| The influence of pre-harvest and post-production factors on the extraction yield, content and stability of parthenolide (PRT) in feverfew was investigated.; The effect of particle size of feverfew powders on the PRT extraction yield was examined. Larger particle-size samples produced lower PRT extraction yield. Samples of 500 μm or smaller particle size yielded 5 times more PRT than that obtained with 500–1000 μm particle size, independent of the extraction method utilized (Soxhlet, bottle stirring, sonication).; The effect of external factors on the PRT content was evaluated by exposing plants to different treatments including visible light, UV light, water stress, and exogenous application of ethephon. Higher visible light, obtained by changing the plant spacing a week prior to harvest and by harvesting at different times of the day, increased PRT content in feverfew plants. Higher PRT concentration was also observed in plants exposed to water stress whereas ethephon treatment reduced PRT content. UV light reduced PRT except in water-stressed plants. In contrast to PRT, phenolics content was higher in plants exposed to reduced light and in watered plants.; The physiology of the accumulation of PRT and its possible connection with the abscisic acid (ABA) pathway was addressed. ABA inhibitors, norflurazon, sodium tungstate, naproxen, and sodium bisulfite inhibited PRT accumulation in cut feverfew flowers. This indicated that PRT may be derived from carotenoid pathway.; The influence of pH, temperature, and light on PRT stability in feverfew products was examined. Extracts with pH <5 had over 40% PRT loss within 30 days of storage, whereas solutions with pH >5 had less than 15% loss in the same period. Parthenolide in powders showed a 30% decline in PRT in 320 days of storage. Light did not appear to affect PRT in stored feverfew products. Evaluation of temperatures regimes showed stability of PRT in feverfew powders at below 130°C.; The results of this study demonstrated that external conditions are significant in obtaining maximum PRT extraction yield and high PRT content, and in extending stability of PRT in feverfew products. |
