Investigation of the molecular interactions between β-lactoglobulin and low methoxyl pectin by multi-detection High Performance Size Exclusion Chromatography

Rheological properties for determining the interaction of soluble cress seed mucilage and β-lactoglobulin nanocomplexes under sucrose and lactose treatments

Protein-polysaccharide complexes are commonly applied in different food products. Their interaction and their functional properties that arise as a consequence of interactions are remarkably influenced by the presence of co-solutes in the system. In this study, general rheological properties and the aggregation behavior of cress seed mucilage (CSM)-β-lactoglobulin (Blg) complexes were studied in the presence of sucrose (5-20% w/v) and lactose (5-20% w/v). The highest values of apparent viscosity and stability (zeta potential) in CSM-Blg complexes were measured when the medium contained 5% w/v lactose (10.00 Pa.s at 0.1 s^-1, -25 ± 0.8 mV) and 20% w/v sucrose (12.89 Pa.s at 0.1 s^-1, -35 ± 0.2 mV). The results of oscillatory experiments indicated that the gel-like feature of the complexes improved, parallel to a decrease in frequency, which highlighted the shear-induced gelation phenomenon. The thermal analysis test demonstrated that the thermal stability of Blg (70.5^◦C), with its complexation to CSM, improved through denaturation. Also, the association of CSM-Blg (82^◦C) nanocomplexes with lactose (96^◦C) can enhance the thermal stability more effectively. Considering the widespread use of protein-polysaccharide complexes in diverse sugar-containing food formulations, the results of this study can contribute to the creation of new compounds with special techno-functional features.

Bovine β-lactoglobulin peptides as novel carriers for flavonoids extracted with supercritical fluids from yellow onion skins

Our study describes in detail the binding mechanism between the main flavonoids that were extracted from onion skins by supercritical CO₂ and peptides from whey proteins, from the perspective of obtaining multifunctional ingredients, with health-promoting benefits. The supercritical CO₂ extract had 202.31 ± 11.56 mg quercetin equivalents/g DW as the major flavonoid and antioxidant activity of 404.93±1.39 mM Trolox/g DW. The experiments on thermolysin-derived peptides fluorescence quenching by flavonoids extract allowed estimating the binding parameters, in terms of binding constants, and the number of binding sites. The thermodynamic analysis indicated that the main forces involved in complex formation were hydrogen bonds and van der Waals interactions. Molecular docking tests indicated that peptide fluorescence quenching upon gradual addition of onion skin extract might be due to flavonoids binding by Val¹⁵ -Ser²¹ . All 7 to 14 amino acids long peptides appeared to have affinity toward quercetin-3,4'-O-diglucoside and quercetin-4'-O-monoglucoside. The study is important as a potential solution for reuse of valuable resources, underutilized, such as whey peptides and yellow onion skins flavonoids for efficient microencapsulation, as a holistic approach to deliver healthy and nutritious food. PRACTICAL APPLICATION: A growing interest was noticed in the last years in investigating the interactions between proteins and different biologically active compounds, such as to provide knowledge for efficient development of new food, pharmaceutical, and cosmetic products. Recent studies suggest that flavonoid-protein complexes may be designed to improve the functional performance of the flavonoids. The results obtained in this study bring certain benefits in terms of exploiting the bioactive potential of both flavonoids and bioactive peptides, for developing of formulas with improved functional properties.

Biocompatible chitosan-pectin polyelectrolyte complex for simultaneous electrochemical determination of metronidazole and metribuzin

Development of novel biocompatible sensor material suitable for modest, cost-effective, and rapid practical application is a demanding research interest in the field of electroanalytical chemistry. In this context, for the first time, we utilized biocompatible chitosan-pectin biopolyelectrolyte (CS-PC BPE) complex for the simultaneous electroreduction of an important antibiotic drug (metronidazole-MNZ) and herbicide (metribuzin-MTZ). This sensor reveals an attractive welfares such as simplicity, biocompatibility, and low production cost. Under optimized experimental conditions, the electroanalytical investigation confirmed that CS-PC BPE modified glassy carbon electrode (CS-PC BPE/GCE) was found to sense MNZ and MTZ in the nanomolar range. Moreover, as-prepared CS-PC BPE/GCE exhibited prominent selectivity, stability, and reproducibility. Additionally, the possible MNZ and MTZ sensing mechanism of CS-PC BPE/GCE have been discussed in detail. Lastly, real sample analysis was also carried out and revealed from several investigations that the CS-PC BPE/GCE is a good electrochemical sensor system for the detection of targeted analytes.

Biocompatible Polyelectrolyte Complex Nanoparticles from Lactoferrin and Pectin as Potential Vehicles for Antioxidative Curcumin

Polyelectrolyte complex nanoparticles (PEC NPs) were fabricated via electrostatic interactions between positively charged heat-denatured lactoferrin (LF) particles and negatively charged pectin. The obtained PEC NPs were then utilized as curcumin carriers. PEC NPs were prepared by mixing 1.0 mg/mL solutions of heat-denatured LF and pectin at a mass ratio of 1:1 (w/w) in the absence of NaCl at pH 4.50. PEC NPs that were prepared under optimized conditions were spherical in shape with a particle size of ∼208 nm and zeta potential of ∼-32 mV. Hydrophobic curcumin was successfully encapsulated into LF/pectin PEC NPs with high encapsulation efficiency (∼85.3%) and loading content (∼13.4%). The in vitro controlled release and prominent antioxidant activities of curcumin from LF/pectin PEC NPs were observed. The present work provides a facile and fast method to synthesize nanoscale food-grade delivery systems for the improved water solubility, controlled release, and antioxidant activity of hydrophobic curcumin.

β-Lactoglobulin: An efficient nanocarrier for advanced delivery systems

Thanks to the progress of nanotechnology there are several agent-delivery systems that can be selected to achieve rapid and specific delivery of a wide variety of biologically active agents. Consequently, the manipulation and engineering of biopolymers has become one of the most exciting subjects for those who study delivery systems on the nanoscale. In this regard, both nanoparticle formation and a carrier role have been observed in the case of the globular milk whey protein, β-lactoglobulin (β-LG), setting it apart from many other proteins. To date, many efforts adopting different approaches have created β-LG nanoparticles useful in forming delivery systems for various agents with specific targets. In this review, the potential of β-LG to play the role of an efficient and diverse carrier protein, as well as its ability to form a well-targeted nano-scale delivery system is discussed.