Studies on self-assembly interactions of proteins and octenyl succinic anhydrate (OSA)-modified depolymerized waxy rice starch using rheological principles

摘要

Dynamic tests (23 degrees C, pH approximate to 7.0) yielding relaxation times, , as a function of frequency and polymer concentration were performed to assess self-assembly characteristics of biopolymers in aqueous solution. Reduction of -values (slope) up to a critical frequency value (CFV) helps characterize structure formation. Proteins and octenyl succinic anhydrate (OSA)-modified depolymerized waxy rice starch (DWxRc) show a well-defined -slope at all concentrations. Except for whey protein isolate (WPI, 0.184 g/L) and 7% OSA-modified DWxRc (1.84 g/L), the -values of the solutions are comparable (P > 0.05), indicating similar structures. Self-assembly interaction of -lactalbumin (3.68 g/L) with OSA-modified polysaccharides is observed with 18.4 g/L of 7% OSA-modified DWxRc (CFV of 0.08 Hz), while WPI (3.68 g/L) exhibits self-assembly with all polysaccharides and concentrations. Transmission electron microscopy (TEM) of electrostatically precipitated proteins alone or in combination with OSA-modified polysaccharides confirms that -slope and CFV values relate to shape, size, and shear stability of the assembled structures. (c) 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43603.