RESUMEN
Schistosomiasis is a fatal zoonotic parasitic disease that also threatens human health. The main pathological features of schistosomiasis are granulomatous inflammation and subsequent liver fibrosis, which is a complex, chronic, and progressive disease. Extracellular vesicles (EVs) derived from schistosome eggs are broadly involved in host-parasite communication and act as important contributors to schistosome-induced liver fibrosis. However, it remains unclear whether substances secreted by the EVs of Schistosoma japonicum, a long-term parasitic "partner" in the hepatic portal vein of the host, also participate in liver fibrosis. Here, we report that EVs derived from S. japonicum worms attenuated liver fibrosis by delivering sja-let-7 into hepatic stellate cells (HSCs). Mechanistically, activation of HSCs was reduced by targeting collagen type I alpha 2 chain (Col1α2) and downregulation of the TGF-ß/Smad signaling pathway both in vivo and in vitro. Overall, these results contribute to further understanding of the molecular mechanisms underlying host-parasite interactions and identified the sja-let-7/Col1α2/TGF-ß/Smad axis as a potential target for treatment of schistosomiasis-related liver fibrosis.
Asunto(s)
Vesículas Extracelulares , Cirrosis Hepática , Schistosoma japonicum , Esquistosomiasis Japónica , Animales , Vesículas Extracelulares/metabolismo , Cirrosis Hepática/parasitología , Cirrosis Hepática/metabolismo , Cirrosis Hepática/patología , Esquistosomiasis Japónica/metabolismo , Esquistosomiasis Japónica/parasitología , Esquistosomiasis Japónica/patología , Ratones , Interacciones Huésped-Parásitos/fisiología , Células Estrelladas Hepáticas/metabolismo , Células Estrelladas Hepáticas/parasitología , Células Estrelladas Hepáticas/patología , MicroARNs/metabolismo , MicroARNs/genética , Transducción de Señal , Humanos , Proteínas del Helminto/metabolismo , Factor de Crecimiento Transformador beta/metabolismo , Ratones Endogámicos C57BLRESUMEN
Schistosomiasis is a neglected tropical disease that affects humans and animals in tropical and subtropical regions worldwide. Schistosome eggs are responsible for the pathogenesis and transmission of schistosomiasis, thus reducing egg production is vital for prevention and control of schistosomiasis. However, the mechanisms underlying schistosome reproduction remain unclear. Annexin proteins (ANXs) are involved in the physiological and pathological functions of schistosomes, but the specific regulatory mechanisms and roles of ANX A13 in the development of Schistosoma japonicum and host-parasite interactions remain poorly understood. Therefore, in this study, the expression profiles of SjANX A13 at different life cycle stages of S. japonicum were assessed using quantitative PCR. In addition, the expression profiles of the homolog in S. mansoni were analyzed in reference to public datasets. The results of RNA interference showed that knockdown of SjANX A13 significantly affected the development and egg production of female worms in vivo. The results of an immune protection assay showed that recombinant SjANX A13 increased production of immunoglobulin G-specific antibodies. Finally, co-culture of S. japonicum exosomes with LX-2 cells using a transwell system demonstrated that SjANX A13 is involved in host-parasite interactions via exosomes. Collectively, these results will help to clarify the roles of SjANX A13 in the development of S. japonicum and host-parasite interactions as a potential vaccine candidate.
Asunto(s)
Schistosoma japonicum , Esquistosomiasis , Humanos , Femenino , Animales , Schistosoma japonicum/genética , Esquistosomiasis/veterinaria , Inmunoglobulina G , Reproducción , Anexinas/metabolismoRESUMEN
Schistosomiasis is an important zoonotic disease affecting up to 40 kinds of animals and is responsible for â¼250 million human cases per year. Due to the extensive use of praziquantel for the treatment of parasitic diseases, drug resistance has been reported. Consequently, novel drugs and effective vaccines are urgently needed for sustained control of schistosomiasis. Targeting reproductive development of Schistosoma japonicum could contribute to the control of schistosomiasis. In this study, five highly expressed proteins (S. japonicum large subunit ribosomal protein L7e, S. japonicum glutathione S-transferase class-mu 26 kDa isozyme, S. japonicum UDP-galactose-4-epimerase and two hypothetical proteins SjCAX70849 and SjCAX72486) in 18, 21, 23, and 25-day mature female worms compared to single-sex infected female worms were selected based on our previous proteomic analysis. Quantitative real-time polymerase chain reaction analysis and long-term interference with small interfering RNA were performed to identify the biological functions of these five proteins. The transcriptional profiles suggested that all five proteins participated in the maturation of S. japonicum. RNA interference against these proteins resulted in morphological changes to S. japonicum. The results of an immunoprotection assay revealed that immunization of mice with recombinant SjUL-30 and SjCAX72486 upregulated production of immunoglobulin G-specific antibodies. Collectively, the results demonstrated that these five differentially expressed proteins were vital to reproduction of S. japonicum and, thus, are potential candidate antigens for immune protection against schistosomiasis.
Asunto(s)
Schistosoma japonicum , Esquistosomiasis Japónica , Esquistosomiasis , Minorías Sexuales y de Género , Femenino , Humanos , Animales , Ratones , Proteómica , Praziquantel/farmacologíaRESUMEN
Induced electric field (IEF), as an alternative non-conventional processing technique, is utilized to sterilize liquid foods. In this study, the survival and sublethal injury of S. aureus under IEF were investigated in 0.85% normal saline, and the inactivation mechanism of IEF was expounded. The plate count results showed that the sublethal injury rates remained above 90% after IEF treatment for more than 8.4 s, and 7.1 log CFU/mL of S. aureus was completely inactivated after 14 s IEF treatment. Scanning electron microscopy and transmission electron microscope images showed that IEF caused the destruction of cell membrane and internal substructure, and the damage to intracellular substructure was more severe. Altered membrane integrity or permeability was demonstrated through flow cytometry and confocal laser scanning microscope analysis, and the different damage to cells was quantified by propidium iodide & 5-carboxy fluorescein diacetate single and double staining. In addition, IEF treatment also decreased the membrane potential and esterase activity of S. aureus cells. Putative inactivation mechanism of IEF against S. aureus is a complex process, and its apoptosis is the result of the combination of several factors, which provide a basis for understanding the inactivation mechanism of IEF.
Asunto(s)
Antiinfecciosos , Staphylococcus aureus , Staphylococcus aureus/fisiología , Membrana Celular , Microscopía Electrónica de RastreoRESUMEN
The large amount of schistosome eggs produced by mature female worms not only induce major pathological damage to the host but also lead to the transmission of schistosomiasis. Mature female schistosome worms need constant pairing contact with a male partner as male signaling is indispensable to female growth, development, and reproduction. The gynecophoral canal protein (GCP), a cell-surface glycoprotein, plays a potential role in the interaction between males and females and in stimulating female development and maturation. In this study, a yeast two-hybrid cDNA library of Schistosoma japonicum (Sj) parasites 18 days post-infection (dpi) was constructed; the Sjgcp gene was inserted into a pGBKT7-BD bait plasmid and used as a bait protein to screen for its molecular interactions using a yeast mating procedure. Twenty-four prey proteins that interacted with the SjGCP were selected after excluding false positives; the interactions between S.japonicum lethal giant larvae (SjLGL) and SjGCP, S.japonicum type V collagen (SjColV) and SjGCP, were verified by co-immunoprecipitation. The RNA interference against SjGCP, SjColV and SjGCP + SjColV led to severe underdevelopment of tegument in male worms and vitelline globules in female worms as well as reduced reproductive capacity of the females. Collectively, SjGCP and its interacting proteins may play pivotal roles in growth and development. The findings also suggested that SjGCP and its interacting protein partners might represent new candidate targets for drug development against schistosomiasis.
Asunto(s)
Schistosoma japonicum , Esquistosomiasis Japónica , Animales , Femenino , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Masculino , Saccharomyces cerevisiae/genética , Schistosoma japonicum/genética , Técnicas del Sistema de Dos HíbridosRESUMEN
Non-conventional heating technology based on electric fields can be utilized to process liquid foods. In this study, the induced electric field (IEF) was investigated to clarify its inactivation mechanism on E.coli. Staining results show that inactivation of E.coli by IEF can be attributed to the reversible destruction of the cell membrane, followed by the denaturation of intracellular enzymes, and finally the irreversible rupture of the cell membrane. The increased levels of extracellular proteins and nucleic acids were also observed. IEF treatment at 400 Hz and 800 V (or 53 V/cm) results in a reduction of 4.5 log CFU·mL-1 in the number of E.coli. Storage life analysis shows that IEF treatment can improve the stability of apple juice and the content of bioactive components. Thus, IEF is a potential technique for liquid food processing.
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Electricidad , Escherichia coli O157 , Manipulación de Alimentos/métodos , Malus , Recuento de Colonia Microbiana , Microbiología de Alimentos , Jugos de Frutas y Vegetales , Malus/microbiologíaRESUMEN
In the present study 114 lactic acid bacteria strains, isolated from raw mare milks from pastoral areas for ethnic minorities in northwest China, were screened for probiotic traits, and their characteristics were compared with those of Lactobacillus rhamnosus GG, a commercial strain. Among the 114 strains identified, the most common species was Pediococcus pentosaceus (n = 52), followed by Leuconostoc lactis (n = 35), Lactobacillus helveticus (n = 7), Lactobacillus plantarum (n = 6), Lactobacillus kefiri (n = 5), Lactobacillus curvatus (n = 4), Lactobacillus paracasei (n = 3), and Lactococcus garvieae (n = 3). Based on acid and bile salt tolerance, 15 strains were further selected. All selected strains were subjected to a series of in vitro tests to assess their technological properties, including cell surface hydrophobicity (13.6-56.2%), autoaggregation ability (9.26-38.30%), coaggregation ability, and heat and lysozyme survival rates (84.74-94.01% and 80.52-99.37%, respectively). In vitro antagonism showed that Lb. plantarum (M5-19, M8-60, M8-59) exhibited the most strong inhibitory activity against 7 tested pathogens. Moreover, antibiotic resistance and hemolytic activity were investigated for safety assessment. No strain exhibited hemolytic activity, and most of the strains were sensitive to a series of 14 antibiotics of clinical importance. Ultimately, the principal component analysis of all data obtained above showed that 2 Lb. plantarum strains (M8-59, M8-60) and Lb. paracasei M1-36 exhibited the best potential for their inclusion as adjunct functional cultures in local fermented dairy products.
Asunto(s)
Productos Lácteos Cultivados , Lactobacillales , Probióticos , Animales , China , Femenino , Fermentación , Caballos , Lactobacillus , Lactococcus , Leuconostoc , LecheRESUMEN
Eggs produced by bisexual infected mature female worms (MF) of Schistosoma japonicum are important in the transmission of the parasite and responsible for the pathogenesis of schistosomiasis. The single-sex infected female worms (SF) cannot mature and do not produce normal eggs; also they do not induce severe damage to the host. In this study, the microRNA (miRNA) expression profiles of 25d MF and 25d SF were investigated through Solexa deep-sequencing technology to explore the developmental mechanisms of schistosome female worms. There were 36 differentially expressed miRNA, 20 up-regulated and 16 down-regulated found in MF/SF worms, including some development related miRNA such as bantam (ban), let-7, miR-124, miR-8, miR-1, miR-7. There were 166 target genes of up-regulated miRNA and 201 target genes of down-regulated miRNA after comparing the target gene prediction software results with RNA-Seq transcriptome results. Analysis of the target genes shows that different ones are involved in MF and SF worms in Gene Ontology terms, with a similar situation in KEGG. This observation indicates that different genes regulated by differentially expressed miRNA take part in MF and SF and lead to differential sexual status. This means that the sexual status of female worms is regulated by miRNA.
Asunto(s)
Expresión Génica , MicroARNs/genética , ARN de Helminto/genética , Schistosoma japonicum/genética , Animales , Femenino , Regulación de la Expresión Génica , MicroARNs/metabolismo , ARN de Helminto/metabolismo , Schistosoma japonicum/crecimiento & desarrolloRESUMEN
Schistosomiasis is a globally important helminthic disease of humans and animals, and it is the second most common parasitic disease after malaria. Eggs produced by mature females are responsible for the disease's occurrence and spread. Frzb2, a secreted frizzled-related protein, can inhibit Wnt signalling by competitive binding to the specific frizzled protein receptor. In this study, the complete gene sequence of SjFrzb2 was obtained by using 3'-rapid amplification of cDNA ends technology. SjFrzb2 transcript levels at different stages of S. japonicum maturation were evaluated by quantitative real-time RT-PCR analysis. SjFrzb2 was expressed at all developmental stages examined and exhibited the highest transcription level in 7-day-old worms, then gradually decreased during the growth and developmental stages to reach the lowest level at 18 days post-infection. SjFrzb2 gene expression was higher in female worms than in male worms and was significantly higher in female worms from a single-sex infection than in female worms from a bisexual infection. The functions of SjFrzb2 were explored via a small interfering RNA-based gene silencing approach and the soaking method. The results showed that SjFrzb2 gene knockdown impaired the growth and development of S. japonicum in mice, affecting not only the survival and morphological structure of the worms but also their reproductive ability and the viability of the produced eggs. Collectively, these observations imply that Frzb2 may be a novel target for the development of immuno- and/or small molecule-based therapeutics to control schistosomiasis fecundity and transmission.
Asunto(s)
Regulación del Desarrollo de la Expresión Génica/fisiología , Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Schistosoma japonicum/genética , Schistosoma japonicum/metabolismo , Animales , Composición de Base , ADN de Helmintos/genética , Femenino , Masculino , Ratones , Ratones Endogámicos BALB C , Caracoles/parasitologíaRESUMEN
During development, Schistosoma japonicum undergoes many morphological and physiological transformations as a result of profound changes in gene expression. Proteins containing zinc finger motifs usually play an important role in DNA recognition, RNA packaging, and transcriptional activation. In our current study, we cloned the open reading frame (ORF) of SjZFP1 of S. japonicum, which encodes a zinc finger protein. We analyzed the complementary DNA (cDNA) sequence of SjZFP1 and examined the expression of SjZFP1 messenger RNA (mRNA) at various developmental stages. We also tested the effects of RNA interference (RNAi) silencing on worm burden, spawning, and egg hatching. The ORF in the SjZFP1 cDNA was 1017 bp in length and was predicted to encode a 338-aa protein with a molecular mass of approximately 38.5 kDa and theoretical isoelectric point (pI) of 7.08. Several conserved regions, including a B-box-type zinc-binding domain, two bipartite nuclear localization signal domains, a paired amphipathic helix repeat, and overlapping RING and PHD finger domains, were identified in the predicted amino acid sequence of SjZFP1. Using real-time PCR, we showed that the SjZFP1 mRNA was expressed across all of the developmental stages of the parasite and that the level of transcription was highest in the cercariae, eggs, schistosomula, and mature adult worms. The level of SjZFP1 mRNA expression in cultured schistosomula treated with one of two SjZFP1-specific small interfering RNAs (siRNAs; AY770 and AY546) was reduced by over 80 %, compared with that in the controls. In RNAi experiments in BALB/c mice, the level of SjZFP1 mRNA increased significantly when the mice were treated with the same SjZFP1-specific siRNAs during the early stages of infection. By contrast, the level of SjZFP1 mRNA decreased significantly when the mice were treated with the SjZFP1-specific siRNAs during the middle to late stages of infection. In four independent experiments, fewer worms were recovered from mice treated with the SjZFP1-specific siRNAs, compared with the number of worms recovered from the control mice. Both the average number and hatching rates of liver eggs recovered from mice treated with the SjZFP1-specific siRNAs during the middle to late stages of infection were significantly lower than those of the liver eggs recovered from the control mice. Our results suggest that the SjZFP1 gene might be important for parasite development, spawning in the vertebrate host, and egg hatching.
Asunto(s)
Proteínas del Helminto/metabolismo , Interferencia de ARN , Schistosoma japonicum/metabolismo , Esquistosomiasis Japónica/parasitología , Secuencia de Aminoácidos , Animales , ADN/genética , ADN Complementario/genética , Proteínas del Helminto/genética , Masculino , Ratones , Ratones Endogámicos BALB C , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , Reacción en Cadena en Tiempo Real de la Polimerasa , Schistosoma japonicum/genéticaRESUMEN
Lethal giant larvae (Lgl) are an evolutionarily conserved tumor suppressor present in fungi and animals. It plays an essential role in establishing apical-basal cell polarity, cell proliferation, differentiation, and tissue organization. Here, we report the presence of Lgl gene in the blood fluke Schistosoma japonicum (SjLgl) (GenBank: KF246684). SjLgl protein was mainly distributed in the unique surface tegument structure by immunofluorescence microscopic staining. Using a simple soaking method, a short interfering RNA (siRNA)-based RNA interference approach knocked down the expression of SjLgl in schistosomula in vitro by up to 89.0%. Moreover, tail vein injection of SjLgl-siRNA into the infected mice reduced SjLgl mRNA levels in vivo by 48.6-85.3%, depending on the duration of treatments. SjLgl-specific siRNA treatment during the infection in mice significantly altered the surface structure of adult worm, featured by the disappearance or significant reduction of sharp spines on the inner all of oral and ventral suckers. The siRNA also reduced the hatching rates in eggs produced by treated mice by up to 85.3%. These observations implied that Lgl plays an important role in the development of tegument in schistosomes, and may be explored as a novel target for developing immuno- and/or small molecule-based therapeutics to control and treat the infections caused by schistosome and other flatworms.
Asunto(s)
Proteínas del Helminto/metabolismo , Schistosoma japonicum/ultraestructura , Animales , Proteínas del Helminto/genética , Masculino , Ratones , Ratones Endogámicos BALB C , Óvulo/fisiología , Interferencia de ARN , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN Interferente Pequeño/genética , Conejos , Ratas Wistar , Schistosoma japonicum/genética , Schistosoma japonicum/metabolismo , Proteínas Supresoras de Tumor/genética , Proteínas Supresoras de Tumor/metabolismoRESUMEN
A novel electromagnetic heat method is presented for green extraction of natural compounds from peel residue. In the processing cavity obtained through 3D printing, a core made of amorphous alloy was applied to strengthen the magnetic flux. During the process, an induced electric field was produced in the extract medium owing to an oscillating magnetic field at 50 kHz rather than a pair of electrodes; thus, electrochemical reactions could be avoided. A thermal effect and temperature rise were observed under the field, and essential oil was obtained via this electromagnetic heat hydrodistillation. In addition, the numerical relationships between magnetic field, induced electric field (IEF), induced current density, and temperature profile were elaborated; they were positively correlated with the extraction yield of essential oils. It was found that the waveforms of the magnetic field, induced electric field, and excitation voltage were not consistent. Using a higher magnetic field resulted in high current densities and terminal temperatures in the extracts, as well as higher essential oil yields. When the magnetic field strength was 1.39 T and the extraction time was 60 min, the maximum yield of essential oil reached 1.88%. Meanwhile, conventional hydrodistillation and ohmic heating hydrodistillation were conducted for the comparison; all treatments had no significant impact on the densities. In addition, the essential oil extracted by electromagnetic heat had the lowest acid value and highest saponification value. The proportion of monoterpenoids and oxygen-containing compounds of essential oil extracted by this proposed method was higher than the other two methods. In the end, the development of this electromagnetic heat originating from magnetic energy has the potential to recover high-value compounds from biomass waste.
RESUMEN
RATIONALE: Methimazole (MMI) is the first-line agent in the treatment of hyperthyroidism. However, rare but severe cholestatic jaundice may occur. Therapeutic plasma exchange (TPE) may provide an alternative treatment for such patients and they received thyroidectomy/radioactive iodine ablation or continued oral anti hyperthyroidism medication immediately after TPE session in the reported literatures. The case reported here is, to our knowledge, the first to describe the long interval between anti hyperthyroidism therapy and TPE in such patients. PATIENT CONCERNS: A 49-year-old Chinese woman had developed worsening jaundice 3 weeks after receiving methimazole (20 mg/day) for the treatment of hyperthyroidism secondary to Graves' disease (GD). Additionally, she had a 2-year history of type 2 diabetes. DIAGNOSIS: Hyperthyroidism secondary to GD, MMI-induced severe cholestatic jaundice and type 2 diabetes. INTERVENTIONS: Methimazole was discontinued and the patient received 3 times of TPE, about 3-month glucocorticoid treatment, insulin administration accordingly and other conventional liver-protecting therapy. OUTCOMES: Her thyroid function was stabilized with small dose of thyroxine substitution and euthyroid status persisted after thyroxine discontinuation until hyperthyroidism recurred 7 months later while her cholestatic jaundice was eventually recovered by about 3-month glucocorticoid therapy. LESSONS: Due to the complex interplay between liver function and thyroid hormones, there may be unusual changes of thyroid function in GD patients with severe liver injury after TPE. By this case, we want to highlight the importance of a closely following up of thyroid function in order to deliver appropriate health suggestions for patients.
Asunto(s)
Diabetes Mellitus Tipo 2 , Enfermedad de Graves , Hipertiroidismo , Ictericia Obstructiva , Neoplasias de la Tiroides , Humanos , Femenino , Persona de Mediana Edad , Metimazol/efectos adversos , Tiroxina , Intercambio Plasmático , Ictericia Obstructiva/terapia , Ictericia Obstructiva/inducido químicamente , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Radioisótopos de Yodo/uso terapéutico , Glucocorticoides/uso terapéutico , Neoplasias de la Tiroides/terapia , Recurrencia Local de Neoplasia/tratamiento farmacológico , Enfermedad de Graves/complicaciones , Enfermedad de Graves/terapia , Hipertiroidismo/tratamiento farmacológico , Antitiroideos/efectos adversosRESUMEN
A novel electromagnetic heat extraction method was presented, whereby mandarin peels residue solution was located in a winding coil subjected to an oscillating magnetic field, and the pectin was extracted under appropriate conditions. Numerical relationships between applied magnetic field and induced electric field (IEF) in the extraction process were elaborated. The results showed that the induced current density, IEF and terminal temperature increased with increasing magnetic field. The maximum current density of 0.35 A/cm corresponds to the highest terminal temperature of 84.6 °C and IEF intensity of 26.6 V/cm. When magnetic field intensity was 1.39 T and the extraction time was 15 min, the maximum yield of pectin reached 9.16 %. In addition, all treatments impacted the ash content, protein content, water-holding capacity (WHC), and oil-holding capacity (OHC) of the obtained pectin. The pectin extracted by electromagnetic heat had the lowest DE value of 71.3 % with 126.55 kDa molecular weight, while the GalA content was at the highest level of 76.18 %. After different treatments, the composition of pectin monosaccharides changed, but there were slight differences in the composition of pectin polysaccharides. Moreover, the electromagnetic heat extracted pectin had light color and an obvious surface fragmentation of the peel residue.
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Calor , Pectinas , Pectinas/química , Polisacáridos , Monosacáridos , Fenómenos ElectromagnéticosRESUMEN
The magnetic field application is emerging as an auxiliary physical strategy to facilitate rapid biomass accumulation and intracellular production of compounds. However, the underlying mechanisms and principles governing the application of magnetic fields for microbial growth and biotransformation are not yet fully understood. Therefore, a better understanding of interdisciplinary technologies integration, expanded magnetic field application, and scaled-up industrial implementation is crucial. In this review, the magnetic field characteristics, magnetic field-assisted fermentation devices, and the working mechanism of magnetic field have been reviewed comprehensively from both physical and microbiological perspectives. The review suggests that magnetic fields affect the biochemical processes in microorganisms by mediating nutrient transport across membranes, electron transfer during photosynthesis and respiration, enzyme activity and gene expression. Moreover, the recent advances in magnetic field application for microbial fermentation and conversion in biochemical, food and agricultural fields have been summarized.
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Campos Magnéticos , Fotosíntesis , Fermentación , Transporte de Electrón , BiomasaRESUMEN
Fresh pork tenderloin was stored at -3 °C under different static magnetic fields (SMF) of 0, 4, and 10 mT (control, MF-4, and MF-10) to investigate their physicochemical properties changes during storage of 8 days. The initial equilibrium temperature of the samples stored with 4 mT MF was found to be -2.3 °C, which was slightly lower (0.3 °C) than that the control value. The super-chilling phenomenon on the pork was then observed, as the samples stored under the magnetic field did not freeze throughout storage period, but the control experienced a sudden change in temperature after 138 h and then froze. The preservation effect of MF-4 on meat quality was the best in all treatment groups. MF-4 achieved a higher water-retention rate, with drip and cook losses of 6.5% and 29.0% lower than the control, respectively. Meanwhile, the MF-4 effectively delayed the color change in the meat during the storage and the texture hardening after cooking, and effectively controlled the growth of the total volatile saline nitrogen content on the samples. In addition, MF-4 delayed the reduction in myofibrillar protein solubility, sulfhydryl content, and emulsification capacity, indicating that this field inhibited the denaturation of myofibrillar protein. This study can be considered as an application reference of magnetic fields during meat storage at a super-chilled temperature.
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This study evaluated the effectiveness of induced electric field (IEF) as a novel electrotechnology to assist dilute acid pretreatment of wheat straw (WS) at atmospheric pressure and low temperature (90 °C). The effects of acid concentration and duration on cellulose recovery, hemicellulose and lignin removal were investigated. Meanwhile, the differences between IEF pretreatment and hydrothermal pretreatment were compared by quantitative and qualitative analysis. The optimal pretreatment condition was acid concentration 1 % with the period of 5 h. Under the parameters, the hemicellulose removal of WS after IEF pretreatment was up to 73.6 %, and the enzymatic efficiency was 55.8 %. In addition, the irregular surface morphology, diminished functional groups associated with hemicellulose, increased specific surface area and pore volume, as well as improved thermal stability of the residual WS support the remarkable effect of IEF pretreatment. The feasibility of IEF pretreatment is might be due to the fact that the magneto-induced electric field promotes ionization of H+ and formation of hydrated hydrogen ions, increasing the acidity of the medium. Secondly, electroporation disrupts the anti-degradation structure of WS and increases the accessibility of cellulose to cellulases. It indicated that IEF is a green and efficient strategy for assisting the separation of hemicellulose from lignocellulose.
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Celulosa , Lignina , Polisacáridos , Lignina/química , Hidrólisis , Celulosa/química , Ácidos , Hidrolasas , Triticum/químicaRESUMEN
This study explored the effect of constant-current pulsed electric field thawing (CC-T) on the proteins and water-holding capacity of pork. Fresh meat (FM), and frozen meat after constant-voltage thawing (CV-T), air thawing (AT) and water immersion thawing (WT) were considered as controls. The results indicated that CC-T had a higher thawing rate than conventional thawing during ice-crystal melting stage (-5 to -1 °C). It also showed a lower water migration and thawing loss, maintaining pH and shear force closer to FM. Meanwhile, CC-T decreased myoglobin oxidation, resulting in a favorable surface color. The results of protein solubility, differential scanning calorimetry, total sulfhydryl, carbonyl and surface hydrophobicity demonstrated that CC-T reduced myofibrillar protein oxidative denaturation by suppressing the formation of disulfide and carbonyl bonds, thus enhancing solubility and thermal stability. Additionally, microstructural observation found that CC-T maintained a relatively intact muscle fiber structure by reducing muscle damage and myosin filament denaturation.
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Congelación , Agua , Animales , Porcinos , Agua/química , Músculo Esquelético/química , Solubilidad , Proteínas Musculares/química , Electricidad , Carne/análisis , Oxidación-Reducción , Manipulación de AlimentosRESUMEN
As an emerging physical technology, magnetic fields have been used to improve the quality of frozen and refrigerated foods. This study compared the effect of applying a static magnetic field (2 mT) at different stages of freezing and storage on the quality of frozen dough. Results suggested that the magnetic field significantly impacted frozen dough quality. It not only prevented the formation of ice crystals during the pre-freezing stage but also inhibited ice crystal growth during the following frozen storage. This effect helped to maintain the integrity of gluten proteins and their adhesion to starch granules by preventing the breakage of disulfide bonds and the depolymerization of gluten macromolecules. It was also observed that yeast inactivation and glutathione release were reduced, resulting in improved air retention and air production capacity of the dough. This, in turn, led to a more appealing volume and texture quality of the finished bread.
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Pan , Harina , Congelación , Campos Magnéticos , Triticum , Triticum/química , Pan/análisis , Harina/análisis , Glútenes/química , Glútenes/análisis , CulinariaRESUMEN
Starch a natural polymer, has made significant advancements in recent decades, offering superior performance and versatility compared to synthetic materials. This review discusses up-to-date diverse applications of starch gels, their fabrication techniques, and their advantages over synthetic materials. Starch gels renewability, biocompatibility, biodegradability, scalability, and affordability make them attractive. Also, advanced theoretical foundations and emerging industrial technologies could further expand their scope and functions inspiring new applications.