文摘
Rapid quantitative near-infrared Fourier transform Raman analyses of the key phytonutrients in carrots, polyacetylenes and carotenoids, are reported here for the first time. Solvent extracts of 31 carrot lines were analyzed for these phytonutrients by conventional methods, polyacetylenes by GC-FID and carotenoids by visible spectrophotometry. Carotenoid concentrations were 0鈥?586 渭g g鈥? dry weight (DW). Polyacetylene concentrations were 74鈥?846 渭g g鈥? DW, highest in wild carrots. The polyacetylenes were falcarinol, 6鈥?237 渭g g鈥? DW; falcarindiol, 42鈥?475 渭g g鈥? DW; and falcarindiol 3-acetate, 27鈥?49 渭g g鈥? DW. Strong Raman bands for carotenoids gave good correlation to results by visible spectrophotometry. A chemometric model capable of quantitating carotenoids from Raman data was developed. A classification model for rapidly distinguishing carrots with high and low polyacetylene (limit of detection = 1400 渭g g鈥?) concentrations based on Raman spectral intensity in the region of 2250 cm鈥? was produced.
Keywords:
Daucus; carrot; Raman; polyacetylenes; carotenoids; spectroscopy; chemometrics