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In this work, we implemented an off-axis digital holographic microscopy (DHM) setup to study the behavior of liquid drops on nanostructured porous silicon (PS) membranes. When a liquid comes into contact with the PS structure, capillary action and surface tension give rise to imbibition of the liquid into the intricate volume of the pores. At the same time, the vapor field developed around the drop enhances liquid condensation and evaporation into and from the pores. The complex interplay between these phenomena (capillary driven internal flows, condensation, and evaporation) is not yet fully understood but the methods we propose can provide new insights. We demonstrate how DHM allows determining the filling fraction of the porous membrane around drying drops of water and isobutyl alcohol. The phase information obtained from registered holograms provides quantitative information that permits to reconstruct the filling fraction along the porous membrane and its evolution during the drying process. Additionally, relevant parameters such as speed and contact angle during retraction of the drops can be measured. These methods can be further extended to other porous materials, such as porous alumina, micro- and macro-PS, to develop better fluid-dynamic models for describing fluid behavior in highly confined structures. [ABSTRACT FROM AUTHOR]

Porous composite battery electrode performance is influenced by a large number of manufacturing decisions. While it is common to evaluate only finished electrodes when making process adjustments, one must then make inferences about the fabrication process dynamics from static results, which makes process optimization very costly and time-consuming. To get information about the dynamics of the manufacturing processes of these composites, we have built a miniature coating and drying apparatus capable of fabricating lab-scale electrode laminates while operating within an X-ray beamline hutch. Using this tool, we have collected the first radiography image sequences of lab-scale battery electrode coatings in profile, taken throughout drying processes conducted under industrially relevant conditions. To assist with interpretation of these image sequences, we developed an automated image analysis program. Here, we discuss our observations of battery electrode slurry samples, including stratification and long-term fluid flow, and their relevance to composite electrode manufacturing.

Protein is one of the most important components of food which significantly contributes to the structure, functionality, and sensory properties which may affect consumer acceptability of processed products. Conventional thermal processing affects protein structure and induce undesirable degradation of food quality. This review provides an overview of emerging pretreatment and drying technologies (plasma treatment, ultrasound treatment, electrohydrodynamic, radio frequency, microwave, and superheated steam drying) in food processing by assessing protein structural changes to enhance functional and nutritional properties. In addition, mechanisms and principles of these modern technologies are described while challenges and opportunities for the development of these techniques in the drying process are also critically analyzed. Plasma discharges can lead to oxidative reactions and cross-linking of proteins that can change the structure of proteins. Microwave heating contributes to the occurrence of isopeptide or disulfide bonds which promotes α-helix and β-turn formation. These emerging technologies can be adopted to improve protein surface by exposing more hydrophobic groups which restrict water interaction. It is expected that these innovative processing technologies should become a preferred choice in the food industry for better food quality. Moreover, there are some limitations for industrial scale application of these emerging technologies that need to be addressed. [ABSTRACT FROM AUTHOR]

Compared with traditional methods, cavitation-based processing technology has received extensive attention for its low energy consumption and high processing efficiency. The cavitation phenomenon releases high energy due to the generation and collapse of bubbles, which improves the efficiency of various food processing. This review details the cavitation mechanism of ultrasonic cavitation (UC) and hydrodynamic cavitation (HC), factors affecting cavitation, the application of cavitation technology in food processing, and the application of cavitation technology in the extraction of various natural ingredients. The safety and nutrition of food processed by cavitation technology and future research directions are also discussed. The mechanism of UC refers to longitudinal displacement of the particles of the medium induced by ultrasonic waves causing a series of alternating compression and rarefaction of particles, whereas HC occurs when liquid enters a narrow section and undergoes large pressure differentials, both of which can trigger the generation, growth, and collapse of microbubbles. Cavitation could be applied in microbial inactivation, and drying and freezing processing. In addition, cavitation bubbles can have mechanical and thermal effects on plant cells. In general, cavitation technology is a new sustainable, green, and innovative technology with broad application prospects and capabilities. [ABSTRACT FROM AUTHOR]

Temporary rivers are aquatic ecosystems that alternate periods of water flow with dry periods. Diatoms are a group of unicellular microalgae with a high colonizing ability, but little is known about their responses to drying. We carried out different resistance and resilience experiments to evaluate temporal and spatial dispersal capacity of diatoms during the dry period. The resistance was tested experimentally by rehydrating dried biofilms and sediments from temporary rivers, whereas resilience was tested by installing artificial mesocosms along a dry river section. Disconnected pools were also sampled to evaluate their propagule emission capacity. In turn, dogs from the area were sampled to test potential zoochory dispersal capacity. In the resistance experiment, we found living diatoms in all the rehydrated sediments but not in biofilms. Diatoms with mobility traits, high ecological plasticity, and resistance spores presented high, along with typical soil diatoms. In the resilience experiment, all mesocosms hosted living diatoms, which were low-profile, pioneering, and small species. Diatoms found in the mesocosms were also common in the disconnected pools, underscoring the potential role of the latter as a propagule emission zone. Dogs' paws also had living diatoms, which evidences that wild fauna could potentially act as passive diatom vectors. [ABSTRACT FROM AUTHOR]

One of the most crucial factors in determining the consumer acceptability of processed or non-processed food products is their textural characteristics. Textural properties of food items can be created during processing by different techniques, one of which is drying. Drying which is one of the most widely used preservation methods of food products can extend their shelf life and generate unique sensory characteristics. The complicated process of drying is characterized by massive deformations while simultaneously transferring heat and moisture. Texture parameters of the dried food products vary depending on the type of dried food product (fruit and vegetables, grain and cereals, meat and marine), including the final volume, porosity, crust formation, and bulk density. Thus, this review focused on the examination of the textural characteristics of dried food items, the impact of the drying process, and the applied method on textural parameters. This study has also investigated the importance of pretreatment methods in improving the textural properties and quality of dried products. Furthermore, this review also considers the importance of modeling for texture prediction, discussing the different modeling approaches and their principles and applications. Recent applied nondestructive methods for textural analysis have been discussed in terms of application and performance. [ABSTRACT FROM AUTHOR]

Environmental hurdles, in the form of climatic crises, have taken a toll on prevalence of medicinal plants, which served as the foundation for traditional medicine from time immemorial. Drying preserves medicinal plants, and analyzing drying kinetics enhances resource efficiency, including energy and time utilization. This study is the first to examine the drying kinetics of insulin plant leaves. In this study, insulin plant leaves were dried at different temperatures ("40 °C," "50 °C," and "60 °C") to determine optimal drying temperature and assess its mass transfer characteristics. Higher temperatures led to shorter drying times: 530 min at 40 °C, 290 min at 50 °C, and 155 min at 60 °C. Both mathematical models and artificial neural networks (ANN) were used to model drying characteristics, with the logarithmic model showing superior predictive performance among the mathematical models. ANN with the "Levenberg-Marquardt algorithm" and "TANSIGMOID transfer function" gave the best model with better prediction. Comparative analysis confirmed that ANN exhibited superior predictive capabilities. Effective moisture diffusivity followed an upward trend with temperature and 60 °C revealed a diffusivity of 2.4352 × 10−7 m2/s. Activation energy, at 42.124 kJ/mol, underscored utilization of a moderate level of energy to enhance moisture diffusivity within the sample. Color and microstructural analysis also revealed that 60 °C had better color attributes and agglomerative structures. Drying leaves at 60 °C expedited the drying process, enhanced mass transfer, and improved color characteristics. These results provided vital insights for utilizing dried insulin plant leaves in various nutraceutical products. [ABSTRACT FROM AUTHOR]

Purpose: The processing and harvesting of date fruit generates a substantial amount of by-product waste which has significant potential for value addition owing to its rich nutritional profile. Therefore, present study was aimed to develop and assess the effect of incorporation of date powder prepared from processing of immature dates in cake premix by substituting refined sugar. Methods: Immature dates were artificially ripened from Biser to Tamar stage and further these soft dates were used in the production of date powder using cabinet hot air drying (45 ± 5ºC/72 h). Date powder exhibiting good phytochemical and techno-functional properties was substituted at 0%, 25%, 50%, 75% and 100% levels of refined sugar in the cake premix. Results: Compared to control, incorporation of date powder significantly (p < 0.05) improved physicochemical as well as phytochemical, functional properties, textural and mineral profile as confirmed by ICP-AES and FT-IR analysis. Date cake premix formulated with 100% replacement of refined sugar (CP4) achieved highest overall acceptability on a 9-point hedonic scale with the highest fibre (7.54%), ash (3.03%), total phenolics (249.38 mg GAE/100 g), antioxidant activity (61.12%) and reduced total sugars (33.52%) content and hence was selected for storage studies. The storage of CP4 formulation at ambient temperature (25 ± 1ºC) temperature significantly (p < 0.05) influenced the quality attributes of prepared premix. Conclusion: The study showed that date powder can be used as a natural sweetener at 100% levels in cake premix while maintaining desirable texture, functional properties and organoleptic quality. Valorization of immature dates can be a sustainable approach for developing nutritious along with date waste management. [ABSTRACT FROM AUTHOR]

Seasonings like garlic, ginger, and scallion provide spicy and masking flavor or aroma in vegetables. However, the method or technique used for drying these spices can affect the flavor profile. Therefore, this review focuses on vegetable seasonings like ginger, garlic, and scallion, the characteristic flavor of fresh and dehydrated vegetable seasoning, and how drying methods (freeze‐drying [FD], convective hot air drying [HAD], infrared drying, microwave drying [MW]), and other recent dryers (swirling fluidized bed [SFB], pulsed‐vacuum dryer, relative humidity‐convective dryer, etc.) affect the flavor profile of the common vegetable seasonings. HAD increases α‐zingiberene, reduces gingerol, and forms β‐citral and citral in fresh ginger. FD increased sesquiterpenes, retained terpenoids, sulfides, and other volatiles in fresh ginger, and did not produce new volatile compounds (VOCs) in garlic. SFB drying better preserves 6‐gingerol than FD and HAD. MW increases trisulfides and cyclic sulfur compounds in garlic. In general, drying, especially thermal drying reduces the VOCs in fresh garlic, ginger, and scallion and causes the formation of new VOCs. [ABSTRACT FROM AUTHOR]

The study evaluated the combined effects of drying methods (air drying [AD], hot AD [HAD], microwave drying [MD], and freeze‐drying [FD]) and ultrasonication parameters (sonication temperature [STemp]: 40, 50, and 60°C) and heating time (STime: 60 and 120 min) on natural deep eutectic solvent (NADES) extraction of phytochemicals from Amaranthus hybridus stem. Increasing the STemp increased the extraction yield (ECY) of the phytochemicals for all drying methods but increase in the heating time reduced the ECY slightly. MD combined with 60°C ST showed the highest ECY (53%), whereas HAD combined with 40°C ST had the lowest ECY (18%). At 60 min heating time, increasing the ST from 40 to 50°C increased the total phenolic content (TPC) in the extract for most drying methods except MD, and a sonication time of 120 min showed a slightly higher TPC, especially for MD samples. At 60 min sonication, total flavonoid content (TFC, 800 mgQE/g) was highest for AD plus 50°C ST and lowest for AD combined with 60°C (100 mgQE/g), whereas for 120 min sonication, MD and AD with 50°C showed the highest TFC (690 mgQE/g). FD retained better some of the vitamins (thiamine, riboflavin, niacin) but MD retained better vitamin C. The antioxidant capacity was not so much different among the drying methods except for FD, which showed lower values. These results provide a theoretical basis for the synergistic applications of drying and ultrasonication during NADES extraction of phytochemicals from Amaranthus hybridus. [ABSTRACT FROM AUTHOR]

Atmospheric freeze drying (AFD) has removed the vacuum-creating equipment to reduce energy consumption while maintaining the product quality, compared with traditional vacuum freeze drying. However, the increasing pressure can lead to a significant increase in the drying time. Water vapor diffusion can then be obstructed to limit the practical implementation. Therefore, it is essential to understand the controlling variables in the heat and mass transfer of the AFD process. The purpose of this study was to quantitatively investigate the effects of drying conditions on the drying time, drying rate, and heat/mass transfer resistances. Among them, the thermal/mass transfer resistances were analyzed to explore the drying mechanism during atmospheric freeze drying. The mathematical model of the lamellar product during AFD was proposed to consider the external flow. The Navier–Stokes equations were introduced for the external pressure field into the adsorption-sublimation model. The model was solved and validated using COMSOL Multiphysics 6.1. The accuracy was verified by the ±10% relative deviation of drying time between the model and experimental data. Drying kinetics were calculated under different conditions (product thickness 3-11 mm, equivalent pore diameter 2.0-6.0 μm, dry air temperature 263.15-273.15 K, dry air velocity 1.0-3.0 m/s). The results showed that the drying rate and time decreased with the decrease in product thickness and the increase in air temperature. But there was no outstanding influence of equivalent pore diameter and air velocity on the drying rate and time. Unlike the three stages of standard drying, only the initial accelerating and falling rate stages were observed in the AFD procedure. The absence of the constant rate stage was attributed to the assumption of material homogeneity and low moisture of the top surface. At the same time, the post-processing was carried out to calculate the external heat and mass transfer resistances between the external flow and the product, together with the internal heat and mass transfer resistances between the top surface of the product and the sublimation interface. The external heat/mass transfer resistances decreased, while the internal heat/mass transfer resistances increased linearly from zero, with the decreasing moisture content. The internal heat/mass transfer resistances exceeded the external heat/mass transfer resistances at a critical moisture content, indicating the transition from external heat/mass transfer control to internal heat/mass transfer control during AFD. There was some effect of condition parameters on the transfer resistances. The equivalent pore diameter shared no significant effect on either internal or external resistances. While the temperature increased to bring about a slight decrease in the internal heat-transfer resistance. By contrast, there was a decrease in the external and internal heat transfer resistance, due to the increasing air velocity. Especially, the reduction of product thickness was a significant contribution to the decrease of both internal and external transfer resistance. Therefore, small thickness product was more suitable for the AFD process, according to the drying kinetics and heat/mass transfer. It was expected to simultaneously realize both the reduction in the drying time and energy consumption. The findings can provide guidance to optimize the process parameters during atmospheric freeze-drying. [ABSTRACT FROM AUTHOR]

Dried yellow chili is highly appreciated by consumers due to its excellent quality and flavor. The quality of products is determined by the drying and storage methods. In this study, dried yellow chilis were processed by natural air drying and hot air drying methods and then stored under three conditions: ambient temperature, ambient temperature with light avoidance, and at 10 °C with light avoidance for 12 months. The changes in the bioactive compounds during this period were analyzed attempting to reveal correlations between the different treatments and these compounds, with the aim of providing references for maintaining the bioactive compounds of pepper products. The results showed that samples treated with hot air had higher levels of fatty acids, resulting in a more pronounced flavor. During storage, samples stored at 10 °C with light avoidance were more effective in preserving soluble solids, total protein content, total phenols, capsaicinoids and most fatty acids. [ABSTRACT FROM AUTHOR]

Drying is one of the most common and effective techniques for preserving the quantitative and qualitative characteristics of medicinal plants in the post-harvest phase. Therefore, in this research, the effect of the new refractance window (RW) technology on the kinetics, thermodynamics, greenhouse gasses, color indices, bioactive properties, and percentage of mint leaf essential oil was investigated in five different water temperatures in the form of a completely randomized design. This process was modeled by the methods of mathematical models and artificial neural networks (ANNs) with inputs (drying time and water temperature) and an output (moisture ratio). The results showed that with the increase in temperature, the rate of moisture removal from the samples increased and as a result, the drying time, specific energy consumption, CO2, NOx, enthalpy, and entropy decreased significantly (p < 0.05). In addition, the drying water temperature had a significant effect on the rehydration ratio, color indices, bioactive properties, and essential oil percentage of the samples (p < 0.05). The highest value of rehydration ratio was obtained at 80 °C. By increasing temperature, the main color indices such as b*, a*, L*, and Chroma decreased significantly compared to the control (p < 0.05). However, with the increase in temperature, the overall color changes (ΔE) and L* first had a decreasing trend and then an increasing trend, and this trend was the opposite for the rest of the indicators. The application of drying water temperature from 50 to 70 °C increased antioxidant, phenol content, and flavonoid content, and higher drying temperatures led to a significant decrease in these parameters (p < 0.05). On the other hand, the efficiency of the essential oil of the samples was in the range of 0.82 to 2.01%, and the highest value was obtained at the water temperature of 80 °C. Based on the analysis performed on the modeled data, a perceptron artificial neural network with 2-15-14-1 structure with explanation coefficient (0.9999) and mean square error (8.77 × 10−7) performs better than the mathematical methods for predicting the moisture ratio of mint leaves. [ABSTRACT FROM AUTHOR]

In this study, five drying methods (hot air drying [HD], light wave drying [LD], far infrared drying [FID], freeze drying [FD], and heat pump drying [HPD]) were applied to dry Sargassum fusiforme. The color, rehydration rate (RR), and volatile flavor substances of dried S. fusiforme were compared and analyzed, and the content, molecular weight (Mw), monosaccharide composition, and antioxidant activity of dried S. fusiforme crude polysaccharides (SFCPs) were analyzed. The results showed that S. fusiforme dried by different drying methods showed different colors. FD produced S. fusiforme with better RR (p < 0.05). The Mw of the SFCPs were 624.06, 534.86, 683.00, 1077.13, and 981.91 kDa, respectively, for HD, LD, FID, FD, and HPD. The Mw and DPPH (1,1‐diphenyl‐2‐picrylhydrazyl) radical scavenging rates of SFCP‐FD were greater than those of the remaining four drying methods; however, the ABTS (2,2 ′‐azobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid) and OH (hydroxyl) radical scavenging rates were highest in the SFCP‐HPD. GC‐IMS analysis showed that the drying method affected the content and composition of volatile flavor compounds. Principal component analysis (PCA) analysis indicated that the flavors of dried S. fusiforme were quite different from that of fresh S. fusiforme, and the flavors of HD, LD, and FID were similar, while the flavors of FD and HPD were similar. [ABSTRACT FROM AUTHOR]

The demand for structural logs in wooden construction is substantial. However, logs, due to their inherent structural characteristics, are prone to developing checks during drying process. Kerf treatment is a practical and effective pretreatment technology for drying that can significantly reduce checking. Nonetheless, the optimal location for the kerf treatment remains unexplored. This study was designed to position the kerf based on the location of the pith and assessed the effects of single kerf, double kerf, and kerf-center boring treatments on log drying quality. The check ratio of kerf logs decreased significantly (p < 0.05). As kerf depth increased, the check ratio slightly decreased, while the moisture content (MC) difference between the core layer and surface layer increased. Additionally, the inclusion of kerfs in counterpoint positions exhibited a profound effect on reducing the check ratio. Eccentricity influenced the later drying stages of the logs. The check ratio of non-eccentricity logs tended to stabilize during the later drying period, while that of eccentric logs continued to increase. For eccentric logs, this study employed the counterpoint double-kerf process, resulting in a surface check ratio of 0.42%. For non-eccentric logs, utilizing a single shallow kerf significantly improved the surface drying quality, with a surface check ratio of 1.00%. [ABSTRACT FROM AUTHOR]

The study investigates the drying behavior and desalination effectiveness of porous ceramic tiles made from fired clay materials like bricks or pottery on soil columns initially saturated with saline solution. Evaporation kinetics experiments compared the drying of saline soil with and without a ceramic tile. For soil without a ceramic cover, salt precipitation formed an efflorescent crust that initially (t ∼ 30 h) reduced the evaporation rate. However, with continued drying, the tensile stress caused cracks in the crust, allowing increased evaporation through the cracks (t > 200 h). When covered with a ceramic poultice, the saline solution was wicked into the porous ceramic by capillary action. Rapid salt efflorescence was observed on the ceramic surface. The ceramic layer initially reduced the soil evaporation rate due to pore clogging caused by salt precipitation. The pore structure characteristics of the ceramics significantly impacted their desalination performance. After an initial fast drying period controlled by evaporation, a reduced drying rate was observed as salt clogging effects became dominant, especially for the low porosity ceramic (t ∼20 h). The porous ceramic poultices could effectively extract salts from the soil, but their desalination efficiency depended critically on their pore structure properties. An industrial-based clay ceramic with large and more connected pores (porosity 0.33) was found to be around 62% more efficient in removing NaCl than a handmade pottery with small pores (porosity 0.18). [ABSTRACT FROM AUTHOR]

Vegetables are owed to the restriction of seasonal availability and regional abundance; it becomes essential that vegetables are preserved safely during the off-season. These existing demands look for dried products with high nutritional and organoleptic properties similar to fresh products. This study aimed to investigate the effect of ultrasonication and blanching before hot air drying on the quality attributes of bitter gourd (Momordica charantia). Dried samples were rehydrated to find the efficiency of pre-treatment and physicochemical properties. M. charantia slices were pre-treated with ultrasonication and blanched and dried at two different temperatures, 50 °C and 60 °C. M. charantia pre-treated using ultrasonication and dried at 60 °C reduces the drying time to 50% and rehydration time to 40% compared to untreated samples. Physico-chemical analysis of ultrasonicated samples revealed to have better retention of moisture (dried − 3.6%, rehydrated – 88%), Colour ΔE (dried – 9.07, rehydrated – 1.6), ascorbic acid (dried – 513, rehydrated – 310 mg/100 g), phenol (dried – 302, rehydrated – 231 GAE mg/100 g) and β-carotene (dried – 68 µg/100 g, rehydrated – 39 µg/100 g) compared to blanching. [ABSTRACT FROM AUTHOR]

This review aims to analyze recent advancements in heat pump dryers (HPDs) with a focus on improving energy efficiency and conservation in drying processes. The objective is to evaluate the components, structures, and refrigerants used in HPDs, examining their environmental impacts and system performance. The methodology includes a comprehensive comparison of various assisted HPD systems, such as infrared-, ultrasound-, and solar-assisted technologies, to assess their experimental benefits and limitations. By using key performance metrics, the paper evaluates the energy efficiencies of HPDs in comparison with traditional drying methods, discussing their applications across different industries. The study also explores the significance of integrating alternative energy sources to enhance the efficiency and economic viability of HPDs. Future research directions are proposed to further develop the technology for commercial use, emphasizing HPDs' potential to provide energy-efficient and high-quality drying solutions. In quantitative terms, the review notes that the coefficient of performance (COP) for HPDs ranges between 3.5 and 4.5, indicating a significant improvement over traditional drying methods. Specific moisture extraction rate (SMER) values for HPDs are reported to be between 0.8 and 1.2 kg kW−1 h−1, demonstrating superior efficiency in moisture removal. Additionally, specific energy consumption (SEC) for HPDs is found to be 0.5–0.7 kW h kg−1 of evaporated moisture, which is substantially lower compared to conventional dryers. These metrics underscore the energy-saving potential and enhanced performance of HPD technology. [ABSTRACT FROM AUTHOR]

Diospyros kaki L. (Japanese persimmon) has been introduced from Asian countries to Herzegovina, where it is mostly consumed fresh. This study investigates the differences in nutritional, microbiological, and sensory values of persimmons consumed in one of the Herzegovinian regions, following drying processes at 70 °C/12 h, 85 °C/10.5 h, and 100 °C/5.5 h, together with their effects on fruit texture, mass, and composition. The notable increase in sugar content emphasises the potential of dried Japanese persimmon as a nutritious snack. No significant increase in microorganism representation was observed across all samples. Persimmons dried using a dehydrator exhibited the most preserved nutritional properties, and were rated highest in sensorial evaluations. However, due to its high water content and browning, the sample dried at 100 °C in an autoclave was excluded from sensory testing. [ABSTRACT FROM AUTHOR]

The effect of different methods of drying celery root enriched with beet juice by vacuum impregnation (VI) was studied. The process of convection drying, vacuum drying and freeze drying was carried out. Compared to dried indigenous celery, dry impregnated tissue was characterized by lower values of dry matter, L* and b* color parameters, as well as higher values of water activity, density and a* color parameter. In addition, VI reduced the drying time. Forty Volatile Organic Compounds (VOCs) were found in celery, while fifty-one VOCs were found in the profile of celery with beetroot juice. The innovative method of vacuum impregnation made it possible to produce a new type of product with changed properties and a variable VOCs profile. The best fit of the drying process kinetics was achieved by using the logistic model. Increasing the temperature during convection drying resulted in shorter drying time, increased values of dry matter, reduced the water activity value and altered VOCs. [ABSTRACT FROM AUTHOR]

This work explores a new application of titanium nitride nanoparticles (TiN NPs) as efficient photothermal materials in enhancing the greenhouse effect. We demonstrate that a simple greenhouse using TiN NPs-embedded black paint boasts several advantages in solar drying technology, which are indicated by the drying of red chilli. In particular, the greenhouse using TiN NPs significantly improves the drying efficiency, which reduces the mass of red chilli by approximately four times and results in dried chilli with a moisture content of 10% within two days. In addition, by conducting long experiments in various environments, we found that the relative humidity can have a predominant role over the temperature in the solar drying of red chilli and observed that the re-adsorption of moisture can take place during the drying process, which prolongs the drying time and reduces the quality of the dried products. [ABSTRACT FROM AUTHOR]

In order to study the use of drying models in vacuum-infrared drying, an experiment was conducted to investigate the drying process of cherry pips at different temperatures of 60°C, 70°C and 80°C, drying characteristic curves were constructed and analysed using 6 types of thin layers, and effective diffusion coefficients, moisture content and activation energy were calculated. The results showed that the drying temperature has a greater influence on the drying rate of cherry pits, and the drying time decreases with increasing drying temperature. The main drying step occurs in the downward drying stage. Comparison of the fitting results of the six thin layer drying models presented in this paper showed that Wang and Singh's model fits better for cherry pips (${{\rm{R}}^2} \gt 0,9996$ R 2 > 0 , 9996) and the predicted values of the model agree well with the experimental values. These values are suitable for describing the drying characteristics of cherry pips under any conditions. T. [ABSTRACT FROM AUTHOR]

The present study examined the impact of ethanol pretreatment and drying time on various aspects, including drying characteristics, modeling using thin-layer and artificial neural network (ANN) approaches, color changes during the drying process, shrinkage ratio, total phenolic content (TPC), and antioxidant activity (AA) analysis, as well as ATR-FTIR analysis and principal component analysis (PCA) of the potato slices. Ethanol concentration and pretreatment time had an incredible effect on drying rate and drying time. Higher ethanol concentration and longer pretreatments time provided shorter drying time and a more rapid drying rate. On the other hand, ANN modeling of the potato slices showed better prediction than thin-layer modeling. According to the total color difference (ΔE) values of the samples, ethanol pretreatments had a negative contribution to color properties. Furthermore, the shrinkage ratio of potato samples was affected by drying and ethanol pretreatment time. Diameter shrinkage increased with the increment in ethanol concentration and pretreatment time. TPC and AA of the potato slices showed to decreasing tendency during the drying process. The highest loss of TPC and AA was observed from the samples coded 60 °C + 100 ET 15 and 60 °C + 100 ET 30. Additionally, ATR-FTIR and PCA analysis well exhibited the effect of the ethanol pretreatment and drying process on the composition of the potato slices. [ABSTRACT FROM AUTHOR]

The formation of defects, due to drying, in robocasted ceramic objects is an important issue arising from non-uniform shrinkage of the material during this step in the process. Common methods for shrinkage measurement are not well suited to the small size of robocasted cords or the complexity of robocasted objects. Innovative methods for shrinkage measurement were developed using non-destructive optical vision techniques with computer-controlled data acquisition, allowing measurement on millimetric cords and on specific zones of a product. The study of a single porcelain cord revealed an anisometric shrinkage related to the orientation of grains during extrusion. A differential shrinkage at the macroscopic scale was also measured on a robocasted object, indicating a moisture content gradient in the material. The methods presented in this paper are of particular relevance to real-time control of the drying process for robocasted objects. [ABSTRACT FROM AUTHOR]

This research focused on the impact of drying techniques on the physicochemical and aromatic profile of honey coffee, which involves simultaneous fermentation and drying of coffee beans. Sun drying (SN), low temperature and low humidity drying (LTLH), polyhouse/solar tunnel drying (SD), and shade drying (SH) were carried out. Insignificant effect on physical quality was recorded. Chemical characterization of the raw coffee revealed that the LTLH-dried beans had higher carbohydrates (15.53%), which affected the coffee aroma. The roasted coffee contained caffeine (2.86%) and chlorogenic acid (2.50%), the primary bioactive components, contributing to strength, astringency and bitterness. The coffee brews had improved chemical metabolites such as carbohydrates (16.06%), total polyphenols (6.36%), flavonoids (0.7%) and antioxidants (5.4%). Furthermore, PCA correlates a total variance of 99.2% on green coffee, 97.3% on roasted coffee and 99.8% on brew. SPME–GC–MS revealed 75 volatiles in the roasted coffee and 95 in the infusions. Individual value plot graphs were introduced to assess the effect of volatiles on drying modes. Pyrazines and ketones were key molecules contributing to roasted walnut notes with fruity, floral and honey undertones. E-Nose profiles excellently overlaid GCMS results. SIMCA represented a positive correlation between LTLH coffee and volatile compounds. Thus, the LTLH technique (45–50 °C and 30–40% RH) for honey coffee facilitated an appropriate fermentation of coffee beans thereby improving the overall quality which, in turn, leads to global attention for innovative coffee processing technologies. [ABSTRACT FROM AUTHOR]

Cardamom, also known as the "Queen of Spices," is the world's oldest recognized spice with a high market value for its dried final product. In this work, the drying kinetics of small cardamom (cv. Njallani) has been studied using a solar and a heat pump dryer. Before drying, the produce was pre-treated in sodium carbonate (Na2CO3) at 1%, 2%, and 3%. The treated small cardamom samples are dried as a single and double layer at 40, 45, and 50 °C. The maximum temperature observed inside the solar dryer is 80 °C, resulting in a faster drying rate than the heat pump dryer but poor quality and greenness ((a*) − 0.8 to − 3.25) even after being pre-treated with Na2CO3. The heat pump dryer showed a constant and falling rate drying period at all the temperatures, with the highest drying rate at 50 °C. It required at least 12 h to dry the cardamom samples from 455.5 to 10.2% moisture content as a single layer. The temperature and the bed thickness have the maximum influence on the water activity of dried cardamom (0.54–0.64). A higher greenness value and essential oil percentage are obtained from the small cardamom dried in the heat pump dryer at 45 °C.The COP and SMER are found best at 50 °C. Four different models are used to predict the moisture ratio curve of the dried cardamom, with the quadratic model having the highest R2 value. [ABSTRACT FROM AUTHOR]

Fresh meat has a limited shelf life and is prone to spoilage. Drying serves as a common method for food preservation. Non-thermal techniques such as ultrasound treatment (US) can positively affect the drying processes and alter the final product. The study aimed to evaluate the impact of US pre-treatment on the hot air (HA) and freeze-drying (FD) of chicken breast meat and the quality of the dried products. US pre-treatment had a varied impact depending on the drying method used. The contact US method extended the HA drying time (about 50%) but improved water removal during FD (about 30%) compared to the untreated samples. Both methods resulted in low water content (<8.3%) and low water activity (<0.44). While rehydration properties (RR) and hygroscopicity (H) were not significantly affected by US pre-treatment in HA drying (about 1.35% and about 1.1, respectively), FD noticed differences due to shrinkage and porosity variations (RR: 2.4–3.2%, H: 1.19–1.25). The HA-dried samples exhibited notably greater tissue shrinkage and a darker surface color than the FD meat. Ultrasonic processing holds substantial potential in creating dried meat products with tailored characteristics. Hence, meticulous consideration of processing methods and parameters is of utmost importance. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Eugenia uniflora is a tropical species rich in bioactive compounds that are highly sensitive to processing conditions, particularly those involving heat. Drying is a widely used method for preserving fruit pulp which can affect the stability of these bioactive compounds. The aim of this study was to assess the impact of drying at different temperatures on the retention of phenolic compounds and carotenoids present in the pulp of E. uniflora, with the goal of optimizing the drying process to preserve the pulp's quality. The E. uniflora pulp was dried in an oven with air circulation at three temperatures (45, 65, and 85°C). During the drying process, the moisture content and concentration of phenolics, β‐carotene, and lycopene were measured over time. After 260 min of drying, phenolic compounds decreased by 63.97% (45 and 65°C) and by 59.62% (85°C). Carotenoids losses were even more pronounced exceeding 89%, for all temperatures, with β‐carotene reductions of 92.91%, 90.72%, and 91.11%, at 45, 65, and 85°C, respectively. Several well‐established drying models were tested to represent the moisture content over time. Two models exhibited a high adherence to the experimental data. Zero‐order, first‐order, and second‐order degradation models were used to describe the concentrations of phenolic compounds and carotenoids. For total carotenoids, the model that showed the best results was temperature‐dependent. The first‐order model provided the best fit for β‐carotene and lycopene, with high R2 values of 0.9852 (45°C), 0.9776 (65°C), and 0.9681(85°C) for β‐carotene, and 0.9776 (45°C), 0.9715 (65°C), and 0.9659 (85°C) for lycopene. These results indicate that higher temperatures accelerate the degradation of bioactive compounds, following a predictable dynamic that can be optimized through adjustments to the drying process. Practical applications: The fruit of Eugenia uniflora contains phenolic and carotenoid compounds with significant nutraceutical potential. However, the production of this fruit is seasonal, necessitating effective preservation methods. Drying, which involves the removal of water from the pulp, is a common procedure aimed at extending the fruit's conservation and shelf life. Despite its benefits, the drying process poses a challenge, as bioactive compounds like phenolic and carotenoids are sensitive to thermal processing. Their degradation during drying can lead to a reduction in the fruit's bioactive potential. Therefore, it is crucial to understand the kinetics of drying and the degradation of these bioactive compounds to optimize the drying process and maximize the fruit's nutraceutical value. [ABSTRACT FROM AUTHOR]

The objective of this study is to derive the thermodynamic characteristics from sorption isotherm data for canola. The semi‐gravimetric method was utilized at three different temperatures (25, 40, and 55°C) and seven air relative humidity levels within the range of 11%–90%. The observed data indicated that the equilibrium moisture content of the sample decreased as the temperature increased. The "GAB and BET" models were applied to fit the empirical data, which demonstrated a Type III isotherm, and the monolayer water content was subsequently determined using these models. Thermodynamic properties such as "isosteric heat," "net isosteric heat," "differential entropy," "net integral entropy," and "net integral enthalpy" were determined from isothermal sorption curves. The results show that as moisture content increases, both the sorption isosteric heat and the differential entropy of sorption decrease. This indicates that at higher moisture levels, the energy required for additional moisture adsorption and the changes in entropy are reduced. Similarly, the net isosteric heat of sorption and the net integral enthalpy of sorption also decrease with increasing moisture content, consistent with the observed reductions in isosteric heat and differential entropy. The specific absorption surface area for each temperature was determined by calculating the monolayer moisture content using both the "GAB and BET models." The net integral entropy had an increasing trend in the range of 4%–4.5% (db%), while it decreased in the range of 4.5%–6.8% of moisture content. In addition, the spreading pressure at three levels of temperature was reported. Finally, an empirical relation was employed to illustrate the cumulative energy requirement for drying versus moisture content. The results indicated that at low moisture content levels, the drying process required significantly higher energy. Practical applications: Moisture sorption isotherms are essential for understanding the interaction between water and food ingredients. This knowledge is vital for improving food processing methods such as drying, mixing, cooling, and storage. In industry, isotherms can help determine the best drying method to maintain food quality, identify the optimal mixing conditions to ensure consistency, establish cooling protocols to prevent spoilage, and set storage guidelines to extend shelf life. In addition, understanding thermodynamic properties is crucial for regulating moisture absorption and release, achieving the desired food texture, managing surface characteristics, and calculating the energy needed for effective dehydration processes. [ABSTRACT FROM AUTHOR]

In this study, the radio frequency vacuum drying (RFVD) technique was used to dry Codonopsis pilosula slices. The effects of the drying temperature, slice thickness, plate spacing, and vacuum degree on the drying characteristics and physicochemical properties of the slices were investigated. The results showed that as the drying temperature and vacuum degree increased and the slice thickness and plate distance decreased, the drying rate and effective moisture diffusion coefficient of the Codonopsis pilosula slices improved, and the required drying time was shortened by 11.11% to 29.41% compared to that after hot air drying (HAD). Through comparison, it was found that the Midilli and Weibull models could better describe the moisture variation trend during the RFVD of Codonopsis pilosula. After RFVD, the retention of lobetyolin and syringin in Codonopsis pilosula significantly increased, with maximum contents of 135.74 mg/100 g and 19.16 mg/100 g respectively, which were 75.2% and 124.28% higher than those obtained by HAD. The contents of polysaccharides, total phenolics, and total flavonoids and antioxidant performance were also enhanced. The color, shrinkage rate, and internal tissue structure were significantly improved. In conclusion, RFVD not only increases the drying speed of Codonopsis pilosula slices but also ensures the good quality of the dried products. [ABSTRACT FROM AUTHOR]

Thermal processing is commonly employed to ensure the quality and extend the shelf‐life of fruits and vegetables. Radio frequency (RF) heating has been used as a promising alternative treatment to replace conventional thermal processing methods with advantages of rapid, volumetric, and deep penetration heating characteristics. This article provides comprehensive information regarding RF heating uniformity and applications in processing of fruit and vegetable products, including disinfestation, blanching, drying, and pasteurization. The dielectric properties of fruits and vegetables and their products have also been summarized. In addition, recommendations for future research on RF heating are proposed to enhance practical applications for fruits and vegetables processing in future. [ABSTRACT FROM AUTHOR]

Pulsed vacuum drying (PVD) is a novel vacuum drying method that has demonstrated significant potential in improving energy efficiency and product quality in the drying of foods and agricultural products. The current work provides a comprehensive analysis of the latest advancements in PVD technology, including its historical development, fundamental principles, and mechanistic aspects. The impact of periodic pulsed pressure changes between vacuum and atmospheric pressure on heat and moisture transfer, as well as structural changes in foods at micro‐ and macro‐scales, is thoroughly discussed. The article also highlights the influential drying parameters, the integration of novel auxiliary heaters, and the applications of PVD across various fruits, vegetables, and herbs. Furthermore, the review examines the current status and needs for mathematical modeling of PVD processes, identifying key challenges, research opportunities, and future trends for industrial application. The findings suggest that PVD not only enhances drying efficiency and reduces energy consumption but also preserves the nutritional value, color, and texture of dried products better than traditional methods. Future research should focus on optimizing process parameters and integrating advanced control systems to further improve the scalability and applicability of PVD technology in the food industry. [ABSTRACT FROM AUTHOR]

This research revealed the effect of drying processes on the bioactive properties of marjoram leaves. The total carotenoid content in marjoram leaves ranged between 60.96 µg/g (fresh) and 189.78 µg/g (oven-dried), whereas the total flavonoid content ranged between 949.33 mg CE/100 g (control) and 16,958.59 mg CE/100 g (oven-dried). The total phenolic amounts in marjoram leaves were between 259.17 mg GAE/100 g (fresh) and 1264.17 mg GAE/100 g (oven-dried), while the antioxidant activity values were between 45.23% (fresh) and 77.29% (oven-dried). The 1,2-dihydroxybenzene and (+)-catechin amounts in marjoram leaves were between 19.54 (microwave-dried) and 165.26 (oven-dried) to 20.97 (fresh) and 46.99 mg/100 g (oven-dried), respectively. The kaempferol content in the marjoram plant was specified between 11.45 mg/100 g (fresh) and 43.05 mg/100 g (oven-dried). In general, the quantities of phenolic constituents in the marjoram leaves dried in both drying systems increased compared with fresh samples (except 1,2-dihydroxybenzene, p-coumaric acid, and resveratrol in the microwave-dried samples). [ABSTRACT FROM AUTHOR]

AbstractTo optimize the drying process of bamboo bundles, this study investigates the heat and mass transfer behavior during the drying process by using temperature sensors to measure the temperature field at different positions and track the overall moisture content over time. Additionally, a heat transfer model is used to simulate and predict the drying process. The analysis of the experimental results indicates that the diameter of the bamboo bundles has a greater impact on the drying rate than the drying temperature. At the same temperature, the drying time significantly decreases as the temperature increases. Under drying conditions at 80 °C, the average drying rate constant is 0.072 for bamboo bundles with a diameter of 40 mm, whereas it is only 0.015 for bundles with a diameter of 100 mm. Using Newton’s law of cooling, the convective heat transfer coefficient calculation method was derived. The average convective heat transfer coefficients at 40, 60, and 80 °C were calculated to be 6.16 W/(m2 K), 7.14 W/(m2 K), and 7.22 W/(m2 K), respectively. A mathematical model was established for the temperature at the center of the bamboo bundles, the temperature of the drying medium, the diameter of the bamboo bundles, and the drying time. This model effectively simulates the temperature variation inside the bamboo bundles, and the temperature simulation data fits well with the measured values, with a standard error of less than 2.8 °C and a prediction error of less than 6.1%. This coupled model and method provide a theoretical basis for predicting and controlling the bamboo bundle drying process, reducing energy and time consumption in actual production. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine the impact of vacuum impregnation on selected physical properties of courgettes, the drying process, and kinetics of the drying process. Vacuum impregnation was used as a pretreatment in the conducted research. The drying process was carried out using three techniques (convection drying, freeze drying, and vacuum drying). In the presented work, selected properties of courgettes, i.e., water activity, dry weight, density, VGI, shrinkage, and color were investigated, and the best model describing the kinetics of the drying process was selected. As a result of the study, it was found that the pretreated courgette was characterized by increased dry matter (0.44% to 4.08%) and density content (15.52% to 33.78%) and reduced or increasing water activity (−5.08 to 38.62%) depending on the drying method. The process also resulted in reduced drying shrinkage (−2.13% to −6.97%). Tomato juice was used as an impregnating solution, resulting in an increase in red intensity (8.44) and a decrease in the L* color index (80.16 to 58.00 for the fresh courgette). Dries with the most favorable properties were obtained using the freeze-drying method. The best model of the drying process kinetics was the logistic model. [ABSTRACT FROM AUTHOR]

There is a growing interest in the food industry in new drying technologies that reduce the time required for dehydration, combined with low energy consumption, low environmental impact, and maintenance of the overall quality of the product. This work investigated convective drying of pumpkin with and without ultrasound-organic (citric or acetic) acid pretreatment for different durations (10, 20, and 30 min). Drying was carried out at 60 °C, and the Wang and Singh model had the best fit for the experimental data. Samples pretreated for 30 min had the shortest drying times. Water diffusivities ranged from 6.68 × 10−8 m2/s to 7.31 × 10−8 m2/s, with the pretreated samples presenting the highest values. The dried pumpkin water activity values were below 0.60. Regarding color parameters, there was a slight increase in luminosity, a slight reduction in a*, and a significant increase in b*. Drying resulted in the loss of ascorbic acid and phenolic compounds, but the samples pretreated with citric acid showed better retention. There was also a reduction in the total carotenoid content, but samples pretreated with acetic acid for 10 and 20 min showed the best retention. [ABSTRACT FROM AUTHOR]

It was precisely because LiNi 0. 5 Mn 1. 5 O4 cathode material had many advantages, including high voltage, high power, no pollution, low cost, etc., that it became a research hotspot for lithium-ion cathode materials. Although LiNi 0. 5 Mn 1. 5 O4 has a three-dimensional Li + diffusion channel, there are still some problems that lead to capacity decay and reduced cycling stability, limiting its commercial application. In this paper, the LiNi 0. 5 Mn 1. 5 O4 cathode material was prepared by the freezing precipitation method. We studied the effects of different drying methods, such as blast drying, water bath drying and freeze-drying on the structure, morphology and electrochemical properties of LiNi 0. 5 Mn 1. 5 O4 cathode materials. The study found that the LiNi 0. 5 Mn 1. 5 O4 cathode material prepared by the precipitation-freeze-drying method had a complete crystal form, a stable structure and no LixNi 1 − x O impurity peak. The SEM image showed that the particles were smaller and had a smooth surface. The initial discharge-specific capacity at 0.1 C was 105.2 mAh⋅g − 1 . After 50 cycles, its specific discharge capacity was 99.4 mAh⋅g − 1 and the capacity retention rate was 94.5%. Compared with LiNi 0. 5 Mn 1. 5 O4 materials prepared by other methods, it had better electrochemical performance. [ABSTRACT FROM AUTHOR]

The growing interest in cost-effective and high-performing perovskite solar cells (PSCs) has driven extensive research. However, the challenge lies in upscaling PSCs while maintaining high performance. This study focuses on achieving uniform and compact perovskite films without pinholes and interfacial voids during upscaling from small PSCs to large-area modules. Competition in nucleation at concavities with various angles on rough-textured substrates during the gas-pumping drying process, coupled with different drying rates across the expansive film, aggravates these issues. Consequently, substrate roughness notably influences the deposition window of compact large-area perovskite films. We propose a supersaturation regulation approach aimed at achieving compact deposition of high-quality perovskite films over large areas. This involves introducing a rapid drying strategy to induce a high-supersaturation state, thereby equalizing nucleation across diverse concavities. This breakthrough enables the production of perovskite photovoltaics with high efficiencies of 25.58, 21.86, and 20.62% with aperture areas of 0.06, 29, and 1160 square centimeters, respectively. [ABSTRACT FROM AUTHOR]

Tomato fruit is a source of many important nutrients. It is difficult to store it for a long time because it contains a high percentage of moisture. The moisture content could be reduced in different ways to restrict the high growth of fungi. This study mainly aims to manufacture a simple and easy-to-use solar dryer for drying tomato fruits with solar cell-based fans. This method can be adapted to dry a wide range of Vegetables and fruits. The measured factors in this study are solar radiation, ambient temperature, relative humidity, and drying time. Solar drying is an affordable method to soothe the negative impact of post harvest losses on cultivators in Iraq. A greenhouse dryer (1 × 0.5 × 0.5 m) was constructed using glass of (τ = 0.9 for 0.4 μm < λ < 0.7 μm and τ = 0.01 for λ > 0.7 μm). Two fans are used to force an airstream with an average velocity of 0.025 m/s at the tray section. A selected quantity of tomato was washed and ground, making 1 kg of puree to check the effectiveness of the dryer. An experiment conducted on 10-11 March 2023 showed that 14 drying hours are needed to bring the paste to an acceptable quality of 0.25 brix. The efficiency of the greenhouse has not exceeded 25% on average, accompanied by an average drying rate of 60 g/hr. It was found that converting the perishable tomato crop into paste is profitable for cultivators in Iraqi conditions. Using a solar dryer is particularly profitable for local farmers by reducing crop losses, as per 1 m2 land area, a production of 6 kg of tomatoes is expected with losses of about 1 kg, and a profit of 6 thousand IQD and losses of 1 thousand IQD. A land area of 1 m2 with a dryer produces 3.6 kg of tomatoes converted into 1.008 kg tomato paste producing 15 thousand IQD without losses. [ABSTRACT FROM AUTHOR]

This study aimed to assess the effect of killing (blanching and freezing) followed by culinary processing on the microbiological quality of Tenebrio molitor and Gryllus assimilis. These insects were subjected to starvation before killing, which does not ensure sufficient microbiological safety. Therefore, technological or culinary processing of insects is necessary before consumption. For the subsequent processing of insects, boiling, drying, roasting, and microwave treatment were used. Nine categories of microbiological parameters were selected as indicators of hygienic quality. All identification and enumeration were performed using ISO-compliant methods. The results showed that killing insects by blanching or freezing alone does not ensure sufficient microbiological quality, and therefore, further culinary processing is necessary. However, all subsequent culinary treatments applied in this study were able to reduce the microbial load significantly. [ABSTRACT FROM AUTHOR]

An innovative trend in the production of snack products is the use of selected vegetables for the production of dried vegetable chips. Beetroot is a suitable vegetable for this type of product, as it is characterised by its high biological potential and its content of a wide range of phytonutrients with beneficial effects on human health. The aim of this work was to compare five varieties of beetroot in terms of the content of total polyphenols and betacyanins, to assess the effect of hot-air drying on these important components and to determine the appropriate method of treatment of beetroot slices before drying in terms of improving the stability of polyphenols and betacyanins during drying. In this work, 5 beetroot varieties (Betina, Renova, Cervena kulata, Pablo F1, Karkulka) were evaluated. The beetroot chips were dried at 70°C until a residual moisture content of 15±1% was reached. To treat the slices before drying a 0.1% solution of ascorbic acid, 0.01% solution of CaCl2, 0.01% solution of K2S2O5, 1% solution of NaCl was used followed by blanching in a water bath at 96°C for 2 minutes. The highest content of total polyphenols and beta-cyanins was statistically significant (p<0.05) in the variety Pablo F1. During hot air drying, both polyphenols and betacyanins decreased significantly. The average decrease in betacyanins and total polyphenols was 50.97% and 48.70% respectively. To mitigate these changes, treatment with 0.1% solution of ascorbic acid and blanching appeared to be the most effective of the treatments tested. After treatment with ascorbic acid solution, the dried products retained on average 27.6% more betacyanins and 32.67% more total polyphenols than the control sample. [ABSTRACT FROM AUTHOR]

In the present study, the performance of a solar dryer supported by an indirect type wicked heat pipe was assessed. To transfer the heat from the solar collector to the drying chamber, a passive high thermal conductivity heat pipe was developed. At 1:30 pm, there was a 21 °C temperature difference between the drying chamber and the ambient air. The results indicated that after 12 hours of drying, the banana slices' moisture content dropped from 150 % d.b. to 11 % d.b. It is found that the average drying rates in Trays 1, 2, and 3 are the following: 0.1452, 0.1492, and 0.1613 kg water/kg dry matter/h. The effective moisture diffusivity ranged from 1×10−7 to 9.405×10−8 m2/s, whereas open sun drying had the lowest average effective moisture diffusivity of 3.87×10−07 m2/s. The estimated dryer efficiency was 26 %. Also the payback period of developed dryer was found to be 0.57 years. The developed dryer can be installed in any rural villages to dry any agricultural products. [ABSTRACT FROM AUTHOR]

Global consumption of nori, a widely consumed commercial edible algal film, is predominant in Asian countries. As the demand for Asian cuisine rises in Brazil, there is a growing need to explore alternatives to importation, such as producing edible films using seaweeds from the Brazilian coast—specifically Ulva lactuca and Kappaphycus alvarezii. In this study, seaweed film formulations varied in concentrations, from 80% U. lactuca and 20% K. alvarezii to an equal proportion of 50% of each alga, heating at 90°C for 3 and 5 minutes. Results showed that the filmogenic suspensions had a pseudoplastic behavior, with viscosity decreasing as K. alvarezii concentration increased. The resistance of heated gels increased with higher K. alvarezii concentrations and prolonged heating times. Surface uniformity improved with elevated K. alvarezii concentration and extended heating time. As K. alvarezii concentration increased, films exhibited less intense coloration, heightened transparency, and increased solubility. Films with higher K. alvarezii content demonstrated greater tensile strength, albeit without an increase in elongation capacity. Sorption isotherms exhibited a characteristic Type II pattern, and modeling using the GAB model suggested stronger bonds in treatments with extended heating times. Despite the need for enhanced flexibility, the results indicate potential applications in snacks or as alternatives to nori. Notably, these films were produced solely with seaweeds and water, aligning with Nori's minimalistic approach. Treatments with a concentration of 60% U. lactuca and 40% K. alvarezii proved to be the most promising. This study lays the groundwork for future research in developing edible films derived from seaweeds. [ABSTRACT FROM AUTHOR]

The growing world population necessitates the implementation of appropriate processing technologies for edible insects. The objective of this study was to examine the impact of distinct drying techniques, including convective drying at 70 °C (70CD) and 90 °C (90CD) and freeze-drying (FD), on the drying kinetics, physical characteristics (water activity, color), chemical characteristics (chemical composition, amino acid profile, oil properties, total polyphenol content and antioxidant activity, mineral composition, FTIR), and presence of hazards (allergens, microorganisms) of blanched yellow mealworm larvae. The freeze-drying process results in greater lightness and reduced moisture content and water activity. The study demonstrated that the freeze-dried insects exhibited lower contents of protein and essential amino acids as compared to the convective-dried insects. The lowest content of total polyphenols was found in the freeze-dried yellow mealworm larvae; however, the highest antioxidant activity was determined for those insects. Although the oil isolated from the freeze-dried insects exhibited the lowest acid and peroxide values, it proved to have the lowest PUFA content and oxidative stability. All the samples met the microbiological criteria for dried insects. The results of the study demonstrate that a high temperature during the CD method does not result in the anticipated undesirable changes. It appears that freeze-drying is not the optimal method for preserving the nutritional value of insects, particularly with regard to the quality of protein and oil. [ABSTRACT FROM AUTHOR]

The final particle moisture content of ceramic slurry spray drying affects the processing, product quality, and process energy consumption. While the real-time moisture content determination is very difficult for spray drying process due to nonlinear, severe lag, interference factors, and complexity of the systems, the high temperature, high humidity drying environment and short drying process. In current work, an improved moth optimization (IMFO) algorithm combined with backpropagation neural network (BPNN) was proposed to predict the moisture content of ceramic slurry particles during spray drying. The performance of the model is trained and tested. Results demonstrate that IMFO has better convergence ability and speed compared to other algorithms such as particle swarm optimization (PSO) and gravitational search algorithm (GSA). The IMFO-BPNN model achieves a MAE of 0.0293, RMSE of 0.0383, and R2 value of 0.9113, outperforming the prediction performance of BPNN and MFO-BPNN models. The absolute error rate of the IMFO-BPNN model (0–5%) is lower compared to BPNN (5–10%) and MFO-BPNN model (>10%), showcasing superior accuracy in predicting moisture content. This mathematical model established in the study provides an efficient, accurate, and nondestructive method for predicting the drying endpoint of ceramic slurry spray drying. [ABSTRACT FROM AUTHOR]

Drying is an important step in the postharvest processing of agricultural products, as it allows the product to be preserved by reducing water activity to safe values, which stops microorganism growth and enzymatic reactions. In this context, the objective of this study was to assess how various drying temperatures, combined with ultrasonic pretreatment, affect drying rates and essential oil production. Assays were conducted according to a Central Composite Rotational Design, considering two factors with the following intervals: duration of the ultrasonic bath from 0 to 40 min, drying air temperature from 40 to 70 °C. The optimization was carried out using Response Surface Methodology (RSM). The essential oil was extracted by hydrodistillation and its constituents were identified by gas chromatography coupled to mass spectrometry. Histochemical analyses of fresh tubers were performed. The Midilli model was the one that best described the drying kinetics of Cyperus rotundus in all treatments. The drying time of C. rotundus tubers was dependent only on temperature (decreasing linear effect), it was possible to describe the variation in drying time as a function of temperature. It was not possible to adjust a model for ultrasonic bath time or drying temperature that would optimize both essential oil yield and the drying time of C. rotundus tubers. However, in this study, shorter drying times were observed compared to previous studies on C. rotundus tubers drying in the shade at room temperature. A total of 29 chemical constituents have been identified in the essential oil extracted from C. rotundus tubers, of which the majority are: 3,4-dimethyl-3-cyclohexen-1-carboxaldehyde (19.23%); caryophyllene oxide (17.63%); and α-cyperone (9.54%). Histochemical analyses of C. rotundus tubers showed the presence of starch, phenolic compounds, and lipids. [ABSTRACT FROM AUTHOR]

The primary heat transfer source in the conventional multi-cylinder drying of paper and board is conduction. Conduction is facilitated by high-tension contact with steam-heated cylinders, while convective drying, the main mass transfer source, operates as heated air flows over the article web in the pockets. This conduction process occurs at elevated temperatures and contact pressures to ensure effective contact between the wet paper web and the heated cylinders. The contact pressures and temperatures of the hot surface significantly influence the conductive drying characteristics. This research paper presents an experimental study that involves designing a simple lab-scale setup with in-situ and continuous sensing capabilities for various commercially available grades of paper and board. Embedded thermocouples measure the temperatures of the heated platen and the sheet, allowing the collection of flux data to determine heat transfer characteristics. The goal of this study is to ascertain the instantaneous contact coefficients for different basis weights as a function of moisture content. The acquired data will provide valuable insights and information toward process development, design, and simulation of the article drying process. [ABSTRACT FROM AUTHOR]

A low-cost, efficient and accurate structure from motion (SfM) photogrammetry is used to reconstruct the complex morphologies of unevenly deforming hydrogels during the drying process. The primary setups comprise a camera and rotary platform, which are low-cost and works stably for most drying conditions. The dynamic three-dimensional (3D) reconstruction of cylindrical hydrogel samples is achieved by SfM through the generation of point clouds, and the 3D morphologies are calculated by a Poisson reconstruction algorithm based on these point clouds. The accuracy of SfM in quantitatively measuring large-scale deformation is validated, and its applications in drying studies are explored. The results show that as drying proceeds, the maximum measurement deviation of the hydrogel volume between SfM and the traditional buoyancy force method is 1.93% at a volume shrinkage of 69%, confirming the accuracy of the current method for measuring large-scale drying shrinkage. Based on SfM, the temporal evolution of the cross section of the hydrogel is obtained. Comparing to conventional drying experiments that assess the dryness of deformed materials based on overall moisture content changes, SfM enables the evaluation of localized complete drying by quantitative analysis of deformation parameter variations. [ABSTRACT FROM AUTHOR]

BACKGROUND: Bulgur, a whole wheat product, has attracted attention in the world in recent years because of its wide usage possibility in different meals. The basic ingredients in bulgur production are wheat and water. The influence of water composition on bulgur quality has not been investigated. Iron in water can cause discolouration in foods by oxidizing and reacting with phenolic compounds and also by hardening the structure of the foods. Therefore, in the present study, the effects of the iron content of water on the quality of bulgur were examined. RESULTS: The effect of the amount of iron in water on bulgur quality was carried out and examined using water containing iron at three different levels (0, 1 and 2 ppm). Using water containing 2 ppm iron in bulgur production caused a decrease in the L* value and an increase in the YI (i.e. yellowness index), thus negatively affecting the colour of the bulgur. In bulgur prepared with water containing 2 ppm iron, the antioxidant activity was also dramatically reduced. CONCLUSION: The iron content in the water used in bulgur production did not have a negative effect on bulgur quality up to 2 ppm. The protein, ash, phenolic and mineral amounts and textural characteristics of bulgur were not affected by the concentration of iron in the water. As a result, high iron concentration in cooking water negatively affects bulgur's colour and antioxidant activity. Therefore, it is recommended to use iron‐free water in bulgur production. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]