The Fabrication And Characterization Of Sodium Caseinate-soy Protein Nanoparticles Complex: Application In The Whipped Cream

Whipped cream,a typical whipped foaming product,prepared by the emulsification and stirring of protein,oil,emulsifier and other components.At present,casein is the main protein component in whipped cream,which has a higher price and mostly dependent on import.The purpose of this paper is to prepare multifunctional soy protein nanoparticle（SPNP）by a specific processing method,which can partially replace casein.Besides reducing the production cost of whipped cream,good quality whipped cream can be prepared,and the application field of plant protein can be expanded.In this paper,SPNP was prepared by enzymatic and homogenization assisted with enzymatic treatment,and the changes in the structure and functional properties of SPNP was investigated.Subsequently,the structure,interfacial behavior and foaming properties of casein-soy protein nanoparticle（Cas-SPNP）complexes were investigated.Finally,the effect of the Cas-SPNP complex on the whipping properties of whipped cream was studied.The degree of hydrolysis（DH）has significant influence on the formation,structure and function of SPNP.SPNP could be prepared when DH was 3%and 6%.The SPNP was small spherical with good uniformity and particle size between 64.20-284.57 nm;SPNP prepared by homogenization assisted with enzymatic treatment has smaller particle size,stronger rigid structure,improved surface hydrophobicity（H₀）,better solubility,emulsifing ability index（1.68times of SPI）and foaming ability（1.99 times of SPI）;Compared with high DH,the SPNP prepared with low DH has better functional properties.The interfacial and foaming properties of Cas-SPNP complexes were significantly affected by different mass ratios of Cas/SPNP.It has been demonstrated that hydrophobic interactions and hydrogen bonds were primarily responsible for the complexation process;High Cas/SPNP ratio was lower than low Cas/SPNP ratio composite particle size,decreased H₀,low interfacial activity,but significantly increased the interfacial viscoelasticity about 2 and 3 times;The bubbles with small diameter and narrow distribution can be prepared and the foam stability was strong.SPNP can be used to substitute Cas in part to produce plant butter with good whipping performance and quality.With the increase of the ratio,the particle size of emulsion gradually increased,the apparent viscosity first increased and then decreased,the shorter optimum whipping time(t_op)first shortened and then extended,and the fat coalescence degree,the interfacial protein concentration,the firmness first increased and then decreased.Compared with the higher ratio,the sensory quality and storage stability are the best when the ratio is 7:3.When the ratio of Cas to SPNP was 7:3,the above indexes reached the peak,and the whipping properties.