Study On Performance And Properties Of Rapeseed Protein Film

Rapeseed protein is a kind of plant protein of high quality, which contains large amount of intermolecular force, Van der Waals’ force, disulfide bond and hydrophobic interaction, which give the rapeseed proteins the potential to form films. In this article we fabricated the proteins films with optimal properties by the blending method, and studied the extraction of the proteins and the best condition of the forming processes. We also explored the application of films using as packaging.Use the rapeseed meal as the feedstock; we extract the rapeseed proteins by using the Acid and alkali extraction. We built a new method to detect the content of the rapeseed proteins which based on the united pigment with the proteins.Drawing the standard curves by using the proteins solution of different content and the absorbance of these solutions, and calibrated the curves by using the Kjeldah method. The linearity was good at the range of 1.0-3.0mg/m L, linearly dependent coefficient R2 greater than 0.999, average recovery rate 99.1%,accuracy and precision of the method are both well. The method is fit to detect the proteins content of large mount of rapeseed proteins of same variety.Fabricated the rapeseed proteins and agar blend films by using the isolated rapeseed proteins and research the properties of the films. The results showed that the optimal conditions to form the films is that the glycerol content 20%, the rapeseed proteins content 30%, temperature 50 ℃, p H 10.0, ultraviolet for 24 h.The tensile strength of the film was about 3.5MPa and the elongation at break was 20% at those conditions.Using sodium dodecyl sulfate modified halloysite nanotubes to improve the properties of the film,the results showed that the optimum usage of the modifier was 3%, the tense strength of the film improved by 20%, however the elongation at break decrease by 10%. The micro structure of the film had changed to a single-layer film after the addition of modifier, and the modified halloysite nanotubes improved the properties of film by through the physical adsorption andchemical cross linking.The optimum condition to fabricate the rapeseed protein and agar blend film was just the same as the protein film, but the ratio of the rapeseed protein and agar was 3:7. The tensile strength and elongation at break of films form at the above mentioned conditions are 35 MPa and 10%, respectively, increased substantially compared with the single proteins films. The opacity property and barrier property of the films were also improved by large mount. The micro-structure of the films showed that the blend films’ surface were more compact than the proteins films. All the results showed that the blending method is a useful way to improve the properties of the proteins films.We preliminary researched the security property of the blend films. The results showed the toxic content of the proteins are less than the relative standard, the films won’t volatilize out noxious gas even at high temperature.