bluuebunny/crossref_metadata_2025 huggingface dataset:
Intensification of Gas Hydrate Formation Processes by Renewal of Interfacial Area between Phases
Authors: Pavlenko Anatoliy M. , Koshlak Hanna
Published: September 2021

This paper presents the analysis of the main reasons for a significant decrease in the intensity of diffusion processes during the formation of gas hydrates; solutions to this problem are proposed in a new process flow diagram for the continuous synthesis of gas hydrates. The physical processes, occurring at the corresponding stages of the process flow, have been described in detail. In the proposed device, gas hydrate is formed at the boundary of gas bubbles immersed in cooled water. The dynamic effects arising at the bubble boundary contribute to the destruction of a forming gas hydrate structure, making it possible to renew the contact surface and ensure efficient heat removal from the reaction zone. The article proposes an assessment technique for the main process parameters in the synthesis of hydrates based on the criterion of thermodynamic parameters optimization. The optimization criterion determines the relationship of intensity of heat and mass transfer processes at the phase contact interface of reacting phases, correlating with the maximum GH synthesis rate, and makes it possible to determine optimum thermodynamic parameters in the reactor zone.
Environmental and Economic Optimization and Sizing of a Micro-Grid with Battery Storage for an Industrial Application
Authors: Khlifi Fethi , Cherif Habib , Belhadj Jamel
Published: September 2021

This study focuses on the sizing and optimization of a micro-grid with storage, which is destined to supply the load of an economic activity zone (EAZ) in Sidi Bouzid, Tunisia. To solve this problem, a genetic algorithm is established and programmed into MATLAB. The objective functions are considered by providing three minimums, namely Greenhouse Gas emissions (GHG), Life Cycle Cost (LCC) and Embodied Energy (EE), for three values of loss of power supply probability (LPSP) previously fixed. The sizing and optimization results are found and evaluated using a time series exchange of energy during a year to determine the optimal component size of a photovoltaic/wind/battery system (PV/WT/Bat). The simulation results show that the lowest ratio of LPSP values corresponds to the higher GHG, EE, LCC, photovoltaic panels area (APV), battery storage capacity (Cn), wind turbines area (AWT) and vice versa. This means that demanding higher energy reliability leads to higher energy cost and pollution. A comparative analysis was made, showing the cons and pros of each LPSP value in order to allow the owner of the plant to choose the most suitable PV/WT/Bat configuration.
Analysis of Methodology for Scaling up Building Retrofits: Is There a Role for Virtual Energy Audits?—A First Step in Hawai’i, USA
Authors: Glick Mark B. , Peppard Eileen , Meguro Wendy
Published: September 2021

Energy audits are a time-consuming and expensive initial step in the building retrofit process. Virtual energy audits purport to be an alternative that remotely identifies energy efficiency measures (EEMs) that may reduce electricity consumption and offset operational costs to businesses operating during and after the COVID-19 pandemic. This case study reviews virtual energy audits as a means to benchmark energy use and estimate cost savings from future EEMs. A novel feature was the estimation of energy costs associated with increasing ventilation to improve indoor air quality. The authors analyzed ten virtual energy audits performed in Honolulu, Hawai’i, over a two-week period that used existing building information and electricity use data to estimate a potential 9% to 41% annual electricity use reduction per building and a 24 MWh to 1195 MWh reduction, respectively. This paper makes a significant contribution through its assessment of virtual energy audits as a step beyond benchmarking, which has merit as an educational tool to motivate business owners to reduce energy use and improve indoor air quality. Further evaluation and improvements are suggested to study how often the virtual energy audits instigate action, how they compare with in-person audits, and their potential for use at a large scale.
On the Practical Evaluation of the Switching Loss in the Secondary Side Rectifiers of LLC Converters
Authors: Escudero Manuel , Kutschak Matteo-Alessandro , Pulsinelli Francesco , Rodriguez Noel , Morales Diego Pedro
Published: September 2021

The switching loss of the secondary side rectifiers in LLC resonant converters can have a noticeable impact on the overall efficiency of the complete power supply and constrain the upper limit of the optimum switching frequencies of the converter. Two are the main contributions to the switching loss in the secondary side rectifiers: on the one hand, the reverse recovery loss (Qrr), most noticeably while operating above the series resonant frequency; and on the other hand, the output capacitance (Coss) hysteresis loss, not previously reported elsewhere, but present in all the operating modes of the converter (under and above the series resonant frequency). In this paper, a new technique is proposed for the measurement of the switching losses in the rectifiers of the LLC and other isolated converters. Moreover, two new circuits are introduced for the isolation and measurement of the Coss hysteresis loss, which can be applied to both high-voltage and low-voltage semiconductor devices. Finally, the analysis is experimentally demonstrated, characterizing the switching loss of the rectifiers in a 3 kW LLC converter (410 V input to 50 V output). Furthermore, the Coss hysteresis loss of several high-voltage and low-voltage devices is experimentally verified in the newly proposed measurement circuits.
A Review of Enhancement of Biohydrogen Productions by Chemical Addition Using a Supervised Machine Learning Method
Authors: Liu Yiyang , Liu Jinze , He Hongzhen , Yang Shanru , Wang Yixiao , Hu Jin , Jin Huan , Cui Tianxiang , Yang Gang , Sun Yong
Published: September 2021

In this work, the impact of chemical additions, especially nano-particles (NPs), was quantitatively analyzed using our constructed artificial neural networks (ANNs)-response surface methodology (RSM) algorithm. Fe-based and Ni-based NPs and ions, including Mg2+, Cu2+, Na+, NH4+, and K+, behave differently towards the response of hydrogen yield (HY) and hydrogen evolution rate (HER). Manipulating the size and concentration of NPs was found to be effective in enhancing the HY for Fe-based NPs and ions, but not for Ni-based NPs and ions. An optimal range of particle size (86–120 nm) and Ni-ion/NP concentration (81–120 mg L−1) existed for HER. Meanwhile, the manipulation of the size and concentration of NPs was found to be ineffective for both iron and nickel for the improvement of HER. In fact, the variation in size of NPs for the enhancement of HY and HER demonstrated an appreciable difference. The smaller (less than 42 nm) NPs were found to definitely improve the HY, whereas for the HER, the relatively bigger size of NPs (40–50 nm) seemed to significantly increase the H2 evolution rate. It was also found that the variations in the concentration of the investigated ions only statistically influenced the HER, not the HY. The level of response (the enhanced HER) towards inputs was underpinned and the order of significance towards HER was identified as the following: Na+ > Mg2+ > Cu2+ > NH4+ > K+.
Deflagration Characteristics of N2-Diluted CH4-N2O Mixtures in the Course of the Incipient Stage of Flame Propagation
Authors: Mitu Maria , Movileanu Codina , Giurcan Venera
Published: September 2021

In this study, experimental measurements in a spherical combustion bomb were performed in order to investigate the flame propagation in N2-diluted CH4-N2O mixtures with stoichiometric equivalence ratio, at several initial pressures (0.5–1.75 bar) and ambient initial temperatures. Methane was chosen as a test-fuel, since it is the main component of natural gas, a fuel often used as a substitute to gasoline in engines with internal combustion and industrial plants. The method approached in this study is based on a simple examination of the cubic law of pressure rise during the early (incipient) period of flame propagation. The incipient stage defined by a pressure rise equal or smaller than the initial pressure, was divided into short time intervals. The burnt mass fractions (obtained using three different Equations) and flame radii at various moments of the flame propagation in the course of the incipient stage were calculated. The cubic law coefficients and corresponding laminar burning velocities at considered time intervals were also reported.
Modeling and Optimization of Wind Turbines in Wind Farms for Solving Multi-Objective Reactive Power Dispatch Using a New Hybrid Scheme
Authors: Syah Rahmad , Faghri Safoura , Nasution Mahyuddin KM , Davarpanah Afshin , Jaszczur Marek
Published: September 2021

Reactive Power Dispatch is one of the main problems in energy systems, particularly for the power industry, and a multi-objective framework should be proposed to solve it. In this study, we present a multi-objective framework for the optimization of wind turbines in wind farms. We investigate a new combined optimization method with Chaotic Local Search, Fuzzy Interactive Honey Bee Mating Optimization, Data-Sharing technique and Modified Gray Code for discrete variables. We use the proposed model to select optimal energy system parameters. The optimization process is based on simultaneous optimization of three functions. Finally, we improve a new method based on Pareto-optimal solutions to select the best one among all candidate solutions. The presented model and methodology are validated on energy systems with wind turbines. The evaluated efficiency is compared with the real system.
Analysis of Hybrid and Plug-In Hybrid Alternative Propulsion Systems for Regional Diesel-Electric Multiple Unit Trains
Authors: Kapetanović Marko , Vajihi Mohammad , Goverde Rob M. P.
Published: September 2021

This paper presents a simulation-based analysis of hybrid and plug-in hybrid propulsion system concepts for diesel-electric multiple unit regional railway vehicles. These alternative concepts primarily aim to remove emissions in terminal stops with longer stabling periods, with additional benefits reflected in the reduction of overall fuel consumption, produced emissions, and monetary costs. The alternative systems behavior is modeled using a backward-looking quasi-static simulation approach, with the implemented energy management strategy based on a finite state machine control. A comparative assessment of alternative propulsion systems is carried out in a case study of a selected regional railway line operated by Arriva, the largest regional railway undertaking in the Netherlands. The conversion of a standard diesel-electric multiple unit vehicle, currently operating on the network, demonstrated a potential GHG reduction of 9.43–56.92% and an energy cost reduction of 9.69–55.46%, depending on the type of service (express or stopping), energy storage technology selection (lithium-ion battery or double-layer capacitor), electricity production (green or grey electricity), and charging facilities configuration (charging in terminal stations with or without additional charging possibility during short intermediate stops) used. As part of a bigger project aiming to identify optimal transitional solutions towards emissions-free trains, the outcomes of this study will help in the future fleet planning.
Reuse of Flowback Water from Hydraulic Fracturing for Drilling Mud Preparation and Secondary Hydrocarbon Recovery
Authors: Knapik Ewa , Chruszcz-Lipska Katarzyna , Łukańko Łukasz , Wysocki Sławomir
Published: September 2021

Flowback water after completion of hydraulic fracturing is one of major waste streams generated during the lifespan of a well so its beneficial reuse is crucial. The application of treated flowback is not limited to stimulation processes but also may include drilling operations and secondary oil recovery. The flowback water used in this work is characterized by high salinity reaching up to ~295 g/L caused mainly by NaCl. The presence of suspended solids, mainly corrosion products, prompts the use of coagulation and filtration as treatment methods. Among tested coagulants the most effective one was the SAX18 (NaAlO2) commercial coagulant applied at concentration of 12 mL/L which reduces the water turbidity from over 400 FTU to 23 FTU. The applied treatment greatly reduces the concentration of scaling ions and so the concentration of SiO2 is reduced by 64%, Ba2+–66%, Fe2–36%, Mn2+–65%, SO42−–66%. The treated flowback fluid can be reused in surfactant flooding for enhanced oil recovery where achieves 7% higher displacing efficiency than fresh water. The drilling muds which were prepared using the untreated flowback water exhibit good rheological properties. The obtained results show that recycling of flowback water in future drilling and exploitation operations is technically feasible.
Linearization of Thermal Equivalent Temperature Calculation for Fast Thermal Comfort Prediction
Authors: Rommelfanger Christian , Fischer Louis , Frisch Jérôme , Van Treeck Christoph
Published: September 2021

Virtual simulations and calculations are a key technology for future development methods. A variety of tools and methods for calculating thermal comfort have not gained sufficient acceptance in practice due to their inherent complexity. This article investigates alternative means of determining thermal comfort, namely, the linearization of the equivalent temperature calculation. This enables a wide range of users to evaluate thermal comfort in a fast and easy manner, for example, for energy efficiency simulation. A flow and thermal model were created according to the requirements of DIN EN ISO 14505 to determine heat transfer coefficients under calibration conditions. The model to simulate the equivalent temperature in calibration conditions comprises a geometrically realistic 3D model of a human test person according to the standard. The influence of the turbulence model, as well as the influence of the equivalent temperature on the heat transfer coefficient in calibration conditions, was investigated. It was found that the dependence of the equivalent temperature is mandatory. The dependence between the heat transfer and the equivalent temperature was taken into account with a continuous linearization approach. An equation-based implementation methodology is proposed, enabling a quick implementation of comfort evaluation in future simulation models. Two test cases show the capabilities of the new model and its application in future work.
Theoretical Analysis of Vuilleumier’s Hypothetical Engine and Cooler
Authors: Liu Qi , Luo Baojun , Yang Jiayao , Gao Qun , Liu Jingping , Huang Yuexin , Ren Chengqin
Published: September 2021

Vuilleumier machines are a promising technology for heating. Respective performances of Vuilleumier’s engine and cooler are generally unclear. In Stirling machines, performances can be determined based on PV power flow and heat flow methods. In this work, respective performances based on two methods in current Vuilleumier models were investigated. It was found that PV power flow and heat flow methods in current Vuilleumier models were ineffective for analysis of respective performances due to there being no piston as a boundary between Vuilleumier’s engine and cooler. Then, a virtual piston was assumed, and a virtual piston based Vuilleumier model (VPBVM) was developed. The relative Carnot efficiencies of the obtained engine and cooler were 53~64% and 43~49%, respectively, at conditions of 550 °C hot temperature, 50~70 °C warm temperature, and −20~10 °C cold temperature. The results indicated that respective performances obtained in VPBVM were reasonable. Moreover, the engine’s compression ratios could be obtained in VPBVM and were 1.2~1.24. Thus, VPBVM could be effective for the analysis of the Vuilleumier machine’s engine and cooler.
Comparing Rooting Ability and Physiological Changes of Two Eucommia ulmoides Improved Varieties
Authors: Lv Gengxin , Qing Jun , Du Hongyan , Du Qingxin , Meng Yide , He Feng , Liu Panfeng , Du Lanying , Wang Lu
Published: September 2021

Eucommia ulmoides (E. ulmoides) is a significant national strategic resource in China. It is a natural high quality rubber resource, with great development potential. We found large differences in rooting ability during adventitious root (AR) formation in two E. ulmoides improved varieties. Therefore, we used two improved varieties of E. ulmoides, ‘Huazhong 6’ (H6, with rooting rate 85.3%) and ‘Huazhong 8’ (H8, with rooting rate 22.5%) to explore the cutting rooting mechanism. In this study, we mainly determined the morphological development process of E. ulmoides cutting rooting, and compared the rooting-related indexes of the two improved varieties, and the changes in physiological indexes closely related to rooting, which include endogenous hormones, oxidases and nutrients in the phloem of the basal stem. The results showed that indole–3–acetic acid (IAA), zeatin riboside (ZR), IAA/ZR and indoleacetic acid oxidase (IAAO) were the key factors that caused big differences in rooting ability between the two E. ulmoides improved varieties. The increase in endogenous hormone IAA content and IAA/ZR value were necessary for the formation of AR. The increase in IAA content was beneficial to AR formation. The activity of IAAO was significantly negatively correlated with the rooting ability of the E. ulmoides cuttings. The high IAAO activity of the H8 cuttings led to the consumption of IAA. Although the content of IAA increased, the rooting conditions were not reached. The accumulation of nutrients before rooting also has an important effect on rooting; it is easy for cuttings to root when the carbon–nitrogen ratio (C/N) value is high. This research provides an improved understanding of the cellular and physiological underpinnings of the AR process in woody plants. In addition, it provides a theoretical basis and foundation for subsequent research on E. ulmoides cuttage technology.
Molecular Identification and Antifungal Properties of Four Thaumatin-like Proteins in Spruce (Picea likiangensis)
Authors: Liu Yufeng , Liu Lijuan , Asiegbu Fred O. , Yang Chunlin , Han Shan , Yang Shuai , Zeng Qian , Liu Yinggao
Published: September 2021

Thaumatin-like proteins (TLPs) are involved in the plant defense response against pathogens, and most of them exhibit antifungal activity. However, the role of TLPs in pathogen-induced defense responses in spruce is not fully understood. In this study, four TLP genes encoding thaumatin-like protein, designated as PlTLP1–4, were isolated and identified from Picea likiangensis needles. Sequence analysis showed that PlTLP1, PlTLP3, and PlTLP4 contained 16 conserved cysteine residues, while PlTLP2 had only 10 conserved cysteine residues. qPCR analysis showed that PlTLPs were expressed in all tissues tested, PlTLP1, PlTLP3, and PlTLP4 had the highest expression levels in young fruits, while PlTLP2 had the highest expression levels in roots. In addition, the expression levels of four PlTLPs were significantly upregulated during infection by Lophodermium piceae. Four recombinant PlTLPs expressed in Escherichia coli exhibited obvious β-1,3-glucanase activity. The antifungal activity assay showed that four recombinant PlTLPs had significant inhibitory effects on the mycelial growth of L. piceae, Fusarium proliferatum, Botrytis cinerea, and Roussoella doimaesalongensis. Microscopic observation revealed that the recombinant PlTLP1–4 induced the morphological changes of the mycelia of L. piceae, and the recombinant PlTLP2 and PlTLP3 induced the morphological changes of the mycelia of F. proliferatum and R. doimaesalongensis, while all the recombinant PlTLPs had no obvious negative effect on the morphology of B. cinerea mycelium. These results suggest that PlTLP genes may play an important role in the defense response of P. likiangensis against L. piceae invasion.
Total and Merchantable Volume Equations for 25 Commercial Tree Species Grown in Canada and the Northeastern United States
Authors: Sharma Mahadev
Published: September 2021

Accurate estimates of tree bole volume are fundamental to sustainable forest management. Total inside and outside bark and merchantable volume equations were developed for 25 major commercial tree species grown in natural stands in eastern and central Canada and the northeastern United States. Data used to develop these equations was collected from 9647 trees sampled from natural stands across the study area. The number of trees sampled varied among species. Jack pine (Pinus banksiana Lamb.) had the most observations (1648 trees) and American basswood (Tilia americana) and red oak (Quercus rubra L.) had the fewest (28 trees each). Two mathematically consistent volume equations (dimensionally compatible and combined variable) were fitted to inside and outside bark and merchantable tree volume data from these tree species. The final volume equation was selected based on fit statistics, predictive accuracy, and logical consistency. Its predictive accuracy was compared with a volume equation previously developed by Honer. Both (total and merchantable) volume equations were fitted using a nonlinear mixed-effects modelling approach. However, random effects were significant for total volumes for only four tree species. A weight (power function) was used to address heteroscedasticity in the data. The modified form of the dimensionally compatible volume equation outperformed the combined variable volume equation in terms of fit statistics and predictive accuracy and was selected as the total inside and outside bark and merchantable volume equations for all tree species. This equation produced logically consistent estimates of total and merchantable volumes and was more accurate than that previously developed by Honer to estimate volumes for most of the tree species used in this study. This new equation can be used to estimate total inside and outside bark and merchantable volumes of major commercial tree species in eastern and central Canada and the northeastern United States.
Nitrogen and Phosphorus Distribution and Relationship in Soils and Plants under Different Aged Chinese Fir Plantation
Authors: Yang Zhen’an , Luo Zhibin
Published: September 2021

As essential nutrients for plant growth and development, the balance of nitrogen (N) and phosphorus (P) between soils and plants is a key component to ecosystem stability. In this study, we examined the distribution of nutrients in the soils and different organs of Chinese fir (Cunninghamia lanceolata) in Hunan Province, southern China. Additionally, we investigated the nutrient concentrations in soil layers (0–80 cm depth) and in plant organs, and the total biomass of 10-, 20-, and 30-year-old plantations. The results suggested that the nutrients in the soil were aggregated in the surface layer. The highest and lowest values of N concentrations in 0–80 cm soil layers and P concentrations in 0–40 cm soil layers were both in 30-year-old plantations and 20-year-old plantations, respectively. Nitrogen in the organs of Chinese fir in all plantations and P concentrations in the organs of 20- and 30-year-old trees decreased in the following order: leaves, fine roots, coarse roots, and stems. Total biomass (N and P pools of four organs) increased consistently with stand age increase, and N and P pools were the highest in leaves and stems, respectively. There were significant, positive correlations between N and P in the soil (0–80 cm), and organs, respectively, and also between N concentrations of fine roots and that of 0–10 and 10–20 cm soil, respectively. In Chinese fir plantations, concentrations of nutrients in specific tree organs and the soil were correlated positively, which can only partially explain the balance of nutrients within the plant–soil ecosystem. This study suggested that incorrect harvesting patterns may effectively deprive the forest ecosystem of valuable nutrients that would ordinarily have been returned to the soil.
On the Mismatches between the Monetary and Social Values of Air Purification in the Colombian Andean Region: A Case Study
Authors: Suarez Andres , Ruiz-Agudelo Cesar , Castro-Escobar Edisson , Flórez-Yepes Gloria Y. , Vargas-Marín Luis A.
Published: September 2021

There is growing interest in air quality and air purification, due to current high pollution levels, their effects on human health, and implications for urban economies. Since the improvement of air quality carries important economic value, air-related benefits have been evaluated monetarily from two perspectives: the first relates to air quality improvements, while the second values air purification as an ecosystem function. This research opted for the second perspective, given that the study area (two Colombian municipalities) does not suffer from poor air quality conditions, but stakeholders prioritized this function as highly important to them. Contingent valuation methods were applied in order to identify the population’s probability of willingness to maintain the air purification function. Although individuals (n = 245) attribute a yearly monetary value of USD 1.5 million to air purification, it was found that, despite the high level of social importance that respondents assigned to air purification (mean = 4.7/5), this had no correlation with payment values (rho = 0.0134, p = 0.8350); that is, households do not really recognize the monetary value of all the benefits they receive or the benefits they would lose if the service suffers changes. Hence, it is posed that monetary values do not necessarily reflect the social importance that individuals assign to ecosystem services, and attention is called to the need to integrate social and monetary values into decision-making processes, so as to encompass the complexity of ecosystem services and conciliate conflicting valuation language.
New Perspectives for LVL Manufacturing from Wood of Heterogeneous Quality—Part 2: Modeling and Manufacturing of Variable Stiffness Beams
Authors: Duriot Robin , Pot Guillaume , Girardon Stéphane , Denaud Louis
Published: September 2021

This paper presents a new strategy in the use of wood of heterogeneous quality for composing LVL products. The idea is to consider veneers representative of the resource variability and retain local stiffness information to control panel manufacturing fully. The placement of veneers is also no longer random as in the first part of this group of papers but optimized for the quality of veneers according to the requirement of bending stresses along the beam. In a four-point bending test arrangement, this means the high-quality veneer is concentrated in the center of the beam in the area between the loading points where the bending moments are the most important, and the low quality is located at the extremities. This initiates the creation of variable stiffness beams. This is driven by an algorithm developed and tested on representative veneer samples from the resource. Four LVL panels were manufactured by positioning the veneers in the same positions as in an analytical calculation model, which allowed the calculation of beam mechanical properties in four-point bending. The proposed optimization of LVL manufacturing from variable quality veneers should help for more efficient usage of forest resources. This optimization strategy showed notable gains for modeled and experimental mechanical properties, whether in terms of stiffness or strength. The analytical calculation of the local modulus of elasticity from modelized beams was satisfactory compared to the tests of the manufactured beams test results, allowing the reliability of the model for this property to be confirmed.
Development of Mangrove Sediment Quality Index in Matang Mangrove Forest Reserve, Malaysia: A Synergetic Approach
Authors: Mohamad Pazi Ahmad Mustapha , Khan Waseem Razzaq , Nuruddin Ahmad Ainuddin , Adam Mohd Bakri , Gandaseca Seca
Published: September 2021

Sediment is an important part of heavy metal cycling in the coastal ecosystem, acting as a potential sink and source of inorganic and organic contaminants as environmental conditions change. The productivity of mangroves is utterly dependent on sediment enrichment. Moreover, mangrove sediment can trap pollutants discharged by households, industries, and agriculture activities. In this regard, it is essential to assess sediment quality in the presence–absence of heavy metals that are toxic to most living organisms. Thus, the question of how sediment quality is used as an index in the mangrove domain has arisen. Due to the many complex characteristics such as seasonal zones, tidal patterns, flora and fauna, and water, no specific method is used in Malaysia for assessing and monitoring mangrove sediment quality. Thus, the current study intended to develop a mangrove sediment quality index (MSQi) in the Matang mangrove forest in Perak, Malaysia. An area was selected based on the distinct level of mangrove disturbances. At 1.5 m depth, sediments were sampled in five segments (0–15, 15–30, 30–50, 50–100, and 100–150 cm). All the sediment physicochemical properties were then analysed. Fourteen variables were chosen and included in MSQi. This index categorises mangrove sediment levels as I = Very Bad, II = Bad, III = Moderate, IV = Good, and V = Excellent. MSQi will be used as a guideline in monitoring mangrove sediment pollution. In conclusion, the data analysis showed that the Sepetang River (SR) was highly disturbed, followed by the Tinggi River (TR) (moderately disturbed), and the Tiram Laut River (TLR) (least disturbed).
Effects of a Mixed Limosilactobacillus fermentum Formulation with Claimed Probiotic Properties on Cardiometabolic Variables, Biomarkers of Inflammation and Oxidative Stress in Male Rats Fed a High-Fat Diet
Authors: de Luna Freire Micaelle Oliveira , do Nascimento Luciana Caroline Paulino , de Oliveira Kataryne Árabe Rimá , de Oliveira Alisson Macário , Napoleão Thiago Henrique , Lima Marcos dos Santos , Lagranha Cláudia Jacques , de Souza Evandro Leite , de Brito Alves José Luiz
Published: September 2021

High-fat diet (HFD) consumption has been linked to dyslipidemia, low-grade inflammation and oxidative stress. This study investigated the effects of a mixed formulation with Limosilactobacillusfermentum 139, L. fermentum 263 and L. fermentum 296 on cardiometabolic parameters, fecal short-chain fatty acid (SCFA) contents and biomarkers of inflammation and oxidative stress in colon and heart tissues of male rats fed an HFD. Male Wistar rats were grouped into control diet (CTL, n = 6), HFD (n = 6) and HFD with L. fermentum formulation (HFD-Lf, n = 6) groups. The L.fermentum formulation (1 × 109 CFU/mL of each strain) was administered twice a day for 4 weeks. After a 4-week follow-up, biochemical parameters, fecal SCFA, cytokines and oxidative stress variables were evaluated. HFD consumption caused hyperlipidemia, hyperglycemia, low-grade inflammation, reduced fecal acetate and propionate contents and increased biomarkers of oxidative stress in colon and heart tissues when compared to the CTL group. Rats receiving the L. fermentum formulation had reduced hyperlipidemia and hyperglycemia, but similar SCFA contents in comparison with the HFD group (p < 0.05). Rats receiving the L. fermentum formulation had increased antioxidant capacity throughout the colon and heart tissues when compared with the control group. Administration of a mixed L. fermentum formulation prevented hyperlipidemia, inflammation and oxidative stress in colon and heart tissues induced by HFD consumption.
Application Research: Big Data in Food Industry
Authors: Tao Qi , Ding Hongwei , Wang Huixia , Cui Xiaohui
Published: September 2021

A huge amount of data is being produced in the food industry, but the application of big data—regulatory, food enterprise, and food-related media data—is still in its infancy. Each data source has the potential to develop the food industry, and big data has broad application prospects in areas like social co-governance, exploit of consumption markets, quantitative production, new dishes, take-out services, precise nutrition and health management. However, there are urgent problems in technology, health and sustainable development that need to be solved to enable the application of big data to the food industry.
Variable Retort Temperature Profiles (VRTPs) and Retortable Pouches as Tools to Minimize Furan Formation in Thermally Processed Food
Authors: Fardella Matías , Ramírez Cristian , Caballero Eduardo , Sánchez Elizabeth , Pinto Marlene , Núñez Helena , Valencia Pedro , Almonacid Sergio , Simpson Ricardo
Published: September 2021

Furan and its derivates are present in a wide range of thermally processed foods and are of significant concern in jarred baby and toddler foods. Furan formation is attributed to chemical reactions between a variety of precursors and a high processing temperature. Also, some kinetic models to represent its formation in different food materials have been studied and could predict the furan formation under simulated operating conditions. Therefore, this review aims to analyze and visualize how thermally processed foods might be improved based on optimal control of processing temperature and package design (e.g., retort pouches) to diminish furan formation and maximize quality retention. Many strategies have been studied and applied to reduce furan levels. However, an interesting approach that has not been explored is the thermal process design based on optimum variable retort temperature profiles (VRTPs) and the use of retortable pouches considering the microstructural changes of food along the process. The target of process optimization would be developed by minimizing the microstructural damage of the food product. It could be possible to reduce the furan level and simultaneously preserve the nutritional value through process optimization.
The Role of Local Seasonal Foods in Enhancing Sustainable Food Consumption: A Systematic Literature Review
Authors: Vargas Alexandre Maia , de Moura Ana Pinto , Deliza Rosires , Cunha Luís Miguel
Published: September 2021

This article aims to review the current literature pertaining to the effects of eating local seasonal food on sustainable consumption. To this end, we examined definitions of seasonal and local food, the methodological approaches adopted to study the impact of seasonal consumption on sustainability, and sustainability dimensions investigated in journal articles. Highlighting what seasonal and local means, it is crucial to evaluate the effect of the consumption of these foods on sustainability. A systematic review of the literature was conducted using Scopus and Clarivate’s Web of Science database in line with the recommendations from the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines. Our findings suggest that the concept of local seasonality provides relevant information to the study of sustainable consumption. However, for better use of this concept, it is crucial to define what is local. At this point, regulation of labels based on geographic proximity or political boundaries proves pertinent.
Current Advances on the Development and Application of Probiotic-Loaded Edible Films and Coatings for the Bioprotection of Fresh and Minimally Processed Fruit and Vegetables
Authors: de Oliveira Kataryne Árabe Rimá , Fernandes Karina Felix Dias , de Souza Evandro Leite
Published: September 2021

The application of probiotics has emerged as an innovative bioprotection technology to preserve fresh and minimally processed fruit and vegetables. This review discusses the most recent advances on the development and application of probiotic-loaded edible films/coatings as a strategy to preserve fresh or minimally processed fruit and vegetables. Available studies have shown a variety of materials, including hydrocolloids (polysaccharides and proteins) and lipids, used alone or in combination to formulate edible films/coatings loaded with probiotics. Plasticizers and surfactants are usually required to formulate these edible films/coatings. The reported antimicrobial effects of probiotic-loaded edible films/coating and quality parameters of coated fruit and vegetables could vary according to the characteristics of the materials used in their formulation, loaded probiotic strain and its dose. The antimicrobial effects of these films/coatings could be linked to the action of various metabolites produced by embedded probiotic cells with inhibitory effects on microorganisms contaminating fruit and vegetable surfaces. The implication of the use of probiotic-loaded edible films/coatings should be their antimicrobial effects against pathogenic and spoilage microorganisms and efficacy to control the ripening of fruit and vegetables, helping the coated products to maintain their safety, quality, nutritional and functional characteristics for a more prolonged storage period.
Is FOP Nutrition Label Nutri-Score Well Understood by Consumers When Comparing the Nutritional Quality of Added Fats, and Does It Negatively Impact the Image of Olive Oil?
Authors: Fialon Morgane , Salas-Salvadó Jordi , Babio Nancy , Touvier Mathilde , Hercberg Serge , Galan Pilar
Published: September 2021

It has been suggested that the current ranking of olive oil by Nutri-Score (C) is not in line with its nutritional quality and could have a negative impact on the sales and consumption of olive oil, especially compared to other added fats with lower nutritional qualities One of the objectives of this study is to investigate consumers’ understanding of Nutri-Score when comparing the nutritional quality of added fats, and to test whether or not Nutri-Score has a negative impact on the image and the choice of olive oil in a sample of Spanish consumers. A cross-sectional study of 486 Spanish adults (mean age ± SD: 45.8 ± 14.0 years; 48.6% women) was conducted. Subjects were recruited through a web panel provider to participate in an online questionnaire. Almost 80% of participants declared that Nutri-Score was useful for recognizing the differences in nutritional quality between the eight added fats presented in the study; 89.1% rightly identified that olive oil was among the added fats with the best nutritional quality (vs. 4.1% for rapeseed oil (Nutri-Score C), and less than 3% for other added fats (Nutri-Score D or E)). When asked about which added fat they would buy more frequently, 86.2% of participants selected olive oil. Then, after being reminded that among added fats, the Nutri-Score C given to olive oil was the best grade, a majority of participants declared that they would keep consuming olive oil as much as before (71.4%). Finally, almost 78% of participants thought that Nutri-Score should be displayed on olive oil. In conclusion, the results of our study suggest that displaying Nutri-Score on olive oil was well accepted and understood by a large majority of participants who appeared to accept the current ranking of the Nutri-Score for olive oil (Nutri-Score C).
Quality and Safety Assessment of Edible Seaweeds Alaria esculenta and Saccharina latissima Cultivated in Scotland
Authors: Lytou Anastasia E. , Schoina Eirini , Liu Yunge , Michalek Kati , Stanley Michele S. , Panagou Efstathios Z. , Nychas George-John E.
Published: September 2021

Within Europe over the last 10 years, there has been an increase in seaweeds cultivated for human consumption. For food safety reasons, it is important to assess the microbiological and nutritional quality of the biomass. The fresh and dried edible seaweeds Alaria esculenta and Saccharina latissima were assessed over two consecutive years for the presence of microorganisms. Seaweed samples supplied from Scotland were stored under isothermal conditions for specific time intervals depending on the sample’s condition (fresh, dried or rehydrated). During storage, microbiological analyses were performed for the enumeration of Total Viable Counts (TVC), Pseudomonas spp., Enterobacteriaceae and Bacillus spp., as well as yeasts and molds. Additionally, bacterial colonies from the Marine Agar growth medium were isolated and subjected to PCR-RAPD analysis for characterization of the bacterial diversity of seaweeds. Bacterial isolates with different fingerprint patterns were further subjected to sequencing (16S rDNA, V1–V4 region). The presence of human pathogenic bacteria was also investigated. Results showed that the initial population of TVC was differentiated depending on the year of seaweed harvest, being closer to the enumeration limit (1.0 log CFU/g) in fresh samples from 2020 and higher in samples from 2019 (6.7 and 3.9 log CFU/g in A. esculenta and S. latissima, respectively). DNA-based analysis revealed the presence of Psychrobacter, Cobetia and Pseudomonas species in A. esculenta, while Psychrobacter and Micrococcus species were present in S. latissima.
Antimicrobial and Antibiofilm Effect of ε-Polylysine against Salmonella Enteritidis, Listeria monocytogenes, and Escherichia coli in Tryptic Soy Broth and Chicken Juice
Authors: Lee Do-Un , Park Yeong Jin , Yu Hwan Hee , Jung Suk-Chae , Park Jung-Hee , Lee Dae-Hee , Lee Na-Kyoung , Paik Hyun-Dong
Published: September 2021

ε-Polylysine (ε-PL) is a safe food additive that is used in the food industry globally. This study evaluated the antimicrobial and antibiofilm activity of antibacterial peptides (ε-PL) against food poisoning pathogens detected in chicken (Salmonella Enteritidis, Listeria monocytogenes, and Escherichia coli). The results showed that minimum inhibitory concentrations (MICs) ranged between 0.031–1.0 mg/mL, although most bacterial groups (75%) showed MICs of 1.0 mg/mL. The reduction in the cell viability of pathogens due to ε-PL depended on the time and concentration, and 1/2 × MIC of ε-PL killed 99.99% of pathogens after 10 h of incubation. To confirm biofilm inhibition and degradation effects, crystal violet assay and confocal laser scanning microscopy (CLSM) were used. The biofilm formation rates of four bacterial groups (Salmonella, Listeria, E. coli, and multi-species bacteria) were 10.36%, 9.10%, 17.44%, and 21.37% at 1/2 × MIC of ε-PL, respectively. Additionally, when observed under a CLSM, ε-PL was found to induce biofilm destruction and bacterial cytotoxicity. These results demonstrated that ε-PL has the potential to be used as an antibiotic and antibiofilm material for chicken meat processing.
Volatile Components and Preliminary Antibacterial Activity of Tamarillo (Solanum betaceum Cav.)
Authors: Diep Tung Thanh , Yoo Michelle Ji Yeon , Pook Chris , Sadooghy-Saraby Saeedeh , Gite Abhishek , Rush Elaine
Published: September 2021

Tamarillo is a nutrient-dense fruit with a unique aroma from its volatile compounds (VCs). In this study, we aimed to compare the volatile profiles: (i) of fresh and freeze-dried tamarillo; (ii) detected using Thermal Desorption–Gas Chromatography–Mass Spectrometry (TD–GC–MS) and Solid-Phase MicroExtraction–Gas Chromatography-Mass Spectrometry (SPME–GC–MS); (iii) of freeze-dried pulp and peel of New Zealand grown tamarillo. The possible antibacterial activity of freeze-dried tamarillo extracts was also investigated. We show that freeze-drying maintained most of the VCs, with some being more concentrated with the loss of water. The most abundant VC in both fresh and freeze-dried tamarillo was hexanoic acid methyl ester for pulp (30% and 37%, respectively), and (E)-3-Hexen-1-ol for peel (36% and 29%, respectively). With the use of TD–GC–MS, 82 VCs were detected for the first time, when compared to SPME–GC–MS. Methional was the main contributor to the overall aroma in both peel (15.4 ± 4.2 μg/g DW) and pulp (118 ± 8.1 μg/g DW). Compared to water as the control, tamarillo extracts prepared by water and methanol extraction showed significant antibacterial activity against E. coli, P. aeruginosa, and S. aureus with zone of inhibition of at least 13.5 mm. These results suggest that freeze-dried tamarillo has a potential for use as a natural preservative to enhance aroma and shelf life of food products.
Synergistic Effect of Enzyme Hydrolysis and Microwave Reactor Pretreatment as an Efficient Procedure for Gluten Content Reduction
Authors: Gazikalović Ivana , Mijalković Jelena , Šekuljica Nataša , Jakovetić Tanasković Sonja , Đukić Vuković Aleksandra , Mojović Ljiljana , Knežević-Jugović Zorica
Published: September 2021

In this study, we assessed the effects of microwave irradiation of wheat gluten proteins as a pretreatment performed in a microwave reactor that could accurately control process parameters as a function of power and temperature, as well as comparing it with conventional heat treatment. The aim was to identify suitable combinations of partial enzymatic hydrolysis and microwave pretreatment parameters to produce gluten hydrolysates with reduced allergenicity and conserved techno-functional features for food application. FTIR analysis, and total and reactive SH group contents confirmed that the microwave-controlled heating can significantly change the secondary structure and conformation of gluten protein. The microwave treatment had the largest effect at 200 W and 100 °C, at which the content of gluten has been reduced by about 2.5-fold. The microwave pretreatment also accelerated the enzymatic hydrolysis of gluten, changing the kinetic profile. The apparent hydrolysis rate constants (k2) were 1.00, 3.68, 3.48, 4.64 and 4.17 min−1 for untreated gluten, and those pretreated with microwave power of 200, 400, 600 and 800 W, respectively. Compared to the heat treatment, it appeared that microwave specific non-thermal effects had a significant influence on the gluten structure and allergenicity and, in combination with the enzymatic hydrolysis, ultimately yielded protein hydrolysates with enhanced antioxidant and functional properties.
Metagenomic Analyses of Plant Growth-Promoting and Carbon-Cycling Genes in Maize Rhizosphere Soils with Distinct Land-Use and Management Histories
Authors: Chukwuneme Chinenyenwa , Ayangbenro Ayansina , Babalola Olubukola
Published: September 2021

Many studies have shown that the maize rhizosphere comprises several plant growth-promoting microbes, but there is little or no study on the effects of land-use and management histories on microbial functional gene diversity in the maize rhizosphere soils in Africa. Analyzing microbial genes in the rhizosphere of plants, especially those associated with plant growth promotion and carbon cycling, is important for improving soil fertility and crop productivity. Here, we provide a comparative analysis of microbial genes present in the rhizosphere samples of two maize fields with different agricultural histories using shotgun metagenomics. Genes involved in the nutrient mobilization, including nifA, fixJ, norB, pstA, kefA and B, and ktrB were significantly more abundant (α = 0.05) in former grassland (F1) rhizosphere soils. Among the carbon-cycling genes, the abundance of 12 genes, including all those involved in the degradation of methane were more significant (α = 0.05) in the F1 soils, whereas only five genes were significantly more abundant in the F2 soils. α-diversity indices were different across the samples and significant differences were observed in the β diversity of plant growth-promoting and carbon-cycling genes between the fields (ANOSIM, p = 0.01 and R = 0.52). Nitrate-nitrogen (N-NO3) was the most influential physicochemical parameter (p = 0.05 and contribution = 31.3%) that affected the distribution of the functional genes across the samples. The results indicate that land-use and management histories impact the composition and diversity of plant growth-promoting and carbon-cycling genes in the plant rhizosphere. The study widens our understanding of the effects of anthropogenic activities on plant health and major biogeochemical processes in soils.