Protein digestibility of textured wheat protein (TWP)-based meat analogs: (II) Effects of sodium tripolyphosphate.

In this study, the effects of adding sodium tripolyphosphate during the extrusion of textured wheat protein (TWP)-based meat analogs were investigated. Five TWPs (TWP-C0, TWP-C0.10, TWP-C0.25, TWP-C0.50, and TWP-C0.75) were prepared with sodium tripolyphosphate concentrations of 0%, 0.10%, 0.25%, 0.50%, and 0.75%, respectively. The fibrous structure of TWPs was analyzed by determining their textural properties, degree of texturization, microstructure, and protein bonds. When the concentration of sodium tripolyphosphate increased from 0% to 0.75%, the fibers in TWPs became more regular and finer with smaller pores, the degree of texturization increased from 2.10 ± 0.09 to 2.73 ± 0.07, and the proportions of solubilized protein from the breaking of hydrophobic bonds and disulfide bonds increased from 2.06 ± 0.14% and 1.38 ± 0.11% to 3.42 ± 0.12% and 1.74 ± 0.05%, respectively. The results of particle size, soluble nitrogen content, and free amino acids of samples during digestion indicated that the disintegration rate and protein digestibility of TWPs increased with the increase in the concentration of sodium tripolyphosphate. After gastrointestinal digestion, the total free amino acids released in TWP-C0, TWP-C0.10, TWP-C0.25, TWP-C0.50, and TWP-C0.75 were 391.5 ± 2.2, 403.9 ± 1.5, 430.0 ± 3.6, 473.8 ± 2.9 and 485.3 ± 5.73 mg/10 g digesta, respectively. Sodium tripolyphosphate may improve the protein digestibility of TWPs by forming a finer fibrous structure with a more unfolded protein structure and more hydrophobic groups being exposed to enzymes.

Single-cell transcriptomic analysis of the tumor ecosystem of adenoid cystic carcinoma.

Adenoid cystic carcinoma (ACC) is a malignant tumor that originates from exocrine gland epithelial cells. We profiled the transcriptomes of 49,948 cells from paracarcinoma and carcinoma tissues of three patients using single-cell RNA sequencing. Three main types of the epithelial cells were identified into myoepithelial-like cells, intercalated duct-like cells, and duct-like cells by marker genes. And part of intercalated duct-like cells with special copy number variations which altered with MYB family gene and EN1 transcriptomes were identified as premalignant cells. Developmental pseudo-time analysis showed that the premalignant cells eventually transformed into malignant cells. Furthermore, MYB and MYBL1 were found to belong to two different gene modules and were expressed in a mutually exclusive manner. The two gene modules drove ACC progression into different directions. Our findings provide novel evidence to explain the high recurrence rate of ACC and its characteristic biological behavior.

Medial Epicanthoplasty With the Classic and Modified Skin Redraping Method: A Retrospective Case Control Study.

ABSTRACT: The skin redraping method for medial epicanthoplasty is characterized by some shortcomings which warrants modification. In this study, clinical data of 193 patients who underwent medial epichanthoplasty by the modified skin redraping technique or the classic skin redraping technique were reviewed retrospectively. The patients underwent operation between May 2018 and June 2020 and were followed up for not less than 6 months. Interepicanthal distance, interpupillary distance, patient satisfaction, and postoperative complications were evaluated. In terms of interepicanthal distance/inter-pupillary distance ratio (P > 0.05) and satisfaction score (P = 0.759), the modified skin redraping technique and the classic skin redraping technique were similar. In the classic skin redraping group, there were 3 cases of visible scarring in the lower eyelid, corresponding to significantly more cases than in the modified skin redraping group (n = 0, P < 0.001). There were more out-fold cases in the modified skin redraping group (76/90) than in the classic skin redraping group (17/88) (P < 0.001). Utilizing the modified skin redraping medial epicanthoplasty can prevent medial hooding of the upper eyelid, reduce the probability of visible scarring, and produce more out-fold with concurrent double eyelidplasty compared with classic skin redraping epicanthoplasty. Level of evidence: IV.

Fabrication and characterization of oil-in-water pickering emulsions stabilized by ZEIN-HTCC nanoparticles as a composite layer.

In this work, the ZEIN-HTCC nanoparticles formed by zein and N-(2-hydroxy)propyl-3-trimethylammonium chitosan chloride (HTCC) were used as stabilizers to prepare oil-in-water (O/W) Pickering emulsions. The preparation conditions including shearing time, volume fraction of corn oil, mass ratio of ZEIN:HTCC and total concentration of ZEIN-HTCC of emulsions were optimized by measuring the droplet size, zeta potential, PDI and surface tension of emulsions. The ZEIN-HTCC emulsions are stable at the pH range of 4-9 and in the low salt ion concentrations up to 0.2 mol L-1, and can keep stable up to 21 d during low temperature storage. Fourier transform infrared spectroscopy (FTIR), the confocal laser scanning microscope (CLSM) and scanning electron microscopy (SEM) were used to analyze the interaction between emulsion components, revealing that zein and HTCC form a composite layer by flocculation to adsorb on the surface of oil droplets, thus preventing emulsion droplets from aggregation. This novel, long-term stable, surfactant-free, and edible zein-based Pickering emulsion could be used as potential carriers for lipophilic nutrients delivery.

Curcumin-loaded core-shell biopolymer nanoparticles produced by the pH-driven method: Physicochemical and release properties.

In this study, core-shell biopolymer nanoparticles were fabricated for the encapsulation and delivery of curcumin using a pH-driven method. The influences of the coating composition on the physicochemical properties and curcumin release characteristics of the core-shell nanoparticles were studied. Fourier transform infrared spectroscopy and X-ray diffraction analyses indicated that curcumin was encapsulated in an amorphous state inside the nanoparticles. Particle size and ζ-potential measurements indicated that the biopolymer nanoparticles were relatively stable under different environmental conditions: long term storage, heating, pH changes and salt. The DPPH radical scavenging activity of the curcumin was increased after encapsulation within the nanoparticles, whereas the gastrointestinal release of curcumin was prolonged. These results were attributed to the ability of alginate and NaCas to form a thick layer around the nanoparticles, which increased the steric and electrostatic repulsion between them, as well as inhibiting the release of curcumin.

Improving solubility and stability of ß-carotene by microencapsulation in soluble complexes formed with whey protein and OSA-modified starch.

In this study, a soluble complex formed between 0.5% (w/v) heated whey protein isolate (HWPI) and 5% (w/v) octenyl succinic anhydride (OSA)-modified starch at pH 4.5 was used to encapsulate ß-carotene for improving its solubility and stability. The apparent aqueous solubility of ß-carotene was increased markedly (264.05 ± 72.53 µg/mL) after encapsulation in the soluble complex. Transmission electron microscopy and scanning electron microscopy were used to evaluate the effect of the encapsulation of ß-carotene on the structure of the soluble complex. Fourier transform infrared spectroscopy showed that the characteristic peaks of ß-carotene disappeared in the soluble complex, suggesting that ß-carotene may have been encapsulated into the soluble complex via hydrophobic interactions. X-ray diffraction indicated that the ß-carotene was in an amorphous form within the soluble complex. An accelerated stability test showed that the soluble complex could effectively improve the chemical stability of ß-carotene during long-term storage under low pH conditions.

Complexation between whey protein and octenyl succinic anhydride (OSA)-modified starch: Formation and characteristics of soluble complexes.

Mixed systems of protein and polysaccharide are widely used in the food industry. It is important for food manufacturers to understand their interactions. In this study, the formation of complexes between whey protein isolate (WPI) and octenyl succinic anhydride (OSA)-modified starch was investigated as a function of pH and protein: starch ratio. OSA-modified starch tended to interact with heated WPI (HWPI) rather than non-heated WPI (NWPI), and the optimum conditions for their complexation were a protein: starch ratio of 1:10 and pH 4.5, probably driven by both electrostatic and hydrophobic interactions. The effects of the degree of substitution (DS) and molecular weight (Mw) of OSA-modified starch on the properties of the complexes formed under the optimum conditions were investigated using absorbance measurements (at 515 nm). Soluble complexes (HWPI-OSA SC) between 0.5% (w/v) HWPI and 5% (w/v) OSA-modified starch with a Mw of 19.24 ± 0.07 × 104 g/mol and a DS of 4.29 ± 0.11% could be formed at pH 4.5. The structure of HWPI-OSA SC was examined using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Characterization of the HWPI-OSA SC revealed that the intermolecular interactions between HWPI and OSA-modified starch led to their different characteristics from HWPI and OSA-modified starch alone.

Dynamic gastric stability and in vitro lipid digestion of whey-protein-stabilised emulsions: Effect of heat treatment.

The stability behaviours of whey-protein-stabilised emulsions under gastric conditions and the effects on the lipolysis of the emulsions were investigated using an in vitro dynamic human gastric simulator and a subsequent small intestinal model. Under gastric conditions, heated whey-protein-stabilised emulsions flocculated to a greater extent and with a larger floc size, whereas unheated emulsions were more prone to coalescence. The greater extent of flocculation delayed the delivery of oil droplets to the small intestine, leading to a lower amount of oil in the emptied gastric digesta from the heated emulsion in the early period of digestion. The differences in oil content, droplet size and interfacial composition led to a greater rate and extent of lipolysis in the subsequent intestinal digestion in the heated emulsion than the unheated emulsion. The results suggest that the lipid digestion of whey-protein-stabilised emulsions in the intestinal stage could be manipulated by thermal treatment.

Self-Assembled Micelles Based on OSA-Modified Starches for Enhancing Solubility of ß-Carotene: Effect of Starch Macromolecular Architecture.

Self-assembled micelles based on octenyl succinic anhydride (OSA)-modified starch were prepared to enhance the solubility of ß-carotene. The critical micelle concentration (CMC) was lower for OSA-modified starch with a lower molecular weight (Mw) or higher degree of substitution (DS). Above the CMC, OSA-modified starch assembled into spherical micelles with an average hydrodynamic diameter of <20 nm, as determined by dynamic light scattering (DLS). All the radii of gyration ( Rg), obtained from Guinier fitting of small-angle X-ray scattering (SAXS) data, were between 3 and 9 nm, and they were positively correlated with the Mw but negatively correlated with both the DS and the starch concentration. ß-Carotene was encapsulated effectively into the starch micelles, and the concentration of ß-carotene in the micelles was positively correlated with the concentration, Mw, and DS of the starch, with a maximum value of 53.14 µg/mL. The incorporation of ß-carotene enlarged the hydrophobic core and induced a significant increase in the Rg of the micelles determined by SAXS, and it may have also promoted the aggregation of the micelles resulting in a marked increase in the Dh determined by DLS.

Gastric digestion of milk protein ingredients: Study using an in vitro dynamic model.

The coagulation behavior and the kinetics of protein hydrolysis of skim milk powder, milk protein concentrate (MPC), calcium-depleted MPC, sodium caseinate, whey protein isolate (WPI), and heated (90°C, 20 min) WPI under gastric conditions were examined using an advanced dynamic digestion model (i.e., a human gastric simulator). During gastric digestion, these protein ingredients exhibited various pH profiles as a function of the digestion time. Skim milk powder and MPC, which contained casein micelles, formed cohesive, ball-like curds with a dense structure after 10 min of digestion; these curds did not disintegrate over 220 min of digestion. Partly calcium-depleted MPC and sodium caseinate, which lacked an intact casein micellar structure, formed curds at approximately 40 min, and a loose, fragmented curd structure was observed after 220 min of digestion. In contrast, no curds were formed in either WPI or heated WPI after 220 min of digestion. In addition, the hydrolysis rates and the compositions of the digesta released from the human gastric simulator were different for the various protein ingredients, as detected by sodium dodecyl sulfate-PAGE. Skim milk powder and MPC exhibited slower hydrolysis rates than calcium-depleted MPC and sodium caseinate. The most rapid hydrolysis occurred in the WPI (with and without heating). This was attributed to the formation of different structured curds under gastric conditions. The results offer novel insights about the coagulation kinetics of proteins from different milk protein ingredients, highlighting the critical role of the food matrix in affecting the course of protein digestion.