Effects of AN-contents and shear flow on the miscibility of PC/SAN blends

Blending Proteins in High Moisture Extrusion to Design Meat Analogues: Rheological Properties, Morphology Development and Product Properties

High moisture extrusion (HME) of meat analogues is often performed with raw materials containing multiple components, e.g., blends of different protein-rich raw materials. For instance, blends of soy protein isolate (SPI) and another component, such as wheat gluten, are used particularly frequently. The positive effect of blending on product texture is well known but not yet well understood. Therefore, this work targets investigating the influence of blending in HME at a mechanistic level. For this, SPI and a model protein, whey protein concentrate (WPC), were blended at three different ratios (100:0, 85:15, 70:30) and extruded at typical HME conditions (55% water content, 115/125/133 °C material temperature). Process conditions, rheological properties, morphology development, product structure and product texture were analysed. With increasing WPC percentage, the anisotropic structures became more pronounced and the anisotropy index (AI) higher. The achieved AI from the extrudates with a ratio of 70:30 (SPI:WPC) were considerably higher than comparable extrudates reported in other studies. In all extrudates, a multiphase system was visible whose morphology had changed due to the WPC addition. The WPC led to the formation of a much smaller dispersed phase compared to the overlying multiphase structure, the size of which depends on the thermomechanical stresses. These findings demonstrate that targeted mixing of protein-rich raw materials could be a promising method to tailor the texture of extruded meat analogues.

Optical properties of polycarbonate/styrene-co-acrylonitrile blends: effects of molecular weight of the matrix

In this paper, the effects of the molecular weight of a polycarbonate (PC) matrix on the phase morphology and optical properties of a PC/styrene-co-acrylonitrile (SAN) blend were investigated. A scanning electron microscope is used to analyze the phase morphology of the blends, and Mie scattering theory is used to analyze the changing laws of the optical properties of PC/SAN blends with the increasing of PC molecular weight. Results show that the average particle diameter is not strongly changed with different PC molecular weight because the values of the viscosity ratios are very close to each other. But it is obvious that the number of large particles gradually reduced while small particles (especially d<2  μm) significantly increased with the increasing of PC molecular weight. And the increase in small particles will result in an increase in backward scattering so the transmittance of PC/SAN blends decreases with the increase of PC molecular weight. However, the balance of the scattering coefficients and the number concentration of particles eventually lead to the haze of the blends being very close, despite having different PC molecular weights. Meanwhile, the photographs of scattering patterns indicate that the PC/SAN blends whose component weight ratios are fixed at 70:30 have excellent antiglare properties, despite the changes in molecular weight of the PC matrix.

Effect of the morphology on the anisotropic light scattering of polycarbonate (PC)/poly(styrene-co-acrylonitrile) (SAN)(70/30) blend

The polycarbonate (PC)/poly(styrene-co-acrylonitrile) (SAN) (70/30) anisotropic light scattering sheet with controllable anisotropic degree was prepared by blending and hot stretching process. The morphological evolution of the dispersed particles for PC/SAN (70/30) blend during hot stretching was observed by a scanning electron microscope (SEM) and the effect of stretching deformation on the light scattering properties was investigated. The SEM photographs revealed that SAN particles deformed into ellipsoid during hot stretching. The scattering properties analysis results revealed the appearance of anisotropic light scattering for PC/SAN (70/30) blends with various deformations, and with the increase of stretching deformation, the anisotropic scattering degree increased, verifying the correctness of geometrical optical scattering theoretical analysis.