Interfacial, Emulsifying And Digestion Properties Of ?-Lactoglobulin Fibrils Aggregates

Anisotropic particles exhibited unique interfacial properties,but only limited types of these particles are available for the food industry.?-lactoglobulin fibrils aggregates were(fibrils)formed by self-assembly of ?–lactoglobulin(?-Lg)under specific conditions.Protein fibrils as anisotropic particles were surface active and expected to function in food systems.In this paper,the formation kinetics and basic physicochemical properties of ?-Lg fibrils aggregates were characterized.Further more,the interfacial,emulsifying properties and emulsion lipid digestion behaviors of ?-Lg fibrils were studied systematically.The main conclusions are as follows:1.Fibrils were shown to be able to stabilize an oil-in-water emulsion in the absence of other surfactant.Fibrils were able to form stable O/W emulsion when the pH is away from the isoelectric point of pI(pH=5.2),while at pH 5.0 fibrils tended to aggregate seriously and resulted in an unstable emulsion.Fibrils concentration above 5 mg/mL was sufficient to provide the long-term stability for the emulsion.Excessive fibrils would result in larger emulsion droplet size,although the stability was acceptable.2.The interfaction between ?-Lg fibrils at air-water interface was studied.The effects of NaCl,Urea and Tween 80 on the interfacial adsorption kinetics and rheological behavior of the fibrils were analyzed.It was founded that the interaction between fibrils was dominated by hydrogen-bond interaction and hydrophobic interaction,supplemented with electrostatic interaction.The emulsion stability was decreased with increasing NaCl,Urea and Tween 80.The result indicated that electrostatic interaction,hydrogen-bond interaction and hydrophobic interaction were important factors to maintain the stability of ?-Lg fibrils emulsion.3.The simulated digestion of ?-lg fibrils emulsion was studied.The lipid digestion of emulsion stabilized by fibrils,?-Lg and ?-Lg nanoparticle(NP)at the same droplet size were compared.It was showed that the digestive rate and extent of fibrils emulsion fibrils emulsion is the fastest and the release rate of free fatty acids(FFA)is the highest(up to 70%).The digestion rate of the NP stabilized emulsion showed to be the slowest.This may be induced by the difference of the interfacial properties of the three different emulsifiers.