Effect of salt ions on an ultrasonically modified soybean lipophilic protein nanoemulsion

A Soy Protein-Based Film Based on Chemical Treatment and Microcrystalline Cellulose Reinforcement Obtained from Corn Husk Byproducts

Developing an environmentally friendly soy protein-based film that offers excellent performance has garnered considerable interest while also posing a significant challenge. Herein, we propose the strategy of covalent and noncovalent cross-linking to improve the mechanical properties of the films. First, chemical denaturation was carried out under the combined action of sodium sulfite, sodium dodecyl sulfate, sodium hydroxide, and urea to reshape the structure of the protein to improve the solubility of protein and release active groups. Then, microcrystalline cellulose (MCC) derived from low-cost agro-industrial byproducts (corn husk) was employed to balance the covalent cross-linking reaction between proteins and the noncovalent reaction between MCC and protein. The results indicate that the structure and properties of the soy protein-based films were modified and improved through chemical treatment in conjunction with biomass enhancement. It is concluded that the addition of 1% MCC improves the tensile strength, elastic modulus, water solubility, and water vapor permeability of "MCC-1%" by 64.7, 75.9, 22.7, and 12.9%, respectively. Additionally, the resulting film of "MCC-1%" exhibits better resistance to thermal degradation and improved thermo-stability. However, the elongation at break decreased by increasing the addition of MCC. Thus, this work may provide a simple and affordable approach to preparing a high-performing soy protein-based film.

Antioxidant Activity, Formulation, Optimization and Characterization of an Oil-in-Water Nanoemulsion Loaded with Lingonberry (Vaccinium vitis-idaea L.) Leaves Polyphenol Extract

The active ingredients in lingonberry leaves and their beneficial properties to the human body have been well confirmed. In order to improve the stability and antioxidant activity of the active ingredients in lingonberry leaves, the response surface optimization method was used to prepare an oil-in-water nanoemulsion of polyphenol extract from lingonberry leaves. The active components in the extract were analyzed by ultra-performance liquid chromatography with triple quadrupole mass spectrometry (UPLC-TQ-MS), and bioactive compounds such as apigenin, sorbitol, and hesperidin were mainly found. Nanoemulsion droplets of 120 nm in diameter were prepared using ultrasonic emulsification. The optimal nanoemulsion formulation was determined through rigorous testing, and it was determined to be 10% (w/w) lingonberry extract and 20% (w/w) medium chain triglyceride (MCT). Additionally, a surfactant mixture was used, which combined soy protein isolate (SPI) and whey protein isolate (WPI) at 4% (w/w). The preparation method utilized ultrasonic emulsification, applying an ultrasonic power of 360 W for a duration of 300 s. The antioxidant activity (DPPH inhibition rate, ABTS inhibition rate and total reducing power) of the lingonberry nanoemulsion was significantly higher than that of the lingonberry polyphenol (LBP) extract. The nanoemulsion prepared using the optimal formulation had an entrapping efficiency of 73.25% ± 0.73% and a diameter of 114.52 ± 0.015 nm, with a satisfactory particle size of nanoscale and a PDI of 0.119 ± 0.065, demonstrating good stability of the emulsion.