.