Numerical computation and experimental assessment of a pressure-retaining gas-tight sediment sampler.

The pressure of the recovered sample is intricately connected to seawater temperature, the recovery velocity, and the pressure of the pre-charged gas. To better understand the sample pressure dynamics during the sampling recovery process, we focus on a gas-tight sediment sampler, delving into its pressure-compensation and pressure-retaining mechanisms. A comprehensive thermal and thermodynamic analysis is conducted throughout the entire pressure-retaining sampling process, examining the temporal variations in the temperatures of seawater and nitrogen within the sampler at various descending velocities. The heat transfer and thermodynamics are examined throughout the entire pressure-retaining sampling process to determine how changes in the temperatures of seawater and nitrogen, as well as the descent velocity, affect the pressure-retaining performance. The influence of pre-charging pressure and recovery velocities on the pressure-retaining performance of the sampler is examined. Then the proposed numerical model was well verified by the ultra-high-pressure vessel experiments of the sampler under 115 MPa. Finally, the sea trial results further verified the accuracy of the numerical model.

Enhancing bread anti-staling with glucose-derived Maillard reaction products: In-depth analysis of starches, gluten networks, and moisture status.

In this study, six types of amino acids (Ala, Phe, Glu, Gly, Ser, and Lys) were combined with glucose to produce Maillard reaction products (MRPs) named G-Ala, G-Phe, G-Glu, G-Gly, G-Ser and G-Lys. The effect of MRPs on bread staling was evaluated through texture and sensory analyses during storage. Furthermore, the study comprehensively analyzed the anti-staling mechanisms of MRPs by examining moisture content, starches, and gluten network changes. The results indicated that G-Gly and G-Glu delayed bread staling, with G-Gly showing the most significant effect. Compared with control, the staling rate and starch crystallinity of G-Gly bread decreased by 24.07% and 7.70%, respectively. Moreover, G-Gly increased the moisture content (3.48%), weakly bound water mobility (0.77%), and α-helix content (1.00%) of bread. Component identification and partial least squares regression further confirmed the aldonic acid, heterocyclic acids and heterocyclic ketones in MRPs inhibit water evaporation, gluten network loosening, and starch degradation, thereby delaying bread staling.

Edible film preparation by anthocyanin extract addition into acetylated cassava starch/sodium carboxymethyl cellulose matrix for oxidation inhibition of pumpkin seeds.

In this study, an edible film was fabricated by incorporating anthocyanin extract from black rice (AEBR) into acetylated cassava starch (ACS)/carboxymethyl-cellulose (CMC) to enhance the shelf life of pumpkin seeds. The effects of AEBR on the rheological properties of film-forming solutions, as well as the structural characterization and physicochemical properties of the film, were evaluated. Rheological properties of solutions revealed that AEBR was evenly dispersed into polymer matrix and bound by hydrogen bonds, as confirmed by Fourier transform infrared spectroscopy analysis. The appropriate AEBR addition could be compatible with polymer matrix and formed a compact film structure, improving the mechanical properties, barrier properties, and opacity. However, with further addition of AEBR, the tensile strength and water vapor permeability decreased and the tight structure was destroyed. After being stored separately under thermal and UV light accelerated conditions for 20 days, the peroxide value and acid value of roasted pumpkin seeds coated with the AEBR film showed a significant reduction. Moreover, the storage stability of AEBR was improved through the embedding of ACS/CMC biopolymers. These results indicated that AEBR film could effectively delay pumpkin seeds oxidation and prolong their shelf life as an antioxidant material.

Study on Physicochemical Properties of Food Protein.

As the global population continues to grow, the demand for sustainable and nutritious food sources has never been higher [...].

Sealing performance of sealing structure in a sediment sampler under ultra-high pressure.

As a key component of a sediment sampler designed for ultra-high pressures, the sealing structure determines whether pressure retention can be reliably achieved. This study constructed a finite element model to study sealing performance and reveal the sealing mechanism. The effects of the hardness and compression rate of O-ring as well as seawater pressure on the sealing performance were studied. The study showed that a self-tightening seal can be formed when the coefficient of friction on the sealing surface is less than or equal to 0.25. In addition, the maximum contact stress of the O-ring increased nearly linearly with increasing pressure, and it was larger than the corresponding pressure. However, with increasing pressure, the maximum Von-Mises stress initially increased rapidly, then tended to stabilize, and then continued to increase. Although increasing the hardness reduced the principal strain, the stress increased correspondingly. Within the compression rate range from 10 to 25%, the hardness of the O-ring had a greater impact on the contact pressure than the compression rate. In order to further verify that the finite element analysis was accurate, the sealing performance was tested, and the results showed that the seal was reliable and capable of sealing a deep-sea sampler.

Dual-channel biosensor for simultaneous detection of S. typhimurium and L. monocytogenes using nanotags of gold nanoparticles loaded metal-organic frameworks.

Simultaneous detection of multiple foodborne pathogens is of great importance for ensuring food safety. Herein, we present a sensitive dual-channel electrochemical biosensor based on copper metal organic frameworks (CuMOF) and lead metal organic framework (PbMOF) for simultaneous detection of Salmonella typhimurium (S. typhimurium) and Listeria monocytogenes (L. monocytogenes). The MOF-based nanotags were prepared by functionalizing gold nanoparticles loaded CuMOF (Au@CuMOF) and PbMOF (Au@PbMOF) with signal DNA sequences 1 (sDNA1) and sDNA2, respectively. By selecting invA of S. typhimurium and inlA gene of L. monocytogenes as targe sequences, a sandwich-typed dual-channel biosensor was developed on glassy carbon electrodes (GCE) through hybridization reactions. The sensitive detection of S. typhimurium and L. monocytogenes was achieved by the direct differential pulse voltametric (DPV) signals of Cu2+ and Pb2+. Under optimal conditions, channel 1 of the biosensor showed linear range for invA gene of S. typhimurium in 1 × 10-14-1 × 10-8 M with low detection limit (LOD) of 3.42 × 10-16 M (S/N = 3), and channel 2 of the biosensor showed linear range for inlA gene of L. monocytogenes in 1 × 10-13-1 × 10-8 M with LOD of 6.11 × 10-15 M (S/N = 3). The dual-channel biosensor showed good selectivity which were used to detect S. typhimurium with linear range of 5-1.0 × 104 CFU mL-1 (LOD of 2.33 CFU mL-1), and L. monocytogenes with linear range of 10 - 1.0 × 104 CFU mL-1 (LOD of 6.61 CFU mL-1).

Numerical simulation and investigation of methane gas distribution and extraction in goaf with U-type ventilation of working face.

The accumulated methane in goaf during coal mining may leak into the working face under the airflow influence, which is possibly causing disasters such as methane gas excessive at the working face and seriously threatening the mine safety. This paper first established a three-dimensional numerical model of the mining area under U-shaped ventilation, introducing the gas state equation, continuity equation, momentum equation, porosity evolution equation, and permeability evolution equation to simulate the airflow field and gas concentration field in the mining area under the natural state. The reliability of the numerical simulations is then verified by the measured air volumes at the working face. The areas in the mining area where gas is likely to accumulate are also delineated. Subsequently, the gas concentration field in goaf under the gas extraction state was theoretically simulated for different locations of large-diameter borehole. The maximum gas concentration in goaf and the gas concentration trend in the upper corner were analyzed in detail, and the critical borehole location (17.8 m from the working face) was determined as the optimum location for gas extraction from the upper corner. Finally, a gas extraction test was carried out on-site to evaluate the application effect. The results show that the measured airflow rate has a small error with the simulated results. The gas concentration in the area without gas extraction is high, with the gas concentration in the upper corner being over 1.2%, which is greater than the critical value of 0.5%. The maximum reduction in gas concentration was 43.9%, effectively reducing the gas concentration in the extraction area after employing a large borehole to extract methane gas. The gas concentration in the upper corner and the distance of the borehole from the working face are expressed as a positive exponential function. The field engineering results show that the implementation of the large borehole at a distance of less than 17.8 m from the working face can control the gas in the upper corner to less than 0.5%, effectively reducing the risk of gas in the upper corner. The numerical simulation work in this paper can provide some basic support for the design of an on-site borehole to extract gas from the mining void and reduce the gas hazard in coal mines.

Enhancement of γ-aminobutyric acid and relevant metabolites in brown glutinous rice (Oryza sativa L.) through salt stress and low-frequency ultrasound treatments at pre-germination stage.

In order to fortify γ-aminobutyric acid (GABA) of brown glutinous rice (BGR), pre-germination strategy was employed, and effects of low-frequency (28 kHz) ultrasound treatment combined with CaCl2 stress on the sprout length, germination rate, morphology, color, water, total polyphenol content (TPC), starch, protein, GABA contents and relevant metabolites were investigated. The germination rate would be inhibited under CaCl2 concentration ≥ 2.0 % during 24 h soaking without ultrasound treatment, and no significant difference was also observed combined with 9 h ultrasound treatment. Ultrasound treatment was beneficial to water absorption, TPC enrichment, energy metabolism, lipid metabolism and protein hydrolysis. Higher contents of GABA (3.29 folds), pyruvic acid (7.63 folds), glycerol (4.88 folds), glutamate (2.02 folds) and glucose (1.32 folds) were obtained due to the antagonistic effect between the 30 w ultrasound treatment and 2.0 % CaCl2 stress at the 9 h pre-germination, and energy, lipid and protein metabolomic pathways were all involved in the GABA accumulation.

Application of Maillard Reaction Products Derived Only from Enzymatically Hydrolyzed Sesame Meal to Enhance the Flavor and Oxidative Stability of Sesame Oil.

The low-temperature roasting of sesame oil has become increasingly popular because of its nutritional benefits; however, the flavor is reduced. In order to improve the quality of sesame oil without exogenous addition, sesame meal was hydrolyzed and further used to prepare Maillard reaction products (MRPs) while protease hydrolysis (PH) and glucoamylase-protease hydrolysis (GPH) were used, and their respective Maillard products (PHM and GPHM) were added in the oils for reducing sugar and total sugar content determination, free amino acid determination, and color and descriptive sensory analysis, as well as electronic nose, SPME-GC-MS, odor activity value, and oxidative stability analyses. Results showed that the MRPs could be produced using the enzymatically hydrolyzed sesame meal without exogenous addition, and the oil flavor blended with GPHM (GPHM-SO) was significantly (p < 0.05) improved with the best sensory quality. The composition of pyrazines (119.35 µg/mL), furans (13.95 µg/mL), and sulfur substances (6.25 µg/mL) contributed positively to sensory properties in GPHM-SO, and 2,5-dimethylpyrazine, 2,6-dimethylpyrazine, and 2,3-dimethylpyrazine were characterized as the key flavor compounds with odor activity values of 7.01, 14.80, and 31.38, respectively. Furthermore, the oxidative stability of the oil was significantly improved with the addition of MRPs, and the shelf life of GPHM-SO was predicted to be extended by 1.9 times more than that of the crude oil based on the accelerated oxidation fitting analysis. In general, the MRPs derived only from sesame meal can enhance the flavor and oxidative stability of sesame oil and can be applied in the oil industry.

Effect of Grain Size on the Plastic Deformation Behaviors of a Fe-18Mn-1.3Al-0.6C Austenitic Steel.

Grain size is a microscopic parameter that has a significant impact on the macroscopic deformation behavior and mechanical properties of twinning induced plasticity (TWIP) steels. In this study, Fe-18Mn-1.3Al-0.6C steel specimens with different grain sizes were first obtained by combining cold rolling and annealing processes. Then the influence of grain size on the plastic deformation mechanisms was investigated by mechanical testing, X-ray diffraction-based line profile analysis, and electron backscatter diffraction. The experimental results showed that the larger grain size could effectively promote twinning during plastic straining, produce an obvious TWIP effect, and suppress the rate of dislocation proliferation. The continuous contribution of dislocation strengthening and twinning functions led to a long plateau in the work-hardening rate curve, and increased the work-hardening index and work-hardening ability. At the same time, the strain could be uniformly distributed at the grain boundaries and twin boundaries inside the grain, which effectively relieved the stress concentration at the grain boundaries and improved the plasticity of deformed samples.

Ultrasound-Assisted Preparation of Maillard Reaction Products Derived from Hydrolyzed Soybean Meal with Meaty Flavor in an Oil-In-Water System.

In the present work, we prepared Maillard reaction products (MRPs) derived from enzyme hydrolyzed soybean meal with ultrasound assistance in an oil-(oxidized lard)-in-water system (UEL-MRPs) or oil-free system (UN-MRPs), and the effect of ultrasound on the properties of the obtained MRPs was evaluated. The analysis of fatty acids in lard with different treatments showed that ultrasound can generate more unsaturated fatty acids in the aqueous phase. The UV-Vis absorbances of UEL-MRPs, UN-MRPs, and MRPs obtained in an oil-in-water system (EL-MRPs) and MRPs obtained in an oil-free system (N-MRPs) at 294 and 420 nm indicated that ultrasound could increase the amount of Maillard reaction intermediates and melanoids in the final products of the Maillard reaction. This was in line with the result obtained from color change determination-that ultrasound can darken the resultant MRPs. Volatile analysis showed ultrasound can not only increase the number of volatile substances, but also greatly increase the composition of volatile substances in UEL-MRPs and UN-MRPs, especially the composition of those contributing to the flavor of the MRPs, such as oxygen-containing heterocycles, sulfur-containing compounds, and nitrogen-containing heterocycles. Descriptive sensory evaluation revealed that UN-MRPs and UEL-MRPs had the highest scores in total acceptance, ranking in the top two, and UEL-MRPs had the strongest meaty flavor among these four kinds of MRPs. Furthermore, the measurements of antioxidant activities, including DPPH radical-scavenging activity, hydroxyl radical scavenging ability, and ferric ion reducing antioxidant power, were conducted, showing that UN-MRPs exhibited the highest antioxidant activity among all the MRPs.

Research progress of anthocyanin prebiotic activity: A review.

BACKGROUND: Anthocyanins are a kind of flavonoids and natural water-soluble pigments, which endow fruits, vegetables, and plants with multiple colors. They are important source of new products with prebiotic activity. However, there is no systematic review documenting prebiotic activity of anthocyanins and their structural analogues. This study aims to fill this gap in literature. PURPOSE: The objective of this review is to summarize and evaluate the prebiotic activity of anthocyanin's, and discuss the physical and molecular modification methods to improve their biological activities. STUDY DESIGN AND METHODS: In this review, the databases (PubMed, Google Scholar, Web of Science, Researchgate and Elsevier) were searched profoundly with keywords (anthocyanin's, prebiotics, probiotics, physical embedding and molecular modification). RESULTS: A total of 34 articles were considered for reviewing. These studies approved that anthocyanins play an important role in promoting the proliferation of probiotics, inhibiting the growth of harmful bacteria and improving the intestinal environment. In addition, physical embedding and molecular modification have also been proved to be effective methods to improve the prebiotic activity of anthocyanins. Anthocyanins could promote the production of short chain fatty acids, accelerate self degradation and improve microbial related enzyme activities to promote the proliferation of probiotics. They inhibited the growth of harmful bacteria by inhibiting the expression of harmful bacteria genes, interfering with the role of metabolism related enzymes and affecting respiratory metabolism. They promoted the formation of a complete intestinal barrier and regulated the intestinal environment to keep the body healthy. Physical embedding, including microencapsulation and colloidal embedding, greatly improved the stability of anthocyanins. On the other hand, molecular modification, especially enzymatic modification, significantly improved the biological activities (antioxidant, prebiotic activity and so on) of anthocyanins. CONCLUSION: All these research results displayed by this review indicate that anthocyanins are a useful tool for developing prebiotic products. The better activities of the new anthocyanins formed by embedding and modification may make them become more effective raw materials. Our review provides a scientific basis for the future research and application of anthocyanins.

An ultrasensitive biosensor for virulence ompA gene of Cronobacter sakazakii based on boron doped carbon quantum dots-AuNPs nanozyme and exonuclease III-assisted target-recycling strategy.

This work presented an electrochemical biosensor for the detection of virulence outer membrane protein A (ompA) gene of Cronobacter sakazakii (C. sakazakii), which was based on the mimic peroxidase activity of boron doped quantum dots-Au nanoparticles (BQDs-AuNPs) and a signal amplification strategy of exonuclease III (Exo III)-assisted target-recycling (EATR). The electrochemical signal was come from the electrochemical reduction of H2O2 by BQDs-AuNPs nanozyme. Due to the enhanced peroxidase-mimic electrocatalytic efficiency of BQDs-AuNPs and the EATR strategy, the biosensor showed a broad linear range (1.0 × 10-15 - 1.0 × 10-8 mol L-1) and a low limit of detection (LOD, 4.0 × 10-17 mol L-1). The constructed biosensor could also be applied in direct detection of extracted DNA from C. sakazakii. A good linear relationship (7.8 - 7.8 × 106 CFU mL-1) between the logarithm concentration of C. sakazakii and electrochemical signal was obtained with a LOD of 2.6 CFU mL-1. The biosensor was applied in the detection of impA gene segments in contaminated infant formula with recoveries ranged in 83.4 - 108.2%.

The potential application of vegetable oils in the D-xylose and L-cysteine Maillard reaction system for meaty aroma production.

Vegetable oils with different unsaturated degrees (corn > peanut > olive > palm > coconut) and corresponding enzymatic hydrolysis-thermal oxidation (ENTH) oils were added into D-xylose and L-cysteine Maillard reaction (MR) system, respectively, for potential meaty aroma production. Results indicated that coconut oil and palm oil had lower peroxide, p-anisidine, total antioxidant values, and malondialdehyde content after ENTH and MR. Corn, peanut, and olive oils after ENTH could significantly promote MR because they caused the lower pH, higher reactants depletion, and higher browning degree in the water phase separated from the oil-Maillard reaction system. Additionally, the volatiles were mainly formed from oil phase. Corn, peanut, and olive oils were beneficial to volatiles formation in the oil-MR system due to fatty acid oxidation, especially oleic acid and linoleic acid. Meanwhile, compared to raw oils, adding ENTH oils to the MR system could reduce the content of oxygen, nitrogen, and sulfur-containing heterocycles.

Producing beef flavors in hydrolyzed soybean meal-based Maillard reaction products participated with beef tallow hydrolysates.

This work investigated the effect of oxidized beef tallow on the volatile compositions and sensory properties of soybean meal-based Maillard reaction products (MRPs). Various tallow oxidation methods included thermal treatment (TT), enzymatic hydrolysis (ET) and enzymatic hydrolysis combined with mild thermal (ETT) treatment. Results showed that all these oxidized tallow contained more types of volatile compounds than those of untreated tallow. Moreover, the composition of almost all types of volatile substances was greatly increased with the addition of the oxidized beef tallow into the hydrolyzed soybean meal-based Maillard reaction system. More importantly, the composition of oxygen-containing heterocycles (63.89 µg/mL), sulfur-containing compounds (76.64 µg/mL), and nitrogen-containing heterocycles (19.81 µg/mL) that contribute positively to sensory properties in ETT-MRPs was found to be the highest among all the MRPs. Correlation assessment revealed that ETT was closely related to the most typical volatile products and sensory attributes, indicating this approach can effectively enhance the sensory and flavor of hydrolyzed soybean meal derived MRPs.

Electro-oxidation and determination 5-hydroxymethylfurfural in food on co-electrodeposited Cu-Ni bimetallic microparticles modified copper electrode.

This study presents a sensitive approach for electrochemical determination of 5-hydroxymethylfurfural (5-HMF) in food. The electrochemical sensor was fabricated on a copper electrode (CuE) modified with co-electrodeposited Cu-Ni bimetallic particles. This sensor, fabricated by 30 cycles of cyclic voltametric scanning with a scan rate of 50 mV s-1, exhibits good electrocatalytic ability to 5-HMF oxidation. Under the optimal conditions, linear scan voltammetry (LSV) and chronoamperometry were conducted for the determination of 5-HMF. The results of LSV show that a linear dependency within the 0.4-10 mM range with a detection limit (LOD) of 3.51 µM (S/N = 3) was achieved, while a linear range in 1 × 10-4-11 mM with a LOD of 0.043 µM (S/N = 3) was obtained by chronoamperometric measurement. The electrochemical sensor was finally applied in determination of 5-HMF in various foods, and the reliability and accuracy of the method were assessed by adopting an UV method as a standard method. Results show that the concentrations of 5-HMF in real samples are close to those measured by the standard method. In addition, standard addition method was further performed to evaluate the accuracy of our approach. The recoveries ranged from 90.0% to 110.0% are calculated, demonstrating good accuracy of the electrochemical sensor.

Interactions of C. frondosa-derived inhibitory peptides against angiotensin I-converting enzyme (ACE), α-amylase and lipase.

The study illustrates the molecular mechanisms by which marine-derived peptides exhibited different structures and inhibition functions to concurrently inhibit multiple enzymes involved in chronic diseases. Peptides (2 mg/mL) exhibited inhibition against angiotensin-converting enzyme (ACE, inhibition of 52.2-78.8%), pancreatic α-amylase (16.3-27.2%) and lipase (5.3-17.0%). Further in silico analyses on physiochemistry, bioactivity, safety and interaction energy with target enzymes indicated that one peptide could inhibit multiple enzymes. Peptide FENLLEELK potent in inhibiting both ACE and α-amylase showed different mechanisms: it had ordered extended structure in ACE active pocket with conventional H-bond towards Arg522 which is the ligand for activator Cl-, while the peptide folded into compact "lariat" conformation within α-amylase active site and the K residue in peptide formed intensive H-bonds and electrostatic interactions with catalytic triad Asp197 - Asp300 - Glu233. Another peptide APFPLR showed different poses in inhibiting ACE, α-amylase and lipase, and it formed direct interactions to lipase catalytic residues Phe77 & His263.

Prediction and characterization of the T cell epitopes for the major soybean protein allergens using bioinformatics approaches.

Protein allergens is a health risk for consumption of soybeans. To understand allerginicity mechanism, T cell epitopes of 7 soybean allergens were predicted and screened by abilities to induce cytokine interleukin (IL) 4. The relationships among amino acid composition, properties, allergenicity, and pepsin hydrolysis sites were analyzed. Among the 138 T cell epitopes identified, YIKDVFRVIPSEVLS, KDVFRVIPSEVLSNS, DVFRVIPSEVLSNSY of Gly m 6.0501 (P04347), and AKADALFKAIEAYLL, ADALFKAIEAYLLAH of Gly m 4.0101 (P26987) were the most possible epitope candidates. In T cell epitopes pattern, the frequencies of amino acids Q, D, E, P, and G decreased, while F, I, N, V, K, H, A, L, and S increased. Hydrophobic residues at positions p1 and p2 and positively charged residues in positions p13 might contribute to allergenicity. Most of epitopes could be hydrolyzed by pepsin into small polypeptides within 12 residues length, and the anti-digestive epitope regions contained I, V, S, N, and Q residues. T cell epitopes EEQRQQEGVIVELSK from Gly m 5.03 (P25974) showed resistance to pepsin hydrolysis and would cause a higher Th2 cell response. This research provides basis for the development of hypoallergenic soybean products in the soybean industry as well as for the immunotherapy design for protein allergy.

Detection of Lectin Protein Allergen of Kidney Beans (Phaseolus vulgaris L.) and Desensitization Food Processing Technology.

With the increase of food allergy events related to not properly cooked kidney beans (Phaseolus vulgaris L.), more and more researchers are paying attention to the sensitization potential of lectin, one of the major storage and defensive proteins with the specific carbohydrate-binding activity. The immunoglobulin E (IgE), non-IgE, and mixed allergic reactions induced by the lectins were inducted in the current paper, and the detection methods of kidney bean lectin, including the purification strategies, hemagglutination activity, specific polysaccharide or glycoprotein interactions, antibody combinations, mass spectrometry methods, and allergomics strategies, were summarized, while various food processing aspects, such as the physical thermal processing, physical non-thermal processing, chemical modifications, and biological treatments, were reviewed in the potential of sensitization reduction. It might be the first comprehensive review on lectin allergen detection from kidney bean and the desensitization strategy in food processing and will provide a basis for food safety control.