Wax Removal Research Articles

Efficient catalyst regeneration through solvent-based wax extraction for Co/Al2O3 Fischer-Tropsch catalysts

The regeneration of Fischer-Tropsch (FT) catalysts plays a crucial role in sustaining their catalytic activity and longevity in sustainable production processes. This research investigates the effectiveness of various solvents, including n-hexane, n-heptane, toluene, xylene, and the liquid fraction of FT products (LF-FT), for catalyst regeneration and extracting wax from the 15 wt%Co/Al2O3 catalyst. Toluene, with a unique combination of key parameters such as polarity, solubility, boiling point, aromatic structure, and chemical interactions, exhibited the highest wax removal efficiency of 90.6%. However, due to its 41 °C lower boiling point compared to toluene and very similar wax removal efficiency, n-hexane appears as a more energy-efficient and cost-effective option for this process. The regenerated catalysts showed comparable characteristics, including the textural properties (surface area, pore size, and pore volume), crystallinity, and reducibility, to fresh catalysts. The slightly lower reduction temperature in the regenerated catalyst indicates a higher possibility for the formation of cobalt active sites during the catalyst reduction process with hydrogen, leading to an increased potential for higher catalytic activity. The LF-FT, comprising paraffins, iso-paraffins, olefins, napthenes, and aromatics, provided a unique combination of aliphatic and aromatic moieties, enhancing the solubility of both polar and nonpolar components in FT wax and improving the wax removal efficiency to 91.5%. The higher boiling point and operating temperature of the LF-FT also contributed to its better performance. Efficient separation of hydrocarbons from solvents allowed for solvent reusability in subsequent FT wax removal cycles, making it advantageous for large-scale applications.

Estimation of critical thickness of wax deposits during mechanical removal from high water cut oil well

The formation of wax deposits in oil wells is one of the most costly problems for oil production companies. The most common method of removing deposits is mechanical removal with a scraper. However, there is still no understanding of the critical conditions for wax removal. As part of this work, the authors consider the process of mechanical removal of wax from a high water cut oil well. The work carried out studies to assess the influence of the aqueous phase on the intensity of wax formation and simulated the thickness of wax deposits during the period of their removal under field conditions. It was found that the aqueous phase is actively included in the volume of deposits, increasing the rate of wax formation and their density. Based on the modeling, it was concluded that in wells with a low inclination, the critical thickness of wax deposits is 0.18 mm. The effect of water cut in production on the critical wax thickness has not been found, while with increasing well flow rate the critical thickness decreases. The work performed is extremely useful for understanding the process of mechanical removal of wax deposits from oil production wells producing water-cut oil.

Wax on the surface of Phragmites australis leaves provides enemy-free space for the aphid Hyalopterus pruni

Abstract The waxy layer on leaf surfaces may restrict the range of arthropod species that can grip the leaf, thus affecting biological interactions. Here, we report that the wax on the leaf surface of Phragmites australis leaves provides enemy-free space for the aphid Hyalopterus pruni. In our experiment, aphids had higher survival rates on Ph. australis leaves than on Prunus mume leaves in the presence of ladybirds. In addition, removal of wax from the surface of Ph. australis leaves enabled ladybugs to grip the surface of Ph. australis leaves and decreased the survival rate of aphids. These results indicate that the leaf wax of Ph. australis provides enemy-free space for H. pruni by inhibiting ladybird adhesion.

Prevalence of Cerumen Impaction and Associated Factors Among Primary School Pupils at an Urban District in Northern Tanzania.

Cerumen impaction is a public problem of great concern due to associated hearing impairment. Despite cerumen impaction being one of the commonest causes of hearing loss among primary school children, there is no any published study to date from northern Tanzania focused on this topic. This study aimed to address this gap. A cross-sectional study design was used where 307 primary school pupils were recruited using a multistage cluster sampling technique and it was conducted from January to July 2023. Data was collected using Swahili translated semi-structured questionnaires. The prevalence of cerumen impaction was 10.7% with the right ear being mostly affected (57.6%). A statistically significant association was found between prevalence of cerumen impaction and mother's education level though no association was found between sex, residence, father's education level and mother's occupation status. Predisposing factors like history or presence of ear infection, habit of cleaning ears and using hearing aids or earphones showed a statistically significant association The commonest clinical presentation was otalgia (36.4%) and washing ears with water (71.5%) was the commonly applied method of cleaning the ears apart from hospital based interventions. The commonest method of wax removal for those who visited health facilities was ear syringing (42.9%). Lesser prevalence of cerumen impaction was found in this study though majority had previous history of impacted wax. Cotton bud was the commonest predisposing factor for cerumen impaction. The commonest clinical presentation among those with impacted cerumen was otalgia though some pupils reported asymptomatic cerumen impaction.

Research on the Calculation Method for the Wellbore Temperature of Hot Nitrogen Gas Circulation Wax Removal and Plug Removal in Offshore Oil Fields

The problem of wax deposition widely exists in offshore oil fields; waxing of the oil tubing will lead to a reduction in the cross-sectional area of the flow and, in serious cases, the flow path will be blocked, causing the well to stop production. In order to cope with this problem, a thermal dynamic wax removal method has emerged in recent years that utilizes hot nitrogen gas circulation between the oil tube and annulus to raise the temperature of the oil tube to achieve the purpose of wax removal and plug removal and is quick and easy to operate. Unlike conventional wellbore temperature calculation methods, the wellbore temperature field under hot nitrogen circulation conditions is influenced both by the reservoir temperature gradient and the hot nitrogen injection temperature, injection pressure, and injection rate. In this paper, a temperature calculation model for a wellbore considering both annulus injection temperature and tubing temperature and their interactions is modeled, which can consider the effects of different hot nitrogen injection temperatures, injection rates, and injection pressures. The model is used to calculate the temperature distribution for different injection parameters in order to ensure that the tubing temperature is higher than the wax precipitation temperature and that the annulus temperature is not higher than the maximum temperature resistance of the rubber in the packer. The study provides a design method for wax removal and plug removal with hot nitrogen gas circulation.

SEM & FTIR Analysis of Rice Husk to Assess the Impact of Physiochemical Pretreatment

The objective of this research is to obtain FTIR and SEM profile of native and pulverized rice husk in order to understand its feasibility for further enzymatic digestion. Pretreatment is one of the pivotal processes in utilizing lignocellulosic biomass for producing bioethanol. An ecofriendly system only allows mild pretreatment strategies for industrial bioethanol production. The steam explosion pretreatment process is reported to be efficient using rice husk for these procedures with the use of mild acids or bases. In the current work, pretreatment method like steam explosion pretreatment method was used with NaOH and HNO3 to degrade the complex structures and release the sugars entrapped within lignin. The pretreatment effect on the matrix of husk cell-wall and its constituents are characterized microscopically and spectroscopically by scanning electron microscopy and Fourier Transform Infrared Spectroscopy respectively, in order to comprehend the future possibility of its digestion by cellulase. The crystallinity index of native substrate is very high (0.94 cm-1), which reduced significantly to -0.277 and -0.34 cm-1 when pretreated with 2% HNO3 and 10% HNO3 respectively. The steam explosion pretreatment does not support the degradation of the cellulosic fibrillar arrangement, but causes intense re-localization of lignin. The descriptions of scanning electron microscopy were in agreement with the findings of Fourier Transform Infrared Spectroscopy; the ordered structure generally found in native rice husk was missing, suggesting that the structure of the 2% HNO3 treated rice husk was more amorphous. The fractional removal of hemicelluloses and total removal of wax is the outcome of this research work. Results revealed that steam explosion pretreatment increases the possibility of digestion by enhancing cellulose accessibility through lignin re-localization and a partial elimination of hemicelluloses rather than by cell wall disruption.

SiO2-Based Nanofluids for the Inhibition of Wax Precipitation in Production Pipelines.

Wax deposition in high-wax (waxy) crude oil has been an important challenge in the oil and gas industry due to the repercussions in flow assurance during oil extraction and transportation. However, the nanotechnology has emerged as a potential solution for the optimization of conventional wax removal and/or inhibition processes due to its exceptional performance in the alteration of wax morphology and co-crystallization behavior. In this sense, this study aims to study the performance of two commercial wax inhibitor treatments (WT1 and WT2) on the wax formation and crystallization due to the addition of SiO2 nanoparticles. Differential scanning calorimetry experiments and cold finger tests were carried out to study the effect of the WT on wax appearance temperature (WAT) and the wax inhibition efficiency (WIE) in a scenario with an initial temperature difference. In the first stage, the behavior of both WT in the inhibition of wax deposition was achieved, ranging in the concentration of the WT in the waxy crude (WC) oil from 5000 to 50,000 mg·L-1. Then, NanoWT was prepared by the addition of SiO2 nanoparticles on WT1 and WT2 for concentrations between 1000 and 500 mg·L-1, and the performance of the prepared NanoWT was studied at the best concentration of WIT in the absence of nanoparticles. Finally, the role of the nanofluid concentration in wax inhibition was accomplished for the best NanoWT. Selected NanoWT with nanoparticle dosage of 100 mg·L-1 added to WC oil at 5000 mg·L-1 displays reductions in WAT and WIE of 15.3 and 71.6 for NanoWT1 and -2.2 and 42.5% for NanoWT2. In flow loop experiments for the crude oil at temperatures above (30 °C) and below (16 °C), the WAT value indicates an increase of 8.3 times the pressure drops when the crude oil is flowing at a temperature below the WAT value. Therefore, when NanoWT1 is added to the crude oil, a reduction of 31.8% was found in the pressure drop in comparison with the scenario below the WAT value, ensuring the flow assurance in the pipeline in an unfavorable environment. Based on the pressure-drop method, a reduction greater than 5% in the wax deposit thickness confirms the wax deposition inhibitory character of the designed NanoWT.

Physiochemical investigation of untreated and alkali treated agave plant fiber

Plant fiber-reinforced composites occupied an important role in the production of bio-degradable goods. Polymer composites with synthetic fiber as reinforcement produce adverse effects on the environment because of their higher decomposition rate. In most cases, natural fiber reinforced composites were used in the automotive industry to make body door parts, interior panels, bumpers, dashboard units, two-wheeler mudguards, doom parts, etc. During the reinforcement of fiber with matrix there are a lot of factors say moisture absorption, interfacial bonding, etc., involes in affecting the composite. So in order to reduce those risk factors, natural fiber has to be pre-treated before involving it in reinforcement. Chemical treatment was useful in the removal of impurities, wax, and other unwanted substances on the outer surface of the fiber. This paper deals with the novel study in identifying the optimum concentration of alkali solution for suitability in making the two-wheeler mudguard. Pre-treatment involves soaking of agave fiber at different concentrations of sodium hydroxide (NaOH) solution say 2, 4, 6, and 8%(w/v) for about 3 h. The impact on different concentrations of NaOH treatment was confirmed with the change in the diameter of the fiber using a digital microscope, chemical composition analysis was performed, a single fiber tensile test, and a scanning electron microscope was also conducted. From the test results, it was noted that sodium hydroxide treatment removes unwanted substances present on the fiber surface. Meanwhile, when the concentration of the sodium hydroxide was increased the fiber got damaged due to the abrasion of cellulosic constituents that reduces the property of fiber, making it unsuitable for reinforcement. At the end of this study, 4% of NaOH-treated fiber showed better results from all tests and that was used for making a mudguard.

Visualization of thermal removal mechanism of paraffin deposits: Providing guidelines for minimum temperature requirements

Active heating is increasingly explored as a cost-effective strategy for managing wax deposition in production flowlines. While active heating is widely used across the industry to maintain or raise the temperature of the production fluid above the wax appearance temperature (WAT), there exists no clear understanding of the mechanism and guidelines for wax removal using active heating technology. Currently, operators tend to aim for temperatures far above the WAT to ensure removal. There is an interest in the finding of the actual temperature targets. If these can be defined, lowering current operational targets, reducing energy requirements, and therefore reducing costs becomes possible. To this end, a novel dynamic microscopic visualization technique is employed to understand the removal mechanism as the deposit is exposed to varying removal temperatures. As the removal temperature is raised to WAT + 54 % the deposit underwent 100 % removal, while increasing it to WAT + 12 % resulted in 97 % removal throughout the experiment. Raising the removal temperature to WAT − 7 % resulted in no removal.A mechanism for thermal removal is proposed based on visual evidence for a counter-diffusion process preceding detachment. During removal, the deposit becomes less dense with wax crystals over time, lowering its yield stress until a point where shear forces from the flow can strip and carry away large chunks of wax deposit. Higher removal temperatures require less time for detachment to occur. Increasing the coolant temperature to WAT + 54 % required only 8 min for detachment to occur, while increasing it to WAT + 12 % extended this time to 46 min. Deposit yield stress and fluid shear stresses are used to determine the minimum removal temperature for active heating. The pipe wall needs to be raised at least to this temperature for removal to occur. The higher the wall temperature is raised above this value, the faster the removal will occur. Understanding this mechanism can inform the development of accurate removal models and improve production economics.

A Method for Epicuticular Wax and Contaminant Removal from Herbarium Specimens for Scanning Electron Microscopy

Abstract We describe a method for cleaning leaf epicuticular wax and contaminants from herbarium specimens in preparation for scanning electron microscopy. Specimens are rinsed in chloroform, heated at 50°C for 8 hrs, ultrasonicated in 70% ethanol, and subjected to critical-point drying. This method helps preserve and reveal the surface details of specimens that are heavily covered with epicuticular wax and contaminants, making many morphologically and functionally important details readily visible. We tested our method by using it to clean herbarium specimens and comparing the results with those obtained using three other chemicals: acetone, xylene, and 1:1 acetone:xylene, confirming that chloroform treatment was the most effective.

Experimental study on the effect of asphaltenes on wax removal rate

ABSTRACT Asphaltenes are the most polar component with the largest average molecular mass in crude oil, and they are important to investigate the effect of the interfacial activity of asphaltene on the efficiency of wax removal. In order to investigate the effect of in-situ asphaltene utilization on the wax removal rate, a dynamic wax removal device is developed. The effects of the asphaltene mass fraction, the water temperature, the cold finger temperature, and the rotation speed of a rotating cylinder on the wax removal rate of the pipeline at a specific mass fraction are investigated. The results show that the wax removal rate increases and then decreases with the increase in asphaltenes mass fraction, and the maximum rate is 3.5%. The wax removal rate considerably increases at 3.5% asphaltenes mass fraction with the increase in the water temperature; the increase in cold finger temperature and the rotation speed of rotating cylinder also contributes to the wax removal increase in rate. The optimal wax removal rate was 5.8 g/min by orthogonal test. In addition, the wax removal rate increased significantly with the increase in water temperature; the increase in cold finger temperature and the increase in rotor speed also contributed to the increase in wax removal rate.

Hazard identification and the prevalence of occupational skin disease in Indonesian Batik workers

Batik, a resist-dyeing technique to decorate a special cotton fabric, has been practiced for centuries in Indonesia. Unfortunately, as an informal enterprise, batik industry activities lack work safety and health regulations. This study aimed to identify potential health hazards, including inventorying the chemicals to which the workers are exposed, the PPE profile, and investigating the prevalence of occupational skin diseases (OSD) in the batik industry. A cross-sectional study and an inventory of exposure to the chemicals were done in traditional batik workplaces in 5 districts in Yogyakarta province, Indonesia. The chemicals were classified as potential sensitizers/irritants, and the workers were examined and interviewed using the Nordic Occupational Skin Questionnaire-2002/LONG. Of 222 traditional batik workers, OSD were diagnosed in 61 (27.5%) workers, with occupational contact dermatitis was the most common OSD encountered (n = 23/61; 37.7%) (allergic contact dermatitis n = 7/23; irritant contact dermatitis n = 16/23). A smaller portion of other OSD was also encountered including callus, miliaria, and nail disorder (9%, 6.3%, and 5.9%, respectively). During each step of the traditional batik manufacturing process, the workers are exposed to substances that act as irritants and/or as potential contact allergens. However, only one-fourth of the workers used PPE regularly, particularly during the coloring process and wax removal (wet processes). Traditional batik manufacturing process exposes the worker to various physical and chemical hazards, resulting in a high prevalence of occupational skin diseases, especially contact dermatitis among the employees.

Ear wax removal: inequities in access

Practice NursingVol. 34, No. 3 EditorialEar wax removal: inequities in accessDebbie BrownDebbie BrownEditor-in-ChiefSearch for more papers by this authorDebbie BrownPublished Online:3 Mar 2023https://doi.org/10.12968/pnur.2023.34.3.93AboutSectionsView articleView Full TextPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareShare onFacebookTwitterLinked InEmail View article References Brown D. To irrigate or not? Practice Nursing. 2021;32(12):463. https://doi.org/10.12968/pnur.2021.32.12.463 Link, Google Scholar FiguresReferencesRelatedDetails 2 March 2023Volume 34Issue 3ISSN (print): 0964-9271ISSN (online): 2052-2940 Metrics History Published online 3 March 2023 Published in print 2 March 2023 Information© MA Healthcare LimitedPDF download

Sustainable and cleaner approach for paraffin wax treatment via CO2-induced polarity transformation of switchable solvents

Paraffin wax has caused obvious detrimental consequences to the extraction for fossil fuels, and posed environmental challenge due to the absence of cleaner methods for paraffin wax removal. A cleaner and sustainable approach for paraffin wax removal was developed using the switchable polarity solvents (SPS). Three SPS with low polarity, including dipropylamine (DPA), ethylbutylamine (EBA), and dibutylamine (DNBA) were selected for paraffin wax removal. Compared with bubbling CO2 into SPS straightway, the transformation of the polarity quantified by normalized polarity energy confirms the addition of water is benefit to enlarge the polarity scope. Paraffin wax is removed at the initial state and separated at the final state by CO2-induced polarity transformation of SPS. The dissolution rates for paraffin wax of DPA and EBA reached 0.071 g/min and 0.062 g/min, which surpassed that of traditional solvents, such as o-xylene (0.045 g/min) and Petroleum ether (0.017 g/min), indicating that these selected SPS is suitable for paraffin wax removal. The paraffin wax dissolution behaviors of SPS can be accurately matched using modified Apelblat models with root-mean-square deviation of 1.085%. With the addition of water, more than 99% of paraffin wax is separated from DPA and EBA by introducing CO2 within 10mins, which is a better alternative method for energy-intensive distillation process. The introduction of water is indispensable for improving the separation efficiency, since it enlarged the polarity difference between solvents and paraffin wax. The thermal behavior of separated paraffin wax detected by Differential Scanning Calorimetry remained steady, and there were negligible residual solvents detected indicate the feasible separation of paraffin wax. Both SPS and water are recovered upon N2/80 °C, which retain good recyclability for paraffin wax removal. These findings confirms the applicability of SPS in the sustainable and cleaner removal of paraffin wax. The use of SPS provides an alternative and promising approach for paraffin wax removal for ensuring the demands of low-energy consumption and environment.

Modeling and experimental study on deformation prediction of thin-walled turbine blades during investment casting process

Due to variable cross-sections and a thin-walled structure, gas turbine blades have stringent dimensional, and geometrical tolerance requirements. Single-crystal hollow blades are manufactured using the following investment casting processes: ceramic core preparation, wax injection, ceramic coating, wax removal, metal casting, and finishing. The main causes of the final casting deformation are wax pattern deformation, core deflection, and metal solidification warpage. This paper proposes a numerical simulation method to predict the deformation of the wax pattern, core deflection, and the directional solidification (DS) process of large single-crystal blades. Additionally, it investigates the displacement field and the influence of casting process parameters on dimensional accuracy. Three groups of DS process parameters were selected for experiments, and the deformation prediction was in agreement with the experimental results. The selected blade section deformation is the smallest when the pouring temperature is 1530°C and the withdrawal rate is 5 mm/min. The proposed finite element model is efficient to predict the deformation in all the investment casting processes, providing geometric guidance for the control of the dimensional accuracy of the turbine blade.

A comprehensive method for determining the dewaxing interval period in gas lift wells

The gas lift method is an artificial lift method of well production using the energy of compressed gas injected into the well to lift the reservoir fluid to the surface. The formation of paraffin deposits has remained one of the critical oil production problems due to the growing percentage of hard-to-recover reserves in the overall structure. This complication is also typical for many oil and gas fields in Vietnam, such as the White Tiger, White Bear, and Dragon fields. Wax deposit formation negatively affects the operation of individual production wells and the development of the field as a whole, which leads to a decrease in productivity and the need to take measures to remove paraffin deposits, subsequently increasing the downtime period of the well. In order to ensure stable production of highly paraffinic oil, it is necessary to take measures to dewax wells systematically. The frequency of wax removal operations depends on the intensity of the wax formation, which is determined by various technological, technical, and geological factors. The interval between dewaxing operations is called the dewaxing interval period (DIP). This value is an important technological parameter and characterizes the efficiency of a well’s operation. In this study, a comprehensive method has been developed to determine the dewaxing interval period (treatment interval) for gas-lift wells when the formation of wax deposits has occurred. The optimal dewaxing interval period is suggested to be determined by the change in the liquid well flow rate at the point when it falls by 20% from the initial value. In addition, a mathematical model of the time-dependent wax thickness, taking into account the heat and mass transfer laws and the laboratory results using the Cold Finger method, has also been developed. The proposed model for determining the dewaxing interval period was applied to an oil well in Vietnam. The DIP prediction model gave a similar value to the actual DIP field data (6.67 and 6 days, respectively). The obtained results showed that the model had proven its accuracy following the results of a comparison with the field's data of dewaxing operations.

Jednostavno rešenje za problem selektivnosti prilikom GC/MS analize boskalida u jabukama

Gas chromatography coupled with mass spectrometry (GC/MS) is commonly applied in pesticide residue analysis in fruit samples. Sample extracts with a high quantity of co-extractives represent a standing problem in such analysis. Co-extractives mainly affect the GC inlet and the chromatographic column performance. Waxes, identified as the main co-extractives from the apple matrix, represent a significant problem in GC/MS analysis due to low volatility and non-polarity. The purpose of this investigation was to develop and evaluate a simplified method for the analysis of boscalid in apples, with the removal of wax compounds as the main outcome. The waxes herein represented a problem not only for the performance of the instrument but directly for the determination of the boscalid since they co-eluted with the pesticide. The applied method included a combination of solvent exchange and low-temperature precipitation and resulted in complete wax removal.

Foliar Residual Toxicity of Insecticides to Brassica Pests and Their Natural Enemies.

Overuse of pesticides can result in the development of resistance, secondary pest outbreaks, and pest resurgence due to a reduction in natural enemies. The present study compares the residual toxicity of lambda-cyhalothrin, a relatively nonselective insecticide, with abamectin, indoxacarb, and spinosad, compounds which have been reported to be less harmful to arthropod natural enemies. Two key cosmopolitan pests of crucifer crops, (Plutella xylostella) and (Myzus persicae), and two of their respective hymenopteran parasitoids, (Cotesia vestalis) and (Aphidius colemani) were used as representative pests and natural enemies. The pyrethroid lambda-cyhalothrin was found to be the most persistent toxicant against both pest and both parasitoid species tested, while the lactones abamectin and spinosad were the least persistent toxicants. A leaf wax stripping technique was used to compare the contact toxicity of insecticide residues against adult C. vestalis and A. colemani in the epicuticular wax layer. For each compound, removal of epicuticular wax reduced the 24 h residual toxicity (LC50) of fresh deposits (day 0) by about an order of magnitude against C. vestalis. A second residual toxicity experiment showed that removal of epicuticular wax significantly reduced the residual toxicity of each compound against A. colemani at 0, 7, and 14 d after application, with little or no detectable residual activity for the oxadiazine indoxacarb or abamectin/spinosad respectively after 14 d. The present data supports the view that in addition to the intrinsic toxicity of insecticides to natural enemies, differences in their persistence as foliar residues should also be considered in IPM systems.

Optimization of Acid-Assisted Extraction of Pectin from Banana (Musa Acuminata) Peels by Central Composite Design

<p>Pectin extraction from various fruits and its application in food products have been debatable issues for ages. We conducted our research on the biomass wastes of the food industry, primarily banana (Musa Acuminata) peels, in order to develop a modified procedure for the effective extraction of this substance. Banana peels were used to extract pectin using the alcohol precipitation technique. This investigation's goal is to contrast yields of pectin from ripe banana peels by varying the conditions of temperature, time, and pH. Pectin was extracted from banana peels with hydrochloric acid and a central composite design was used to determine the effects of pH (1.5–2.5), extraction temperature (40–85°C), and time (90–240 min) on the yield and purity. The provenience procedure was improved by the removal of phenols, flavonoids, fats, oils, wax, and pigments well before the extraction of pectin. It results in better purity and high yield of Pectin. Soxhlet extraction was initially used to remove them followed by maceration of Alcohol Insoluble Residue (AIR). An FTIR spectrum of the extracted pectin was compared with the commercial pectin and results are reported. Different techniques and methodology are also discussed in this study.</p>

Role of epicuticular wax involved in quality maintenance of table grapes: Evidence from transcriptomic data

Epicuticular wax is the natural protective coating of fruit which is vulnerable to insect, microbe, pollutant, or scrape incidence. Herein, the epicuticular wax of table grapes was removed to mimic the natural wax loss/damage, and the quality attributes of fruit were investigated. Results demonstrated wax removal triggered fruit weight loss, softening and browning during storage. Transcriptomic analysis showed 623 up-regulated and 573 down-regulated genes, focusing on polyphenols biosynthesis, cell wall metabolism, photosynthesis, and so forth. Up-regulated expression levels of genes involved in chlorophyll degradation contributed to visible browning; and the facilitated cell wall collapse observed by transmission electron microscope (TEM) and doubled pectinesterase expression were illustrated in fruit softening. Taken together, our findings provide novel insights into the role of epicuticular wax as the natural coating in quality maintenance of table grapes from the transcriptomic evidence.