Dry Method Research Articles

Electrochemical Investigation of Moisture Byproducts in Molten Calcium Chloride

Residual water in molten CaCl2 reacts to form different byproducts, such as HCl, which can impact the corrosivity of the salt and efficiency of electrochemical operations, such as electrolytic oxide reduction and electrorefining. The ability to detect and quantify these byproducts electrochemically can provide feedback on the efficacy of vacuum drying and other purification methods, as well as the impact of these byproducts on process operations. An electrochemical signal’s association with the production of H2 is verified and characterized using cyclic voltammetry (CV) and residual gas analysis. CV estimated a 2-electron exchange process associated with H2 production. CV detected trace quantities of an oxidized species containing hydrogen in the salt on the order of 10 ppm. Different salt handling methods were compared for their impact on the hydrogen electrochemical signal. It was found that 30 min of exposure of CaCl2 in a beaker to low-humidity air (<20%) had minimal impact on the H2 production signal.

Green and renewable thermoplastic polyvinyl alcohol/starch blend film fabricated by melt processing

In this study, the PVA/starch blend films were prepared by dry melting method. The microstructure showed that the starch existed in the continuous PVA matrix in granular structure. When the amount of starch was 30 wt%, the tensile strength increased from 12.8 to 14.7 MPa, and the elastic modulus increased from 15.4 to 20.5 MPa, and the water absorption increased by about 2 %. The addition of starch increased the Tmax by 8.1–29.64 °C compared to pure PVA. Considering the mechanical, hydrophilic and optical properties of the blend films, PVA/starch at 7:3 was the most promising packaging material. Notably, the blend films exhibit great reusability and renewability. Overall, these findings highlight the potential of PVA/starch blend films as environmentally friendly materials with enhanced properties.

Innovation in Cassava Bagasse Valorization: Efficiency of Convective Drying Enhanced with Ultrasound and Pulsed Electric Fields.

This research proposes an efficient alternative for dehydrating cassava bagasse to address the inherent challenges in the handling, transportation, storage, and preservation of this agro-industrial residue generated in cassava starch production plants. This residue is characterized by high moisture retention, considerable volume, and hydrophilic nature, complicating conventional drying methods. This study evaluates the impact of emerging ultrasound (US) and pulsed electric field (PEF) technologies prior to convective drying to enhance the dehydration efficiency of cassava bagasse, aiming at its valorization and contributing to the sustainability of the cassava starch industry. The findings reveal that pretreatment with ultrasound (US) and pulsed electric fields (PEF) significantly reduces the drying time of cassava bagasse compared to convective drying alone. With probe ultrasound at 26 kHz for 30 min, the drying time is reduced by 72% (3.83 h vs. 14.0 h); with bath ultrasound at 37 kHz for 30 min, it is reduced by 56.0% (6.16 h vs. 14.0 h); and with PEF at 7.5 kV/cm for 30 min, it is reduced by 52.4% (6.66 h vs. 14.0 h). These emerging technologies increased the effective diffusivity and modified the molecular structure of the bagasse, thereby improving mass transfer and drying process efficiency. These results are particularly useful for developing more efficient and sustainable strategies for drying agricultural by-products, with direct implications for the post-industrial treatment of agro-industrial residues with high water content.

Assessing health hazards of dried fish consumption from coastal markets in a developing nation

Dried fish is a crucial protein source for coastal populations in developing countries, but it is becoming increasingly contaminated with heavy metals due to the use of traditional drying methods. This study assessed Cd, Cr, Pb, and Mn levels and their health risks in four commonly consumed dried fish species (Harpodon nehereus, Trichiurus lepturus, Penaeus affinis, and Amblypharyngodon mola) from the central coast of Bangladesh. Results showed Mn levels (17.47 ± 4.69 mg/kg) exceeded FAO limits (4.35 mg/kg), with the highest concentrations in H. nehereus. Cd levels (0.24 ± 0.16 mg/kg) in A. mola were also above safety thresholds. Lead was found in all species except P. affinis, with the highest concentration in A. mola (0.432 ± 0.06 mg/kg), which was within safe limits. Risk assessments revealed higher health risks for children, with elevated Target Hazard Quotient (THQ) and Hazard Index (HI) values compared to adults. H. nehereus had the highest THQ values for Cr (0.0014 mg/kg) and Mn (0.00044 mg/kg). Multivariate analyses indicated contamination from both anthropogenic and natural sources. The study stressed the need for better monitoring and mitigation to ensure the safety and nutritional value of dried fish.

Impact of variety and drying methods on the physicochemical, functional, and thermal properties of Ethiopian potato (Plectranthus edulis) tuber flour

This study aimed to analyse the physicochemical, structural, functional, and thermal properties of flour from two indigenous Ethiopian Potato (Plectranthus edulis) varieties, Chanqua and Loffo, and to compare with wheat flour (WF). The study also investigated how oven and sun drying methods affected the physicochemical properties of the flours. The results demonstrated a significant distinction (p ≤ 0.05) between the flour samples and WF, attributable to variations in both the varieties and the drying methods except that no significant difference in pH was observed due to the varieties, and the fibre and ash content did not vary significantly with the drying methods. The moisture content (MC) of the flours ranged from 5.72 % in oven-dried Chanqua Ethiopian potato flour (OD-CEPF) to 7.53 % in sun-dried Loffo Ethiopian potato flour (SD-LEPF), both of which were lower compared to WF. The protein content varied from 4.47 % (SD-CEPF) to 5.93 % (OD-LEPF). FTIR tests revealed a significant impact on the structural changes, leading to variations in the location and intensity of infrared absorption peaks, particularly in sensitive regions. Whereas, the XRD patterns showed characteristic B-type diffraction, with a relative crystallinity (RC) of 31.97 % in CEPF and 30.53 % in LEPF having a significant difference (p ≤ 0.05) between them. LEPF had better flow properties than CEPF, with lower Hausner ratio (HR) (1.16 vs. 1.25), Carr's index (CI) (14.51 % vs. 20.26 %), and angle of repose (31.00° vs. 34.67°). It also showed significantly higher (p ≤ 0.05) water absorption capacity (WAC), oil absorption capacity (OAC) and swelling power (SP) properties than CEPF. The study also indicated notable distinctions in the thermal and paring properties of flours. The oven drying method was found to be superior in enhancing the physicochemical properties, with LEPF showing better physicochemical, functional, structural, and thermal properties than CEPF.

Physicochemical properties and volatile compounds of Rosa roxburghii fruit using different drying methods

To enhance the drying quality of Rosa roxburghii fruit, this study examined the effects of four methods: Natural Drying (ND), Hot Air Drying (AD), Heat Pump Drying (PD), and Vacuum Freezing Drying (FD). Fresh R. roxburghii fruit was used to assess drying characteristics, color, microstructure, active ingredient content, antioxidant activity, and volatile substances. Drying times for ND, AD, PD, and FD were 28, 7, 6, and 21 h, respectively, with the rate order PD > AD > FD > ND. AD samples showed superior water-binding capacity, solubility, and highest levels of flavonoids and polyphenols, enhancing antioxidant activity. FD samples had the best color performance and retained more intact cell structures and higher Vitamin C and polysaccharide levels. Volatile compounds were analyzed, revealing 45, 60, 61, and 50 compounds for ND, AD, PD, and FD, respectively. AD proved to be the most efficient method, providing optimal drying time, color, active ingredient content, antioxidant activity, and volatile components. This finding offers valuable guidance for selecting a drying method that preserves the quality of dried R. roxburghii fruit and suits industrial production.

Influence of Liquid Nitrogen Pre-Freezing and Drying Methods on the Collagen Content, Physical Properties, and Flavor of Fish Swim Bladder.

Fish swim bladder (FSB) is a type of traditional nutraceutical, but the lack of high-quality drying methods limits its premium market development. In order to obtain optimal-quality dried FSBs from Chinese longsnout catfish, the effects of liquid nitrogen pre-freezing (LNF) and drying on the physical properties and flavor of FSB were evaluated. Four methods were used for FSB drying, including natural air-drying (ND), hot-air-drying (HD), LNF combined with freeze-drying (LN-FD), and LNF combined with HD (LN-HD). Color, collagen content, rehydration ratio, textural properties, and flavor characteristics (by GC-IMS, E-nose, and E-tongue) were measured to clarify the differences among four dried FSBs. The results showed that ND cannot effectively remove moisture from FSB as the final product showed a stronger sourness in taste. HD led to a decrease in the collagen content and the collapse of the fiber structure in FSB. Compared to HD, LN-HD showed a higher collagen content (0.56 g/g) and a different flavor fingerprint. FSB treated by LN-FD had better physical qualities in terms of an attractive color, a high collagen content (0.79 g/g), low shrinkage, a higher rehydration ratio (2.85), and a soft texture, while also possessing richer characteristic flavors. The application of LN-FD may help the optimization of the nutrition level, rehydration ability, mouthfeel, and flavor of dried FSB.

Precipitation measurements experiment using microwave links in Eastern China from October 2020 to March 2022

Precipitation is an important piece of information needed in many areas such as transportation, military and agriculture, and microwave links have proven to be an effective means of acquiring it and can be used as a complementary means for professional precipitation measurement instruments such as rain gauges, weather radar, rain measuring satellites, etc. In this paper, two microwave links (at 26 GHz, both vertically polarised) located across a river in eastern China and a nearby OTT PARSIVEL disdrometer were used to carry out a precipitation observation experiment from October 2020 to March 2022 (March to November 2021 for liquid precipitation, others for possible non-liquid precipitation). The applicability of the dry and rainy period identification methods (standard deviation method and correlation coefficient method) based on this link data is analyzed first. In addition, a wet antenna attenuation correction model based on a Long Short-Term Memory (LSTM) neural network was applied to non-winter precipitation inversion. The results show that the rain rate and cumulative rainfall calculated from the two links are in good agreement with that calculated by the disdrometer data. Furthermore, quantitative inversion of winter precipitation using two microwave links is performed, and the variation characteristics of the link levels during non-liquid precipitation periods are also analyzed.

Acceleration of Final Residual Solvent Extraction From Poly(lactide-co-glycolide) Microparticles.

The removal of the residual solvent dichloromethane from biodegradable poly(D,L-lactic-co-glycolic acid) (PLGA) microparticles was investigated by aqueous or alcoholic wet extraction or vacuum-drying. Microparticles were prepared by the O/W solvent extraction/evaporation method. The solidified microparticles were separated by filtration and the effect of subsequent drying and wet extraction methods were investigated. The residual solvent content was analysed with gas chromatography (organic solvents) and Karl Fischer titration (water). The effect of extraction conditions on microparticle aggregation, surface morphology and encapsulation of the drugs dexamethasone and risperidone was investigated. Residual dichloromethane was reduced to 2.43% (w/w) (20°C) or 0.03% (w/w)(35°C) by aqueous wet extraction. With vacuum-drying, residual dichloromethane only decreased from about 5% (w/w) to 4.34% (w/w) (20°C) or 3.20% (w/w) (35°C) due to the lack of the plasticizing effect of water. Redispersion of filtered, wet microparticles in alcoholic media significantly improved the extraction due to an increased PLGA plasticization. The potential of different extractants was explained with the Gordon-Taylor equation and Hansen solubility parameters. Extraction in methanol: or ethanol:water mixtures reduced residual dichloromethane from 4 - 7% (w/w) to 0.5 - 2.3% (w/w) within 1 h and 0.08 - 0.18% (w/w) within 6 h. Higher alcohol contents and higher temperature resulted in aggregation of microparticles and lower drug loadings. The final removal of residual dichloromethane was more efficient with alcoholic wet extraction followed by aqueous wet extraction at elevated temperature and vacuum drying of the microparticles.

Multilayer Core-Shell Fiber Device for Improved Strain Sensing and Supercapacitor Applications.

1D fiber devices, known for their exceptional flexibility and seamless integration capabilities, often face trade-offs between desired wearable application characteristics and actual performance. In this study, a multilayer device composed of carbon nanotube (CNT), transition metal carbides/nitrides (MXenes), and cotton fibers, fabricated using a dry spinning method is presented, which significantly enhances both strain sensing and supercapacitor functionality. This core-shell fiber design achieves a record-high sensitivity (GF ≈ 4500) and maintains robust durability under various environmental conditions. Furthermore, the design approach markedly influences capacitance, correlating with the percentage of active material used. Through systematic optimization, the fiber device exhibited a capacitance 26-fold greater than that of a standard neat CNT fiber, emphasizing the crucial role of innovative design and high active material loading in improving device performance.

Effect of Various Treatment and Drying Methods of Blood Meal Additive on Fresh State Properties of Grouting Materials

Effect of Various Treatment and Drying Methods of Blood Meal Additive on Fresh State Properties of Grouting Materials

Quality Characteristics, Antioxidant Activity, and Acrylamide Content of Jerusalem Artichokes according to the Drying Method Used

Quality Characteristics, Antioxidant Activity, and Acrylamide Content of Jerusalem Artichokes according to the Drying Method Used

Addressing the Housing Shortage Gap in Nigeria: An exploration of Dry Construction Method

Due to Nigeria's housing shortage, which has been increasing since the late 20th century and currently stands at 20 million units with a loss rate of 780,000 units annually, Nigeria's construction industry has been under pressure to adopt a modern, timely, and premium construction strategy. This research aims to assess how the dry construction method affects mass housing delivery in developing countries, focusing on Nigeria. This study employed a qualitative research approach, conducting semi-structured interviews with sixteen experts and specialists in dry construction and housing who work for various organisations in Nigeria. The study concluded that, although dry construction is infrequently used in developing countries, it offers significant potential for emerging economies and mortgage companies to ensure prompt housing delivery. By reducing building time and improving housing accessibility, dry construction can address the current challenges of delivering affordable housing in Nigeria. To successfully implement the dry construction method in closing the housing deficit in Nigeria, the research also noted that the government must change its priority beyond direct house development towards creating a conducive framework for the industry. This study presents key stakeholders in the housing sector with the information they need to adopt and implement the dry construction method to close the housing gap, especially in Nigeria, which has received less attention.

Modified H‐BEA Zeolites from Fluorinated Silica Slag Waste by Dry Gel Conversion Method for Shape‐Selective Acylation of 2‐Methoxynaphthalene

Modified H‐BEA Zeolites from Fluorinated Silica Slag Waste by Dry Gel Conversion Method for Shape‐Selective Acylation of 2‐Methoxynaphthalene

Evaluation of a Compact Dry Method for Enumerating Bacteria in Contaminated Foods

Evaluation of a Compact Dry Method for Enumerating Bacteria in Contaminated Foods

Evaluation of carob tree (Ceratonia siliqua L.) pods, through three different drying techniques, and ultrasonic assisted extraction, for presence of bioactives

The Mediterranean evergreen carob tree (Ceratonia siliqua L.) produces pods, that may be edible and even therapeutic. The purpose of this study was to determine how ethanolic extracts of carob pods from Morocco, prepared with ultrasonic assistance were affected by microwave (525 °C for 2.5 min), hot air (65 °C for 16 h), and spray drying (input and output air temperatures 180 and 90 °C, respectively, feed flow rate 2.5 mL/min and 5 bars, respectively), in terms of their physicochemical composition and biological activity. Colorimetric techniques were utilized to ascertain the phytochemical contents of pod extracts, whereas standardized in vitro methodologies were employed to quantify the antioxidant and antimicrobial activities. Physicochemical analysis showed that microwaved powders of carob pods presented significantly high (p<0.05) values of L* (62.15±0.06) and b* (21.32±0.06), and lower values of a* (4.16±0.03), as compared to spray dried and hot air-dried powders. Significantly high (p<0.05) amounts of ash (3.92±0.05 %), fat (1.48±0.02 %), fiber (7.45±0.12 %) and protein (2.65±0.06 %) were found in microwave dried powders, followed by spray dried and hot air dried. Significant difference in macro and micro minerals among three powders was also observed, as microwave dried powders were found to be significantly high (p<0.05) in Mg, K, Ca, Fe, Zn and Mn, followed by spray dried powders, whereas hot air-dried powders presented lowest values. Similarly, spectrophotometric analysis of phytochemicals revealed that ultrasonic assisted ethanolic extracts of microwave dried powders were found to be highest in total phenolics, flavonoids and carotenoids, with values 69.18±0.15 mg GAE/g, 34.88±0.08 mg QE/g and 24.05±0.15 mg g-1, respectively. In vitro antioxidant and antimicrobial analysis also showed a similar trend as, extracts of microwave dried powders exhibited significantly high (p<0.05) antioxidant and antimicrobial activities, followed by spray dried and hot air-dried. As compared to hot air and spray drying, the microwave drying and ultrasonic assisted extraction using 70 % ethanol as solvent could be employed on carob pods, to obtain powders and extracts, respectively, with minimum degradation of physicochemical characteristics, and maximum retention of nutritional, bioactive and antioxidant contents. Practical applicationsIn recent years, Morocco has become more and more dependent on the use of carob fruit and its powders. Nonetheless, very rare is known about the composition and carob pod quality of those grown in Mediterranean nations. The current study presents a comparison of the effects of three distinct commercial drying methods on the composition and physical characteristics of flour made from carob pods. The study's findings can also be used to evaluate how well information is composed, processed, and preserved for use in future research and commercial applications.

Advanced Dehydration Techniques Standardized for Flowers of Gomphrena globosa L.

The present experiment was conducted on standardizing dehydration technique for Gomphrena globose flower by using embedding drying methods in room temperature and hot air oven at 55°C was done. The experiment consisted of 10 treatments with 3 replications designed in completely randomized design. Treatments used were as; T1-Boric acid (room temperature), T2-Silica gel (room temperature), T3-Sand (room temperature), T4-Sawdust (room temperature), T5-Cocopeat (room temperature), T6-Boric acid (hot air oven at 55 °C), T7-Silica gel (hot air oven at 55 °C), T8-Sand (hot air oven at 55 °C), T9-Sawdust (hot air oven at 55 °C), T10-Cocopeat (hot air oven at 55 °C). The most reduction in flower fresh and dry weight, measuring 2.36 and 2.12 g, was observed in Treatment T7 (Silica gel with hot air oven at 55°C), where silica gel was employed as the desiccant. The least reduction in flower fresh and dry diameter, measuring 1.92 and 1.81 g, was observed in Treatment T7 (Silica gel with hot air oven at 55°C), where silica gel was employed as the desiccant. The highest drying duration for gomphrena in T3 (Sand) and T4 (Sawdust) treatments was 234.21 and 210.40 hrs at room temperature. The boric acid and silica gel demonstrated outstanding performance in terms of quality parameters, including texture, color, and overall appearance. Among all treatment, embedding drying with silica with hot air oven dehydration at 55°C was found to be best in term of reduction in weight, diameter and overall colour, appearance and texture of Gomphrena globose flowers.

Physicochemical Characterisation of White Pepper: A Comparative Study Between Traditional Sun Drying and Convective Rotary Drum Drying Methods

Drying is a crucial process in preserving the physicochemical qualities of white pepper. This study investigates the impact of two drying processes, namely traditional sun drying (TSD) and rotary drum drying (RDD), on the quality of white pepper. TSD requires three consecutive sunny days for drying, whereas RDD achieves the target moisture content of 12% within a rapid drying time of 120 min. The research employs thermo-gravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy analysis, and scanning electron microscopy (SEM) to analyse the dimensions, thermo-physical profiles, chemical constituents, and microstructure of the pepper samples. RDD, with a drying temperature of 55°C and centrifugation force of 129.7 × g, ensures fast and uniform drying while preserving the physicochemical qualities of white pepper. In terms of physical characteristics, RDD results in larger dried pepper dimensions, measuring 4.56 mm on average, compared to TSD, which measures 4.35 mm. SEM observations reveal varying pore sizes and cracks in both drying methods. Additionally, quality validation conducted by the Malaysian Pepper Board demonstrates that RDD exhibits superior quality compared to TSD. The RDD samples show moisture content, piperine, volatile, and ash percentages of 11.83, 8.18, 2.53, and 0.82, respectively, while the TSD samples show 10.37, 7.16, 2.43, and 0.74. All samples complied with Standard Malaysian White Pepper No. 1 and International Pepper Community Grade 1. Future studies should focus on enhancing different drying methods to achieve efficient white pepper drying while preserving its quality.

Revealing the differences in aroma of black tea under different drying methods based on GC–MS, GC-O

Drying greatly affects the aroma of black tea. In this study, the differences in aroma of black tea under hot-air drying (HD), sun drying (SD), and pan-fired drying (PD) were investigated through quantitative descriptive analysis. Headspace solid-phase microextraction and solvent assisted flavor evaporation combined with gas chromatography–mass spectrometry and gas chromatography-olfactory were used to analyze the overall aroma profile of black tea. Aroma extract dilution analysis and odor activity values revealed that 15 aroma-active compounds led to differences in aroma, namely linalool, geraniol, phenylethyl alcohol, phenylacetaldehyde, (Z) -linalool oxide (furanoid), β-damascenone, dimethyl sulfide, methional, 2-methylbutanal, 3-methylbutanal, methyl salicylate, β-myrcene, hexanal, 1-octen-3-ol, and heptanal. Among them, geraniol, linalool, and methional significantly enhanced the floral and roasty aroma of HD, while hexanal enhanced the green aroma of SD. Finally, our results were validated through aroma recombination and addition experiments. This study provides a theoretical basis for improving the aroma of black tea.

Energy Performance of Zeolite-Based Drying Bead Desiccants Used to Dry Paddy Rice.

This study utilizes differential scanning calorimetry and thermogravimetric analysis to assess the total energy required to regenerate saturated zeolite-based drying beads (DBs) used to dry paddy rice. We quantify the required heat energy for DB regeneration by calculating the area under the curve in a heat flow rate versus time graph, with the end of the regeneration process indicated by stabilization of the DB weight. Our findings suggest that at DB regeneration temperatures ranging from 120 to 350 °C, the process varied from 813 to 22 min, demonstrating that higher temperatures lead to faster regeneration speeds. The total energy used for regeneration showed similar values at 250 and 350 °C, averaging around 2032 and 2136 kJ per kg of dried DB, respectively. Additionally, the study showed that DBs can hold water between 28.7% and 54.4% higher than the manufacturer's specifications, suggesting a reduced quantity of DBs required for effective paddy rice drying. The overall required heat energy for the regeneration process was calculated at 4.86 MJ/kg, with a carbon intensity of approximately 275.61 g of CO2-eq per kg of water removed, resulting in lower values compared to conventional drying methods. The study underscores DB's possibility of lower total energy (thermal and electrical) consumption and greenhouse gas emissions, alongside its flexibility to regenerate with intermittent energy sources.