Epsilon Open Archive

Abstract

Consumption of fruits and berries have positive effects on human health by reducing the risk of e.g. cardiovascular diseases, age-related macular degeneration and cataracts, and different forms of cancer. These positive effects are believed to be related to the high content of bioactive compounds such as different antioxidants in fruits and berries. Increased intake of bioactive compounds can be promoted by selecting species/cultivars with high contents and by harvesting at the optimal time. Recent interest for cultivating sea buckthorn berries and rose hips partly depends on their more or less well documented health related statements. Products containing sea buckthorn berries or rose hips are steadily growing in number on the market and there is a need for increasing the knowledge of the content of the bioactive compounds in the fruit and berry raw material. This thesis investigated the content of carotenoids, tocochromanols (tocopherols and tocotrienols) and chlorophylls in berries from different cultivars of sea buckhorn (Hippophae rhamnoides) and fruits from different species of roses (Rosa sp.) during the harvest period of three consecutive years. The carotenoid and tocopherol content were also investigated during processing and storage in juices with sea buckthorn berries and rose hips as ingredients. Carotenoids and tocochromanols are fat-soluble antioxidants, some of which have activity as pro-vitamin A and vitamin E. All analyses were carried out by HPLC on extracts made from lyophilised material. The concentration of carotenoids, tocochromanols and chlorophylls generally varied depending on cultivar/species and over the ripening period in both sea buckthorn berries and rose hips. This variation was not simultaneous for different compounds of the same type, e.g. all carotenoids did not show similar variation. For carotenoid content, harvesting time and choice of cultivar were more important than year of harvest, and a general increase occurred over the season. The tocochromanol content was mostly influenced by cultivar/species and year of harvest, although vitamin E activity generally decreased during ripening. The chlorophyll content decreased during ripening, when the fruits/berries changed colour from green to yellow-red, and proved suitable for use as a maturity marker of optimal harvesting time.