Search

Freezing has been widely used to preserve meat and aquatic products. However, environmental fluctuations in freezing/thawing would bring inevitable damage to the structure and characteristics of myofibrillar proteins. The gelation of myofibrillar proteins during thermal processing significantly impacts the quality of gel-type muscle foods. Therefore, it is of critical importance to understand role of freezing-induced damage to myofibrillar proteins in heat-induced gelation. This review covers recent developments on quality changes of myofibrillar protein gels in relation to freezing/thawing and presents the mechanisms and the control technologies available for improving gelling properties of frozen-thawed myofibrillar proteins. The mechanisms are based on the denaturation and oxidation of myofibrillar proteins occurring in freezing/thawing and the relationship with molecular aggregation during gelation. The emerging technologies discussed herein focus on freezing/thawing technologies and applications of cryoprotectants. The degree of myofibrillar protein cross-linking in relation to denaturation and oxidation plays a crucial role in further molecular aggregation during gelation. We here propose that freezing-induced over-aggregation of myofibrillar proteins in relation to denaturation and oxidation would spatially hinder salt dissolution and further intermolecular assembling of myosin during gelation, thus producing an amorphous gel network. Recent novel technologies preserve myofibrillar protein characteristics from freezing-induced denaturation and oxidation by accelerating freezing/thawing rate and inhibiting ice crystal growth and therefore modify gelling properties of frozen-thawed myofibrillar proteins. This review could be helpful for the development of gel-type muscle foods processed from frozen-thawed meat and aquatic products as raw materials. • Degree of myosin aggregation related to denaturation/oxidation affects gelation. • Frozen-thawed myofibrillar proteins form a cracked gel during heating. • Protein denaturation/oxidation in freeze/thaw induces molecular over-aggregation. • A model is proposed linking denaturation/oxidation in freeze/thaw for the impaired gels. • Novel anti-freeze techniques improve freeze/thaw myofibrillar protein gelation. [ABSTRACT FROM AUTHOR]

This study explored the use of pig blood fibrinogen hydrolysates, enzymatically hydrolyzed with trypsin and flavorzyme, to enhance myofibrillar protein gels, addressing issues like poor gel strength and water loss in meat products. By incorporating varying concentrations of fibrinogen hydrolysates into myofibrillar proteins, heat-induced gels were prepared. The composite gels showed improved textural properties, rheological characteristics and water-holding capacity. Scanning electron microscopy and atomic force microscopy analyses revealed a uniform, dense surface and an orderly internal structure in the composite gels. The study also noted decreased α-helix and random coil and increased β-sheet and β-turn contents, indicating a more ordered secondary structure. Hydrophobic interactions and disulfide bonds were identified as key factors in enhancing gelation, and a model was proposed to explain these molecular effects. This research demonstrates a potential of fibrinogen hydrolysates to improve quality and structure of myofibrillar protein gels designed for high-quality meat products. • Fibrinogen hydrolysates were used to promote myofibrillar protein gelation. • Increased texture, WHC and rheological properties were found in composite gels. • Microstructural study revealed a more uniform and dense network in composite gels. • Hydrophobic interactions and disulfide bonds were suggested as key molecular forces. • A model was proposed to explain the molecular interaction during gelation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Myosin/high-density lipoprotein composite emulsions were constructed at varied pH. • The pH-dependent effects on emulsification stability were discovered. • Enhanced emulsion activity and stability were found in composite protein emulsion. • Smaller and uniform droplets were observed in composite emulsion at alkaline pH. The emulsification activity of myosin plays a significant role in affecting quality of emulsified meat products. High-density lipoprotein (HDL) possesses strong emulsification activity and stability due to its structural characteristics, suggesting potential for its utilization in developing functional emulsified meat products. In order to explore the effect of HDL addition on emulsification stability, rheological properties and structural features of myosin (MS) emulsions, HDL-MS emulsion was prepared by mixing soybean oil with isolated HDL and MS, with pH adjustments ranging from 3.0 to 11.0. The results found that emulsification activity and stability in two emulsion groups consistently improved as pH increased. Under identical pH, HDL-MS emulsion exhibited superior emulsification behavior as compared to MS emulsion. The HDL-MS emulsion under pH of 7.0–11.0 formed a viscoelastic protein layer at the interface, adsorbing more proteins and retarding oil droplet diffusion, leading to enhanced oxidative stability, compared to the MS emulsion. Raman spectroscopy analysis showed more flexible conformational changes in the HDL-MS emulsion. Microstructural observations corroborated these findings, showing a more uniform distribution of droplet sizes in the HDL-MS emulsion with smaller particle sizes. Overall, these determinations suggested that the addition of HDL enhanced the emulsification behavior of MS emulsions, and the composite emulsions demonstrated heightened responsiveness under alkaline conditions. This establishes a theoretical basis for the practical utilization of HDL in emulsified meat products. [ABSTRACT FROM AUTHOR]

• A nonlinear mixed model for reliability of aviation cables with non-constant shape parameters is established. • The aviation cable reliability modelling with small accelerated life test data is investigated. • Uncertainty of the Weibull scale parameter is considered. In this paper, a reliability model of aviation cables that using nonlinear mixed model and Bayesian estimation is proposed. Considering the small sample character of accelerated life test data, the sample is expanded by Bootstrap method, least square regression is used to get the initial Weibull distribution parameters, and non-constant shape parameter is got by maximum likelihood estimation. Then, considering the uncertainty of the scale parameter, a nonlinear mixed model is established, and Bayesian estimation based on the prior information is used to make the reliability model more accurately. Accelerated life test case study is given to illustrate the performance of the proposed method under temperature and vibration stresses. Simulation results indicate the effectiveness of proposed model compared with nonlinear mixed model or Bayesian estimation individually. The proposed model can be extended to the reliability modelling of other insulated cables. [ABSTRACT FROM AUTHOR]

To achieve long-term effective protection of food by continuously controlling the release of active substances in an active film, IRMOF-3 was post-synthetic modified with benzoic acid (BA) to obtain BA-IRMOF-3. This modification enhanced the loading capacity of carvacrol (CA) and slowed down its release rate. Research on IRMOF-3 synthesis has found that increasing the proportion of metal nodes can improve its crystallinity. The post-synthesis modification of IRMOF-3 through amide reaction successfully enhanced the binding energy with CA from −5.1 kcal/mol to −6 kcal/mol, resulting in an improved CA loading rate of 28.62% ± 0.15% and delayed release. Furthermore, the BA-IRMOF-3/CA assembly was added to the sodium alginate matrix to prepare the active film BMC@SA, which improved the mechanical and physical properties of the film. The release and antibacterial/antioxidant properties were investigated. The results demonstrated that the active film BMC@SA exhibited significant sustained-release properties and antibacterial/antioxidant activities, reducing the growth of E. coli and S. aureus by 61.95% and 49.33% respectively. In refrigerated pork experiments, the film BMC@SA slowed down the color, weight, pH changes and inhibited microbial growth of fresh pork effectively, and extended the shelf life of pork from 6 d to 12 d, which demonstrated the potential application of active film BMC@SA in food preservation. [ABSTRACT FROM AUTHOR]

Background: Photodynamic therapy (PDT) has been reported as a treatment for cutaneous squamous cell carcinoma in situ (SCCis), but only limited data are available on the effectiveness of PDT with aminolevulinic acid (ALA-PDT).Objective: To review the outcomes of SCCis treated with ALA-PDT and examine factors associated with response.Methods: A retrospective review identified 58 patients with 68 primary SCCis lesions treated with ALA-PDT and blue light illumination. Patient demographics, lesion features, treatment details, clinical response, and subsequent recurrence were extracted from medical record reviews.Results: On completion of PDT the initial complete response rate was 77.9% and was not associated with the number of PDT treatments. On multivariate analysis factors associated with response were location on the face, tumor diameter <2 cm, and longer ALA incubation time. Lesions treated with a maximum incubation time of <3 hours had a 53.3% response compared with 84.9% for longer incubation. Subsequent recurrence of SCCis was noted in 7 of 53 cases (13.2%) at a median time of 11.7 months.Limitations: This was a retrospective study performed at a single institution without systematic follow-up.Conclusions: ALA-PDT may be an effective treatment for selected cases of SCCis. Effectiveness is impacted by anatomic location, tumor diameter, and ALA incubation time. [ABSTRACT FROM AUTHOR]

G-protein-signaling modulator 1 (GPSM1) has been proved the potential role in brain tissues, however, whether GPSM1 in hypothalamic nuclei, especially in POMC neurons is essential for the proper regulation of whole-body energy balance remains unknown. The aim of our current study was to explore the role of GPSM1 in POMC neurons in metabolic homeostasis. We generated POMC neuron specific GPSM1 deficiency mice and subjected them to a High Fat Diet to monitor metabolic phenotypes in vivo. By using various molecular, biochemical, immunofluorescent, immunohistochemical analyses, and cell culture studies to reveal the pathophysiological role of GPSM1 in POMC neurons and elucidate the underlying mechanisms of GPSM1 regulating POMC neurons activity. We demonstrated that mice lacking GPSM1 in POMC neurons were protected against diet-induced obesity, glucose dysregulation, insulin resistance, and hepatic steatosis. Mechanistically, GPSM1 deficiency in POMC neurons induced enhanced autophagy and improved leptin sensitivity through PI3K/AKT/mTOR signaling, thereby increasing POMC expression and α-MSH production, and concurrently enhancing sympathetic innervation and activity, thus resulting in decreased food intake and increased brown adipose tissue thermogenesis. Our findings identify a novel function of GPSM1 expressed in POMC neurons in the regulation of whole-body energy balance and metabolic homeostasis by regulating autophagy and leptin sensitivity, which suggests that GPSM1 in the POMC neurons could be a promising therapeutic target to combat obesity and obesity-related metabolic disorders. [Display omitted] • Deletion of GPSM1 in POMC neurons protects against diet-induced obesity and obesity-related disorders. • Lacking of GPSM1 in POMC neurons decreases food intake and increased BAT thermogenesis. • GPSM1 regulates POMC expression and α-MSH production through altering leptin sensitivity and autophagy of POMC neurons. [ABSTRACT FROM AUTHOR]

The chitosan (CS)-based bioactive packaging film with good antibacterial and antioxidant activities was developed using AHNT (modified halloysite nanotube) loaded with carvacrol (AHNT-Car) as the nanofiller. The zeta potential, Fourier transform infrared, and rheology analysis indicated that hydrogen bonding and electrostatic interactions were formed between AHNT-Car and CS film substrate, and scanning electron microscope images exhibited that the cross-sections of the bioactive film were denser. The mechanical and barrier properties (water vapor, oxygen, and light barrier properties) of the bioactive film were enhanced by adding AHNT-Car due to the hydrogen bonding, electrostatic interactions, and compact structure. Specifically, when the additional amount of AHNT-Car was 10 wt%, the film's tensile, oxygen barrier, and water vapor barrier properties were improved by 49.7%, 36.78%, and 11.92%, respectively. Moreover, compared to CS-Car film (adding Car into the CS film directly), the CS-10% film (AHNT-Car added at 10 wt%) had a slow-release effect on Car and could effectively protect the Car from external high temperature and UV light. In addition, the prepared bioactive film had sustained antioxidant and antibacterial properties and could significantly slow down the spoilage of pork during storage, proving the promising application of the bioactive film as food packaging. [Display omitted] • The CS-based bioactive film incorporated with AHNT-Car was successfully developed. • CS film connected AHNT-Car via electrostatic interaction and hydrogen bonding. • Physical property and functional activity were improved of the bioactive film. • The prepared bioactive film had a significant preservation effect on pork. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effect of frozen-then-chilled storage on free Ca 2+ , proteolytic enzyme activity of calpains and the proteasome, water-holding capacity and shear force of porcine longissimus thoracis et lumborum muscle. Pork loins were subjected to either chilled storage at 2 ± 1 °C for 1, 2, 4, 6 and 9 days, or frozen-then chilled storage (−20 ± 1 °C for 1 week followed by thawing overnight). Free Ca 2+ increased with chilled storage in the non-frozen group. Frozen-then-chilled storage increased free Ca 2+ concentration, followed by a faster decrease of calpain-1 activity and activation of around 50% of calpain-2. Proteasome activity was reduced by around 40% following freezing-thawing. Purge loss increased and water-holding capacity of myofibrils decreased in the frozen-thawed group, suggesting considerable denaturation of myofibrillar proteins. Shear force was not affected by freezing-thawing, and we speculate that the tenderizing effect of calpain activation was counteracted by loss of proteasome activity and substantial exudate loss. [ABSTRACT FROM AUTHOR]

This study investigates the nanomechanical properties of different oil bodies (OBs), including soybean, peanut, sesame, and rapeseed, coated with sodium alginate (ALG), and the interaction between ALG-coated OBs using atomic force microscopy (AFM). Hooke's law, Reissner theory, and the Membrane model were respectively applied to analyze the nanomechanical properties of the linear and non-linear mechanics of the ALG-coated OBs. It was found that stiffness K b and modulus E R from the linear deformation of ALG-coated OBs increased with the increase of the ALG layer thickness, while modulus E m from the non-linear deformation was larger than E R and correlated with the compression degree of the ALG layer. The interaction between pure OBs depended on the OB type. Electrostatic interaction which is related to the surface ζ -potential of the OBs occurs at a relatively long interaction distance, while at a relatively short distance, interfacial deformation of OBs occurs and the interaction force is affected by the structure and mechanics of OB interfacial membrane. After coating by ALGs, the electrostatic repulsion occurred from a longer distance than that between pure OBs, and both electrostatic repulsion and steric hindrance exist for a long interaction distance as the ALG-coated OBs continued to approach each other. ALG coating can also weaken the electrostatic screening effect of salt ions, avoiding aggregation of OBs and thus improving their stability. The present work demonstrates the feasibility of using AFM to study the mechanical properties and interaction of OB droplets at the molecular level, and reveals the mechanism of the influence of polysaccharide macromolecules on the stability of OB emulsions from the microscopic scale. [Display omitted] • Stiffness K b and modulus E R of ALG-coated OBs from linear deformation increased with increase of ALG layer thickness. • Modulus E m from non-linear deformation was larger than E R and decreased with increase of compressed ALG-layer thickness. • Electrostatic repulsion and steric hindrance occurred and existed for a long interaction distance between ALG-coated OBs. • Reveal mechanism of ALG stabilizing OBs at molecular level, and correlate it with the macroscale results. [ABSTRACT FROM AUTHOR]

Formation of thaw loss cannot generally be avoided when meat is frozen and then thawed. Explanations have mainly focused on the damage to muscle fibers resulting from ice crystallization and the freezing-induced denaturation of myofibrillar proteins, the latter of which has, however, not received much research focus. This review discusses the relationship between myofibrillar protein denaturation and water-holding capacity of meat in freezing-thawing with the aim to improve the understanding the relative importance of protein denaturation in the formation of thaw loss. The contribution of decreased pH and high ionic strength in the unfrozen water in freezing is emphasized and we hypothesize that these two factors are causing protein denaturation and conformational changes within muscle fibers, and consequently loss of water-holding capacity. Slow freezing produces more thaw loss than fast freezing, and this is discussed here in relation to the impacts on myofibrillar protein denaturation induced by the freezing rate. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effect of storage at −3 °C on myofibrillar protein in fast or slow frozen pork. Five pork loins at 48 h post-mortem were subjected to either fast (cold metal plate/−80 °C) or slow freezing (still air/−20 °C) followed by storage at −3 °C for 0, 1, 3, and 7 days before thawing. Freezing rate significantly influenced myofibrillar proteins within 3 days at −3 °C, evidenced by higher thaw loss, higher surface hydrophobicity and reduced water-holding of myofibrils, and accelerated appearance of a myosin-4 fragment (160 kDa) in slow freezing. However, these observed differences disappeared after 7 days of storage at −3 °C. The meat pH after thawing did not differ between fast and slow freezing rate. However, the pH values after thawing in both groups decreased with extended storage at −3 °C. Our results suggest that the beneficial effects of fast freezing are gradually lost by holding at −3 °C due to more extensive protein denaturation. • Myofibrillar protein in fast or slow frozen pork was studied at storage of −3 °C. • Storage at −3 °C decreased water-holding of myofibrils. • pH decreased in fast and slow frozen groups with extended storage at −3 °C. • Fast freezing showed less protein denaturation & degradation up to 3 days at −3 °C. • Protein attributes in fast or slow frozen pork did not differ on day 7 at −3 °C. [ABSTRACT FROM AUTHOR]

• Freezing-thawing cycles of pork decreased water-holding capacity of myofibrils. • A 160 kDa myosin-4 fragment appeared in SDS-PAGE following freezing-thawing cycles. • Water-holding of myofibrils decreased after exposure to low pH-high ionic strength. • Low pH-high ionic strength exposure mimics myofibril denaturation in freezing. • A model is proposed linking low pH-high ionic strength to protein denaturation. This study aims at providing new insight on protein denaturation in freezing-thawing. Freezing-thawing minced pork reduced water-holding of myofibrils and increased surface hydrophobicity. One additional freezing-thawing cycle at slow freezing rate caused appearance of a 160 kDa myosin-4 fragment in SDS-PAGE, further decreased water-holding of myofibrils and increased surface hydrophobicity. Fresh minced pork was exposed to either high salt (2 M KCl) only or high salt with lower pH to mimic conditions in freezing. Exposure to high salt only increased water-holding of myofibrils and hence did not reproduce myofibrillar protein changes in freezing. Exposure to combinations of lower pHs and high salt decreased water-holding and increased surface hydrophobicity, suggesting myofibrillar protein denaturation occurred by a comparable mechanism as in freezing-thawing. We propose that exposure to decreased pH combined with high solute concentrations in the unfrozen water of frozen meat is the primary cause of myofibrillar protein denaturation in frozen-thawed meat. [ABSTRACT FROM AUTHOR]

[Display omitted] • Increased myofibrillar protein denaturation/oxidation was found in freeze–thaw cycles. • A cryoprotective role of thawed drip and its components was observed. • Enhanced myofibrillar gel quality was found with thawed drip addition. • A model is proposed linking myofibrillar gelation to protein over-aggregation. Myofibrillar proteins are crucial for gel formation in processed meat products such as sausages and meat patties. Freeze-thaw cycles can alter protein properties, impacting gel stability and product quality. This study aims to investigate the potential of thawed drip and its membrane-separated components as potential antifreeze agents to retard denaturation, oxidation and gel deterioration of myofibrillar proteins during freezing-thawing cycles of pork patties. The thawed drip and its membrane-separated components of > 10 kDa and < 10 kDa, along with deionized water, were added to minced pork at 10 % mass fraction and subjected to increasing freeze–thaw cycles. Results showed that the addition of thawed drip and its membrane separation components inhibited denaturation and structural changes of myofibrillar proteins, evidenced by reduced surface hydrophobicity and carbonyl content, increased free sulfhydryl groups, protein solubility and α-helix, as compared to the deionized water group. Correspondingly, improved gel properties including water-holding capacity, textural parameters and denser network structure were observed with the addition of thawed drip and its membrane separation components. Denaturation and oxidation of myofibrillar proteins were positively correlated with gel deterioration during freezing-thawing cycles. We here propose a role of thawed drip and its membrane separation components as cryoprotectants against myofibrillar protein gel deterioration during freeze-thawing cycles. [ABSTRACT FROM AUTHOR]

• Workflows of molecular docking and molecular dynamic simulation are overviewed. • Molecular docking reveals binding modes between myosin or myoglobin and additives. • Molecular dynamic simulation explores binding process of protein-additive complex. • Recent research of molecular methods in monitoring muscle quality is summarized. • Hydrogen and hydrophobic forces in protein-additive are proved by molecular methods. During storage and processing, muscle proteins, e.g. myosin and myoglobin, will inevitably undergo degeneration, which is thus accompanied by quality deterioration of muscle foods. Some exogenous additives have been widely used to interact with muscle proteins to stabilize the quality of muscle foods. Molecular docking and molecular dynamics simulation (MDS) are regarded as promising tools for recognizing dynamic molecular information at atomic level. Molecular docking and MDS can explore chemical bonds, specific binding sites, spatial structure changes, and binding energy between additives and muscle proteins. Development and workflow of molecular docking and MDS are systematically summarized in this review. Roles of molecular simulations are, for the first time, comprehensively discussed in recognizing the interaction details between muscle proteins and exogenous additives aimed for stabilizing color, texture, flavor, and other properties of muscle foods. Finally, research directions of molecular docking and MDS for improving the qualities of muscle foods are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Salting is the key driving force toward swelling/rehydration of oxidized myosin. • Myosin S1 and HMM subunits undergo both peptide oxidative scission and reversible assembling at 1–2% salt content. • Up to 5% salt brining greatly induced solubilization and stabilization with cross-linkages at myosin rod portion. • >3% salt improved elasticity and macroscopic viscosity of oxidized myosin during thermal gelation. Myosin filament plays a critical role in water-trapping and thermodynamic regulation during processing of brined muscle foods. The redox state and availability of proteolytic/antioxidant enzymes affected by salt may change the ion-binding capacity of myosin consequently contributing to swelling and rehydration. Thus, this study investigated the impact of different salt content (0%, 1%, 2%, 3%, 4%, 5% NaCl) and oxidation in vitro (10 mM H 2 O 2 /ascorbate-based hydroxyl radical (OH)-generating system) on the oxidative stability, solubility/dispersion capacity, chymotrypsin digestibility, aggregation site and the microrheological properties of isolated porcine myosin. The result showed that, brining at 2% salt exposed more sulfhydryl groups and inhibited the formation of disulfide bond, whereby smaller dispersed structure (diameter within 10–50 nm) and higher Ca2+-ATPase activity of the denatured myosin were observed. Accordingly, gel electrophoresis showed that myosin S1 and HMM subunits were highly oxidized and susceptible to reversible assembles. Despite enhanced hydrophobic interactions between swelled myosin at 3% salt content, ≥4% salt greatly promoted the exposure/polarization of tryptophan and cross-linking structures, mainly occurring at myosin S2 portion. The results of micro-rheology proved that oxidized myosin formed a tighter heat-set network following rehydration at high ion strength (≥4% salt), suggesting an increased inter-droplet resistance and macroscopic viscosity. This work is expected to give some useful insights into improved texture and functionality of engineered muscle foods. [ABSTRACT FROM AUTHOR]

Egg yolks (EY) are widely used in food emulsions due to their high contents of amphiphilic proteins. This study investigated the different characterization and interactions among low-density lipoproteins (LDL), high-density lipoproteins (HDL) and phosvitins (Pv) using fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM). The high internal-phase Pickering emulsions (HIPPEs) prepared by those protein complexes were analyzed on the basis of droplet size, optical microstructure, confocal microscopy images, interfacial protein compositions and rheological behavior. Results showed that LDL had a smaller particle size (56.44 ± 1.27 nm) and a greater ability to reduce interfacial tension, resulting in smaller droplet sizes (7.09 ± 0.25 μm) in LDL-stabilized HIPPEs. In contrast, HDL possessed higher hydrophobicity and a greater number of free sulfhydryl groups. The droplets in HDL-stabilized HIPPEs were larger, more compact, and exhibited lower solid lipid balance values in rheological tests. The competing adsorption of HDL and LDL at the interface influenced the properties of HDL-LDL prepared emulsions. However, an appropriate amount of Pv promoted the formation of an electrical double layer between LDL and HDL, further reducing interfacial tension. LDL-HDL-Pv complex stabilized HIPPEs displayed more gel-like rheological properties and the highest stability during the storage. This study provides insights for the development of EY protein-based emulsification systems in food industry. [Display omitted] • Investigation of the interactions of different EY proteins after their isolation. • Adsorption of different EY protein complexes at the oil-water interface was analyzed. • Different of HPPEs prepared by EY protein complexes were compared. • Provide a basis for the use of natural or dissociated EY as an emulsifier in the food industry. [ABSTRACT FROM AUTHOR]

This study aims to provide new insight on the association between the development of wooden breast myopathy and mitochondrial and glycolytic activity under oxidative stress. Myopathic muscle had higher oxidative stress together with altered glycolytic metabolism and tricarboxylic acid (TCA) cycle. This was evidenced by significantly elevated antioxidant enzyme activities (catalase, superoxide dismutase, and glutathione peroxidase), decreased citrate synthase activity and postmortem glycolytic potential with increasing wooden breast severity. In addition, affected muscles also exhibited higher initial and ultimate pH values as well as reduced total glucose and lactate contents. Citrate synthase activity was negatively correlated to antioxidant enzyme activities. Taken together, we propose that the development of the wooden breast lesion is a chronic process that may be related to the failure of muscle fibers to defend against the excessively generated oxidative products promoted by mitochondrial damage accompanied by impaired TCA cycle. Furthermore, there was a positive correlation between citrate synthase activity and glycolytic potential, which suggests that the wooden breast condition is linked to the overall altered energy metabolism of the muscle, including the oxidative phosphorylation and glycolytic pathways. [ABSTRACT FROM AUTHOR]

Traditional Beijing roast duck often suffers from uneven color and high sugar content after roasting. Water-in-oil (W/O) nanoemulsion is a promising alternative to replace high concentration of sugar solution used in sugaring process according to similarity-intermiscibility theory. Herein, 3% of xylose was embedded in the aqueous phase of W/O emulsion to replace 15% maltose solution. W/O emulsions with different ratios of lecithin (LEC) and polyglycerol polyricinoleate (PGPR) were constructed by high-speed homogenization and high-pressure homogenization. Distribution and penetration extent of solutions and emulsions through the duck skin, as well as the color uniformity of Beijing roast duck were analyzed. Emulsions with LEC:PGPR ratios of 1:3 and 2:2 had better stability. Stable interfacial film and spatial structure were important factors influencing emulsion stabilization. The stable W/O emulsions could more uniformly distribute onto the surface of duck skin and longitudinally penetrate through the skin than solutions. • Stability mechanisms of W/O nanoemulsions emulsified by PGPR and LEC were explored. • Beijing roast duck with emulsion instead of solution had a better odour and taste. • Color uniformity of Beijing roast duck was significantly improved. • Distribution and penetration of emulsions on the surface of duck skin was observed. [ABSTRACT FROM AUTHOR]

In metal‒rich borides, numerous boron fragments B n (n = 2, 3, 4, 5, 6) have been discovered, the B 4 units being the most versatile with four different shapes (bent, zigzag, trigonal planar and tetrahedral). We report on the new boride series Ti 2-x M 1+x–δ Ir 3+δ B 3 (x = 0.5 for M = V–Mn, x = 0 for M = Mn–Ni and δ < 0.2), in which a structural change occurs by successive substitution of the 3d transition metal M = V, Cr, Mn, Fe, Co and Ni. It is found that the change in structure from the Ti 1+x Os 2‒x RuB 2 ‒type structure (P 6 ‾ 2m , no. 189) to the Ti 1+x Rh 2‒x+y Ir 3‒y B 3 ‒type (Pbam , no. 55) leads to a change of B 4 shape from trigonal planar B 4 (M = V–Mn) to zigzag B 4 fragment (M = Mn–Ni). Even though there is no group‒subgroup relationship between the two structures, we present how the Ti 1+x Os 2‒x RuB 2 ‒type structure can easily be geometrically derived from the Ti 1+x Rh 2-x+y Ir 3-y B 3 ‒type. Image 1 • The new boride series Ti 2-x M 1+x–δ Ir 3+δ B 3 (x = 0.5 for M = V–Mn, x = 0 for M = Mn–Ni and δ < 0.2) is reported. • A structural change occurs within the series at M = Mn from the Ti 1+x Os 2‒x RuB 2 ‒ to Ti 1+x Rh 2‒x+y Ir 3‒y B 3 ‒type structure. • A change of B 4 shape from trigonal planar to zigzag B 4 fragment is found. • A substructure change from chains of triangles to ladders is found for the magnetic 3d elements. [ABSTRACT FROM AUTHOR]

Aims The total glucosides of paeony (TGP) are used to treat psoriasis in the clinic. However, its active components and mechanisms are not clear. Paeoniflorin is the main constituent of TGP. Thus, the anti-psoriasis effect of paeoniflorin was studied, and its mechanism was explored. Materials and methods The effect of paeoniflorin was evaluated using a psoriasis-like model of guinea pigs. The levels of IL-6, IL-17A, IL-22, p38 MAPK, and ERK1/2 in HaCaT cells stimulated by lipopolysaccharide (LPS) were determined using RT-qPCR, enzyme linked immunosorbent assays (ELISAs) and western blot. Key finding Compared with the control group, the model group showed edema, redness, and lesions in the ear upon stimulation with propranolol hydrochloride, and the Baker Score increased by 7-fold. Paeoniflorin ameliorated the lesion and decreased the Baker Score by 37% ( p < 0.05). In vitro, paeoniflorin significantly inhibited the mRNA expression of IL-6, IL-17A and IL-22 at both 2.08 and 10.41 μM ( p < 0.01), and paeoniflorin had a marginal effect on the protein expression of IL-17A and IL-6. However, it inhibited the protein expression of IL-22 significantly, with inhibition ratios of 48.5% and 47.8% at 2.08 and 10.41 μM, respectively ( p < 0.05). This effect was achieved by inhibiting the phosphorylation of p38 MAPK. Significance The results of this work demonstrated that paeoniflorin is the active components of TGP and support its use as a therapeutic compound for psoriasis therapy. [ABSTRACT FROM AUTHOR]

To investigate and predict quality of 2% brined common carp ( Cyprinus carpio ) fillets during frozen storage, free fatty acids (FFA), salt extractable protein (SEP), total sulfhydryl (SH) content, and Ca 2+ -ATPase activity were determined at 261 K, 253 K, and 245 K, respectively. There was a dramatic increase ( P < 0.05) in FFA and a sharp decrease ( P < 0.05) in SH at 261 K during the first 3 weeks. SEP decreased to 67.31% after 17 weeks at 245 K, whereas it took about 7 weeks and 13 weeks to decrease to the same extent at 261 K and 253 K, respectively. Ca 2+ -ATPase activity kept decreasing to 18.28% after 7 weeks at 261 K. Furthermore, radial basis function neural networks (RBFNNs) were developed to predict quality (FFA, SEP, SH, and Ca 2+ -ATPase activity) of brined carp fillets during frozen storage with relative errors all within ±5%. Thus, RBFNN is a promising method to predict quality of carp fillets during storage at 245–261 K. [ABSTRACT FROM AUTHOR]

The effects of stunning methods (percussion (T1), stunning at −22 °C in a freezer (T2), and immersion in ice slurry (T3)) on the flesh quality of grass carp fillets were evaluated in terms of K -value, total volatile base nitrogen (TVB-N), electrical conductivity (EC), total viable counts (TVC), biogenic amines, and sensory scores during storage. Moreover, fillets were analyzed periodically for pH, hardness, acid phosphatase activity, and the content of glycogen, adenosine triphosphate (ATP), and lactate. Significantly slower ATP depletion, slower reduction in pH, slower lactate formation, and higher initial glycogen level were observed in T3 compared to T1 and T2 ( P < 0.05). Grass carp stunned by percussion showed higher TVB-N, EC, TVC, total biogenic amines, and lower sensory scores. Significantly lower TVC ( P < 0.05) was exhibited in T3, which indicated that stunning in ice slurry could improve the quality and prolong the shelf life of grass carp. [ABSTRACT FROM AUTHOR]

Natural oil bodies (OBs) are micron-sized oil droplets found in parts of plants. Due to their nutritional value and characteristic that they are naturally emulsified, OBs have potential applications in food industry. In this study, κ-carrageenan (KC, 1.0 wt %) gels filled with soybean OBs (up to 10 wt % oil content) bound or unbound with the matrix were constructed. Their structure, rheological and tribological properties were characterized. It was found that in the boundary lubrication regime, the lubrication properties of the OB cream and OB emulsion-gels were significantly improved compared with pure water and the KC gels, and are better than the emulsion-gels with medium chain triglycerides (MCT) droplets stabilized by Tween 80. An ultralow boundary friction coefficient (μ) of 0.038 was achieved. The viscosity of the OB cream, the elasticity of the OB emulsion-gels, as well as the ball-bearing and rolling effect of the OBs in and out the gel fragments under shear were believed to contribute to the promising lubrication properties. It was also found that there was no significant difference in μ between the bound and unbound emulsion-gels, although μ of both types of emulsion-gels decreased with increase of oil concentration. The fragmentation and structure failure of the emulsion-gels under shear were believed to weaken the difference. Image 1 • Two types of emulsion-gels filled with uniformly distributed OBs are constructed. • OB emulsion-gels have better lubricant properties than pure water, KC gels, and MCT/Tween80 emulsion-gels. • There is no significant difference in μ between bound and unbound emulsion-gels. [ABSTRACT FROM AUTHOR]