Hybrid Complexes Of Cellulose Nanofiber And Soy Protein Isolate As New-Type Fat Substitutes

As living standard is constantly improving, great changes have happened in dietary pattern and habits that the intake of high fat and high calorie food is increasing which result in many problems such as obesity and other diseases. This paper mainly research on SPI and CNF. As both soybean isolated protein (SPI) and cellulose nanofiber (CNF) are natural polymer materials, which makes them have the structure characteristics of non-toxic, low fat and dietary components, the application potential of the mixture of SPI and CNF which acted as low energy fat mimic is explored. Main research work and results are as follows:(1)Using poplar powder as raw material for the preparation of CNF, through chemical pretreatment and high intensity ultrasonic fibrillation process, the CNF had the advantage of high length-diameter ratio, strong reactivity and easy assembly, etc. And it also had the function of bodiness, reinforcement, adjust the rheological effect. Added 2% of the CNF hydrogels into SPI solution, by changing the parameters such as content of SPI solids (4%-10%), the adding ratio of CNF (SPI:CNF=20:1,15:1,10:1,7:1), reaction temperature, PH value so that the best technology of gelation solution of SPI and CNF could be found. Scanning electron microscope (SEM), Fourier transform infrared spectrometer (FTIR), rotational rheometer, and texture analyzer, the microstructure, rheological properties, viscoelasticity and structure performance were represented and analyzed, the influence rule of adding ratio of CNF and reaction temperature on compound viscoelasticity and gelation was found.(2) In the compound detection of SPI/CNF complex gel and light cream, it appeared to be highly consistent in terms of hardness, cohesiveness, viscosity, elasticity, resilience, chewiness, etc. When the displacement rate (SPI/CNF displace light cream to make ice cream) was 10%, it appeared to be similar with pure milk in properties of inflation rate and hardness, but it appeared to be significant improvement in melting resistance and decrease in consistency property to a certain extent and the performance of low fat and low calorie metabolism.(3)Froze and dried the SPI/CNF compound gel, aerogel foam structure was obtained. Structure and performance test results showed that the compound density was 0.090-0.097g/cm3 with three-dimensional porous structure, uniform size of aperture. The increase of adding ratio of CNF had significant effects on stress and strain, and the yield point and the stress of compound was obviously higher than that of pure SPI, it also proved the enhancement effect of CNF on SPI. The quality and structure analysis showed that the SPI/CNF compound aerogel had obviously increased the effect of hardness and brittleness.