Author/Authors :
ali, h. department of food science and agricultural chemistry,mcgill university,macdonald campus,21,111 lakeshore road,st-anne-de-bellevue, Canada , alli, i. department of food science and agricultural chemistry,mcgill university,macdonald campus,21,111 lakeshore road,st-anne-de-bellevue, Canada , ismail, a. department of food science and agricultural chemistry,mcgill university,macdonald campus,21,111 lakeshore road,st-anne-de-bellevue, Canada , kermasha, s. department of food science and agricultural chemistry,mcgill university,macdonald campus,21,111 lakeshore road,st-anne-de-bellevue, Canada
Abstract :
Interest in protein-phenol interactions in biological systems has increased substantially during the past two decades. More recently,there has been particular interest in protein-phenol interactions in food systems,as a result of widespread reports on the roles of phenolic compounds in nutrition and health. Many phenolic compounds are now recognized for their nutraceutical properties. The biochemical,nutritional and immunological properties of these phenolic compounds,can be associated with their relationship with certain proteins. A good example is the recent recognition of soybean proteins containing isoflavones,for their health benefits and for prevention of certain diseases. In order to understand protein-phenol relationships,it is essential to determine the nature of the chemical/physicochemical interactions between the proteins and the biologically active phenols. The overall objective of our study was to use a model system to investigate the mode of interaction between selected food proteins and phenolic compounds. Bovine serum albumin (BSA) and soybean glycinin were used with two phenolic compounds: Gallic acid (3,4,5-trihydroxybenzoic acid) and biochanin-A (5,7-dihydroxy 4-methoxy isoflavone). The interactions were investigated at incubation temperatures of 35°C,45°C and 55°C at pH 5,7 and 9. SDS and Native polyacrylamide gel electrophoresis (PAGE),differential scanning calorimetry (DSC),and Fourier transform infrared (FTIR) spectroscopy were used to identify protein-phenol interactions. Certain phenolic compounds combined with BSA resulting in higher migration bands and prevention of protein aggregation. In general,the thermal stability of the proteins increased as a result of interaction with the phenolic compounds. The interaction of the phenols with the proteins resulted in changes in protein secondary structure. The most pronounced effects were observed with gallic acid,while the least effects were observed with the isoflavone biochanin-A. © 2012 Moment Publication.
Keywords :
BSA , DSC , FTIR , Isoflavones , Phenolic compounds , SDS , PAGE
