Feverfew as a source of bioactives for functional foods: Storage stability in model beverages

The potential of feverfew infusions, used traditionally for the treatment of various ailments associated with pain and inflammation, was investigated as a source of nutraceuticals in the manufacture of beverages with anti-inflammatory properties. Acidified feverfew model beverages (2.9 ⩽ pH ⩽ 6) were stored at 5 and 22 °C in order to assess the degradation of one of the key bioactives, parthenolide and their colour stability. Parthenolide degradation followed pseudo-first order kinetics. The acidic infusions (pH ⩽ 4.6) exhibited good colour stability at both 5 and 22 °C, but the rate of parthenolide hydrolysis increased dramatically with decreasing pH. In contrast, more neutral infusions (pH 6.0) exhibited higher parthenolide stability, but displayed progressive browning possibly due to enzymatic oxidation of phenols. Therefore, refrigerated storage of mildly acidic infusions (pH 4.6) was found to be the optimum for colour retention, phenolic and parthenolide content with a shelf-life of approximately 4 months.

Research highlights
► Parthenolide degradation followed pseudo-first order kinetics.
► Parthenolide hydrolysis increased with decreasing pH.
► Acidic infusions (pH ⩽ 4.6) exhibited good colour stability at 5 and 22 °C.
► Infusions at pH 6.0 displayed progressive browning with storage.
► pH 4.6 was the optimum to retain colour, phenolic and parthenolide content.