Structures, fabrication mechanisms, and emulsifying properties of self-assembled and spray-dried ternary complexes based on lactoferrin, oat β-glucan and curcumin: A comparison study

Physicochemical Properties, Stability, and Functionality of Non-Covalent Ternary Complexes Fabricated with Pea Protein, Hyaluronic Acid and Chlorogenic Acid

The aim of this study was to prepare and characterize stable non-covalent ternary complexes based on pea protein (PP, 0.5%), hyaluronic acid (HA, 0.125%), and chlorogenic acid (CA, 0~0.03%). The ternary complexes were comprehensively evaluated for physicochemical attributes, stability, emulsifying capacities, antioxidant properties, and antimicrobial efficacy. PP-HA binary complexes were first prepared at pH 7, and then CA was bound to the binary complexes, as verified by fluorescence quenching. Molecular docking elucidated that PP interacted with HA and CA through hydrogen bonding, hydrophobic and electrostatic interactions. The particle size of ternary complexes initially decreased, then increased with CA concentration, peaking at 0.025%. Ternary complexes demonstrated good stability against UV light and thermal treatment. Emulsifying activity of complexes initially decreased and then increased, with a turning point of 0.025%, while emulsion stability continued to increase. Complexes exhibited potent scavenging ability against free radicals and iron ions, intensifying with higher CA concentrations. Ternary complexes effectively inhibited Staphylococcus aureus and Escherichia coli, with inhibition up to 0.025%, then decreasing with CA concentration. Our study indicated that the prepared ternary complexes at pH 7 were stable and possessed good functionality, including emulsifying properties, antioxidant activity, and antibacterial properties under certain concentrations of CA. These findings may provide valuable insights for the targeted design and application of protein-polysaccharide-polyphenol complexes in beverages and dairy products.

The Effect of Nanoscale Modification of Nisin by Different Milk-Derived Proteins on Its Physicochemical Properties and Antibacterial Activity

Nisin is used as a natural food preservative because of its broad-spectrum antimicrobial activity against Gram-positive bacteria. However, free nisin is susceptible to various factors that reduce its antimicrobial activity. Milk protein, a protein derived from milk, has self-assembly properties and is a good carrier of bioactive substances. In this study, lactoferrin-nisin nanoparticles (L-N), bovine serum albumin-nisin nanoparticles (B-N), and casein-nisin nanoparticles (C-N) were successfully prepared by a self-assembly technique, and then their properties were investigated. The studies revealed that lactoferrin (LF) and nisin formed L-N mainly through hydrophobic interactions and hydrogen bonding, and L-N had the best performance. The small particle size (29.83 ± 2.42 nm), dense reticular structure, and good thermal stability, storage stability, and emulsification of L-N laid a certain foundation for its application in food. Further bacteriostatic studies showed that L-N enhanced the bacteriostatic activity of nisin, with prominent inhibitory properties against Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus, which mainly disrupted the cell membrane of the bacteria. The above results broaden our understanding of milk protein-nisin nanoparticles, while the excellent antibacterial activity of L-N makes it promising for application as a novel food preservative, which will help to improve the bioavailability of nisin in food systems.

Ultrasound and enzyme assisted preparation of novel lactoferrin-cereal phenolic acid conjugates: structural, physicochemical and functional properties

The effects of covalent binding of protocatechuic acid (PA) and gallic acid (GA) to lactoferrin (LF) on the structure, functional, and antioxidant properties of the protein conjugate were investigated. These protein-phenolic conjugates were produced by laccase cross-linking and ultrasound-assisted free radical grafting, which were characterized using turbidity, particle size, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analyses. Structural changes in conjugates were monitored by endogenous fluorescence spectroscopy, fourier transform infrared spectroscopy (FTIR), and circular dichroism (CD). The antioxidant capacities and pH stability were determined using DPPH, ABTS, FRAP, and potentiometric analysis. The enzymatic cross-linking and free radical grafting yielded LF-PA/GA conjugates with altered hydrodynamic diameter and zeta-potential. Spectroscopic and chromatographic analyses revealed that binding to PA/GA altered the molecular structure of LF, with a decrease in LF isoelectric point post binding to PA/GA, without affecting antioxidant activities. In conclusion, LF-PA/GA conjugates present potential applications in the food industry.

Noncovalent interactions between biomolecules facilitated their application in food emulsions' construction: A review

The use of biomolecules, such as proteins, polysaccharides, saponins, and phospholipids, instead of synthetic emulsifiers in food emulsion creation has generated significant interest among food scientists due to their advantages of being nontoxic, harmless, edible, and biocompatible. However, using a single biomolecule may not always meet practical needs for food emulsion applications. Therefore, biomolecules often require modification to achieve ideal interfacial properties. Among them, noncovalent interactions between biomolecules represent a promising physical modification method to modulate their interfacial properties without causing the health risks associated with forming new chemical bonds. Electrostatic interactions, hydrophobic interactions, and hydrogen bonding are examples of noncovalent interactions that facilitate biomolecules' effective applications in food emulsions. These interactions positively impact the physical stability, oxidative stability, digestibility, delivery characteristics, response sensitivity, and printability of biomolecule-based food emulsions. Nevertheless, using noncovalent interactions between biomolecules to facilitate their application in food emulsions still has limitations that need further improvement. This review introduced common biomolecule emulsifiers, the promotion effect of noncovalent interactions between biomolecules on the construction of emulsions with different biomolecules, their positive impact on the performance of emulsions, as well as their limitations and prospects in the construction of biomolecule-based emulsions. In conclusion, the future design and development of food emulsions will increasingly rely on noncovalent interactions between biomolecules. However, further improvements are necessary to fully exploit these interactions for constructing biomolecule-based emulsions.

Effect of oat β-glucan on in vitro digestion characteristics of set- type yogurt

The main objective of the study was to evaluate the effect of added 0.3% (w/w) oat β-glucan (OG) in set-type yogurt on its protein digestion using an in vitro gastrointestinal model. During gastric digestion phase, the amount of soluble proteins and peptides increased to 25% and 40% for control yogurt (yogurt without OG) and 0.3% OG yogurt, respectively. Buccal digestion has little effect on the structure of yogurts, while large spherical vesicles were formed for both control yogurt and 0.3% OG yogurt after gastric digestion. The presence of 0.3% OG promoted the hydrolysis of yogurt in the gastric digestion phase and caused higher antioxidant activity. Compared with that of control yogurt, the inhibition of cholesterol solubility of 0.3% OG yogurt showed no differences after buccal digestion but significantly higher after gastrointestinal digestion (21.3% for gastric and 22.7% for intestinal digestion). Overall, this study enhances the understanding of digestion characteristics of 0.3% OG-fortified set-type yogurt and provides a theoretical basis for the development of this kind of dairy products.

Improving method, properties and application of polysaccharide as emulsifier

At present, there are still some problems for the emulsification of polysaccharides such as lack of green, efficient and industrialized methods, lack of systematic and in-depth structure-activity relationship, and need of expanding its application scope. The physical, chemical and biological methods for improving the emulsifying of polysaccharides, the emulsifying properties and influencing factors of polysaccharides and application in food were reviewed herein. It was pointed out that the future research should focus on the effect of physical-biological synergistic function on the emulsification of polysaccharides, the effect of processing process on the structure and emulsification mechanism of polysaccharides, and further expanding the application field of polysaccharides with emulsification activity to improve the quality of products.

Recent advances of cereal β-glucan on immunity with gut microbiota regulation functions and its intelligent gelling application

β-glucan from cereals such as wheat, barley, oats and rye are a water-soluble dietary fiber, which are composed of repeating (1→4)-β-bond β-D-glucopyranosyl units and a single (1→3)-β-D-bond separated unit. β-glucan has a series of physicochemical properties (such as viscosity, gelling properties, solubility, etc.), which can be used as a food gel and fat substitute. Its structure endows the healthy functions, including anti-oxidative stress, lowering blood glucose and serum cholesterol, regulating metabolic syndrome and exerting gut immunity via gut microbiota. Due to their unique structural properties and efficacy, cereal β-glucan are not only applied in food substrates in the food industry, but also in food coatings and packaging. This article reviewed the applications of cereal β-glucan in hydrogels, aerogels, intelligent packaging systems and targeted delivery carriers in recent years. Cereal β-glucan in edible film and gel packaging applications are becoming more diversified and intelligent in recent years. Those advances provide a potential solution based on cereal β-glucan as biodegradable substances for immune regulation delivery system and intelligent gelling material in the biomedicine field.

Nanoencapsulated curcumin emulsion utilizing milk cream as a potential vehicle by microfluidization: Bioaccessibility, cytotoxicity and physico-functional properties

Curcumin loaded milk cream emulsion was microfluidized at different pressures (50-200 MPa) and passes (1-4) using a full-factorial experimental design. Ultrasonicated and microfluidized emulsion was evaluated for particle size, morphological characteristics, antioxidant activity, rheological properties, bioaccessibility and cytotoxicity. Significant reduction was observed in the average particle size (358.2 nm) after microfluidization at 100 MPa/2nd pass. Transmission electron micrographs of the control (homogenized) and microfluidized (100 MPa/2nd pass) samples showed uniform distribution of fat globules in the microfluidized sample with partially dissolved curcumin particles (50-150 nm). Encapsulation efficiency of microfluidized emulsion was found to be significantly higher (97.88%) after processing as compared to control (91.21%). Two-fold (100%) increase in the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and 25% increase in ferric-reducing antioxidant power (FRAP) was observed for microfluidized emulsions over control. Infrared spectrums of the emulsion exhibited shift in high intensity peaks indicating bond cleavage after microfluidization. After characterization, emulsions were subjected to in vitro digestion (oral, gastric and intestinal phase) to evaluate its bioaccessibility which was found to be remarkably increased by 30% after microfluidization. For assessing processing induced safety of the formulation, in vitro cytotoxicity of the microfluidized nanocurcumin emulsion was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on HepG2 cells, wherein high % of cell viability (>93%) was seen even at a dose as high as 900 µg/mL revealing no toxic effect of the processing technique (microfluidization). This study highlights the efficacy of microfluidization as a technique and that of milk cream as an inexpensive, yet potential vehicle for generating stable and bio-accessible nano-curcumin emulsion.