Construction And Application Of Egg White Protein-Xanthan Gum Structured Oil

Plastic fat,particularly saturated fatty acids and trans fatty acids,is harmful to human health.Structured oil with zero trans fatty acids and low saturated fatty acids could be prepared using emulsion-templated approach with vegetable oil as oil-phase and macromolecular polymer as stabilizer,which is a promising substitute of plastic fat.Food grade polymers(such as proteins and polysaccharides)can be used in the construction of emulsion and structured oil due to their unique interface characteristics and network forming ability.In this study,a novel structured oil was formulated based on emulsion-templated approach using the egg white microgels and polysaccharides as materials.The physical properties and rheological properties of the composite emulsions and the corresponding structured oil were studied,and the performance of the structured oil in baking product was also explored.The main research contents and conclusions of the paper are listed as follows:Firstly,the stabilizers of emulsion and structured oil were screened.The composite emulsions and structured oil were prepared by emulsion-templated approach with different polysaccharides and egg white protein microgel particles.The stability and rheological properties of the composite emulsions were evaluated by inverted fluorescence microscope and rheometer.It was found that xanthan gum could obviously reduce particle size and enhance the physical stability of the emulsion.The composite emulsions exhibited the properties of the gellike solid.The oil binding capacity of the structured oil was evaluated by measuring the oil loss rate.It was found that the xanthan gum greatly enhanced the oil binding capacity of the structured oil.Secondly,the effects of the concentration of emulsifier(egg white protein microgel particles)and stabilizer(xanthan gum)on the properties of the composite emulsions and structured oil were studied.It was found that macro-properties of the samples were linked to their microstructure characteristic.High concentration of egg white protein tended to form a composite emulsion with better physical stability and higher mechanical strength,resulting in structured oil with a tighter network structure,better oil binding capacity and antioxidant capacity.The effect of xanthan gum on composite emulsions and structured oil at a concentration of less than 0.4% also followed the above rules.Furthermore,when the concentration of xanthan gum was greater than 0.4%,excess xanthan gum was helpful to form a gel network of composite emulsion,which played a role of physical barrier in the aggregation of oil droplets.However,the changes in the concentration of xanthan gum had no significant effect on the antioxidant capacity of the structured oil.Finally,the substitute properties of structured oil in the sponge cake were evaluated.The application performance of the structured oil into cake was evaluated by physical properties and sensory evaluation.The results showed that the cake prepared by the structured oil was superior to the cake prepared from vegetable oil in terms of hardness,chewiness,chewiness and other programs,and was close to the cake prepared with margarine,but the springiness still need to be further improved.Sensory evaluation indicated that structured oil cake reached the level of commercial margarine cake.In this paper,egg white protein microgel particles-xanthan gum composite structured oil was prepared by emulsion-template method,and the synergistic mechanism of egg white protein microgel particles and xanthan gum in structured oil system was clarified.The application characteristics of structured oil in the baked food system provide a methodological guide for the development of special-purpose structured oil products,which has great theoretical research significance and practical application value.