This study was performed to estimate the effect of the incorporation of different cotton-nanocrystalline cellulose (C-NCC) contents with soy protein isolate (SPI) films. The results indicated that the C-NCC content had no effect on the thickness of the composite films ( 0.06 ± 0.01   mm ), and the optical property of the composite films decreased as the C-NCC contents increased. Water vapor, carbon dioxide, and oxygen permeability decreased with the introduction of C-NCC and started to increase when the peak of 7% C-NCC was reached. Water solubility of the SPI/C-NCC films decreased from 44.46% of the SPI films to 35.36% of the SPI/C-NCC films with 5% C-NCC. The tensile strength (TS) of films increased from 4.25 MPa to 6.02 MPa by increasing the C-NCC content from 0 to 7%. Then, the TS decreased as the C-NCC content was further increased. The trend of the elongation at break was opposite to that of the TS. The results from FTIR and DSC indicated that the addition of C-NCC did not change functional groups of the SPI films, and the glass transition temperature shifted toward a higher temperature as the C-NCC content increased. Hence, the addition of C-NCC enhanced the barrier and mechanical properties of the SPI/C-NCC composite films.

In this study, nano-SiO 2 /soy protein isolate composite film was prepared by casting method. The effects of (adding 0%, 1%, 3%, 5%, 7%, and 9% w/w) nano-SiO 2 on the properties of the resulting blend films were investigated. Results showed that the addition of 5% nano-SiO 2 exhibited good barrier properties.The mechanical properties including tensile strength and elongation at break of the film with 7% nano-SiO 2 is increased by 82.6% and 31.49% correspondingly. Differential scanning calorimetry indicated that the melting temperature of the composite film is increased by 56.6 C compared with the pure film. The wall material modified by nano-SiO 2 (adding 1%, 3%, 5%, 7%, and 9% w/w) was used for encapsulating walnut oil by spray drying. After accelerating oxidation test at 63 C for 12 days, we found that the encapsulation efficiency value of walnut oil microcapsules with 0%, 1%, 3%, 5%, 7%, and 9% nano-SiO 2 decreased by 64.23%, 48%, 21%, 22%, 21.00%, and 31% respectively. The results suggested that the stability of the core material was improved by adding nano-SiO 2 to the wall material.