Characterization and Modeling of the Interactions between Coffee Storage Proteins and Phenolic Compounds
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- 作者：Mostafa Ali ; Thomas Homann ; Janka Kreisel ; Mahmoud Khalil ; Ralf Puhlmann ; Hans-Peter Kruse ; Harshadrai Rawel
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2012
- 出版时间：November 21, 2012
- 年：2012
- 卷：60
- 期：46
- 页码：11601-11608
- 全文大小：346K
- 年卷期：v.60,no.46(November 21, 2012)
- ISSN：1520-5118
文摘
This study addresses the interactions of coffee storage proteins with coffee-specific phenolic compounds. Protein profiles of Coffea arabica and Coffea canephora (var. robusta) were compared. Major phenolic compounds were extracted and analyzed with appropriate methods. The polyphenol鈥損rotein interactions during protein extraction have been addressed by different analytical setups [reversed-phase high-performance liquid chromatography (RP-HPLC), sodium dodecyl sulfate鈥損olyacrylamide gel electrophoresis (SDS鈥揚AGE), matrix-assisted laser desorption ionization鈥搕ime of flight鈥搈ass spectrometry (MALDI鈥揟OF鈥揗S), and Trolox equivalent antioxidant capacity (TEAC) assays], with focus directed toward identification of covalent adduct formation. The results indicate that C. arabica proteins are more susceptible to these interactions and the polyphenol oxidase activity seems to be a crucial factor for the formation of these addition products. A tentative allocation of the modification type and site in the protein has been attempted. Thus, the first available in silico modeling of modified coffee proteins is reported. The extent of these modifications may contribute to the structure and function of 鈥渃offee melanoidins鈥?and are discussed in the context of coffee flavor formation.