14th World Congress of Food Science & Technology, Oct.19th -23rd , 2008, Shanghai,.China
Functional Properties of Fruit Seed Extracts
Gerhard Kroyer
Institute of Chemical Engineering, University of Technology Vienna, A-1060 Vienna, Austria
Introduction
There is a growing interest in nutrition and preventive health care in the development and evaluation of natural bio-active and antioxidant active products from plant resources. Consumption of a diet rich in polyphenol compounds has been linked with a reduced risk for cardiovascular diseases and certain types of cancer due to their significant radical scavenging capacity. Seeds of fruits like grapes are well known for their high content of polyphenols and radical scavenging capacity. Based on this evidence in this study the total polyphenol content and the antioxidant and free radical scavenging properties of edible seeds from selected fruit species was investigated.
Materials and Methods
Fruit seed extracts of pomegranate, papaya and melon were prepared by extraction of the ground and dried seeds with 80% ethanol in water. The obtained solid extracts were analyzed for their content of total polyphenols (Folin-Ciocalteu method). The antioxidant activities were determined with the DPPH* radical scavenging method in terms of their Efficient Concentration EC50 (mg antioxidant /mg DPPH*).
Results and Discussions
All the seed extracts showed remarkable amounts of total polyphenols and considerable free radical scavenging activity (EC50). Comparatively, the amount of total polyphenols (mg/g) in the seed extracts decreased in the order papaya (20,9) > pomegranate (9,9) > melon (3,5). Correlating with the polyphenol content, the extract of papaya seeds proved to have the highest antioxidant properties (EC50: 6,2), followed by the pomegranate seed extract (EC50: 10,1), whilst the extract of melon seeds showed only relatively poor inhibitory effectiveness (EC50: 28,4).
According to this study an application of fruit seed extracts as potent natural antioxidant additives for food products and as functional dietary supplements with special regard to their nutritional-physiological implications and health promoting effects seems to be worth considering.