Concentrations Of Ethylene Gas Research Articles

Potassium permanganate-based ethylene gas indicator of kiwifruit ripeness

A kiwifruit ripeness indicator was developed using potassium permanganate (KMnO4), an ethylene gas scavenger. A total of 500 g of kiwifruit was packaged in polypropylene (PP) containers (20 × 16 × 11.5 cm) with a heat-sealed PP, polyethylene (PE), and ethylene-vinyl alcohol copolymer (EVOH) cover film (50 µm thick) with the indicator inside, and stored at 15, 20, and 25 °C. The ethylene gas permeability of the cover films, kiwifruit firmness (ripeness parameter, ≤ 8 N), ethylene gas concentration, and indicator color were measured. The indicator changed from purple to brown. When the firmness reached 7.9 N, the ethylene gas concentrations for each cover film were different due to film permeability. The indicator color index (ΔE) for each cover film was also different and ranged from 15.2 to 23.9, falling within the visually detectable change.

과일 숙성 에틸렌가스 지시계 기술개발 현황

Recently, intelligent packaging of foods has been increasingly developed in response to the growing interest of consumers in checking food quality. Indicators, an important element in intelligent packaging, change color to detect specific substances or indicate food quality changes. Gas indicators can be built into food packaging to detect volatile substances that are released when food quality changes. Ethylene gas is produced as climacteric fruits ripen. Climacteric fruit ripening results from a rapid increase in ethylene production and respiration. In the case of packaged fruits, the ethylene gas concentration in the headspace is closely related to the ripeness of each fruit variety. If an ethylene gas indicator that can be used in fruit packaging is available, the consumer will be able to eat the fruit at the optimal time. In this paper, the characteristics and pros and cons of the ethylene gas indicators developed so far were analyzed by reviewing various types of indicators such as metal reduction-based indicator, fluorescence-based indicator, pH indicator-based indicator, and liposome-based indicator.

Nitrogen-fixation and phosphate-solubilization bacteria isolated from alluvial and latosol soil paddy field

Abstract. Ikhwani, Saribanon N, Setia TM, Yuniarti E, Jumakir. 2021. Nitrogen-fixation and phosphate-solubilization bacteria isolated from alluvial and latosol soil paddy field. Biodiversitas 22: 4722-4730. This study aims to isolate, select and identify molecular characterization of bacteria from alluvial and latosol soil paddy field. This study has been conducted from February-June 2020 in the Soil Biology Laboratory, ICALRRD, Bogor. Alluvial and latosol soil samples were selected from Pusakanagara and Muara experimental gardens, Muara district. The result showed that bacteria growth in N-free media was higher from latosol soil as compared to alluvial soil. The higher nitrogenase activity isolates, could form ethylene gas concentration 1.1.E + 09 µmol/mL/hours, 1.7.E + 09 µmol/mL/hours and 1.3.E + 09 µmol/mL/hours from alluvial 6, latosol 4, and latosol 9. Three isolates have great PSB performances, i.e. isolates No. 4.2, 2.1 and 2 could dissolve 14.398 mg l-1, 12.648 mg l-1 and 12.145 mg l-1 of phosphate, from latosol soil. The highest N-fixing and solubilization capacity identified by molecular characterization i.e latosol 4, 4.2 and alluvial 7.1, alluvial-1.11. The phylogeny analyzed the presence of bacterial isolates in two distinct groups. Latosol 3.1 and latosol 4.2 isolates clustered in the same as the genus Lysinibacillus bacteria. The Alluvial 7.1 bacterial isolate showed similarities by Fictibacillus sp. and alluvial 1.2 isolate showed similarities by the genus Bacillus sp.

Covalent Immobilization of Polyaniline Doped with Ag+ or Cu2+ on Carbon Nanotubes for Ethylene Chemical Sensing.

Multi-walled carbon nanotubes (MWCNTs) are promising materials for chemical gas sensing because of their high electrical and mechanical properties and significant sensitivity to changes in the local environment. However, high-content MWCNT films suffer from the low tunability of the electrical resistance, which is crucial for high chemoresistive sensing performance. This study reports the conjugation of MWCNTs and oligomers of polyaniline (PANI) doped with Ag+ or Cu2+ incorporated into a PVC/polyacrylate. MWCNTs were sonicated in n-methyl pyrrolidine (NMP), and PANI was conjugated via a 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and an N-hydroxysuccinimide (EDC/NHS) process. MWCNT/PANI Ag+ or Cu2+ conjugates were doped to form a coordinate bond. The doped conjugates were successfully incorporated into the PVC/polyacrylate. These MWCNT/PANI conjugates doped were exposed to different concentrations of ethylene gas to examine their feasibility for ethylene detection.

The Influence of Ethylene Gas Concentration on LDPE/C2H4 Hybrid Explosion Process and its Severity

The influence of ethylene (C2H4) gas concentration on the LDPE dust hybrid explosion in a 20-L spherical vessel, equipped with a chemical ignitor was analysed for the determination of maximum explosion overpressure, Pmax and deflagration index, KG. The LDPEC2H4 dust hybrid explosibility was evaluated based on the Pmax development, measured by the Kistler piezoelectric pressure transducer. The adiabatic flame temperature was calculated based on ideal gas law. It is speculated that the LDPE/C2H4 explosion undergoes three-phase process, starting with the ignition, followed by flame growth and flame regression. The highest Pmax (17.9 bar) and flame temperature (5200 K) was obtained at flame growth phase, recorded at C2H4 concentration of 3 vol/vol%. It was found that the Pmax and flame temperature is dependent on C2H4 concentration. The calculated KG values in a range of 14 – 60 bar.m/ms obtained in this study, suggesting that the LDPE/C2H4 dust hybrid explosion might subject to an extreme explosion characteristic.

Preserving Climacteric Fruits by Ripening Hormone Oxidation using nano-KMnO4 Confined within Nanoporous Carbon

Climacteric fruits naturally can be over-ripened because of ripening hormone composed of ethylene gas. Removal of ethylene gas by potassium permanganate (KMnO4) has successfully preserved the fruit, but there is still a room for improvement through nano-confinement process. This study was conducted to compare the ethylene oxidation rate and fruit preservation ability of KMnO4 and nano-KMnO4. Ethylene oxidation experiment was conducted in a gas-tight vial filled with ethylene gas (~20%v) and either KMnO4 or nano-KMnO4. Ethylene gas concentration inside the vial was periodically measured using gas chromatography (GC). The result revealed that ethylene oxidation rate by nano-KMnO4 is higher than KMnO4. The ethylene oxidation rate kinetic was modeled with a gas-solid reaction model, which is fundamentally more accurate than first-order reaction model. Fruit preservation experiment was conducted in sealed containers filled with banana (Musa acuminata) samples and either KMnO4 or nano- KMnO4, and stored at room temperature. The result revealed that banana preservation duration by nano-KMnO4 is remarkably longer than KMnO4, where unpreserved fruit was ripened after 7 days and fruit preserved by KMnO4 and nano-KMnO4 were ripened after 13 and 16 days respectively.

Optimization of process parameters for banana ripening using ethylene gas

The study on organic ripening of banana (Musa sp. var ‘Robusta’) fruit was carried out to optimize the best suitable combination of ethylene concentration, temperature and relative humidity. Process parameters were optimized using the design-expert version 8.0.6 software (Stat-Ease Inc, Minneapolis, USA) and applying factorial methodology to the experimental data. Quality parameter of well ripen banana were taken as standard for comparing the experimental results. The temperature, relative humidity, ethylene gas concentration and duration of ripening were observed to have profound influence on ripening characteristics of banana fruit. Among all, the combination of 40°C temperature, 80% relative humidity and 90 ppm ethylene concentration was found optimum for producing ripening effect after 72 hours with quality parameters i.e. total soluble solid (17.68%), pH(4.79), L*(60.26) a* (12.35) and b* (37.73) which were very close to values of standard sample. The study concluded that ripening of banana can be performed with the help of ethylene gas in closed chamber within three days.

Synthesis of SnO2 Nanoparticles via Hydrothermal Method and Their Gas Sensing Applications for Ethylene Detection

Abstract Tin oxide (SnO2) nanorods, nanocubes and nanospheres were prepared using facile hydrothermal method. 3% of palladium (Pd) dopant was added during hydrothermal synthesis in order to investigate its sensing performance toward ethylene gas. For ethylene gas sensing characterization, SnO2 nanostructures (NSs) with different crystallite sizes, and with and without Pd dopant produced by hydrothermal method were analyzed for gas sensing properties towards the low concentrations of ethylene gas. From the analysis, it can be found that, SnO2 NSs with the smallest crystallite size (H1) exhibited high sensitivity (28.69), fast response time (20s) compared to SnO2 NSs with larger crystallite size. For Pd dopant effect, the sensing performances in terms of sensitivity, optimum operating temperature, response and recovery times and reversibility were greatly improved compared to SnO2 NSs without Pd which indicates its excellent potential application as the gas sensor for ethylene gas detection.

Effect of operational conditions on photocatalytic ethylene degradation applied to control tomato ripening

Ethylene is a phytohormone that promotes the ripening of climacteric fruits. When present in the transport and storage environments of fruits and vegetables, ethylene can cause the acceleration of maturation and senescence, leading to the need to dispose of the products. Thus, the elimination of this gas in storage chambers has been studied as an efficient way to improve the shelf-life of climacteric fruits and vegetables. The main objective of this study was to investigate the effect of the operating conditions on the photocatalytic degradation of ethylene in a continuous flow reactor using TiO2 under UV-A light in the absence or presence of tomato fruits. The results for the catalyst deposition showed a linear increase in the photocatalytic degradation of ethylene with increasing thickness of the catalyst deposited on the inner wall of the reactor, up to a constant degradation value. The dependence of the reaction rate was linear with high values for the flow rate, which is associated with the surface reaction. However, at a low flow rate, mass transfer limitations can affect the ethylene reaction rate. Under a kinetic regime, the Langmuir-Hinshelwood model was able to describe the effect of the ethylene gas concentration on its degradation rate. Increasing incident irradiance led to a linear increase in the ethylene conversion over the range studied. A continuous rate of ethylene gas production during tomato ripening of 0.3182 μmol kg−1 h−1 was observed. In a real application, the reactor with a TiO2 film thickness of 0.419 μm under an incident irradiance of 5.18 W m−2 was able to maintain the ethylene concentration in the gas phase close to zero and a lower value for the carbon dioxide in the gas phase was achieved. This is related to a decrease in the respiration rate, indicating that this is an efficient technology for improving the shelf life of cherry tomatoes.

A Low Cost Compact Measurement System Constructed Using a Smart Electrochemical Sensor for the Real-Time Discrimination of Fruit Ripening.

Ethylene as an indicator for evaluating fruit ripening can be measured by very sensitive electrochemical gas sensors based on a high-resolution current produced by a bias potential applied to the electrodes. For this purpose, a measurement system for monitoring ethylene gas concentrations to evaluate fruit ripening by using the electrochemical ethylene sensor was successfully developed. Before the electrochemical ethylene sensor was used to measure the ethylene gas concentrations released from fruits, a calibration curve was established by the standard ethylene gases at concentrations of 2.99 ppm, 4.99 ppm, 8.01 ppm and 10 ppm, respectively, with a flow rate of 0.4 L·min−1. From the calibration curve, the linear relationship between the responses and concentrations of ethylene gas was obtained in the range of 0–10 ppm with the correlation coefficient R2 of 0.9976. The micropump and a novel signal conditioning circuit were implemented in this measurement, resulting in a rapid response in detecting ethylene concentrations down to 0.1 ppm in air and in under 50 s. In this experiment, three kinds of fruits—apples, pears and kiwifruits—were studied at a low concentration (under 0.8 ppm) of trace ethylene content in the air exhaled by fruits. The experimental results showed that a low cost, compact measurement system constructed by using an electrochemical ethylene sensor has a high sensitivity of 0.3907 V·ppm−1 with a theoretical detection limit of 0.413 ppm, and is non-invasive and highly portable.

Study on the Manufacture of Ethylene Gas Absorbing Corrugated Board

ABSTRACT Ethylene gas is a natural hormone that directly affects the freshness of agricultural prod-ucts, so it is very important for the maintenance of freshness to remove ethylene gas from corrugated board boxes . Many methods for the removal of this and other gases have been reported. In this study, the utilization of an absorbent using activated carbon was adopted for the removal of ethylene gas from a corrugated board box. Activated carbon powders were prepared by grinding in a laboratory and were used to treat the surface and to laminate paperboards with a starch solution. The ethylene gas absorption was evaluated by using a gas chromatography to measure the residual ethylene gas concentration. About 60% of the ethylene gas was absorbed by the activated carbon itself. However, the paperboards that were surface-treated and laminated with starch and activated carbon showed lower than 20% ethylene gas absorption . This was because the starch and small-er particles of activated carbon blocked the surface pores of activated carbon particles. Therefore, either the use of the binders must be minimized for the surface treatment of paperboards, or activated carbon packs can be used as absorbents in corrugated boxes.Keywords: Ethylene gas, activated carbon, agricultural products, paperboard, corrugated board box

A coal mine multi-point fiber ethylene gas concentration sensor

Spontaneous combustion of the coal mine goaf is one of the main disasters in the coal mine. The detection technology based on symbolic gas is the main means to realize the spontaneous combustion prediction of the coal mine goaf, and ethylene gas is an important symbol gas of spontaneous combustion in the coal accelerated oxidation stage. In order to overcome the problem of current coal ethylene detection, the paper presents a mine optical fiber multi-point ethylene concentration sensor based on the tunable diode laser absorption spectroscopy. Based on the experiments and analysis of the near-infrared spectrum of ethylene, the system employed the 1.62 μm (DFB) wavelength fiber coupled distributed feedback laser as the light source. By using the wavelength scanning technique and developing a stable fiber coupled Herriot type long path gas absorption cell, a ppm-level high sensitivity detecting system for the concentration of ethylene gas was realized, which could meet the needs of coal mine fire prevention goaf prediction.

SnO2 Nanoparticle‐Based Passive Capacitive Sensor for Ethylene Detection

A passive capacitor‐based ethylene sensor using SnO2 nanoparticles is presented for the detection of ethylene gas. The nanoscale particle size (10 nm to 15 nm) and film thickness (1300 nm) of the sensing dielectric layer in the capacitor model aid in sensing ethylene at room temperature and eliminate the need for microhotplates used in existing bulk SnO2‐resistive sensors. The SnO2‐sensing layer is deposited using room temperature dip coating process on flexible polyimide substrates with copper as the top and bottom plates of the capacitor. The capacitive sensor fabricated with SnO2 nanoparticles as the dielectric showed a total decrease in capacitance of 5 pF when ethylene gas concentration was increased from 0 to 100 ppm. A 7 pF decrease in capacitance was achieved by introducing a 10 nm layer of platinum (Pt) and palladium (Pd) alloy deposited on the SnO2 layer. This also improved the response time by 40%, recovery time by 28%, and selectivity of the sensor to ethylene mixed in a CO2 gas environment by 66%.

Merging ethylene NDIR gas sensors with preconcentrator-devices for sensitivity enhancement

Automated and reliable measurement of low concentrations of ethylene gas in ambience during transport of fruits is of great interest in fruit logistics. Knowledge about the ethylene concentration can be used for ripeness and quality prediction as well as for new logistic approaches like FEFO. One suitable approach is the use of non-dispersive-infrared detectors because of their robustness and selectivity. The main disadvantage of those detectors is limited sensitivity. In this paper such a measurement system is presented. To overcome sensitivity limitations, the system was combined with an ethylene preconcentrator to increase the system sensitivity indirectly by using adsorption effects on graphitized carbon. This provides the possibility to measure ethylene concentrations below the measurement limit of the NDIR-detector.

Merging ethylene NDIR gas sensors with preconcentrator-devices for sensitivity enhancement

Automated and reliable measurements of low concentrations of ethylene gas in ambience during transport of fruits are of great interest in fruit logistics. Knowledge about the concentration can be used for ripeness and quality prediction as well as for new logistic approaches. Here it makes sense to use non-dispersive-infrared-sensors as autonomous ethylene measurement systems because of their robustness and selectivity. In this paper such a measurement system is presented. It measures ethylene down to 10 ppmv. To overcome sensitivity limitations, the system was additionally combined with an ethylene preconcentrator to increase the system sensitivity down to the ppbv region indirectly by using adsorption effects on graphitized carbon.

A Chipless RFID Sensor System for Cyber Centric Monitoring Applications

A chipless RF identifiction (RFID) sensor system platform consisting of passive chipless RFID sensor tags and specialized reader has been developed for cyber centric monitoring applications. The sensor tags are fabricated on a flexible substrate, and the tag identification (ID) generation circuit consists of microstrip transmission lines. Two tag configurations are presented. The first configuration (conf-I) consists of an antenna and an integrated sensor. The second configuration (conf-II) consists of an antenna, ID generation circuit, and a sensor. The specialized reader system, consisting of an analog reader section and an on-board computer system, communicates with the sensor tags using load modulated backscattered communication techniques, at 915-MHz carrier signal. The reader, receiving the ID code generated by a tag, constructs it into a standardized RFID data frame, suitable for cyberspace information exchange. The developed system has been tested for wireless monitoring of ethylene gas. Using a conf-I tag, demodulated voltage change of 3.05 mV is observed at the reader, when the ethylene gas concentration changes from 0 to 100 ppm. The presented conf-II tag prototype allows generation of eight different ID codes and an average of 26.51deg/pF phase change in the backscattered signal, when the load capacitance (sensor) of the tag changes between 1-5 pF.

1-Methylcyclopropene Counteracts Fry Color Darkening Attributable to Carbon Dioxide and Ethylene Interaction

The fry color of potatoes (Solanum tuberosum L.) stored for processing remains an important quality characteristic that can be affected by many factors, including ethylene gas from various sources and the interaction of very low concentrations of ethylene gas (less than 1 μL·L−1) and accumulated CO2. Because previous studies show that pretreatment with 1-methylcyclopropene (1-MCP) can substantially reduce fry color darkening attributable to applied ethylene, we hypothesized that 1-MCP could also reduce fry color darkening attributable to the interaction of ethylene and CO2. Trials were conducted over two storage seasons, using ‘Russet Burbank’ tubers, either untreated or treated with 0.5 μL·L−1 ethylene gas ± 2 kPa CO2 and ± 1-MCP. Tubers exposed to ethylene gas had darker fry color than untreated tubers, whereas the fry color of tubers exposed to ethylene plus CO2 was darker still. However, the fry color of tubers pretreated with 1-MCP was as light as that of the untreated tubers. This provides a potential new tool for the potato industry to manage potato fry color of stored processing potatoes.

Cambial activity in 'normal' spruce Picea abies Karst (L.) and snake spruce Picea abies (L.) Karst f. virgata (Jacq.) Rehd in response to ethylene

The concentration of ethylene accumulating in the outer portion of sapwood in stems was measured in normal spruce and snake spruce from March to July in 1997. During growth, the endogenous levels of ethylene were higher in stem sapwood in the common spruce than in the snake spruce. Dormant cuttings of both varieties were treated with various concentrations of ethylene gas or Ethrel and maintained for up to 5 weeks under environmental conditions favourable for growth. After harvest, cambial activity, measured as the number of tracheids formed, was measured both at, above and below the application point of ethylene gas or Ethrel. Both treatments stimulated cambial activity at the point of application with the effect being more pronounced in the snake spruce cuttings. The role of ethylene in the regulation of cambial growth rate in normal and snake spruce cuttings is evaluated.

V–E energy transfer in ethylene and alkali gas mixtures using infrared multiphoton excitation

V–E energy transfer in C2H4 and alkali gas system C2H‡4+M→C2H4+M*(M=Na, K, Rb, and Cs, ‡ denotes high vibrationally excited state, * denotes electronically excited state) was investigated by using IR multiphoton excitation of C2H4 and probing the atomic fluorescence due to the above process. The atomic decay rates were determined as a function of alkali or ethylene gas concentration. The rate constants of V–E energy transfer were originally obtained by comparing the decay rate under different experimental conditions with the solution of the set of equations based on a proposed kinetic model. The kinetic information with respect to the inverse E–V energy transfer and the deexcitation process of the highly vibrationally excited state C2H‡4 were also obtained which agreed well with the results obtained from other methods. The large cross sections of the V–E energy transfer and their weak dependence on temperature obtained were interpreted based on a harpooning mechanism.

Ethylene-induced Defoliation in Ficus Species and Ethylene Depletion by Soil Bacteria in Peat-amended Media and in Vitro

Abstract Ficus benjamina L. and F. stricta Miguel. were exposed to various concentrations of ethylene gas and ethephon to determine their sensitivity to defoliation. F. stricta was more sensitive to ethephon, whereas F. benjamina was more sensitive to ethylene gas. Plants growing in medium exposed to ethylene gas depleted ethylene from the ambient atmosphere. Double-autoclaving the peat : perlite growing medium prevented ethylene depletion, indicating soil microbes as the source of depletion. Bacterial isolates from the medium depleted ethylene in vitro; fungal isolates did not deplete ethylene. The eight species of bacteria isolated into pure culture depleted 9% to 46% of the ethylene from the flask atmosphere over 5 days, with two Enterobacter spp. and one Pseudomonas sp. being the most effective depleters. Chemical name used: (2-chloroethyl)phosphonic acid (ethephon).