Research advances in technologies and mechanisms to regulate vinegar flavor.

New vinegar needs a long maturing time to improve its poor flavor before sale, which greatly increases its production cost. Therefore, it is urgent to explore regulation technologies to accelerate vinegar flavor maturation. Based on literature and our research, this review introduces the latest advances in flavor regulation technologies of vinegar including microbial fortification/multi starters fermentation, key production processes optimization and novel physical processing technologies. Microbial fortification or multi starters fermentation accelerates vinegar flavor maturation via enhancing total acids, esters and aroma precursors content in vinegar. Adjusting raw materials composition, fermentation temperature, and oxygen flow reasonably increase alcohols, organic acids, polyphenols and esters levels via generating more corresponding precursors in vinegar, thereby improving its flavor. Furthermore, novel processing technologies greatly promote conversion of alcohols into acids and esters in vinegar, shortening flavor maturation time for over six months. Meanwhile, the corresponding mechanisms are discussed and future research directions are addressed.

Elastoplastic Mechanical Properties and Kinematic Hardening Model of 35CrNi3MoVR.

The existing tensile-compression elastoplastic models are not suitable for varies of materials. An accurate constitutive model of the elastoplastic mechanical properties more suitable for 35CrNi3MoVR was produced by optimizing the existing fitting equations based on uniaxial tensile-compression tests, which are able to describe the elastoplastic stress-strain relation and Bauschinger effect varying with the maximum tensile plastic strain. A UMAT subroutine of the constitutive model in ABAQUS was proposed and conducted for FEM calculation. Hydraulic autofrettage tests were carried out under different pressures on thick-walled 35CrNi3MoVR tubes, and the results were compared with those of FEM calculations to further validate the accuracy of the fitting model. The results show that the constructed power function kinematic hardening model can effectively describe the elastoplastic mechanical properties of 35CrNi3MoVR and can be applied to the autofrettage calculation of this material. The comparison among the calculation results of different models proved that the model proposed in this research has better performance compared to other existing models. Taking the Mises stress at the inner surface of the thick-walled tubes as the evaluation criterion, the error of the power function kinematic hardening model reaches less than 3%, decreasing the error by at least 50%.

Effects of Ultra-High-Pressure Treatment on Chemical Composition and Biological Activities of Free, Esterified and Bound Phenolics from Phyllanthus emblica L. Fruits.

Phyllanthus emblica L. fruits (PEFs) were processed by ultra-pressure (UHP) treatment and then extracted by the ultrasonic-assisted extraction method. The influence of UHP on the phenolic composition, enzyme inhibitory activity and antioxidant activity of the free, esterified, and bound phenolic fractions from PEFs were compared. UHP pretreatment of PEFs significantly increased the total phenolic and flavonoid contents (p < 0.05). A total of 24 chemical compositions were characterized in normal and UHP-treated PEFs by UHPLC-ESI-HRMS/MS. Compared with normal PEFs, these three different phenolic fractions had stronger antioxidant activities and inhibitory effects on the intracellular reactive oxygen species (ROS) production in H2O2-induced HepG2 cells (p < 0.05). The ROS inhibition might be due to an up-regulation of the expressions of superoxide dismutase (SOD) and glutathione (GSH) activities. In addition, these three different phenolic fractions also significantly inhibited the activities of metabolic enzymes, including α-glucosidase, α-amylase and pancreatic lipase. This work may provide some insights into the potential economics and applications of PEFs in food and nutraceutical industries.

Effect of ultra-high pressure heat-assisted technology combined with L-cysteine on the color of ready-to-eat shrimp during storage.

This study used ultra-high pressure processing (HPP) heat-assisted technology combined with L-cysteine (L-cys) to process ready-to-eat (RTE) shrimp. Subsequently, the effects of physical field and chemical modifications on the color of RTE shrimp were studied. The results showed that the RTE shrimp treated with HPP-Heat-L-cys showed better performance in terms of brightness value (65.25) and astaxanthin (AST) content (0.71 µg/g) during storage, maintaining the original color of RTE shrimp effectively. In addition, it was observed that the application of HPP-Heat-L-cys significantly delayed phenol oxidation, lipid oxidation, and Maillard reaction compared with traditional HPP or heat treatments. Specifically, the total phenolic content of RTE shrimp treated with HPP-Heat-L-cys was higher than that of other samples, but the TBARS and browning index were lower. Furthermore, HPP-Heat-L-cys could delay the production of dark products (such as 2-methylanthraquinone, p-benzoquinone, lipofuscin and melanin), ultimately safeguarding the color stability of RTE shrimp during storage.

Ultra-high pressure treatment improve the content of characteristic aromatic components of melon juice from the view of physical changes.

Introduction: The effectiveness of ultra-high pressure (UHP) technology in retaining the flavor of fresh fruit and vegetable juices has been acknowledged in recent years. Along with previously hypothesized conclusions, the improvement in melon juice flavor may be linked to the reduction of its surface tension through UHP. Methods: In this paper, the particle size, free-water percentage, and related thermodynamic parameters of melon juice were evaluated in a physical point for a deeper insight. Results: The results showed that the UHP treatment of P2-2 (200 MPa for 20 min) raised the free water percentage by 7,000 times than the other treatments and both the melting enthalpy, binding constant and Gibbs free energy of P2-2 were minimized. This significantly increased the volatility of characteristic aromatic compounds in melon juice, resulting in a 1.2-5 times increase in the content of aromatic compounds in the gas phase of the P2-2 group compared to fresh melon juice.

Metabolomics, volatolomics, and bioinformatics analyses of the effects of ultra-high pressure pretreatment on taste and flavour parameters of cured Culter alburnus.

The effects of ultra-high pressure (UHP) pretreatment (50-250 MPa) on the fish curing were studied. UHP increased the overall volatile compound concentration of cured fish. Among 50-250 MPa five treatment groups, 150 MPa UHP group exhibited the highest total free amino acid content (294.34 mg/100 g) with that of the control group being 92.39 mg/100 g. The activity of cathepsin L was increased under 50-200 MPa UHP treatment (62.28-58.15 U/L), compared with that in the control group (53.80 U/L). UHP treatment resulted in a significant increase in small molecule compounds, especially the amino acid dipeptides and ATP metabolic products. Under UHP treatments, the bacterial phyla Actinobacteriota (1.04-5.25 %), Bacteroidota (0.20-4.47 %), and Deinococcota (0.00-0.05 %) exhibited an increased abundance, and they promoted taste and flavor formation. Our results indicated that UHP is a promising pretreatment method to improve taste and flavour in cured fish by affecting the microorganisms, cathepsin, and proteins.

The Physicochemical Properties and Antioxidant Activities of the Hawthorn Pectin Extracted Using Ultra-High Pressure Assisted Acid Extraction (UPAAE).

This study aims to investigate the positive effects of ultra-high pressure assisted acid extraction (UPAAE) on both physicochemical properties and antioxidant activities of hawthorn pectin. The basic indicators, structure characterization, and antioxidant activities were measured, which could indicate the disadvantages and advantages among traditional water extraction (WE), acid extraction (AE), and UPAAE. The results show that the hawthorn pectin of UPAAE has a decrease in esterification degree, protein content, and total polyphenols, but has an increase in total galacturonic acid aldehyde compared to the hawthorn pectin of AE. In the Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM) analyses, the hawthorn of UPAAE has typical pectin absorption peaks in the FT-IR spectrum and a distinct layered structure in the SEM surface image. The ion chromatography profiles show that the molar ratio of galacturonic acid to arabinose in the hawthorn pectin of UPAAE increases and 5.50 µg/mg ribose appears compared to the pectin of AE and WE. The high performance gel permeation chromatography (HPGPC) profile indicates that the molecular weight distribution of hawthorn pectin of UPAAE is more concentrated and has the highest molecular weight compared to the pectin of the other two extraction methods. In the vitro antioxidant activity analysis, the pectin of UPAAE exhibits the highest scavenging rate against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals (93.70%), which is close to the scavenging rate of vitamin C (96.30%). These findings demonstrated that UPAAE is a more efficient and environmentally friendly method for pectin extraction from hawthorn. It is also an effective way to enhance its antioxidant activity, which has great application prospects in the food industries.

Untargeted Maternal Plasma Metabolomics in Hirschsprung Disease: A Pilot Study.

Background and Aims: Hirschsprung disease (HSCR) is a congenital disorder of unknown etiology affecting the enteric nervous system (ENS). Since the early gestational development of the ENS is dependent on the prenatal maternal metabolic environment, the objective of this pilot study was to explore the role of specific maternal plasma metabolites in the etiology of HSCR. Methods: In this cross-sectional study, postnatal (as a surrogate for prenatal) plasma samples were obtained from mothers of children diagnosed with HSCR (n = 7) and age-matched mothers of normal children (n = 6). The plasma metabolome was analyzed by ultra-high-pressure liquid chromatography and mass spectrometry. Metabolites were identified by mzCloud using Compound Discoverer software. Using an untargeted metabolomics workflow, metabolites with case versus control group differences were identified. Results: A total of 268 unique plasma metabolites were identified and annotated in maternal plasma. Of these, 57 were significantly different between case and control groups (P < 0.05, t-test). Using a false discovery rate corrected cutoff of 10% to adjust for multiple comparisons, 19 metabolites were significantly different in HSCR cases, including carnitines, medium-chain fatty acids, and glutamic acid. Pathways affected were for amino acid and lipid metabolism. Conclusion: Disordered prenatal metabolic pathways may be involved in the etiopathogenesis of HSCR in the developing fetus. This is the first study to assess maternal plasma metabolomics in HSCR.

Enhancing peach slices radio frequency vacuum drying by combining ultrasound and ultra-high pressure as pretreatments: Effect on drying characteristics, physicochemical quality, texture and sensory evaluation.

To maximally maintain fruits and vegetables quality after harvest, this study used ultrasonic (US) and ultra-high pressure (UHP) techniques as pretreatments for radio frequency vacuum (RFV) drying of peach slices, and investigated the effects of different pretreatments (US, UHP, UHP-US, and US-UHP) on drying characteristics, physicochemical qualities, texture properties, and sensory evaluation of peach slices. Results showed that the drying rate was increased by 15.79 âˆ¼ 54.39 % and the contents of pectin, hemicellulose, total phenolic, total flavonoid, phenolic acids, individual sugar annd antioxidant of the samples were significantly increased after US combined with UHP pretreatment (P < 0.05). US-UHP + RFV dried peach slices obtained brighter color, better texture attributes of hardness, cohesiveness, chewiness, springiness, and resilience. The dehydrated samples pretreated by UHP-US had the best overall acceptance, appearance, and crispness with lower off-odor and sourness compared to the dehydrated peach slices with US and UHP pretreatment. Notably, the highest cellulose and organic acids were found in dehydrated peach slices by control, followed by samples US, and samples with UHP pretreatment. The microstructure showed that the internal organization of peach slices appeared as uniform and regular honeycomb porous structure after US-UHP pretreatment. The findings may provide theoretical reference for the development of energy-efficient and high-quality drying technology for fruits and vegetables.

Prediction of overloaded concentration profiles under ultra-high-pressure liquid chromatographic conditions.

In this study, overloaded elution profiles under ultra-high-pressure liquid chromatographic (UHPLC) conditions and accounting for the severe pressure and temperature gradients generated, are compared with experimental data. The model system consisted of an C18 column packed with 1.7-µm particles (i.e., a UHPLC column) and the solute was 1,3,5-tri­tert-butylbenzene eluted with a mobile phase composed of 85/15 (v/v) acetonitrile/water. Two thermal modes were considered, and the solute was eluted at the very high inlet pressures necessary to achieve a highly efficient and rapid chromatographic process, as provided by using columns packed with small particles. However, the high inlet pressure and high linear velocity of the mobile phase caused the production of a significant amount of heat, and consequently, the formation of axial and radial temperature gradients. Due to these gradients, the retention and the mobile phase velocity were no longer constant. Thus, simple mathematical models consisting only of the mass balance equations are unsuitable to properly model the elution profiles. Here, the elution concentration profiles were predicted using a combined two-dimensional heat and mass transfer model, also including the calculation of the mobile phase velocity distribution. The isotherm adsorption model was the bi-Langmuir isotherm model with Henry constants that depended on the local temperature and pressure in the column. These adjustments allowed us to precisely account for changes in the shape and retention of the overloaded concentration profiles in the mobile phase. The proposed model provided accurate predictions of the overloaded concentration profiles, demonstrating good agreement with experimental profiles eluted under severe pressure and temperature gradients in the column even in the most extreme cases where the pressure drops reached 846 bar and the temperature gradients equaled 0.15 K mm-1 and 0.95 K mm-1 in the axial and the radial directions, respectively. In such cases 36 % decrease of the retention factor was observed along the column and 2 % increase in radial direction. These changes, combined with the velocity distribution, shifted the overloaded elution profile's shock towards the center of the column, advancing approximately 3 mm from its initial position close to the column wall. Ultimately, this resulted in the broadening of the elution band.

Ultra-high pressure improved gelation and digestive properties of Tai Lake whitebait myofibrillar protein.

This study investigated the effects of ultra-high pressure (UHP) at different levels on the physicochemical properties, gelling properties, and in vitro digestion characteristics of myofibrillar protein (MP) in Tai Lake whitebait. The α-helix gradually unfolded and transformed into ß-sheet as the pressure increased from 0 to 400 MPa. In addition, the elastic modulus (G') and viscous modulus (G'') of the 400 MPa-treated MP samples increased by 4.8 and 3.8 times, respectively, compared with the control group. The gel properties of the MP also increased significantly after UHP treatment, e.g., the gel strength increased by a 4.8-fold when the pressure reached 400 Mpa, compared with the control group. The results of in vitro simulated digestion showed that the 400 MPa-treated MP gel samples showed a 1.8-fold increase in digestibility and a 69.6 % decrease in digestible particle size compared with the control group.

Chemical characterization and sensory properties of apple brandies aged with different toasted oak chips and ultra-high-pressure treatments.

Aging is an important processing step of producing high quality apple brandy. In this study, apple brandies aged by traditional method and using three different toasted oak chips combined with or without ultra-high-pressure (UHP) treatment were prepared to compare their differences in chemical characterization and sensory properties. The results indicated that the brandies aged with toasted oak chip increased the levels of total acidity, volatile acidity and phenolic compounds. It also had the desirable color and taste. The brandy aged with toasted oak chip combined with UHP reached the highest levels of total acidity (1.06 g/L), total phenolic content (284.92 mg/L) and aromatic esters (49.37 %). Therefore, the aging with high toasted oak chip combined with UHP treatment could cut the traditional aging time to meet the same quality as traditional aging method. The results are very useful to develop a fast and efficient aging technique for brandy production.

Effects of ultra-high pressure, thermal pasteurization, and ultra-high temperature sterilization on color and nutritional components of freshly-squeezed lettuce juice.

The aim of this study was to evaluate the effects of ultra-high pressure (UHP, 600 MPa/2 min), thermal pasteurization (TP, 95 °C/1 min) and ultra-high temperature (UHT, 115 °C/5 s) sterilization on the color, sensory evaluation, microorganisms, physicochemical characteristics and nutritional components of freshly-squeezed lettuce juice (FLJ). Results showed that three sterilization methods demonstrated desirable inactivation effects on total aerobic bacteria, yeast and mold, and there were no significant changes in the main nutritional components, including ash, protein, carbohydrate and total dietary fiber. However, UHT and TP significantly affected the color of FLJ from bright green to light brown and made chlorophyll, ß-carotene and vitamins (VE, VC, VK1, VB6, VB12, and folic acid) contents markedly decreased. By contrast, UHP maintained the original color, fresh-like sensory qualities, vitamins, and carotene of FLJ to the greatest extent. Our results provide a promising application of UHP in the large-scale processing of FLJ.

Transformations of bamboo into bioethanol through biorefinery.

The increasing demand for energy has prompted scholars to research alternative energy sources. Bamboo is a species of woody perennial grass that belongs to the Gramineae family and the Bambuseae subfamily. It could be considered a possible lignocellulosic substrate for the production of bioethanol due to its favourable environmental effects and increased yearly biomass yield. Non-renewable fossil fuels cannot provide enough energy to meet the needs of contemporary societies. Among the various alternative energy sources, bioethanol has drawn a lot of attention from people all around the world. This paper reviews the cost and process parameters for the synthesis of bioethanol from bamboo. This review aims to increase the effectiveness of the entire ethanol production process by focusing on pretreatment, enzymatic hydrolysis, and fermentation. The emphasis of this review is on the efficient process for producing bioethanol while maintaining environmental sustainability. When compared to other NaOH pretreatment techniques, bamboo substrates prepared with NaOH and ultra-high-pressure explosion (UHPE) exhibit higher enzymatic hydrolyzability when processed under optimal conditions, such as 100 MPa, 121 °C, and 70 rpm for 2 h, yielding 89.7-95.1% ethanol after 24 h. The article lists the bamboo species responsible for creating each product, making it straightforward for producers to study and select the species based on whatever value-added product they wish to produce bioethanol with different parameters.

A High-Precision Quartz Resonant Ultra-High Pressure Sensor with Integrated Pressure Conversion Structure.

A quartz resonant pressure sensor is proposed for high-precision measurement of ultra-high pressure. The resonant unit realizes a push-pull differential layout, which restrains the common-mode interference factor, and the resonator is only subject to axial force. The pressure conversion unit is made in an integrated manner, avoiding output drift problems caused by residual stress and small gaps during assembly, welding, and other processes in sensor preparation. Theoretical and simulation analysis was conducted on the overall design scheme of the sensor in this paper, verifying the feasibility. Sensor prototypes were created and performance experiments were conducted. The experimental results show that the sensitivity of the ultra-high pressure sensor is 46.32 Hz/MPa at room temperature within the pressure range of 120 MPa, and the comprehensive accuracy is 0.0266%. The comprehensive accuracy of the sensor is better than 0.0288% FS in the full temperature range environment. This proves that the sensor scheme is suitable for high-precision and high-stability detection of ultra-high pressure, providing new solutions in special pressure measurement fields such as deep-sea and oil exploration.

Preparation of Bovine Hides Gelatin by Ultra-High Pressure Technique and the Effect of Its Replacement Fat on the Quality and In Vitro Digestion of Beef Patties.

Beef skin gelatin can be used as a good substitute for animal fat in meat patties. In this paper, the effect of different parameters on low-fat beef patties with cowhide gelatin substituted for beef fat (0, 25%, 50%, 75%, 100%) prepared by ultra-high pressure assisted technology was investigated by texture, cooking loss, and sensory scores. The beef patties were also stored at 0-4 °C for 0, 7, 14, 21, and 28 d. The differences and changing rules of fatty acid and amino acid compositions and contents of beef patties with different fat contents were investigated by simulating gastrointestinal digestion in vitro. The optimal process formulation of low-fat beef patties with cowhide gelatin was determined by experimental optimization as follows: ultra-high pressure 360 MPa, ultra-high of pressure time of 21 min, NaCl addition of 1.5%, compound phosphate addition of 0.3%. The addition of cowhide gelatin significantly increased monounsaturated fatty acids, polyunsaturated fatty acids, amino acid content, and protein digestibility of beef patties (p < 0.05). Moreover, with the extension of storage time, the content of saturated fatty acids was significantly higher (p < 0.05), the content of monounsaturated and polyunsaturated fatty acids was significantly lower (p < 0.05), the content of amino acids was significantly lower (p < 0.05), and protein digestibility was significantly lower (p < 0.05) under all substitution ratios. Overall, beef patties with 75% and 100% substitution ratios had better digestibility characteristics. The results of this study provide a theoretical basis for gelatin's potential as a fat substitute for beef patties and for improving the quality of low-fat meat products.

Ultra-high-performance liquid chromatography-tandem high-resolution elevated mass spectrometry profiling of anti-methicillin-resistant Staphylococcus aureus metabolites from the endophytic bacteria collected from the weeds of a previous dumpsite.

The culturable endophytic bacteria from the weeds Cleome rutidosperma of the family Cleomaceae and Digitaria sanguinalis of the family Poaceae obtained from a previous dumpsite in Pampanga, Philippines have been assessed for their anti-methicillin-resistant Staphylococcus aureus (MRSA) activity, and the analytes with such activity should be identified. However, due to the limited amounts collected from the isolation process, 1.8 mg yield of compound 1 from the endophyte of C. rutidosperma and 1.2 mg of a mixture from the endophyte of D. sanguinalis were selected for LC-MSE analysis. The production of compounds from the culturable endophytic bacteria Pseudomonas aeruginosa- determined by gene-sequencing, an untargeted and data-independent analysis (DIA) by ultra-high performance liquid chromatography-high resolution-elevated energy mass spectrometry (UHPLC-HR-MSE) technique was employed to profile the metabolites present in the two high-performance liquid chromatography (HPLC) fractions. The analytes present from P. aeruginosa detected by UHPLC-HR-MSE isolated from C. rutidosperma was phenazine-1-carboxylic acid (1), and for D. sanguinalis were chamigrenal (2), dialkyl resorcinol (3), and a pyoverdine elicitor (4). This study proves that UHPLC-HR-MSE could identify the anti-MRSA constituents in P. aeruginosa from commensal weeds C. rutidosperma and D. sanguinalis. The UHPLC-HR-MSE could help strengthen metabolomics antibacterial research and its related applications from a future perspective. Application of metabolomics research using UHPLC-HR-MSE could enhance the rehabilitation of dumpsites by the microbial community present.

Evaluation of Ultra-High-Pressure Sterilization in Terms of Bactericidal Effect, Qualities, and Shelf Life of 'Xinli No. 7' (Pyrus sinkiangensis) Pear Juice.

In this study, ultra-high-pressure sterilization (UHPS) of Xinli No. 7 juice (XL7) was explored and optimized. A challenge to implement UHPS in juice as a full alternative to thermal treatment could be represented by the adoption of a pressure level of up to 500 MPa for 20 min at one cycle followed by the packaging in aseptic conditions. It was found that UHPS and HS treatments could effectively kill the microorganisms in XL7 juice but HS treatment would inevitably lose the nutritional quality in the juice, while UHPS treatment could better maintain the glyconic acid content, functional components, and antioxidant activity and reduce Browning degree and improve the stability of XL7 juice. The deterioration rate of UHPS and HS-treated XL7 juice increased with the increased storage temperature. The predicted shelf life of UHPS and HS-treated XL7 juice was 68 and 41 days at 4 °C, respectively. Collectively, UHPS treatment combined with low-temperature storage might be an effective way to prolong the shelf life of XL7 juice.

Ultra-high-pressure passivation of soybean agglutinin and safety evaluations.

Soybean agglutinin (SBA) is a heat-sensitive anti-nutritional factor (ANF). It affects nutrient absorption and causes organism poisoning. This study explored the SBA passivation ability and mechanism by ultra-high pressure (HHP), a non-thermal food processing technology. The results indicated that more than 500 MPa HHP treatment reduced the SBA activity by destroying its secondary and tertiary structures. Also, the cell and animal experiments showed that HHP treatment reduced the cytotoxicity of SBA, improved the mice's body weight, and alleviated liver, kidney, and digestive tract damage in Vivo. These results demonstrated that HHP had a high passivation efficiency against the SBA, thereby HHP promoting the safety of soybean products. This study provided supporting evidence for ultra-high-pressure treatment applications in soybean processing.

Electron beam irradiation modification of ultra-high pressure treated broad bean starch: Improvement of multi-scale structure and functional properties.

To investigate the synergistic effect of electron beam irradiation (EBI) on the ultra-high pressure (UHP) modification of broad bean starch, various pressures (200, 400, 600 MPa) combined with different irradiation doses (3, 6, 12 kGy) were used to modify the structure-properties of broad bean starch in this study. The results showed that both UHP and EBI induced a reduction of amylopectin molecular weight (Mw) and depolymerization of long chains, caused the loss of short-range ordered structure and imperfection of crystal structure, and improved starch viscosity, solubility and enzyme sensitivity. Furthermore, the applied pressure causes changes in starch granule structure, upon which EBI promotes further degradation and depolymerization of starch by affecting the crystalline and amorphous regions. Hence, appropriate doses of EBI treatment can impart more desirable processing properties to UHP-modified starches, and EBI can be used as a promising way to promote starch modification further.