Macromolecular crowding conditions enhance glycation and oxidation of whey proteins in ultrasound-induced Maillard reaction

Harnessing the Potential of Blood Proteins as Functional Ingredients: A Review of the State of the Art in Blood Processing

Blood is generated in very large volumes as a by-product in slaughterhouses all around the world. On the one hand, blood generation presents a serious environmental issue because of its high pollutant capacity; however, on the other hand, blood has the potential to be collected and processed to generate high-added-value food ingredients based on its exceptional nutritive value and its excellent functional properties. In this paper, we review the current state of the art for blood processing, from collection to final recovery of protein isolates, the functional properties of blood, impact of processing on functional properties, and potential applications as food ingredients. Furthermore, future challenges are outlined for this underutilized and abundant product from the meat industry.

Mechanism of Formation and Stabilization of Nanoparticles Produced by Heating Electrostatic Complexes of WPI-Dextran Conjugate and Chondroitin Sulfate

Protein conformational changes were demonstrated in biopolymer nanoparticles, and molecular forces were studied to elucidate the formation and stabilization mechanism of biopolymer nanoparticles. The biopolymer nanoparticles were prepared by heating electrostatic complexes of whey protein isolate (WPI)-dextran conjugate (WD) and chondroitin sulfate (ChS) above the denaturation temperature and near the isoelectric point of WPI. The internal characteristics of biopolymer nanoparticles were analyzed by several spectroscopic techniques. Results showed that grafted dextran significantly (p < 0.05) prevented the formation of large aggregates of WD dispersion during heat treatment. However, heat treatment slightly induced the hydrophobicity changes of the microenvironment around fluorophores of WD. ChS electrostatic interaction with WD changed the fluorescence intensity of WD regardless of heat treatment. Far-UV circular dichroism (CD) and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopies confirmed that glycosylation and ionic polysaccharide did not significantly cause protein conformational changes in WD and ChS (WDC) during heat treatment. In addition, hydrophobic bonds were the major molecular force for the formation and stabilization of biopolymer nanoparticles. However, hydrogen bonds slightly influenced their formation and stabilization. Ionic bonds only promoted the formation of biopolymer nanoparticles, while disulfide bonds partly contributed to their stability. This work will be beneficial to understand protein conformational changes and molecular forces in biopolymer nanoparticles, and to prepare the stable biopolymer nanoparticles from heating electrostatic complexes of native or glycosylated protein and polysaccharide.