Effect of pectin on properties of potato starch after dry heat treatment

Purpose: To evaluate the effect of pectin on the properties of potato starch after dry heat treatment. Methods: Rapid visco analyzer (RVA), differential scanning calorimetry (DSC), texture profile analyzer (TPA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and x-ray diffractometry (XRD) were used to determine the properties of modified potato starch and pectin blends after dry heat treatment. Results: Results from RVA showed that the peak viscosity of modified potato starch decreased gradually with increase in pectin concentration, dry heat time and dry heat temperature, while starch breakdown decreased and setback was increased to varying degrees. The lowest breakdown was 792 cP at dry heat temperature of 140 °C. Modified potato starch had broader ranges of gelatinization temperatures and lower gelatinization enthalpy than raw potato starch. Dry heat treatment improved the hardness, gumminess and chewiness of the gels of modified potato starch and pectin blends SEM micrographs showed some cluster shapes in microstructure after dry heat treatment of starch-pectin blends. Infrared spectra revealed that pectin addition and dry heat treatment did not cause changes in starch structure. However, x-ray diffractograms indicated that dry heat treatment weakened the third peak of potato starch. Conclusion: These results indicate that dry heat treatment effectively alters the properties of potato starch and pectin blends. This finding broadens the applications of modified potato starch in food and pharmaceutical industries

Effect of dry heat, microwave and ultrasonic treatments on physicochemical properties of potato starch with or without pectin

Purpose: To investigate the effects of dry heat, microwave and ultrasonic treatments on the physicochemical properties of potato starch alone or blended with pectin. Methods: The physicochemical properties of potato starch gels prepared using microwave, ultrasonic and dry heat treatments were assessed. Pasting properties, gel strength, thermal properties and crystal texture of the potato starch were determined using Rapid Visco analyzer, texture profile analyzer, differential scanning calorimeter and x-ray diffractometer. Results: Dry heat and ultrasonic treatments significantly increased the peak viscosity of the potato starch, and significantly decreased its setback and pasting temperatures (p < 0.05). Dry heat treatment significantly increased the hardness, while dry heat and ultrasonic treatments significantly improved retrogradation of the potato starch (p < 0.05). Transparency of potato starch paste was significantly increased by the different treatments, except microwave treatment (p < 0.05). Potato starch gels blended with pectin and subjected to any of the treatments exhibited significantly increased hardness, when compared with raw potato starch (p < 0.05). The retrogradation of the potato starch was significantly improved by the different treatments. Dry heat and ultrasonic treatments significantly decreased the syneresis of potato starch with or without pectin (p < 0.05). The three treatments also significantly affected the gelatinization enthalpy of the potato starch with or without pectin, and exerted some effects on the crystallinity of the gels. Conclusion: The results obtained in this study suggest that differences in physicochemical properties of potato starch gels are due mainly to the degree of damage to starch granules caused by different treatments. The addition of pectin to potato starch gel greatly improves its hardness and retrogradation

Sp1, Instead of AhR, Regulates the Basal Transcription of Porcine CYP1A1 at the Proximal Promoter

Pigs are commonly used as an animal model to evaluate the toxic effects of exogenous compounds. Cytochrome P450 1A1 (CYP1A1) metabolizes numerous exogenous compounds and is abundantly expressed in the liver, kidneys, and intestines. The high amino acid similarity between human and porcine CYP1A1 indicates that they probably have the same metabolic characteristics. Therefore, understanding the regulatory mechanism of CYP1A1 expression in pigs is particularly important for predicting the toxicology and metabolic kinetics of exogenous chemicals. Currently, the transcriptional regulation of porcine CYP1A1 has rarely been studied, especially regarding basal transcription. In this study, we first confirmed that the key regulatory elements of porcine CYP1A1 basal transactivation are in the proximal promoter region using promoter truncation analysis via a dual luciferase assay in a porcine kidney cell line LLC-PK1. Two overlapping cis-elements, the xenobiotic response element (XRE) and GC box, in this proximal region potentially play key roles in the basal transactivation of porcine CYP1A1. Furthermore, using electrophoretic mobility shift assay and chromatin immunoprecipitation, the GC box binding protein Sp1 was confirmed to bind to the proximal promoter of porcine CYP1A1, instead of AhR, the XRE binding protein. In LLC-PK1 cells, by knocking down either Sp1 or AhR, the expression of porcine CYP1A1 at the mRNA level and protein level was significantly downregulated, suggesting both proteins are important for porcine CYP1A1 expression. However, promoter activity analysis in LLC-PK1 cells treated with an AhR agonist and antagonist confirmed that AhR does not participate in the basal regulation of porcine CYP1A1 at the proximal promoter. In conclusion, our study revealed that the proximal promoter is the key regulatory region for porcine CYP1A1 basal expression. Although AhR plays an important role in the transactivation of porcine CYP1A1 expression, the key determinant transcription factor for its basal transactivation is Sp1 at the proximal promoter of porcine CYP1A1

Epidemiological characteristics of Vibrio parahaemolyticus outbreaks, Zhejiang, China, 2010–2022

BackgroundVibrio parahaemolyticus is one of the most common foodborne pathogens and poses a significant disease burden. The purpose of the study was to elucidate the epidemiological characteristics of Vibrio parahaemolyticus outbreaks in Zhejiang Province, and provide insights for the targeted prevention and control of foodborne diseases.MethodsDescriptive statistical methods were utilized to analyze the data on Vibrio parahaemolyticus outbreaks reported by all Centers for Disease Control and Prevention (CDCs) through Foodborne Disease Outbreaks Surveillance System (FDOSS) in Zhejiang Province from 2010 to 2022.ResultsFrom 2010 to 2022, a total of 383 outbreaks caused by Vibrio parahaemolyticus were reported by 90 CDCs in 11 prefectures of Zhejiang Province, resulting in 4,382 illnesses, 326 hospitalizations and 1 death. The main symptoms of the outbreak-related cases were diarrhea (95.18%), abdominal pain (89.23%), nausea (55.64%), vomiting (50.57%), fever (24.21%), etc. The outbreaks occurring between July and September accounted for 77.54% of all outbreaks (297 out of 383). Outbreaks associated with restaurants accounted for the majority (57.96%, 222/383) of all outbreaks, followed by those linked to staff canteens (15.40%, 59/383) and rural banquets (11.23%, 43/383). 31.85% of all outbreaks were associated with the consumption of aquatic products, while ready-to-eat foods such as Chinese cold dishes and cooked meat products accounted for 12.53% of all outbreaks. Serotype O3:K6 (81.94%, 118/144) was the predominant serotype responsible for outbreaks from 2010 to 2020, while serotype O10:K4 (57.89%, 33/57) was the predominant serotype from 2021 to 2022.ConclusionIn-depth and comprehensive analysis of long-term surveillance data on Vibrio parahaemolyticus outbreaks is essential to gain insight into the epidemiological characteristics, identify long-term patterns and recent trends, and enable governments to prioritize interventions and develop targeted policies to mitigate such outbreaks

Rational Design of Synergistic Structure Between Single-Atoms and Nanoparticles for CO2 Hydrogenation to Formate Under Ambient Conditions

Single-atom catalysts (SACs) as the new frontier in heterogeneous catalysis have attracted increasing attention. However, the rational design of SACs with high catalytic activities for specified reactions still remains challenging. Herein, we report the rational design of a Pd1-PdNPs synergistic structure on 2,6-pyridinedicarbonitrile-derived covalent triazine framework (CTF) as an efficient active site for CO2 hydrogenation to formate under ambient conditions. Compared with the catalysts mainly comprising Pd1 and PdNPs, this hybrid catalyst presented significantly improved catalytic activity. By regulating the ratio of Pd1 to PdNPs, we obtained the optimal catalytic activity with a formate formation rate of 3.66 molHCOOM·molPd−1·h−1 under ambient conditions (30°C, 0.1 MPa). Moreover, as a heterogeneous catalyst, this hybrid catalyst is easily recovered and exhibits about a 20% decrease in the catalytic activity after five cycles. These findings are significant in elucidating new rational design principles for CO2 hydrogenation catalysts with superior activity and may open up the possibilities of converting CO2 under ambient conditions

Construction of a cross-species cell landscape at single-cell level.

Individual cells are basic units of life. Despite extensive efforts to characterize the cellular heterogeneity of different organisms, cross-species comparisons of landscape dynamics have not been achieved. Here, we applied single-cell RNA sequencing (scRNA-seq) to map organism-level cell landscapes at multiple life stages for mice, zebrafish and Drosophila. By integrating the comprehensive dataset of > 2.6 million single cells, we constructed a cross-species cell landscape and identified signatures and common pathways that changed throughout the life span. We identified structural inflammation and mitochondrial dysfunction as the most common hallmarks of organism aging, and found that pharmacological activation of mitochondrial metabolism alleviated aging phenotypes in mice. The cross-species cell landscape with other published datasets were stored in an integrated online portal-Cell Landscape. Our work provides a valuable resource for studying lineage development, maturation and aging

Application of Shannon Wavelet Entropy and Shannon Wavelet Packet Entropy in Analysis of Power System Transient Signals

In a power system, the analysis of transient signals is the theoretical basis of fault diagnosis and transient protection theory. Shannon wavelet entropy (SWE) and Shannon wavelet packet entropy (SWPE) are powerful mathematics tools for transient signal analysis. Combined with the recent achievements regarding SWE and SWPE, their applications are summarized in feature extraction of transient signals and transient fault recognition. For wavelet aliasing at adjacent scale of wavelet decomposition, the impact of wavelet aliasing is analyzed for feature extraction accuracy of SWE and SWPE, and their differences are compared. Meanwhile, the analyses mentioned are verified by partial discharge (PD) feature extraction of power cable. Finally, some new ideas and further researches are proposed in the wavelet entropy mechanism, operation speed and how to overcome wavelet aliasing

Protocol for ambient CO2 capture and conversion into HCOOH and NH4H2PO4

Summary: CO2 capture and utilization into liquid fuels and high-added-value chemicals has been regarded as an attractive strategy to mitigate excessive carbon emissions. Here, we present a protocol to capture and convert CO2 into pure formic acid (HCOOH) solution and solid fertilizer (NH4H2PO4). We describe steps for synthesis of an IRMOF3-derived carbon-supported PdAu heterogeneous catalyst (PdAu/CN-NH2), which can efficiently catalyze (NH4)2CO3-captured CO2 into formate under ambient conditions.For complete details on the use and execution of this protocol, please refer to Jiang et al. (2023).1 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

T-2 toxin and deoxynivalenol (DON) exert distinct effects on stress granule formation depending on altered activity of SIRT1

The T-2 toxin and deoxynivalenol (DON), as the most concerned members of trichothecenes, induce cellular stress responses and various toxic effects. Stress granules (SGs) are rapidly formed in response to stress and play an important role in the cellular stress response. However, it is not known whether T-2 toxin and DON induce SG formation. In this study, we found that T-2 toxin induces SG formation, while DON surprisingly suppresses SG formation. Meanwhile, we discovered that SIRT1 co-localized with SGs and regulated SG formation by controlling the acetylation level of the SG nucleator G3BP1. Upon T-2 toxin, the acetylation level of G3BP1 increased, but the opposite change was observed upon DON. Importantly, T-2 toxin and DON affect the activity of SIRT1 via changing NAD+ level in a different manner, though the mechanism remains to be clarified. These findings suggest that the distinct effects of T-2 toxin and DON on SG formation are caused by changes in the activity of SIRT1. Furthermore, we found that SGs increase the cell toxicity of T-2 toxin and DON. In conclusion, our results reveal the molecular regulation mechanism of TRIs on SG formation and provide novel insights into the toxicological mechanisms of TRIs

A Transient Fault Recognition Method for an AC-DC Hybrid Transmission System Based on MMC Information Fusion

At present, the research is still in the primary stage in the process of fault disturbance energy transfer in the multilevel modular converter based high voltage direct current (HVDC-MMC). An urgent problem is how to extract and analyze the fault features hidden in MMC electrical information in further studies on the HVDC system. Aiming at the above, this article analyzes the influence of AC transient disturbance on electrical signals of MMC. At the same time, it is found that the energy distribution of electrical signals in MMC is different for different arms in the same frequency bands after the discrete wavelet packet transformation (DWPT). Renyi wavelet packet energy entropy (RWPEE) and Renyi wavelet packet time entropy (RWPTE) are proposed and applied to AC transient fault feature extraction from electrical signals in MMC. Using the feature extraction results of Renyi wavelet packet entropy (RWPE), a novel recognition method is put forward to recognize AC transient faults using the information fusion technology. Theoretical analysis and experimental results show that the proposed method is available to recognize transient AC faults