Evaluation of Verbascum flower extracts as a natural source of pigments with potential health benefits

Abstract

Crocins are bioactive glucosylated apocarotenoids that confer a yellow pigmentation. In addition to their coloring ability, crocins offer potential health benefits because of their antioxidant and anti-inflammatory properties. These compounds are present in the flowers and fruits of a few plant species, including saffron, gardenia, Buddleja and Verbascum species. Saffron extracts have been used for the formulation of functional foods. However, there is no evidence of the use of the other plants producing crocins in the food industry. This study evaluated the effect of the addition of ground dry flowers of two Verbascum species, with antioxidant activity, as well as dry fruit powder, from a recently engineered tomato plant producing fruits that accumulate high levels of crocins, as functional ingredients during the processing of rice, wheat cous–cous and maize noodles, providing a yellow pigmentation. Correlation analyses revealed that the increased antioxidant activity in the three food matrices was due to the presence of crocins, which showed no toxicity. Furthermore, in vitro digestion showed that crocins were more bioaccessible from rice than from cous–cous or maize noodles, inferring the importance of the food matrix in bio accessibility. The obtained results showed the commercial potential of Verbascum's flowers, as a source of crocins, natural pigments with antioxidant activities.