bluuebunny/crossref_metadata_2025 huggingface dataset:
Early Detection of Faults in Induction Motors—A Review
Authors: Garcia-Calva Tomas , Morinigo-Sotelo Daniel , Fernandez-Cavero Vanessa , Romero-Troncoso Rene
Published: October 2022

There is an increasing interest in improving energy efficiency and reducing operational costs of induction motors in the industry. These costs can be significantly reduced, and the efficiency of the motor can be improved if the condition of the machine is monitored regularly and if monitoring techniques are able to detect failures at an incipient stage. An early fault detection makes the elimination of costly standstills, unscheduled downtime, unplanned breakdowns, and industrial injuries possible. Furthermore, maintaining a proper motor operation by reducing incipient failures can reduce motor losses and extend its operating life. There are many review papers in which analyses of fault detection techniques in induction motors can be found. However, all these reviewed techniques can detect failures only at developed or advanced stages. To our knowledge, no review exists that assesses works able to detect failures at incipient stages. This paper presents a review of techniques and methodologies that can detect faults at early stages. The review presents an analysis of the existing techniques focusing on the following principal motor components: stator, rotor, and rolling bearings. For steady-state and transient operating modes of the motor, the methodologies are discussed and recommendations for future research in this area are also presented.
Building Heat Demand Prediction Based on Reinforcement Learning for Thermal Comfort Management
Authors: Wang Chendong , Zheng Lihong , Yuan Jianjuan , Huang Ke , Zhou Zhihua
Published: October 2022

The accurate prediction of building heat demand plays the critical role in refined management of heating, which is the basis for on-demand heating operation. This paper proposed a prediction model framework for building heat demand based on reinforcement learning. The environment, reward function and agent of the model were established, and experiments were carried out to verify the effectiveness and advancement of the model. Through the building heat demand prediction, the model proposed in this study can dynamically control the indoor temperature within the acceptable interval (19–23 °C). Moreover, the experimental results showed that after the model reached the primary, intermediate and advanced targets in training, the proportion of time that the indoor temperature can be controlled within the target interval (20.5–21.5 °C) was over 35%, 55% and 70%, respectively. In addition to maintaining indoor temperature, the model proposed in this study also achieved on-demand heating operation. The model achieving the advanced target, which had the best indoor temperature control performance, only had a supply–demand error of 4.56%.
A Mini-Review on Straw Bale Construction
Authors: Tlaiji Ghadie , Biwole Pascal , Ouldboukhitine Salah , Pennec Fabienne
Published: October 2022

Straw bale building construction is attracting a revived public interest because of its potential for reduced carbon footprint, hygrothermal comfort, and energy savings at an affordable price. The present paper aims to summarize the current knowledge on straw bale construction, using available data from academic, industry, and public agencies sources. The main findings on straw fibers, bales, walls, and buildings are presented. The literature shows a wide variability of results, which reflects the diversity of straw material and of straw construction techniques. It is found that the effective thermal conductivity, density, specific heat, and elastic modulus of straw bales used in construction are in the range 0.033–0.19 W/(m·K), 80–150 kg/m3, 1075–2000 J/(kg·K), and 150–350 kPa respectively. Most straw-based multilayered walls comply with fire resistance regulations, and their U-value and sound reduction index range from 0.11 to 0.28 W/m2 K and 42 to 53 dB respectively, depending on the wall layout. When compared to standard buildings, straw bale buildings do provide yearly reductions in carbon emissions and energy consumption. The reductions often match those obtained after applying energy-saving technologies in standard buildings. The paper ends by discussing the future research needed to foster the dissemination of straw bale construction.
Analyzing Optimal Battery Sizing in Microgrids Based on the Feature Selection and Machine Learning Approaches
Authors: Khan Hajra , Nizami Imran , Qaisar Saeed , Waqar Asad , Krichen Moez , Almaktoom Abdulaziz
Published: October 2022

Microgrids are becoming popular nowadays because they provide clean, efficient, and lowcost energy. Microgrids require bulk storage capacity to use the stored energy in times of emergency or peak loads. Since microgrids are the future of renewable energy, the energy storage technology employed should be optimized to provide power balancing. Batteries play a variety of essential roles in daily life. They are used at peak hours and during a time of emergency. There are different types of batteries i.e., lithium-ion batteries, lead-acid batteries, etc. Optimal battery sizing of microgrids is a challenging problem that limits modern technologies such as electric vehicles, etc. Therefore, it is imperative to assess the optimal size of a battery for a particular system or microgrid according to its requirements. The optimal size of a battery can be assessed based on the different battery features such as battery life, battery throughput, battery autonomy, etc. In this work, the mixed-integer linear programming (MILP) based newly generated dataset is studied for computing the optimal size of the battery for microgrids in terms of the battery autonomy. In the considered dataset, each instance is composed of 40 attributes of the battery. Furthermore, the Support Vector Regression (SVR) model is used to predict the battery autonomy. The capability of input features to predict the battery autonomy is of importance for the SVR model. Therefore, in this work, the relevant features are selected utilizing the feature selection algorithms. The performance of six best-performing feature selection algorithms is analyzed and compared. The experimental results show that the feature selection algorithms improve the performance of the proposed methodology. The Ranker Search algorithm with SVR attains the highest performance with a Spearman’s rank-ordered correlation constant of 0.9756, linear correlation constant of 0.9452, Kendall correlation constant of 0.8488, and root mean squared error of 0.0525.
Geothermal Heat Pump Production Sustainability—The Basis of the Swiss GHP Success Story
Authors: Rybach Ladislaus
Published: October 2022

Geothermal heat pump systems (GHP) are the spearhead of geothermal achievement and development, and one of the fastest growing applications of renewable energy technologies worldwide. When Swiss GHP activities started in the late 1970s, market introduction and penetration needed science-based proof of reliable, stable, long-term GHP operation. A special, extended project, realized in a field-laboratory setting, provided this proof. Detailed measurements, as well as numerical model simulations, proved the sustainable operation of the installed GHP system. The measurement setup, the recording of the various time series, and their interpretation are presented. Furthermore, basic perceptions were elaborated concerning geothermal resources behavior in production and regeneration. The Swiss GHP was developed from nothing. Early GHP installation costs halved within 20 years; GHP growth was nearly exponential from 1980 to 2020 (8.5% annually). Drilled borehole heat exchanger (BHE) meters are today around 300,000 m per year; heat delivery of GHPs in Switzerland amounted to 3280 GWh 2020—over 85% of Swiss geothermal direct uses (among others like thermal spas, district heating). Large installations with hundreds of BHEs are now common, and are also used for heating and cooling. The international ranking of Swiss GHP realizations is excellent in terms of annual energy use (TJ/yr/area), and is number one worldwide. Switzerland is a global GHP leader, and the Swiss success story is well documented.
MGRIT-Based Multi-Level Parallel-in-Time Electromagnetic Transient Simulation
Authors: Strake Julius , Döhring Daniel , Benigni Andrea
Published: October 2022

In this paper, we present an approach for multi-level parallel-in-time (PinT) electromagnetic transient (EMT) simulation. We evaluate the approach in the context of power electronics system-level simulation. While PinT approaches to power electronics simulations based on two-level algorithms have been thoroughly explored in the past, multi-level PinT approaches have not yet been investigated. We use the multigrid-reduction-in-time (MGRIT) method to parallelize a dedicated EMT simulation tool which is capable of switching between different converter models as it operates. The presented approach yields a time-parallel speed-up of up to 10 times compared to the sequential-in-time implementation. We also show that special care has to be taken to synchronize the time grids with the electronic components’ switching periods, indicating that further research into the usage of different models from adequate model hierarchies is necessary.
Induction Motors Speed Estimation by Rotor Slot Harmonics Frequency Using Zoom Improved Chirp-Z Transform Algorithm
Authors: Diarra Mahamadou , Zhao Xuyang , Wu Xuandong , Nketsiah Isaac , Li Yonggang , Zhao Haisen
Published: October 2022

This paper analyzes the digital signal processing techniques and estimates induction motor (IM) rotational speed operating in stationary or non-stationary conditions. Rotor slot harmonics present in the stator current waveform are used to estimate the induction motor speed with a given or identified rotor slot numbers. This paper’s contribution is the following: First, zoom improved short-time Chirp-Z transform is used to find supply frequency and the rotor slot harmonic frequency to improve the estimation accuracy without increasing computing complexity. Second, a technique is described that can be used to determine whether or not a motor can generate principal slot harmonics (PSH). Finally, an algorithm is designed to figure out the perfect window length and estimate the motors’ speed. This proposed technique was investigated when the motor was fed by an inverter-fed supply driving a variable load and operating in non-stationary conditions. Experimental test results on 5.5 kW and 22 kW induction motors have confirmed the correctness of this method.
Hf Incorporation in (Ti,Zr)NiSn Half Heusler Solid Solutions via Mechanical Alloying
Authors: Mesaritis Georgios , Kyratsi Theodora
Published: October 2022

Half Heusler materials are promising thermoelectric materials with potential application in generators at medium range temperatures. Solid solutions are typically prepared by arc melting, presenting interesting properties. In this work, the effect of Hf incorporation and the formation of solid solutions is discussed. More specifically, Ti1−xHfxNiSn and (Ti0.4Zr0.6)1−yHfyNiSn half Heusler materials were synthesized via mechanical alloying and consolidated via hot press sintering. Hf incorportation in the lattice strongly affected the lattice thermal conductivity due to the large mass fluctuation. The power factor and thermoelectric figure of merit was optimized via Sb doping the values of 34 μW/cmK2 and 38 μW/cmK2; 0.72 and 0.76 at 762 K for Ti0.4Hf0.6NiSn0.985Sb0.015 and (Ti0.4Zr0.6)0.7Hf0.3NiSn0.98Sb0.02, respectively, were reached.
Faults Feature Extraction Using Discrete Wavelet Transform and Artificial Neural Network for Induction Motor Availability Monitoring—Internet of Things Enabled Environment
Authors: Zuhaib Muhammad , Shaikh Faraz Ahmed , Tanweer Wajiha , Alnajim Abdullah M. , Alyahya Saleh , Khan Sheroz , Usman Muhammad , Islam Muhammad , Hasan Mohammad Kamrul
Published: October 2022

Motivation: This paper presents the high contact resistance (HCR) and rotor bar faults by an extraction method for an induction motor using Discrete Wavelet Transform (DWT) and Artificial Neural Network (ANN). The root mean square (RMS) and mean features are obtained using DWT, and ANN is used for classification using activation functions. Activation provides output by assigning the specific input with respect to the transfer function according to the nature and type of the activation function. Method: The faulty conditions are induced using MATLAB by adopting the motor current signature analysis (MCSA) method to achieve current signature signals of the healthy and faulty motors. Results: The DWT technique has been applied to obtain fault-specific features of the average continuously varying signal (RMS) and an average of the data points (mean) at levels 5, 7, 8, and 9, followed by ANN to classify the faults for condition monitoring. Utility: The utility of the results is to reduce unscheduled downtime in the industry, thus saving revenue and reducing production losses. This work will help provide support to ensure early indication of faults in induction motors under operating conditions, enabling in-service engineers to take timely preventive measures as part of the availability of resources in IoT-enabled systems. Application: Resource availability and cybersecurity are becoming vital in an environment that supports the Internet of Things (IoT) as the essential components of Industry 4.0 scenarios. The novelty of this research lies in the implementation of high contact resistance and rotor bar faults using DWT and ANN with different activation functions to achieve accuracy up to 98%.
Synergetic Roles of Mangrove Vegetation on Sediment Accretion in Coastal Mangrove Plantations in Central Thailand
Authors: Hongwiset Sarawan , Rodtassana Chadtip , Poungparn Sasitorn , Umnouysin Suthathip , Suchewaboripont Vilanee
Published: October 2022

Mangrove plantations can potentially restore the vegetation structures protecting coastal areas. In Avicennia alba plantations in central Thailand, we investigated the vegetation structures (trees, seedlings, pneumatophores, and belowground roots), sedimentation rates, and elevation changes over one year across the shore. The results showed a heterogeneous vegetation structure with an increasing tree basal area (BA) and seedling density towards the interior. The pneumatophore quantitative characteristics decreased towards the interior in association with the topographic gradient and inundation period. The sedimentation rates, which were greater in the plantation than on the mudflat, showed a negative correlation with the height, total surface area, and total volume of the pneumatophores. This indicates that the pneumatophores facilitated the transportation of fine sediments into the interior. Our results suggest that an optimal complexity of the aboveground vegetation structure might enhance the sedimentation rates. According to the gradient of tree BA and seedling density, the fine root density increased towards the interior. The monthly elevation changes in the plantation showed less fluctuation than those on the mudflat. The net elevation changes indicated sediment accretion within the plantation and erosion on the mudflat. Our results demonstrate the synergetic roles of mangrove plantations in which the aboveground structures facilitate sediment redeposition and the belowground roots stabilize sediment accretion in coastal areas.
Influence of Water Limitation and Provenance on Reproductive Traits in a Common Garden of Frangula alnus Mill.
Authors: Vander Mijnsbrugge Kristine , Schouppe Marc , Moreels Stefaan , Aguas Guerreiro Yorrick , Decorte Laura , Stessens Marie
Published: October 2022

Drought periods during the growing season will increase and intensify in Western Europe due to climate change. To better understand the consequences for woody perennials, we restricted watering of potted cuttings of Frangula alnus Mill. in a common garden setting in Belgium during the growing season of 2020. We focused on the responses of three provenances (Belgian, Italian and Swedish) for several reproductive traits in the year of the water limitation. F. alnus, as a shrub species, bears fruits fast. It can blossom on current season’s growth and can therefore produce ripened berries continuously during several months. The total berry count across the whole growing season was much lower in the water-limited plants, independent of the provenance. The local Belgian provenance produced more ripened berries in total than the Italian and Swedish provenances, both in the water-limited plants as in the control plants. Maximal berry production occurred in July. The control plants from the Belgian and Italian provenances displayed a second lower maximum in August. Mainly the Swedish provenance displayed a clear advancement of the maximum berry production among the water-limited plants in comparison to the control plants. Slight differences were detected in the average stone count per berry and in the average stone weight, with both traits displaying a single maximum through time. The Swedish provenance displayed the highest average stone count per berry and the Belgian provenance had the lightest average stone weight, both likely attributable to local adaptation. Remarkably, both stone traits were not affected by the water limitation. Results are discussed in the context of several drought response mechanisms including drought escape, drought avoidance, compensation growth, growth/reproduction trade-off and seed size/number trade-off.
Carbon Allocation of Quercus mongolica Fisch. ex Ledeb. across Different Life Stages Differed by Tree and Shrub Growth Forms at the Driest Site of Its Distribution
Authors: Qi Yang , Liu Hongyan , He Wenqi , Dai Jingyu , Shi Liang , Song Zhaopeng
Published: October 2022

There are less than 10% of woody species that can have both tree and shrub growth forms globally. At the xeric timberline, we observed the tree-to-shrub shift of the Quercus mongolica Fisch. ex Ledeb.. Few studies have explored the underlined mechanism of this morphological transition of tree-to-shrub in arid regions. To examine whether the tree-to-shrub shift affects carbohydrate allocation and to verify the effect of life stage on non-structural carbohydrate (NSC) storage, we measured the concentration of soluble sugar and starch of Q. mongolica in the seedlings, saplings, and adult trees by selecting two sites with either tree or shrub growth forms of Q. mongolica at the driest area of its distribution. Accordingly, there was no significant difference in the radial growth with different growth forms (p > 0.05). The results showed that the effects of growth form on NSC concentrations are significant in the seedling and sapling stages, but become less pronounced as Q. mongolica grows. The results of the linear mixed model showed that life stage has a significant effect on soluble sugar concentration of tree-form (p < 0.05), starch and TNC concentration of shrub-form (p < 0.05). Compared with a shrub form without seedling stage, a tree form needs to accumulate more soluble sugar from seedling stage to adapt to arid environment. Saplings and adult shrubs store more starch, especially in thick roots, in preparation for sprout regeneration. Our study shows that the same species with tree and shrub forms embody differentiated carbohydrate allocation strategies, suggesting that shrub form can better adapt to a drier habitat, and the tree-to-shrub shift can benefit the expansion of woody species distribution in dryland.
Forestry Canopy Image Segmentation Based on Improved Tuna Swarm Optimization
Authors: Wang Jingyu , Zhu Liangkuan , Wu Bowen , Ryspayev Arystan
Published: October 2022

Forests play a vital role in increasing carbon sequestration in the biosphere. In recent years, segmenting forest canopy images in order to obtain various plant population parameters has become an essential means to assess the ecosystem. The objective of forest canopy image segmentation is to separate and extract sky regions from the background. This study proposes a hybrid method based on improved tuna swarm optimization (ITSO) for forestry canopy image segmentation. The symmetric cross-entropy is introduced to perform forestry canopy image thresholding by modeling the classes of an image as membership functions. In order to achieve the optimal thresholds of the forest canopy image, the entropy-solving procedure is arduous and time-consuming. In order to resolve this issue, the ITSO method was adopted to search for the most significant threshold. Meanwhile, the Tent chaotic map is used to initialize the tuna population according to the chaotic factor. The experiment is carried out on four different types of forest canopy images, with four indices (MAE, RVD, IoU, and ASD) used for quantitative analysis. The experiment’s results show that the ITSO-based segmentation method outperforms others, making it a better way to segment images of forest canopies.
Temporal and Spatial Characteristics of Soundscape Ecology in Urban Forest Areas and Its Landscape Spatial Influencing Factors
Authors: Zhao Yujie , Xu Shaowei , Huang Ziluo , Fang Wenqiang , Huang Shanjun , Huang Peilin , Zheng Dulai , Dong Jiaying , Chen Ziru , Yan Chen , Zhong Yukun , Fu Weicong
Published: October 2022

We explored the spatial and temporal characteristics of the urban forest area soundscape by setting up monitoring points (70 × 70 m grid) covering the study area, recorded a total of 52 sound sources, and the results showed that: (1) The soundscape composition of the park is dominated by natural sounds and recreational sounds. (2) The diurnal variation of sound sources is opposite to that of temperature, 6:00–9:00 is the best time for the public to perceive birdsong, and after 18:00, the park is dominated by insect chirps. (3) The PSD (power spectral density) and the SDI (soundscape diversity index) of the park are greatly affected by public recreation behaviors, and some recreation behaviors may affect the vocal behavior of organisms such as birds. (4) Spaces with high canopy density can attract more birdsong and recreational sounds in summer, and the combination of “tree + lake” can attract more birdsong. Vegetation has a significant dampening effect on traffic sound. (5) Landscape spatial elements, such as the proportion of hard ground, sky, trees, and shrubs, have a significant impact on changes in the PSD, the SDI and different kinds of sound sources. The research results provide effective data support for improving the soundscape of urban forests.
Exploring the Valorization of Buckwheat Waste: A Two-Stage Thermo-Chemical Process for the Production of Saccharides and Biochar
Authors: Yuan Yongheng , Li Faqinwei , Han Nanding , Zeng Bingyao , Imaizumi Yoshiaki , Na Risu , Shimizu Naoto
Published: October 2022

To realize the utilization of the valorization of buckwheat waste (BW), a two-stage thermal-chemical process was explored and evaluated to produce saccharides and biochar. During the first stage, BW underwent a hydrothermal extraction (HTE) of varying severity to explore the feasibility of saccharides production; then, the sum of saccharides yields in the liquid sample were compared. A higher sum of saccharides yields of 4.10% was obtained at a relatively lower severity factor (SF) of 3.24 with a byproducts yield of 1.92 %. During the second stage, the contents of cellulose, hemicellulose, and lignin were analyzed in the residue after HTE. Enzymatic hydrolysis from the residue of HTE was inhibited. Thus, enzymatic hydrolysis for saccharides is not suitable for utilizing the residue after HTE of BW. These residues with an SF of 3.24 were treated by pyrolysis to produce biochar, providing a higher biochar yield of 34.45 % and a higher adsorption ability (based on methyl orange) of 31.11 % compared with pyrolysis of the raw BW. Meanwhile, the surface morphology and biomass conversion were analyzed in this study. These results demonstrate that the two-stage thermal-chemical process is efficient for treating BW and producing saccharides and biochar. This work lays a foundation for the industrial application of BW, and for improving the economic benefits of buckwheat cultivation.
Production and 3D Printing of a Nanocellulose-Based Composite Filament Composed of Polymer-Modified Cellulose Nanofibrils and High-Density Polyethylene (HDPE) for the Fabrication of 3D Complex Shapes
Authors: Dalloul Feras , Mietner Jakob Benedikt , Navarro Julien R. G.
Published: October 2022

This work aims to produce a 3D-printable bio-based filament composed of high-density polyethylene (HDPE) and chemically modified cellulose nanofibrils. Printing using HDPE as a raw material is challenging due to its massive shrinkage and warping problems. This paper presents a new method to overcome those difficulties by enhancing the mechanical properties and achieving better print quality. This was achieved using modified cellulose nanofibrils (CNFs) as fillers. Firstly, CNF was converted to a CNF-based macroinitiator through an esterification reaction, followed by a surface-initiated single-electron transfer living radical polymerization (SI-SET-LRP) of the hydrophobic monomer stearyl acrylate. Poly stearyl acrylate-grafted cellulose nanofibrils, CNF-PSAs, were synthesized, purified and characterized with ATR-FTIR, 13C CP-MAS NMR, FE-SEM and water contact angle measurements. A composite was successfully produced using a twin-screw extruder with a CNF-PSA content of 10 wt.%. Mechanical tests were carried out with tensile testing. An increase in the mechanical properties, up to 23% for the Young’s modulus, was observed. A morphologic analysis also revealed the good matrix/CNF compatibility, as no CNF aggregates could be observed. A reduction in the warping behavior for the composite filament compared to HDPE was assessed using a circular arc method. The 3D printing of complex objects using the CNF-PSA/HDPE filament resulted in better print quality when compared to the object printed with neat HDPE. Therefore, it could be concluded that CNF-PSA was a suitable filler for the reinforcement of HDPE, thus, rendering it suitable for 3D printing.
Computational Fluid Dynamics Approach for Oscillating and Interacting Convective Flows
Authors: Gergely Attila , Néda Zoltán
Published: October 2022

The oscillation and collective behavior of convective flows is studied by a computational fluid dynamics approach. More specifically, the rising dynamics of heated fluid columns is simulated in gravitational field using a simplified 2D geometry. The numerical method uses the FEniCS package for solving the coupled Navier–Stokes and heat-diffusion equations. For the flow of a single heated fluid column, the effect of the inflow yield and the nozzle diameter is studied. In agreement with the experiments, for a constant nozzle diameter the oscillation frequency increases approximately linearly as a function of the the flow rate, while for a constant flow rate the frequency decreases as a power law with the increased nozzle diameter. For the collective behavior of two nearby flows, we find a counter-phase synchronization and a decreasing trend of the common oscillation frequency with the distance between the jets. These results are in agreement with the experiments, and our computational study also suggests that the phenomenon is present on largely different length-scales.
Effects of Different Processing Methods of Coffee Arabica on Colour, Acrylamide, Caffeine, Chlorogenic Acid, and Polyphenol Content
Authors: Cwiková Olga , Komprda Tomas , Šottníková Viera , Svoboda Zdeněk , Simonová Jana , Slováček Jan , Jůzl Miroslav
Published: October 2022

An effect of a processing method (dry and wet) and a degree of roasting (light, medium, and dark) of 15 coffee (Coffea arabica) samples on the content of caffeine, chlorogenic acid (CQA), total polyphenols (TPP), acrylamide (AA), and on the colour parameters L*, a*, and b* was evaluated. Neither processing nor roasting affected caffeine content (p > 0.05). The degree of roasting accounted for 46% and 72% of explained variability of the CQA content and AA content, respectively (p < 0.05). AA content was in the range from 250 (wet-processed, light-roasted samples) to 305 µg·kg−1 (wet-processed, dark-roasted coffees), but the dark roasting only tended (p > 0.05) to increase AA content. Wet-processed, dry-roasted coffee had higher (p < 0.05) TPP content (48.5 mg·g−1) than its dry-processed, dry-roasted counterpart (42.5 mg·g−1); the method of processing accounted for 70% of explained variability of TPP. Both the method of processing and the degree of roasting affected the L*, a*, and b* values (p < 0.01), but the lower values (p < 0.05) of these parameters in the dark-roasted samples were found only within the wet processing. A negative correlation between the AA content and lightness (L*) was established (r = −0.39, p < 0.05). It was concluded that from the consumers’ viewpoint, the results of the present study indicate relatively small differences in quality parameters of coffee irrespective of the method of processing or degree of roasting.
The Application of Metagenomics to Study Microbial Communities and Develop Desirable Traits in Fermented Foods
Authors: Srinivas Meghana , O’Sullivan Orla , Cotter Paul D. , Sinderen Douwe van , Kenny John G.
Published: October 2022

The microbial communities present within fermented foods are diverse and dynamic, producing a variety of metabolites responsible for the fermentation processes, imparting characteristic organoleptic qualities and health-promoting traits, and maintaining microbiological safety of fermented foods. In this context, it is crucial to study these microbial communities to characterise fermented foods and the production processes involved. High Throughput Sequencing (HTS)-based methods such as metagenomics enable microbial community studies through amplicon and shotgun sequencing approaches. As the field constantly develops, sequencing technologies are becoming more accessible, affordable and accurate with a further shift from short read to long read sequencing being observed. Metagenomics is enjoying wide-spread application in fermented food studies and in recent years is also being employed in concert with synthetic biology techniques to help tackle problems with the large amounts of waste generated in the food sector. This review presents an introduction to current sequencing technologies and the benefits of their application in fermented foods.
A Novel Metabolite as a Hapten to Prepare Monoclonal Antibodies for Rapid Screening of Quinoxaline Drug Residues
Authors: Song Wanyao , Luo Mengyu , Li Huaming , Xiao Jiaxu , He Xiuping , Liang Jixiang , Peng Dapeng
Published: October 2022

Quinoxalines (Qx) are chemically synthesized antibacterial drugs with strong antibacterial and growth-promoting effects. Qx is heavily abused by farmers, resulting in large residues in animal-derived foods, which pose a serious threat to human health. Desoxyquinoxalines (DQx), which have the highest residue levels, have been identified as the major toxicant and have become a new generation of residue markers. In this study, we prepared monoclonal antibodies (mAb) based on a new generation metabolite (desoxymequindox, DMEQ) and establish an indirect competitive enzyme-linked immunosorbent assay (ic-ELISA) for the rapid determination of Qx residues in food. The mAb exhibited high sensitivity with half maximal inhibitory concentration (IC50) and a linear range of 2.84 µg/L and 0.8–12.8 µg/L, respectively. Additionally, the cross-reactivity (CR) of the mAb showed that it recognized multiple DQx to varying levels. The limits of detection (LOD), limits of quantification (LOQ), and recoveries for the ic-ELISA assay of pork, swine liver, swine kidney, chicken, and chicken liver were 0.48–0.58 µg/kg, 0.61–0.90 µg/kg, and 73.7–107.8%, respectively, and the coefficients of variation (CV) were less than 11%. The results of the ic-ELISA showed a good correlation with LC–MS/MS in animal-derived foods. This suggests that this analytical method can be used for the rapid screening of QX residues.
Purification, Identification and Molecular Docking of Immunomodulatory Peptides from the Heads of Litopenaeus vannamei
Authors: Jiang Weiwei , Ren Keyu , Yang Zhiyan , Fang Zhou , Li Yan , Xiang Xi , Song Yishan
Published: October 2022

In order to realize the high-value utilization of Litopenaeus vannamei (L. vannamei) heads, immunomodulatory peptides were prepared from the enzymatic hydrolysate of L. vannamei heads, and the action mechanism of immunomodulatory peptides was determined by molecular docking. The results showed that six proteases were used to hydrolyze L. vannamei head proteins, with the animal protease hydrolysate exhibiting the highest macrophage relative proliferation rate (MRPR). The enzymatic products were then sequentially purified by ultrafiltration, Sephadex G-15 gel chromatography, identified by liquid chromatography-mass spectrometry (LC-MS/MS), and finally selected for six immunomodulatory peptides (PSPFPYFT, SAGFPEGF, GPQGPPGH, QGF, PGMR, and WQR). These peptides maintained good immune activity under heat treatment, pH treatment, and in vitro gastrointestinal digestion. Molecular docking analysis indicated that these peptides showed great binding to both toll-like receptor 2 and 4 (TLR2 and TLR4/MD-2), leading to immunomodulation. The discarded L. vannamei heads in this article are considered to be promising food-borne immunomodulators that contribute to enhancing the immune function of the body.
Chitosan-Based Edible Coatings Containing Essential Oils to Preserve the Shelf Life and Postharvest Quality Parameters of Organic Strawberries and Apples during Cold Storage
Authors: Popescu Paul-Alexandru , Palade Laurentiu Mihai , Nicolae Ioana-Cătălina , Popa Elisabeta Elena , Miteluț Amalia Carmen , Drăghici Mihaela Cristina , Matei Florentina , Popa Mona Elena
Published: October 2022

Edible coatings and films have been researched for more than three decades due to their ability to be incorporated with different functional ingredients or compounds as an option to maintain the postharvest quality of fruits and vegetables. The aim of this study was to evaluate the effect of three types of chitosan-based (CH) edible coatings obtained from medium and high molecular weight chitosan, containing ascorbic or acetic acid and sea buckthorn or grape seed essential oils on the physical–chemical and microbiological properties of organic strawberries and apple slices during cold storage at 4 °C and 8 °C. Scanning electron microscope images showed both a smooth structure and a fracture and pore structure on strawberry coatings and a dense and smooth structure on the apple slices coatings. Further, the edible coatings managed to reduce the microbial load of yeasts and molds of the coated strawberries during the storage period. Overall, the treatments preserved the ascorbic acid, total polyphenol content, and antioxidant activity for all the tested samples compared to the control sample, throughout the storage period. In addition, the water activity (aw) of the coated samples presented lower values (0.96–0.98) than the control samples. The obtained results indicate that the developed chitosan-based edible coatings could maintain the postharvest parameters of the tested samples, also leading to their shelf-life prolongation.
Geographical Origin Differentiation of Rice by LC–MS-Based Non-Targeted Metabolomics
Authors: Li Zhanming , Tan Mengmeng , Deng Huxue , Yang Xu , Yu Yue , Zhou Dongren , Dong Hao
Published: October 2022

Many factors, such as soil, climate, and water source in the planting area, can affect rice taste and quality. Adulterated rice is common in the market, which seriously damages the production and sales of high-quality rice. Traceability analysis of rice has become one of the important research fields of food safety management. In this study, LC–MS-based non-targeted metabolomics technology was used to trace four rice samples from Heilongjiang and Jiangsu Provinces, namely, Daohuaxiang (DH), Huaidao No. 5 (HD), Songjing (SJ), and Changlixiang (CL). Results showed that the discrimination accuracy of the partial least squares discriminant analysis (PLS-DA) model was as high as 100% with satisfactory prediction ability. A total of 328 differential metabolites were screened, indicating significant differences in rice metabolites from different origins. Pathway enrichment analysis was carried out on the four rice samples based on the KEGG database to determine the three metabolic pathways with the highest enrichment degree. The main biochemical metabolic pathways and signal transduction pathways involved in differential metabolites in rice were obtained. This study provides theoretical support for the geographical origins of rice and elucidates the change mechanism of rice metabolic pathways, which can shed light on improving rice quality control.
Bioaccessibility of Phenolic Compounds from Mistletoe Infusions and Effect of In Vitro Digestion on Its Antioxidant and Pancreatic Lipase Inhibitory Activity
Authors: Gutiérrez-Grijalva Erick Paul , Zamudio-Sosa Victor Eduardo , Contreras-Angulo Laura Aracely , Leyva-López Nayely , Heredia J. Basilio
Published: October 2022

Phoradendron brachystachyum is an American mistletoe distributed in México and used ethnobotanically in infusions to treat hypertriglyceridemia and lower cholesterol levels. This study aimed to evaluate the bioaccessibility of the phenolic acids from mistletoe infusions and the effect of simulated digestion on its antioxidant and lipase inhibitory properties. The in vitro digestion process decreased the antioxidant capacity activity by the TEAC and ORAC assays in infusions from leaves, stems, and whole plant samples. Moreover, the individual phenolic content of mistletoe infusions was also affected by the in vitro digestion process; the most abundant individual phenolic constituents at the end of the digestion process were ferulic and quinic acids. These compounds showed low bioaccessibility values ranging from 7.48% to 22.60%. In addition, the in vitro digestion diminished the pancreatic lipase inhibition percentage of leaves and whole plant infusions but increased it in the stem samples. This research showed that given the phenolic content and pancreatic lipase inhibitory activity of mistletoe infusions, it could be used as a potential source for the development of functional foods and nutraceuticals; nonetheless, its phenolic content is affected by gastrointestinal digestion; thus, encapsulation strategies are encouraged to protect these metabolites from the gastrointestinal environment while preserving their antioxidant and hypolipidemic potentials.
A Method for Screening Proteases That Can Specifically Hydrolyze the Epitope AA83-105 of αs1-Casein Allergen
Authors: Liu Di , Lv Xiaozhe , Cong Yanjun , Li Linfeng
Published: October 2022

Milk protein hydrolysates are common in infant formula, but some of them retain allergenicity due to incomplete hydrolysis of the epitopes for milk allergens. This study explored a method for screening proteases that could specifically hydrolyze the epitope of αs1-casein allergen. Firstly, the αs1-casein epitope AA83-105 was synthesized by the solid-phase synthesis method. Then, after purification and identification, the complete antigen was prepared through coupling with bovine serum albumin (BSA) and was used to raise monoclonal antibodies (mAb) in BALB/c mice. Additionally, an indirect competitive-enzyme-linked immunosorbent assay (icELISA) was established. The mAb raised against αs1-casein protein was used as a control. The results showed that the purity of the synthetic epitope was >90%, and the coupling rate with BSA was 6.31. The mAb subtype is IgG1, with a titer of 1:320,000. The mAb reacted specifically with αs1-casein but did not cross-react with soybean protein. The linear regression equation of the competitive inhibition curve was y = −9.22x + 100.78 (R2 = 0.9891). The detection limit of icELISA method was more sensitive, and the method showed good accuracy and repeatability. The amounts of antigen residues in papain protease hydrolysates were relatively small, and the epitope fragment was detected in papain hydrolysate via mass spectrometry. This study provides ideas and methods for screening proteases that specifically hydrolyze the epitopes of milk allergens and also provides a superior foundation for the development of an advanced hypoallergenic formula.
Effects of Dietary Tannic Acid on Obesity and Gut Microbiota in C57BL/6J Mice Fed with High-Fat Diet
Authors: Fang Jiangmin , Zeng Lirong , He Yalun , Liu Xiong , Zhang Tongcun , Wang Qiong
Published: October 2022

Dietary tannic acid, as a natural polyphenolic, has many important biological activities. This study aimed to investigate the effect of dietary tannic acid on obesity and gut microbiota in mice with a high-fat diet. Male C57BL/6J mice fed a high-fat diet were treated with dietary tannic acid for eight weeks. Results showed that dietary tannic acid reduced the body weight gain, regulated glycolipid metabolism, improved the insulin resistance, and attenuated the liver oxidative stress in high-fat diet-fed mice. Moreover, both dietary tannic acid intervention groups repaired the gut barrier damage caused by a high-fat diet, especially in the 50 mg/kg/d dietary tannic acid intervention group. Interestingly, the effect of dietary tannic acid on serum endotoxin lipopolysaccharide (LPS) content was correlated with the abundance of the LPS-producing microbiota. In addition, dietary tannic acid altered the abundance of obesity-related gut microbiota (Firmicutes, Bacteroidetes, Bacteroides, Alistipes, and Odoribacter) in the 150 mg/kg/d dietary tannic acid intervention group, while it was not effective in the 50 mg/kg/d dietary tannic acid intervention group. These findings suggested the potential effect of dietary tannic acid for the prevention and control of obesity.
Study on Protein Structures of Eight Mung Bean Varieties and Freeze-Thaw Stability of Protein-Stabilized Emulsions
Authors: Sun Hongrui , Fan Jieying , Sun Hongjiao , Jiang Guochuan , Meng Yue , Zeng Xianpeng , Yang Zhiqiang , Nan Xiping , Kang Lining , Liu Xiangying
Published: October 2022

In order to evaluate the freeze-thaw stability of mung bean protein isolate (MPI)-stabilized emulsions and its relationship with protein structure, proteins of eight mung bean varieties were compared. The results revealed that MPIs prepared from all eight varieties were mainly composed of five subunit bands, with albumin and globulin content ranges of 188.4–310.3 and 301.1–492.7 mg/g total protein, respectively. Protein structural analysis revealed that random coil structure (32.34–33.51%) accounted for greater than 30% of MPI secondary structure. Meanwhile, analysis of protein properties revealed emulsifying activity index (EAI), emulsifying stability index (ESI) and flexibility value ranges of 6.735–8.598 m2/g, 20.13–34.25% and 0.125–0.182, respectively. Measurements of freeze-thaw stability of MPI emulsions demonstrated that exposures of emulsions to multiple freeze-thaw cycles resulted in significantly different emulsion creaming index, oiling-off, particle size and zeta potential values for the various emulsions. Moreover, the stabilities of all eight protein emulsions decreased with each freeze-thaw cycle, as demonstrated using optical micrographs. The correlation analysis method was used to study the correlation between the original structures, emulsifying properties of proteins and the freeze-thaw stability of MPI emulsions. Correlation analysis results revealed significant relationships between albumin content, subunit bands with a molecular weight of 26.9 kDa and emulsifying properties were significantly related to the freeze-thaw stability of MPI emulsion. Thus, by determining these indicator values, we can predict the freeze-thaw stability of MPI-stabilized emulsions.
Three Pillars of Advanced Biofuels’ Sustainability
Authors: Mizik Tamás , Gyarmati Gábor
Published: October 2022

Today, reducing GHG emissions is an important goal worldwide. Initially, first-generation biofuels were considered as a solution; however, they created a conflict between food and fuel. Advanced biofuels, which use non-edible materials, have emerged and are becoming more widespread, thus resolving this conflict. The paper aimed to investigate the three pillars of advanced biofuels’ sustainability (economic, environmental, and social). In the frame of a systematic literature review, 41 out of the initially screened 3407 articles were analyzed in depth. The economic aspect of sustainability was the most frequently occurring topic, followed by the environmental aspect, while the number of articles related to the social aspect was limited. From the economic point of view, all the analyzed articles agreed that advanced biofuels are far from commercialization at this stage; however, there are promising options related to different feedstocks or production technologies. Advanced biofuels perform unequivocally better environmentally than even conventional biofuels. For third-generation biofuels, negative net GHG emissions can even be possible, while fourth-generation biofuels can theoretically be produced from CO2. With respect to the social pillar, job creation was the core element of the articles analyzed. This can be experienced at the farm, production, and research levels. Although the commercialization of advanced biofuel production will take time, humanity must turn to them in order to avoid the food versus fuel problem, as well as to successfully fight against climate change and global warming.
Macrophage Delivered HSV1716 Is Active against Triple Negative Breast Cancer
Authors: Kwan Amy , Howard Faith , Winder Natalie , Atkinson Emer , Jailani Ameera , Patel Priya B. , Allen Richard , Ottewell Penelope D. , Shaw Gary C. , Conner Joe , Wilson Caroline , Srivastava Sanjay K. , Danson Sarah J. , Lewis Claire , Brown Janet E. , Muthana Munitta
Published: October 2022

Oncolytic viruses (OV) promote anti-tumour responses through the initiation of immunogenic cancer cell death which activates the host’s systemic anti-tumour immunity. We have previously shown that intravenously administered HSV1716 is an effective treatment for mammary cancer. However, intravenous administration of a virus has the potential to result in neutralization and sequestration of the virus which may reduce efficacy. Here, we show that the oncolytic virus HSV1716 can be administered within a cellular carrier (macrophages). PyMT and 4T1 murine mammary cancer cell lines were implanted into immuno-competent murine models (orthotopic primary, early metastatic and brain metastasis models). HSV1716 or macrophages armed with HSV1716 (M-HSV1716) were administered intravenously, and tumour size was quantified using caliper measurement or bioluminescence imaging. Administration of M-HSV1716 led to tumour shrinkage and increased the survival of animals. Furthermore, these results were achieved with a 100-fold lower viral load, which has the potential for decreased toxicity. Our results demonstrate that M-HSV1716 is associated with activity against murine mammary cancers and provides an alternative platform for the systemic delivery of OV.