Improvement of Surimi Gel from Frozen-Stored Silver Carp.

Silver Carp (SC) is an under-utilized, invasive species in North American river systems. In this study, the synergistic effects of manufactured Microfiber (MMF), Transglutaminase (TG), and chicken skin collagen (CLG)) to enhance surimi gel quality from frozen SC were studied. The gel strength, textural properties, rheological properties, water-holding capacity (WHC), water mobility, microstructure, and protein composition of the gel samples were determined to assess the impact of the additives individually and synergistically. The results suggested that TG had the most pronounced effect on the surimi gel properties by promoting protein cross-linking. Synergistic effects between TG, MMF, and CLG can bring effective gel property enhancement larger than the individual effect of each additive alone. With the established response-surface models, the combination of CLG and MMF can be optimized to produce surimi gels with less TG but comparable in properties to that of the optimal result with high TG usage. The findings of this study provided a technical foundation for making high-quality surimi gel products out of frozen-stored SC with synergistic utilization of additives, which could serve as guidelines for the industrial development of new surimi products.

Effect of C Addition on the Microstructure and Fracture Properties of In Situ Laminated Nb/Nb5Si3 Composites.

//Nbss and α-Nb5Si3 phases were detected. Meanwhile, Nb2C was observed, and the crystal forms of Nb5Si3 changed in the C-doped composites. Furthermore, micron-sized and nano-sized Nb2C particles were found in the Nbss layer. The orientation relationship of Nb2C phase and the surrounding Nbss was [001]Nbss//[010]Nb2C, (200) Nbss//(101) Nb2C. Additionally, with the addition of C, the compressive strength of the composites, at 1400 °C, and the fracture toughness increased from 310 MPa and 11.9 MPa·m1/2 to 330 MPa and 14.2 MPa·m1/2, respectively; the addition of C mainly resulted in solid solution strengthening.

Rational design of oral drugs targeting mucosa delivery with gut organoid platforms.

Effective oral drugs and vaccines require high delivery efficiency across the gastrointestinal epithelia and protection of medically effective payloads (i.e., immunogens) against gastric damage. In this study, hollowed nanocarriers (NCs: silica nanospheres and gold nanocages) with poly-l-lysine (PLL) coating and mammalian orthoreovirus cell attachment protein σ1 functionalization (NC-PLL-σ1) were explored as functional oral drug delivery vehicles (ODDVs). The transport of these ODDVs to mucosal lymphoid tissues could be facilitated by microfold cells (M-cells) mediated transcytosis (via σ1-α2-3-linked sialic acids adherence) across gastrointestinal epithelia. PLL coating provided protection and slow-release of rhodamine 6 G (R6G), a model payload. The transport effectiveness of these ODDVs was tested on intestinal organoid monolayers in vitro. When compared with other experimental groups, the fully functionalized ODDV system (with PLL-σ1) demonstrated two significant advantages: a significantly higher transport efficiency (198% over blank control at 48 h); and protection of payloads which led to both better transport efficiency and extended-release of payloads (61% over uncoated carriers at 48 h). In addition, it was shown that the M cell presence in intestinal organoid monolayers (modulated by Rank L stimulation) was a determining factor on the transport efficiency of the ODDVs: more M-cells (induced by higher Rank L) in the organoid monolayers led to higher transport efficiency for ODDV-delivered model payload (R6G). The fully functionalized ODDVs showed great potential as effective oral delivery vehicles for drugs and vaccines.

Transmission and retention of antibiotic resistance genes (ARGs) in chicken and sheep manure composting.

Transmission of ARGs during composting with different feedstocks (i.e., sheep manure (SM), chicken manure (CM) and mixed manure (MM, SM:CM = 3:1 ratio) was studied by metagenomic sequencing. 53 subtypes of ARGs for 22 types of antibiotics were identified as commonly present in these compost mixes; among them, CM had higher abundance of ARGs, 1.69 times than that in SM, while the whole elimination rate of CM, MM and SM were 55.2%, 54.7% and 42.9%, respectively. More than 50 subtypes of ARGs (with 8.6%, 11.4% and 20.9% abundance in the initial stage in CM, MM and SM composting) were "diehard" ARGs, and their abundance grew significantly to 56.5%, 63.2% and 69.9% at the mature stage. These "diehard" ARGs were transferred from initial hosts of pathogenic and/or probiotic bacteria to final hosts of thermophilic bacteria, by horizontal gene transfer (HGT) via mobile gene elements (MGEs), and became rooted in composting products.

Bacterial community succession in aerobic-anaerobic-coupled and aerobic composting with mown hay affected C and N losses.

The primary objective of this work was to investigate how the dominant microbial species change and affect C and N losses under aerobic and aerobic-anaerobic-coupled composting of mown hay (MH, ryegrass) and corn stover (CS) mix. Results showed that C and N losses in aerobic compost of MH-CS were significantly decreased by 19.57-31.47% and 29.04-41.18%, respectively. 16S rRNA gene sequencing indicated that the bacterial microbiota showed significant differences in aerobic and aerobic-anaerobic-coupled composting. LEfSe analyses showed that aerobic composting promoted the growth of bacteria related to lignocellulosic degradation and nitrogen fixation, while aerobic-anaerobic-coupled composting promoted the growth of bacteria related to denitrification. Correlation analysis between bacterial community and environmental factors indicated that moisture content (MC) was the most important environmental factor influencing the differentiation of bacterial growth. KEGG analysis showed that aerobic composting enhanced the amino acid, carbohydrate, and other advantageous metabolic functions compared to that of aerobic-anaerobic-coupled composting. As a conclusion, the addition of 10-20% corn stover (w/w) to new-mown hay (ryegrass) appeared to inhibit anaerobic composting and prompt aerobic composting in MH-CS mix, which led to the effective utilization of mown hay as a resource for composting.

Re-examining the governance effect of China's environmental protection tax.

China has long exercised environmental control through the imposition of sewage charges. The start of the environmental protection tax on January 1, 2018, means that China has entered a new phase of environmental control. Unlike many previous studies on the role of environmental taxes at the firm level, this paper examines whether environmental taxes affect pollution emissions by influencing the behavioral choices of micro-actors. This paper first reviews the Pyrrhic tax, the Porter hypothesis, and the "double dividend effect." We then construct provincial panel data for 30 provinces in China from 2012 to 2019 as a sample, use the environmental protection tax as a natural experiment to evaluate the policy of this environmental protection tax using propensity score matching and difference-in-differences model, investigate the intermediate transmission mechanism of the policy implementation, and then analyze the differences in policy effects between provinces with different levels of economic development. The increased tax burden in 2018 led to a general reduction in provincial pollution emissions in which technological innovation by various groups, including firms and universities, had a mediating role.

Continuous cropping of potato changed the metabolic pathway of root exudates to drive rhizosphere microflora.

For potato production, continuous cropping (CC) could lead to autotoxicity buildup and microflora imbalance in the field soil, which may result in failure of crops and reduction in yield. In this study, non-targeted metabolomics (via liquid chromatography with tandem mass spectrometry (LC-MS/MS)) combined with metagenomic profiling (via high-throughput amplicon sequencing) were used to evaluate correlations between metabolomics of potato root exudates and communities of bacteria and fungi around potato plants to illustrate the impacts of CC. Potato plants were grown in soil collected from fields with various CC years (0, 1, 4, and 7 years). Metabolomic analysis showed that the contents and types of potential autotoxins in potato root exudates increased significantly in CC4 and CC7 plants (i.e., grown in soils with 4 and 7 years of CC). The differentially expressed metabolites were mainly produced via alpha-linolenic acid metabolism in plant groups CC0 and CC1 (i.e., no CC or 1 year CC). The metabolomics of the groups CC4 and CC7 became dominated by styrene degradation, biosynthesis of siderophore group non-ribosomal peptides, phenylpropanoid biosynthesis, and biosynthesis of various plant secondary metabolites. Continuous cropping beyond 4 years significantly changed the bacterial and fungal communities in the soil around the potato crops, with significant reduction of beneficial bacteria and accumulation of harmful fungi. Correlations between DEMs and microflora biomarkers were established with strong significances. These results suggested that continuous cropping of potato crops changed their metabolism as reflected in the plant root exudates and drove rhizosphere microflora to directions less favorable to plant growth, and it needs to be well managed to assure potato yield.

Seaweed Slurry Improved Gel Properties and Enhanced Protein Structure of Silver Carp (Hypophthalmichthys molitrix) Surimi.

In order to improve the gel quality of silver carp (Hypophthalmichthys molitrix) surimi, the texture and rheological properties and microstructure of silver carp surimi gel products were analyzed by adding Laminaria japonica (LJ), Undaria pinnatifida (UP) and Sargassum fusiforme (SF) slurries. After adding kelp slurry (KS), the gel strength reached the highest level of 1047.26 ± 85.04 (g·mm). The carbonyl content and surface hydrophobicity of surimi protein increased, while the free amino groups, total sulfhydryl groups, and fluorescence intensity decreased significantly. The results of transform infrared spectroscopy (FT-IR), circular dichroic (CD), and Raman spectra showed that the KS promoted the change of the secondary structure of protein. Scanning electron microscopy (SEM) images revealed that kelp slurry had a more compact gel microstructure. In conclusion, the kelp slurry could significantly increase the gel strength, improve the quality of surimi products, enrich the nutrition of silver carp surimi, and have great significance for expanding the application range of seaweed.

Feedstock-dependent abundance of functional genes related to nitrogen transformation controlled nitrogen loss in composting.

The objective of this work was to explore how selection of feedstock affects nitrogen cycle genes during composting, which eventually determines the nitrogen loss. Four composting mixes (CM: chicken manure; SM: sheep manure; MM1/3: mixed manure with CM: SM = 1:3 w/w, MM3/1: CM: SM = 3:1 w/w) were investigated. Results showed that adding 25 % and 75 % SM to CM reduced 26.5 % and 57.9 % nitrogen loss, respectively. CM contained more ammonification genes and nrfA gene, while SM had more denitrification genes. Nitrogen fixation genes in CM were slightly higher than that in SM at the initial stage, but they sharply dropped off as the composting entered the high temperature stage. MM1/3 showed significantly reduced ammonification genes than CM, and increased nitrogen fixation and NH4+ assimilation genes. Therefore, adding SM to CM could change the abundance of genes and enzymes related to nitrogen cycle to reduce nitrogen loss.

Bioanalytical approaches for the detection, characterization, and risk assessment of micro/nanoplastics in agriculture and food systems.

This review discusses the most recent literature (mostly since 2019) on the presence and impact of microplastics (MPs, particle size of 1 µm to 5 mm) and nanoplastics (NPs, particle size of 1 to 1000 nm) throughout the agricultural and food supply chain, focusing on the methods and technologies for the detection and characterization of these materials at key entry points. Methods for the detection of M/NPs include electron and atomic force microscopy, vibrational spectroscopy (FTIR and Raman), hyperspectral (bright field and dark field) and fluorescence imaging, and pyrolysis-gas chromatography coupled to mass spectrometry. Microfluidic biosensors and risk assessment assays of MP/NP for in vitro, in vivo, and in silico models have also been used. Advantages and limitations of each method or approach in specific application scenarios are discussed to highlight the scientific and technological obstacles to be overcome in future research. Although progress in recent years has increased our understanding of the mechanisms and the extent to which MP/NP affects health and the environment, many challenges remain largely due to the lack of standardized and reliable detection and characterization methods. Most of the methods available today are low-throughput, which limits their practical application to food and agricultural samples. Development of rapid and high-throughput field-deployable methods for onsite screening of MP/NPs is therefore a high priority. Based on the current literature, we conclude that detecting the presence and understanding the impact of MP/NP throughout the agricultural and food supply chain require the development of novel deployable analytical methods and sensors, the combination of high-precision lab analysis with rapid onsite screening, and a data hub(s) that hosts and curates data for future analysis.

Gelation properties and protein conformation of grass carp fish ball as influenced by egg white protein.

Dried egg white powder (EWP) and purified ovalbumin (OVA, 98%) were used as supplements to improve grass carp (GC) fish balls (FB) quality. The effects of EWP and/or OVA contents on the gel strength, water holding capacity (WHC), moisture migration and distribution, and rheological properties of GC-FB, as well as on myofibrillar protein (MfP) structures in the GC-FB were evaluated. The results showed that with the increase of EWP addition from 0 to 4% (w/w), the gel strength, and WHC of the GC-FB samples were increased from 34.28 to 66.63 N × mm, and 83.02 to 88.36%, respectively, but the increases were insignificant between 3 and 4% EWP-added GC-FBs (p > .05). As the EWP increased, the T2 relaxation time shifted toward lower values, indicating a general decline in water mobility. The effects of EWP on rheological properties were insignificant. Addition of OVA and/or EWP led to changes in secondary structural units in the FB, with α-helix (27.53%) reaching the highest value in OVA-added GC-FB, ß-sheet (46.07%) reaching the highest value in GC-FB, and ß-turn (33.54%) reaching the highest value in EWP-added GC-FB, respectively. Raman spectroscopy revealed that OVA-added GC-FB had the lowest hydrophobic interlinkages. Protein pattern analysis suggested that the OVA (1.58%) might contribute to the decrease in the myosin heavy chain band intensity through cross-linked with MfP. These results suggested that EWP could improve the quality of GC-FBs and OVA played an important role with MfP gelation.

Characterization of a synthetic zinc-chelating peptide from sea cucumber (Stichopus japonicus) and its gastrointestinal digestion and absorption in vitro.

BACKGROUND: Zinc absorption in intestinal system could be strongly affected by the gastrointestinal digestion and absorption of zinc-chelating peptides serving as zinc carriers. In this study, a novel zinc-chelating sea cucumber synthetic peptide (SCSP) was synthesized to estimate its gastrointestinal digestion and promotive effect of zinc absorption in vitro. RESULTS: Analysis of isothermal titration calorimetry suggested that the binding of SCSP and zinc (N ≈ 1) was exothermic, with relatively weak binding affinity (K = 1.0 × 10-3  mol L-1 ). The formation of SCSP-Zn complexes brought morphological changes to the peptides confirmed by scanning electron microscopy (SEM), which also indicated 6.88% of the existence of zinc element. In addition, the SCSP-Zn complexes remained stable under simulated human gastrointestinal digestion. In an in vitro study, the SCSP-Zn complex could successfully transport through the intestinal membrane in the model of everted rat gut sacs (nearly 7.5 µM cm-2 ) as well as Caco-2 cells where the zinc transport reached 0.0014 mg mL-1 carried by SCSP. Fluorescence staining experiments revealed free zinc accumulation inside the tissues and cells treated with the SCSP-Zn complex. CONCLUSIONS: The chelation SCSP-Zn had the promotion ability of zinc absorption in vitro and ex vivo experiments, which suggested a theoretical basis for the design and production of effective zinc chelating peptides as zinc carriers to improve zinc bioavailability. © 2022 Society of Chemical Industry.

Additives improved saprotrophic fungi for formation of humic acids in chicken manure and corn stover mix composting.

The objective of this study was to analyze the effects of additives (biochar (BC) and palygorskite (PG)) on predominant fungi succession throughout composting of corn stover/chicken manure mix to influence humic substances formation (HS). Results indicated that BC and PG promoted the polymerization of HS and formation of more humic acids (HA), and BC performed better than PG, 10% additive was better than 5%. ITS rRNA gene sequencing showed that predominant fungi succession was significantly affected by BC and PG in composting, correlation between HS formation and predominant fungi indicated that BC and PG boosted lignocellulose-degrading fungi which could break down fulvic acids (FA) and HM to form more HA. Fungi function analysis showed that 10% BC significantly increased saprotrophic fungi, and decreased pathogenic fungi. Therefore, addition of 10% BC was conductive to promote the formation of HA and improve compost quality.

Gastrointestinal digestion and absorption characterization in vitro of zinc-chelating hydrolysate from scallop adductor (Patinopecten yessoensis).

BACKGROUD: Zinc (Zn) is an essential catalytic element in the human health system but its absorption in the intestinal system can be strongly affected by gastrointestinal (GI) digestion. In this study, the food-derived potential Zn carrier, scallop adductor hydrolysates (SAHs), was produced and characterized. RESULTS: During temporary storage at 4 °C, SAH decreased in Zn-chelating capacity in the aqueous phase, whereas the SAH-Zn complex exhibited high stability. Moreover, the secondary structure of SAH had no significant alteration. Zn morphologically altered the surface structures of SAH, which was involving in carboxyl group of SAH. Results of in vitro GI digestion suggested that the SAH-Zn maintained good stability in GI system and only proportion of high molecular weight cleaved. In addition, SAH could successfully carry and transport Zn while the fluorescence staining revealed free Zn accumulation inside the tissue. Finally, three representative absorbed peptides (around 600 Da) were identified and synthesized. Three synthetic peptides exhibit higher Zn-chelating capacity than SAH and could also successfully transported through the intestine. CONCLUSION: This study provided a theoretical basis for the investigation of digestion and absorption of marine animal-derived peptides as Zn carriers. © 2021 Society of Chemical Industry.

Effects of microbial transglutaminase on textural, water distribution, and microstructure of frozen-stored longtail southern cod (Patagonotothen ramsayi) fish mince gel.

Frozen-stored fish mince tend to have poor gelling ability due to significant myosin denaturation caused by freezing. In this study, microbial transglutaminase (MTGase) was used to improve the quality of fish mince gel products made from frozen-stored longtail southern cod (LSC). The gel strength of the gel product increased with the addition of MTGase and reached a plateau value of ~19 N mm beyond 300 U/kg of MTGase, at the same condition, T22 was reduced from 57.22 to 49.77 ms, T23 was reduced from 1,273.88 to 1,072.27 ms. As the MTGase addition increased from 0 to 400 U/kg, the hardness of the fish surimi gel increased from 14.52 to 21.36 N, and the microstructure changed from loose to dense, respectively. This study showed that MTGase could promote gelation to improve the quality of frozen-stored LSC fish mince gel, especially at 300 U/kg, which potentially can be utilized to produce good surimi gel products out of frozen-stored fish.

Advances in Algin and Alginate-Hybrid Materials for Drug Delivery and Tissue Engineering.

In this review, we aim to provide a summary of recent research advancements and applications of algin (i.e., alginic acid) and alginate-hybrid materials (AHMs) in medical fields. Algin/alginate are abundant natural products that are chemically inert and biocompatible, and they have superior gelation properties, good mechanical strengths, and biodegradability. The AHMs have been widely applied in wound dressing, cell culture, tissue engineering, and drug delivery. However, medical applications in different fields require different properties in the AHMs. The drug delivery application requires AHMs to provide optimal drug loading, controlled and targeted drug-releasing, and/or visually guided drug delivery. AHMs for wound dressing application need to have improved mechanical properties, hydrophilicity, cell adhesion, and antibacterial properties. AHMs for tissue engineering need improved mechanical properties that match the target organs, superior cell affinity, and cell loading capacity. Various methods to produce AHMs that meet different needs were summarized. Formulations to form AHMs with improved stability, drug/cell-loading capacity, cell adhesion, and mechanical properties are active research areas. This review serves as a road map to provide insights into the strategies to develop AHMs in medical applications.

Influence of Domestic Cooking on Quality, Nutrients and Bioactive Substances of Undaria pinnatifida.

Undaria pinnatifida (UP) is a brown algae commonly consumed as food in Asian countries. The purpose of this study was to compare the effects of different domestic cooking methods (i.e., air frying (AF), microwaving, and high temperature and pressure (HTP) cooking) on the nutritional and bioactive substances in UP, as well as on UP color and texture, in order to identify methods to retain beneficial components better. In this study, microwave treatment resulted in better retention of color, polysaccharide (4.17 ± 0.07 mg glucose equivalents (GE)/g dry weight (dw) ), total phenol content (TPC) (1.50 ± 0.0062 mg gallic acid equivalents (GAE)/g dw) as well as chlorophyll a (18.18 ± 0.41 mg/g fresh weight (fw) ) and fucoxanthin (281.78 ± 17.06 µg/g dw). HTP treatment increased the TPC of UP (1.69 ± 0.0075 mg GAE/g dw), and AF treatment resulted in a lower loss of total amino acids (2.14 ± 0.15%). Overall, microwave cooking appeared to be the best among the three in producing cooked UP with high quality. This study provided a useful guideline in selection of cooking for UP which could retain more health-beneficial substances and yield products with better eating qualities to improve human diet.

Extraction and Nano-Sized Delivery Systems for Phlorotannins to Improve Its Bioavailability and Bioactivity.

This review aims to provide an informative summary of studies on extraction and nanoencapsulation of phlorotannins to improve their bioavailability and bioactivity. The origin, structure, and different types of phlorotannins were briefly discussed, and the extraction/purification/characterization methods for phlorotannins were reviewed, with a focus on techniques to improve the bioactivities and bioavailability of phlorotannins via nano-sized delivery systems. Phlorotannins are promising natural polyphenol compounds that have displayed high bioactivities in several areas: anticancer, anti-inflammation, anti-HIV, antidiabetic, and antioxidant. This review aims to provide a useful reference for researchers working on developing better utilization strategies for phlorotannins as pharmaceuticals, therapeuticals, and functional food supplements.

A phosphorescence resonance energy transfer-based "off-on" long afterglow aptasensor for cadmium detection in food samples.

Cadmium contamination is a severe food safety risk for human health. Herein, a long afterglow "off-on" phosphorescent aptasensor was developed based on phosphorescence resonance energy transfer (PRET) for the detection of Cd2+ in complex samples which minimizes the interference of background fluorescence. In this scheme, initially the phosphorescence of Cd2+-binding aptamer conjugated long afterglow nanoparticles (Zn2GeO4:Mn) was quenched by black hole quencher 1 (BHQ1) modified complementary DNA. Upon encountering of Cd2+, the aptamer interacted with Cd2+ and the complementary DNA with BHQ1 was released, leading to phosphorescence recovery. The content of Cd2+ could be quantified by the intensity of phosphorescence recovery with 100 µs gate time (which eliminated the sample autofluorescence) with a linear relationship between 0.5 and 50 µg L-1 and a limit of detection (LOD) of 0.35 µg L-1. This method was successfully demonstrated for Cd2+ detection in drinking water and yesso scallop samples. The "off-on" phosphorescent aptasensor based on PRET of long afterglow nanomaterials could be an effective tool for Cd2+ detection in food samples.

Surface-enhanced Raman spectroscopic chemical imaging reveals distribution of pectin and its co-localization with xyloglucan inside onion epidermal cell wall.

The primary plant cell wall is a complex matrix composed of interconnected polysaccharides including cellulose, hemicellulose, and pectin. Changes of this dynamic polysaccharide system play a critical role during plant cell development and differentiation. A better understanding of cell wall architectures can provide insight into the plant cell development. In this study, a Raman spectroscopic imaging approach was developed to visualize the distribution of plant cell wall polysaccharides. In this approach, Surface-enhanced Raman scattering (SERS through self-assembled silver nanoparticles) was combined with Raman labels (4-Aminothiophenol. 4ATP) and targeted enzymatic hydrolysis to improve the sensitivity, specificity, and throughput of the Raman imaging technique, and to reveal the distribution of pectin and its co-localization with xyloglucan inside onion epidermal cell (OEC) wall. This technique significantly decreased the required spectral acquisition time. The resulted Raman spectra showed a high Raman signal. The resulted Raman images successfully revealed and characterized the pectin distribution and its co-localization pattern with xyloglucan in OEC wall.