Food proteins are a potential resource for mining cathepsin L inhibitory drugs to combat SARS-CoV-2

The entry of SARS-CoV-2 into host cells proceeds by a proteolysis process, which involves the lysosomal peptidase cathepsin L. Inhibition of cathepsin L is therefore considered an effective method to decrease the virus internalization. Analysis from the perspective of structure-functionality elucidates that cathepsin L inhibitory proteins/peptides found in food share specific features: multiple disulfide crosslinks (buried in protein core), lack or low contents of (small) α-helices, and high surface hydrophobicity. Lactoferrin can inhibit cathepsin L, but not cathepsins B and H. This selective inhibition might be useful in fine targeting of cathepsin L. Molecular docking indicated that only the carboxyl-terminal lobe of lactoferrin interacts with cathepsin L and that the active site cleft of cathepsin L is heavily superposed by lactoferrin. A controlled proteolysis process might yield lactoferrin-derived peptides that strongly inhibit cathepsin L.</p

Food based carriers for delivery of proteins and enzymes

Food based carriers for delivery of proteins and enzymes. STLOpenday

An overview on preparation of emulsion-filled gels and emulsion particulate gels

Background: Emulsion gels are a class of soft solid-like materials. These composite materials are structurallyeither a polymeric gel matrix into which emulsion droplets are incorporated (emulsion-filled gels), or a networkof aggregated emulsion droplets (emulsion particulate gels). Emulsion gels are increasingly used in pharmaceutics, cosmetics and food industries.Scope and approach: This article reviews fabrication methods of emulsion gels, and describes factors that influence gel properties and functionality. Effect of polymer-surfactant interactions on the rheology of emulsiongel systems is explained. Then, irreversible and reversible clustering of oil droplets as the basis of makingemulsion particulate gels is deliberated.Key Findings and Conclusions: Oil droplets depending on their interfacial composition act as either active orinactive fillers in an emulsion-filled gel. Actively functioning oil droplets can increase gel modulus, whereas,inactive oil droplets typically weaken gel texture. Interactions between surfactants and polymers, which influences filler affinity to gel matrix, have significant consequences on emulsion gel rheology. For protein-based emulsion gels, surfactant may also influence proteins unfolding and aggregation.In situ gelation of an emulsion can be triggered by environmental factors such as temperature changes duringprocessing and storage or by physiological stimuli such as acidic pH in the stomach. The clustering approach,which is used to form emulsion particulate gels may be utilized to control digestibility of lipids in the gastrointestinal tract. The capability of encapsulating two or more different lipophilic components within a single delivery system may be achieved via heteroaggregation technique

Gelation by bioactives : Characteristics of the cold-set whey protein gels made using gallic acid

A bioactive molecule, gallic acid (GA), was used to form cold-set whey protein gels. This method enables exploitation of the bioactive compound per se to gel whey proteins. Also, citric acid was used to crosslink whey proteins before gelation by GA. Compared with phosphoric acid (PA), gelation by GA prevented formation of intermolecular β-sheets and resulted in a porous microstructure. Also, the GA-induced gel had a lower firmness and water-holding capacity (WHC), but a higher swellability in pepsin-free simulated gastric fluid. Citric acid pre-crosslinking decreased the proportion of α-helix structures in favour of β-turns in the GA-induced gel. It also increased the size of ordered structures (α-helix and β-sheets), caused formation of larger protein aggregates and increased gel WHC. The PA-induced gel initially underwent a lower in vitro peptic disintegration; however, the disintegration of the PA-induced gel rapidly increased, surpassing those of GA-induced gels.</p

Food based carriers for the delivery of pancreatic enzymes to elderly for restoring digestion and tackling malnutrition.

Food based carriers for the delivery of pancreatic enzymes to elderly for restoring digestion and tackling malnutrition. . 5.AgreenSkills Annual Meeting in Edinburg

A viewpoint on the gastrointestinal fate of cellulose nanocrystals

Background: Cellulose nanocrystalline (CNC) particles possess unique functional properties such as vastlymodifiable surface, considerable mechanical strength and acid resistance, as well as, high aspect ratio. CNCshave received great attention for application in diverse fields of technology including (composite) hydrogelsfabrication for the gastric protection and enteral delivery of drugs and nutraceuticals.Scope and approach: The orogastrointestinal digestibility and absorbability of the orally administered CNCs isoverviewed in the current article. At first, some surface charge-related characteristics of acid-isolated CNCs are communicated. Then, the biocompatibility and biodegradability of CNCs and CNC-reinforced hydrogels arereviewed, followed by presenting credible digestion and absorption scenarios. Finally, the post-absorptionmetabolism of CNCs is briefly debated.Key findings and conclusions: Bacterial cellulose shows good biocompatibility and hemocompatibility. CNCoxidation provides biologically beneficial impacts; for instance, the TEMPO- and periodate-oxidized CNCs have been shown to regulate some blood metabolic variables and improve the degradability in simulated human blood plasma, respectively. Spherical and carboxyl-bearing cellulose nanoparticles can be isolated through ammonium persulfate digestion. The sphericity of particles results in faster cellular uptake. Negatively-charged CNCs are non-mucoadhesive and thus upon ingestion can penetrate into the buccal and intestinal mucosa. One may augment the absorption of CNCs by targeted receptor-mediated endocytosis. It was postulated that sodium bicarbonate secretion into the duodenum can alter CNCs surface chemistry and influence CNC interaction with gut microbiot

Technological functionality and biological properties of food protein nanofibrils formed by heating at acidic condition

BackgroundNanofibrillation of proteins by heating at extremely acidic condition for long durations (several hours to days) is studied enthusiastically in food science. The process progresses by the unidirectional self-assembly of peptides as building units of the fibrils.Scope and approachThis communication provides a review on the underlying mechanism of protein fibrillation, and various technological properties of the fibrils, followed by discussing their biological and cellular effects.Key findings and conclusionsFibrillation of proteins and addition of the fibrils into liquid foods causes a significant increase of apparent viscosity. Nevertheless, certain post-fibrillation processes such as freeze-drying may result in viscosity reduction. Fibrils form cohesive viscoelastic interfaces, bringing about high foam and emulsion stability. The presence of non-fibrillated peptides and low molecular weight surfactants influence the foaming and emulsification properties of fibrillated protein solutions. Fibrillated protein can yield cold-set gels at extremely low concentrations, which is attributed to formation of space filling networks. Reinforcing polymeric films, conferring hydrophilic character to graphene, developing drug and nutraceutical delivery vehicles such as microcapsules, microgels and fibrillosome and utilization (mostly as scaffolds) in fabrication of biosensors and bio-sorbents are the other applications of protein fibrils. Fibrillation may increase the antioxidant activity of proteins. It can also influence protein digestibility. Fibrils do not exert any major toxicity towards human cell lines and can be exploited as biomimetic cell culture platforms and cellular transport shuttles

Food based carriers for the delivery of pancreatic enzymes to elderly for restoring digestion and tackling malnutrition.

Food based carriers for the delivery of pancreatic enzymes to elderly for restoring digestion and tackling malnutrition. . 5.AgreenSkills Annual Meeting in Edinburg

Effects of acetyl grafting on the structural and functional properties of whey protein microgels

Whey protein microgels (WPMs) are self-assembled sub-micron particles, with diverse applications in food science such as emulsion and foam stabilization. This study evaluated the influence of acetylation at different acetic anhydride-to-protein molar ratios (AA-to-protein MRs) on structural characteristics, colloidal stability, and technological functionality of WPMs. N-acetylation degree progressively increased with increasing the AA-to-protein MR and reached 96% when AA-to-protein MR was 3270. O-acylation increased significantly only after N-acylation extensively (96%) occurred. Acetylation process increased the randomness of proteins in WPMs (assessed by circular dichroism and Fourier transform infrared spectroscopies) as well as conferred a less compact structure (assessed by intrinsic fluorescence spectroscopy). The isoelectric point (pI) of WPMs shifted from roughly 4.5 to 3.0–3.9 depending on the acetylation extent; the higher the acetylation degree, the lower was the pI. Acetylation at any extent did not improve the colloidal stability of WPMs at their corresponding pI. However, the emulsification activity of WPMs at pH values between 5.0 and 7.0 increased with increasing the acetylation extent. The highest foaming and oil absorption capacities of WPMs at pH 7.0 was obtained at a N-acetylation extent of 40%.</p