|Jarret, Robert - Bob|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/2/2009
Publication Date: 3/25/2009
Publication URL: http://hdl.handle.net/10113/33173
Citation: Singh, S., Jarret, R.L., Russo, V.M., Majetich, G., Shimkus, J.M., Bushway, R., Perkins, L.B. 2009. Determination of capsinoids by HPLC-DAD in Capsicum species. Journal of Agricultural and Food Chemistry. 57:3452-3457. Interpretive Summary: A new class of compounds identified in the garden pepper (Capsicum annuum) was reported earlier in the decade. These compounds (capsinoids) are closely rerlated to, but distinct from the compounds (capsaicinoids) that confer pungency (heat) to hot peppers. In contrast to capsaicinoids, capsinoids are not pungent. They do, however, share many other characteristics with capsaicinoids including certain bioactive/medicinal properties. This report details the development of an analytical technique for the quantification of capsinoids in pepper fruit, and then proceeds to examine capsinoid content in a variety of pepper (Capsicum ssp.) types. Capsinoids were detected in samples of all Capsicum species examined including C. annuum, C. baccatum, C. chinense, and C. frutescens. Levels of capsinoids ranged from 13 to 410 micrograms per gram of fruit tissue.
Technical Abstract: Capsicum fruit contain a number of phytochemicals, including the newly characterized capsinoids that have been shown to have positive effects on human health (10-15). Closely related to the pungent capsaicinoids, the non-pungent casinoids exhibit antioxidant activity, promote energy metabolism and reduce body fat in rats (10-15). Because little is known about the quantities of these compounds in both sweet and pungent pepper fruit, we developed a high performance liquid chromatography (HPLC) method to identify and quantify the capsinoids (naturally present E-capsiate and dihydrocapsiate) utilizing fruit obtained from a variety of Capsicum ssp. in the United States Department of Agriculture's Capsicum germplasm collection. Capsinoids were extracted with acetonitrile, filtered, and analyzed using an HPLC system equipped with a C18 monolithic column, gradient pump, and diode array detector. The elution solvents were acetonitrile and water (60:40) with an isocratic flow rate of 1.0 mL per minute. Forty-nine samples representing distinct morphotypes of four cultivated species (C. annuum var. annuum, C. annuum var. glabriusculum, C. baccatum, C. chinense and C. frutescens) contained detectable levels (13-410 ug/g) of E-capsiate quantified at a wavelength of 280 nm. Eleven of the E-capsiate containing samples also contained dihydrocapsiate (13-96 ug/g). Gas chromatography with a mass spectrometry detector (GC-MS) confirmed the presence of these compounds in the Capsicum ssp.