第 1页原文题目: Concentration of? avonoids and pounds in aqueous and ethanolicpropolis extracts through nano ? ltration Abstract Propolis has a variable plex position with high concentration of ? avonoids pounds present in the extract. The extract varies with the solvent used in extraction. Ethanol extracts more phenolic acid and pounds than water. Before their use in industry, extracts must be concentrated but the use of high temperatures can degrade pounds. Membrane pro-cesses is an option that allows concentration at low temperatures. Nano ? ltration was carried out withaqueous and ethanolic extracts and each extract results in two distinct fractions: permeate and retentate. The capacity of the membrane to retain pounds was veri ? edby spectrophotometric analysis: for aqueous solution, the membrane retained around 94% of the pounds and 99% of the ? avonoids, while for the ethanolic solution these values were 53% and 90%, respectively. Ferulic acid retentionindex was and to aqueous and ethanolic solutions, respectively. Thus, the nano ? ltration processshowed high ef? ciency in the concentration of propolis extracts. 1 Introduction Over the last few decades, interest in functional foods has beengrowing fast, leading to the discovery of new ponents or processes that can improve food processing, as well as products that may help to retard aging or avoid diseases. In this context, bee products have gained the attention of consumers and researchers, due to their positions and functional properties. Propolis is one of the bee products with functional properties, but it cannot be consumed asa food because it isa resinous substance. It is prepared from the buds and exudates of certain trees and plants. These substances are transformed by the addition of wax and the enzyme glucosidase present in the bee saliva in order to form propolis (Bankova et al., 2000; Park et al., 1998). The product obtained is used by honeybees to protect the hives against invaders and contami
