Behaviour of an oil-in-water emulsion stabilized by β-lactoglobulin in an in vitro gastric model
2009
Sarkar, Anwesha | Goh, Kelvin K.T. | Singh, R Paul | Singh, Harjinder
The behaviour of @b-lactoglobulin (@b-lg)-stabilized emulsions (1.0wt% protein and 20.0wt% soy oil) using pepsin digestion under simulated gastric conditions (37^oC, pH 1.2 and 34mM NaCl ionic strength, with continuous shaking at approximately 95rev/min for 2h) was investigated. Changes in particle size, @z-potential and microstructure were monitored as a function of incubation time in the gastric fluid. Initially, @b-lg formed a stable anionic emulsion at pH 7, but the emulsion underwent extensive droplet flocculation, with some coalescence, on mixing with the simulated gastric fluid. The @z-potential values gradually changed from -57.1+/-0.5mV to +17.6+/-1.2mV because of pH change and peptic hydrolysis of the interfacial layer. Native @b-lg was largely resistant to pepsin attack but, when @b-lg was present at the interfacial layer of the oil-in-water emulsion, it was rapidly hydrolysed by pepsin, as shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The droplet flocculation and the coalescence observed during hydrolysis were markedly dependent on the digestion time.
显示更多 [+] 显示较少 [-]