|Jarret, Robert - Bob|
Submitted to: Journal of Environmental Science and Health
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/3/2006
Publication Date: 7/1/2006
Citation: Antonious, G.F., Jarret, R.L. 2006. Screening capsicum accessions for capsaicinoids content. Journal of Environmental Science and Health. 41:717-729
Interpretive Summary: Pungency is an economically important trait in peppers (Capsicum sp.). The genus Capsicum contains a number of cultivated species that bear pungent fruit. These include the species C. annum, C. baccatum, C. chinense, C. frutescens, and C. pubescens. Within each of these species, individual lines or types can vary greatly in the concentrationis of the compounds that contribute to pungency. This study examined the diversity present in fruit of these five species for the major compounds that contribute to fruit pungency (capsaicin and dihydrocapsaicin). As expected, concentrations of capsaicin and dihydrocapsaicin varied widely among and within the species examined. Capsaicin concentrations were typically greater than those of dihydrocapsaicin. Concentra- tions of total capsaicinoids (capsaicin+ dihydrocapsaicin) varied from not detectable to 11.2 mg per fruit. Plant Introduction (PI) number 441624 (C. chinense) had the highest concentration of capsaicinoid. PI497984 (C. frutescens) contained the highest concentrations of total capsaicinoids.
Technical Abstract: Ninety Capsicum accessions selected from the USDA Capsicum germplasm collection were screened for their capsaicinoids content using gas chromatography with nitrogen phosphorus detection (GC/NPD). Fresh fruits of Capsicum chinense, C. frutescens, C. baccatum, C. annum, and C. pubescens were extracted with methanol, and analyzed for capsaicin, dihydrocapsaicin and nordihydrocapsaicin. Mass spectrometry of the fruit crude extracts indicated that the molecular ions at m/z 305, 307, and 293 which correspond to capsaicin, dihydrocapsaicin, and nordihydrocapsaicin, respectively, ahve a common benzyl cation fragment at m/z 137 that can be used for monitoring capsaicinoids in pepper fruit extracts. Capsaicin and dihydrocapsaicin were the dominant capsaicinoids detected. Capsaicin concentrations were typically greater than dihydrocapsaicin. Concentrations of total capsaicinoids varied from not detectable to 11.2 mg fruit-1. Statistical analysis revealed that accession PI441642 (C. chinense) had the highest concentration of capsaicinoid and PI 497984 (C. frutescens) had the highest dihydrocapsaicin content (2.3 mg g-1 fresh fruit). Genebank accessions PI 439522 (C. frutescens) and PI-497984 contained the highest concentrations of total capsaicinoids.