Changes in the contents of oleoresin and pungent bioactive principles of Jamaican ginger (Zingiber officinale Roscoe.) during maturation.

Changes in the yields of the oleoresin and content of pungent bioactive principles: [6], [8], [10] gingerols and [6] shogaol of Jamaican ginger ( Zingiber officinale) were investigated during different stages of maturity (7-9 months). Ethanolic oleoresin extracts were prepared (95%, w/w) by cold maceration of dried ginger powder, and their percentage yields were calculated (w/w). The pungent bioactive principles in the ginger oleoresin were extracted with methanol and quantitatively analyzed by high performance liquid chromatography (HPLC). Ginger harvested at 8 months from Bourbon, Portland had the highest oleoresin yield (8.46 +/- 0.46%). [6] Gingerol was found to be the most abundant pungent bioactive principle in all the oleoresin samples investigated, with the 9 months sample from Bourbon, Portland containing the highest level (28.94 +/- 0.39%). The content of [6] gingerols was also found to be consistently high (7-9 months) in oleoresin samples from Johnson Mountain, St. Thomas (15.12 +/- 0.39 to 16.02 +/- 0.95%). The results suggest that Bourbon in Portland may be the most ideal location for cultivating ginger for high yields and quality, however, Johnson Mountain in St. Thomas could prove to be the least restrictive location, allowing for harvesting of good quality material throughout the maturity period (7-9 months).

Extraction, processing, and storage effects on curcuminoids and oleoresin yields from Curcuma longa L. grown in Jamaica.

Aromatic diarylheptanoid compounds from Curcuma longa Linn grown in Jamaica were quantified by UV-vis spectrophotometry and high-performance liquid chromatographic (HPLC) analyses. The oleoresin yields from ethanolic extracts were quantified and evaluated with regard to the effects of the type of postharvesting process and the type of extraction method conducted on the plant material. Fresh samples that were hot solvent extracted provided the highest oleoresin yields of 15.7% +/- 0.4 ( n = 3), and the lowest oleoresin yields of 7.8% +/- 0.2 ( n = 3) were from the dried milled samples that were cold solvent extracted. Data from the ASTA spectrophotometer assay confirmed that dried samples contained the highest curcuminoid content of 55.5% +/- 2.2 ( n = 6) at the fifth month of storage, and the fresh samples showed a curcuminoid content of 47.1% +/- 6.4 ( n = 6) at the third month of storage. A modified HPLC analysis was used to quantify curcumin content. Data from the HPLC analysis confirmed that the dried treated, hot extracted, room temperature stored samples had the highest curcumin content of 24.3%. A novel high-performance thin layer chromatography (HPTLC) method provided a chemical fingerprint of the C. longa with the use of a commercial curcumin standard.