Search Results (118)

Kelp is a high-moisture, flexible, sheet-like marine biomass whose drying behavior is strongly affected by the coupled effects of radiative heating, convective vapor removal, internal moisture migration, tissue shrinkage, curling, and material overlap. Traditional sun drying and hot-air drying remain widely used but are limited by long processing cycles, environmental dependence, high energy consumption, and inconsistent product quality. With the development of infrared heating, heat-pump dehumidification, Internet of Things (IoT)-enabled sensing, fifth-generation (5G) mobile communication, multiphysics simulation, and digital control, kelp drying is progressively shifting toward monitored, model-assisted, and intelligent processing. This review critically summarizes recent advances in kelp and related seaweed drying, with particular emphasis on infrared-assisted heat and mass transfer, drying kinetics, coupled computational fluid dynamics–finite element method (CFD–FEM) simulation, quality evaluation, and intelligent control. Representative published studies demonstrate the engineering potential of these approaches. In a suspended infrared-array kelp drying system, an infrared power density of 1.2 kW m−2 combined with an air velocity of 3 m s−1 maintained the drying temperature at approximately 55–62 °C, while relative humidity decreased from about 80% to 20–30%. Under these conditions, the Page model achieved R² = 0.987 and RMSE = 0.019, the rehydration ratio exceeded 94%, and the total color difference remained below ΔE = 6.5. A recent CFD–FEM–MATLAB workflow further reported a composite operating-condition index of J = 0.4535, with mapped mean and maximum kelp surface temperatures of 62.23 and 63.57 °C, respectively. These quantitative results indicate that the key challenge in infrared kelp drying is not simply to increase heat input, but to coordinate radiation distribution, airflow organization, internal moisture transport, structural response, and quality preservation. Future research should therefore focus on experimentally validated heat–mass-transfer models, adaptive sensing and control, multi-objective optimization, and pilot-scale verification under realistic production conditions. Full article

Purpose: Maintaining fluid homeostasis is crucial, and replenishing electrolytes—particularly sodium (Na⁺)—is critical for effective rehydration after thermal hypohydration. Despite the growing consumption of carbonated water (CW), its impact on post-hypohydration body fluid balance, either alone or combined with electrolytes, remains inadequately investigated. Therefore, this study was designed to examine the separate and interactive effects of carbonation and electrolyte provision in rehydration fluids—utilizing a 2 × 2 factorial design (carbonation × electrolytes)—on ingestive behavior and systemic fluid balance following mild thermal stress-induced hypohydration. Methods: Subjects (eight women and seven men, age range: 19–25 years) were dehydrated by performing three bouts of stepping exercise for 20 min, separated by 10 min of rest, at 25 °C. Following the dehydration protocol, subjects ingested pure water (W), CW (gas volume, 3.43 ± 0.20 (mean ± standard deviation)), electrolyte-added water (EW), or electrolyte-added CW (ECW) (gas volume, 3.04 ± 0.29 (mean ± standard deviation)) ad libitum. EW and ECW contained 19 mEq/L Na⁺. We assessed ingestive behavior and body fluid balance during the 180 min rehydration period. Results: The dehydration protocol induced hypohydration by ~10 g/kg body weight (~1% of body weight). Cumulative fluid intake was greater in the W trial than in the CW, EW, and ECW trials. Cumulative urine output was greater in the W and CW trials than in the EW trial. The fluid retention ratio was greater in the EW and ECW trials than in the CW trial. Consequently, the final fluid recovery was lower in the CW trial compared to the W, EW, and ECW trials; however, the combination of carbonation and electrolytes (ECW) did not significantly surpass the non-carbonated trials (W and EW) due to the reduced intake volume caused by carbonation. Conclusions: The data suggest that ad libitum ingestion of carbonated water is less effective than plain water for recovering from mild hypohydration (~1% body weight loss), as it reduces spontaneous fluid intake. However, electrolyte supplementation mitigates this reduced recovery by attenuating diuresis and consequently improving fluid retention ratio. Full article

Freeze-drying is a crucial technique for preserving bacterial strains, yet its efficiency depends heavily on the precise selection of protective agents. This study aimed to optimize freeze-drying conditions for the commercially relevant, non-GMO strain Lactiplantibacillus plantarum K KKP/593/p. The cryoprotective effects of glycerol, dimethyl sulfoxide (DMSO), and trehalose were evaluated, alongside various carriers including skim milk powder, maltodextrin, inulin, and starch. Survival rates were determined using the plate count method on MRS agar, complemented by scanning electron microscopy (SEM) for microstructural analysis. Results indicated that skim milk powder was the superior carrier, significantly outperforming polysaccharides. Among the protective agents, glycerol exhibited the highest efficacy, while trehalose and DMSO were suboptimal. The most effective formulation 20% glycerol without prior incubation combined with skim milk powder at 0.75:1 (w/w, total mass) ratio maintained maximum viability with no statistically significant decrease. SEM observations confirmed that this synergistic combination ensured a stable, porous matrix favorable for rehydration. These findings emphasize that while synergistic multi-component systems are essential for maximizing post-process viability, cryoprotective formulations must be empirically tailored to specific bacterial strains to ensure industrial efficiency. Full article

Forest plantations, including those of Norway spruce, are increasingly threatened by drought in Central Europe. One of the measures understating this threat might be the use of drought-mitigative additives at planting. The effects of induced water limitation and the application of hydrogel Agrisorb and commercial ectomycorrhizal fungi (EMF) inoculum Ectovit on the development of 2 + 1 spruce seedlings were estimated in this study. The root systems of 2 + 0 seedlings were treated with the additives, along with their spring transplantation into peat-filled pots. The seedlings were then exposed throughout the entire growing season either to full watering (FW)—volumetric soil water content 70%, reduced watering (RW)—water content 40%, periodic watering (PW)—substrate rehydrated to 70% after drying to the wilting point (21%), or remained non-watered (NW). Survival, growth and chlorophyll fluorescence of the seedlings decreased proportionally to the increased drought intensity, while the highest root-to-shoot ratio and EMF colonization of roots occurred under PW and RW, respectively. NW seedlings died after 9 weeks of desiccation, whereas the EMF inoculum prolonged the survival time by one week. Ectomycorrhizas were formed predominantly with native EMF in all the treatments; nevertheless, compared with the uninoculated control, the formation of a treatment-specific EMF root morphotype and increased EMF colonization under PW and RW were observed on the inoculated seedlings. Both the EMF inoculum and the hydrogel increased survival under PW by approximately 15% but did not significantly affect growth, regardless of the watering regime. These results are limited to the experimental conditions and suggest a more dominant effects of the watering regimes compared with the additives tested. Full article

Apple pomace, a major by-product of juice processing, requires effective drying for valorization and preservation. This study investigated the thin-layer drying kinetics of apple pomace from three varieties (Starkrimson, Idared, and Jonagold) under forced convection at 57 °C, 63 °C, and 68 °C. Seven mathematical models were used to fit the experimental moisture ratio data and evaluated using statistical indicators (R², RMSE, χ², and MBE). In addition, the proximate composition, titratable acidity, water activity, color parameters, rehydration capacity, total phenolic content, antioxidant activity, and phenolic and organic acid profiles of the resulting apple pomace powders were assessed. Of the models tested, the Midilli–Kucuk model demonstrated superior performance with the highest R² (>0.99) and lowest RMSE and χ² values across all varieties and temperatures. The Page and Logarithmic models also showed good predictive capability. Significant differences in phenolic content and antioxidant activity were observed between powders from different apple varieties, with Starkrimson showing the highest values, followed by Jonagold and Idared. These findings provide essential kinetic parameters for optimizing apple pomace drying processes and support the development of value-added products from this abundant agro-industrial by-product. Full article

Mesenchymal stem cells (MSCs) are candidates for the treatment of palatal wounds in combination with biomaterials. In this study, we developed a method for the production of a ready-to-use mucoadhesive hydrogel containing MSCs for palatal wounds and evaluated its healing effects. Dental follicle MSCs (DFMSCs) were isolated from the dental follicle tissue of a healthy twenty-year-old donor. DFMSCs were suspended in a cell-preserving solution containing platelet-rich plasma, trehalose, and DMSO, and loaded into a catechol–chitosan hydrogel solution at a ratio of 1:400 (v/v) with 5 × 10⁵ or 6 × 10⁶ cells per hydrogel to create a novel lyophilization method for cell integration into the biomaterial. Hydrogels were fabricated as scaffolds with a diameter of 5 mm and a depth of 4 mm. After lyophilization of the hydrogels with cells, a viability test was performed after the production of hydrogels on the seventh day and the fifth month. Palatal wounds were created as full-thickness wounds in rats using a 5 mm diameter punch. The hydrogels were applied to the palatal wounds of rats, and histochemical and immunohistochemical analyses were performed. The results showed that, after rehydration of the hydrogels, DFMSCs had over 80% viability and were homogeneously distributed in the hydrogels. After the application of DFMSC-loaded hydrogels, palatal wounds healed within 7 days, and inflammatory cell infiltration, fibroblastic proliferation, and ulceration were significantly reduced, while epithelial regeneration was significantly increased compared to the control group. The viability ratio of DFMSCs was 83.7% on the seventh day and 71.3% in the fifth month. Hydrogels loaded with DFMSCs represent a promising, ready-to-use biomaterial approach for supporting palatal wound healing. Full article

Dill is a valuable herb recognized for its rich nutritional composition and bioactive properties. Drying is an efficient preservation technique for maintaining its quality characteristics and ensuring longer storage stability. Incorporating ultrasonic pretreatment before the drying process can significantly reduce energy consumption (SEC) and greenhouse gas emissions. To the best of our knowledge, this is the first study to comprehensively evaluate ultrasound-assisted hybrid microwave–convective drying of dill (Anethum graveolens L.) leaves, focusing on the combined effects on drying kinetics, energetic and exergetic performance, providing an indirect emission estimate and multiple quality attributes. This study aimed to evaluate the drying kinetics, energy and exergy performance parameters, greenhouse gas emissions, quality properties (water activity, rehydration ratio and color) and antioxidant capacity of dill leaves dried by the microwave–hot-air (MW-HA) technique combined with ultrasonic (US) pretreatment. The experiments were conducted at MW power levels of 20%, 40%, and 60% (corresponding to a total output of 900 W), air temperatures of 40 and 60 °C, and US pretreatment durations of 0, 10, and 30 min. The results illustrated that rising MW power, air temperature and US duration significantly reduced the drying time, SEC and greenhouse gas emissions. At higher process conditions, specifically, 40% MW power, 60 °C drying temperature, and 30 min US pretreatment, the maximum energy efficiency (10.17%) and exergy efficiency (11.35%) were obtained. In terms of quality attributes, the best results were achieved at 40% MW power, 60 °C air temperature, and 10 min ultrasonic pretreatment, with reduced water activity (0.258), minimal color variation (ΔE = 11.44), improved rehydration ratio (3.88), and high retention of antioxidant activity. These findings demonstrate the potential of ultrasound pretreatment to enhance drying performance by reducing energy use and emissions while improving quality and antioxidant retention in dill, offering new guidelines for sustainable processing of this herb. Future studies should optimize microwave–hot-air-drying conditions to balance energy efficiency, exergy, and product quality. Full article

Edible mushrooms (Suillus luteus) represent valuable sources of nutrients and bioactive compounds that are sensitive to drying conditions. The objective of this study was to determine the drying time, kinetic model, effective diffusivity, activation energy, and color changes in S. luteus samples subjected to convective and vacuum drying at 70 and 50 °C, respectively, following pretreatments with 1% citric acid or blahing. The shortest drying time to reach equilibrium moisture was 14 h at 70 °C under a vacuum, whereas the longest was 44 h at 50 °C under convective drying. The Midilli, logarithmic, and Henderson and Pabis models provided the best fits for vacuum drying. The effective moisture diffusivity values ranged from 5.83 × 10⁻⁹ m²s⁻¹ at 50 °C to 1.159 × 10⁻⁸ m²s⁻¹ at 70 °C, while the mean activation energies for vacuum and convective drying were 10.27 kJmol⁻¹ and 24.7 kJmol⁻¹, respectively. The highest rehydration capacity was observed in untreated samples dried under a vacuum, with a value of 3.5 g H₂O/g dry matter, whereas convective drying yielded 2.4 g H₂O/g dry matter. The greatest shrinkage with respect to thickness was observed in those treated with citric acid and blanching. Correlation analysis of color revealed a strong negative relationship between lightness (L*) and total color difference (ΔE), as well as high positive correlations among a*, b*, and C*, suggesting that color transformations occur jointly throughout dehydration. The findings indicate that effective diffusivity increased with temperature, untreated samples exhibited greater water loss, and rehydration ratios were higher in untreated compared with pretreated samples. Full article

Climate change has intensified summer drought and high solar radiation in Mediterranean ecosystems, generating abiotic stress that limits the establishment of riparian species. We conducted a nursery experiment to evaluate the effects of two levels of water availability and light intensity on the growth and physiological responses of two native riparian species from Mediterranean Chile: Drimys winteri and Persea lingue. A bi-factorial design combined two irrigation treatments (well-watered and water restriction) and two light intensity levels manipulated through a light protection treatment (20% shade mesh and full light exposure). Water restriction was applied gradually until 15–20% (v/v) substrate moisture, defined as maximum water restriction, followed by rehydration. Morphological variables (height, root collar diameter, and shoot-to-root ratio) and physiological traits (predawn water potential, chlorophyll fluorescence, and electron transport rate) were measured. Growth responses were affected by the light protection treatment, which promoted a significant height growth in both species. Water stress affected the global response of both species but they differed in their post-stress hydraulic recovery: P. lingue fully recovered its predawn water potential, whereas Drimys winteri did not. Our study provides measurable and quantifiable values that demonstrate the sensitivity of these species to water stress. Full article

Achieving comprehensive improvements in the drying rate (DR) and the quality after drying of agricultural products is a major goal in the field of drying. To further shorten the drying time while improving product quality, this study introduced a Convolutional Neural Network (CNN) and MultiHead Attention (MHA) to enhance the prediction accuracy of the Long Short-Term Memory (LSTM) network regarding the properties of dried samples. These properties included DR, shrinkage rate (SR), and total color difference (ΔE). The CNN-LSTM-MHA network was proposed, developing a novel hot-air drying (HAD) scenario utilizing an intelligent temperature control system based on the real dynamics of material properties. The results of drying experiments with temperature-sensitive yuba showed that the CNN-LSTM-MHA network’s predictive accuracy was better than that of other networks, as evidenced by its coefficient of determination (R²: 0.9855–0.9999), root mean square error (RMSE: 0.0001–0.0099), and mean absolute error (MAE: 0.0001–0.0120). Comparative analysis with fixed-temperature drying indicated that CNN-LSTM-MHA-controlled drying significantly reduced drying time and enhanced the SR, color, rehydration ratio (RR), texture, protein content, fat content, and microstructure of yuba. Overall, the findings highlight the potential of CNN-LSTM-MHA-based intelligent drying as a viable strategy for yuba stick processing, providing insights for other food drying applications. Full article

The desiccation tolerant moss Hedwigia ciliata was investigated to assess its early reaction to water stress in controlled conditions. Thus, various photosynthetic parameters and water contents were studied during a selected time frame within 48 h of two main events, namely water loss after full hydration and activity (preparation for anabiosis) and water uptake after the state of anabiosis. The observations of the changes in the photosynthetic efficiency of Hedwigia ciliata in response to fluctuating relative water contents (RWCs) during rehydration and dehydration periods provide valuable insights into the species’ physiological adaptation mechanisms. Hedwigia ciliata rapidly uptakes water upon anabiosis, and despite being poikilohydric, it is able to retain water for a prolonged period compared to the water availability in its immediate environment. The delayed decrease in relative water content (RWC) corresponds to the photosynthetic parameters and preparation for anabiosis, including the maintenance of photosystems and general cell integrity. The low values of non-photochemical quenching during desiccation imply limited photoinhibition and effective photoprotective regulation. Conversely, the rather high values of the fluorescence decline ratio during rehydration reflect the efficient recovery of photosynthetic performance. The postponed physiological shutdown while drying and photosynthetic activity in the early dehydration phase suggest anticipatory acclimation to desiccation, i.e., non-active phase anabiosis. Hedwigia ciliata is a desiccation-tolerant moss, with anatomical, morphological, and eco-physiological adaptations, making it a useful model species in drought and abiotic stress studies of bryophytes in a rapidly changing environment. Full article

Background: The incorporation of edible mushrooms into fish-based products offers a promising approach to enhance nutritional quality and oxidative stability. Oyster mushrooms (Pleurotus ostreatus) are valued for their β-glucans and bioactive compounds. This study aimed to evaluate the effects of hot-air dried and freeze-dried oyster mushrooms, added at different levels, on the nutritional composition, lipid quality, and oxidative stability of carp burgers. Methods: Carp burgers were prepared with 0.5–2.0% (w/w) of hot-air dried or freeze-dried oyster mushrooms, rehydrated at a standardized ratio of 5:1. Nutritional composition, β-glucan content, fatty acid profile, and lipid oxidation were determined. Oxidative stability was assessed by peroxide, p-anisidine, and total oxidation, while nutritional quality was evaluated using lipid indices, including polyunsaturated-to-saturated fatty acid ratio (PUFA/SFA), and atherogenicity index. Results: Freeze-dried mushrooms preserved higher β-glucan content (5.80 g/100 g at 2% inclusion) than hot-air dried samples (2.21 g/100 g). Their addition lowered fat by 19.6% and enhanced oxidative stability, with peroxide and anisidine values reduced by 23% and 35%, respectively. Lipid nutritional indices improved, as the PUFA/SFA ratio increased by 15% and the atherogenicity index remained below 0.36 across all treatments. At 2.0% inclusion, freeze-dried mushrooms maximized β-glucan retention (96.9%) and reduced TOTOX by 22.2%. The optimal range for balanced oxidative protection was 1.5–2.0%. Conclusions: Incorporating freeze-dried oyster mushrooms at 1.5–2.0% with standardized rehydration improves the nutritional profile, fatty acid composition, and oxidative stability of carp burgers. These results provide practical parameters for developing functional fish products with enhanced health value and extended shelf-life. Full article

The high incidence of cardiovascular disease and the early failure of bioprosthetic valves due to calcification have driven the development of anti-calcification technologies. As a new storage technology, drying treatment is expected to delay the calcification process by reducing glutaraldehyde residues. However, the effects of drying treatment on the mechanical properties and valve functions of bovine pericardial materials are still unclear. The objective of this study is to evaluate the influence of drying and rehydration treatments on the mechanical integrity and geometric properties of bovine pericardium and the hemodynamic performance of bioprosthetic valves made with these tissues. Cross-linked bovine pericardial samples (n = 15) were divided into three groups—wet (control group progressed with normal glutaraldehyde), dehydrated (ethanol–glycerol dehydration), and rehydration (saline immersion) groups—and the geometric stability and nonlinear mechanical behaviors of the materials were analyzed via thickness measurements and uniaxial and biaxial tensile tests. Quantitative results showed that thickness remained stable across groups (wet: 0.356 ± 0.052 mm; dry: 0.361 ± 0.053 mm; rehydrated: 0.361 ± 0.053 mm, p > 0.05). Elastic modulus values were preserved (wet: 12.5 ± 1.8 MPa; dry: 13.1 ± 2.0 MPa; rehydrated: 12.7 ± 1.9 MPa, p > 0.05), and anisotropy ratio showed no significant changes (1.53 ± 0.06 vs. 1.57 ± 0.07, p > 0.05). The hemodynamic performance of bioprosthetic valves made with these materials was evaluated in vitro using a pulsating flow simulation. Hemodynamic parameters demonstrated excellent preservation: effective orifice area (wet: 2.625 ± 0.11 cm²; rehydrated: 2.585 ± 0.12 cm², Δ = 1.5%, p = 0.32) and regurgitation fraction (wet: 39.35 ± 2.9%; rehydrated: 42.78 ± 3.2%, p = 0.15) showed no statistically significant differences. The geometric properties of the material were not significantly changed by the drying treatment, and the material maintained its nonlinear viscoelastic characteristics and anisotropy. The rehydrated bioprosthetic valves did not differ significantly from those in the wet group in terms of the effective orifice area, regurgitation fraction, and transvalvular pressure difference, and the hemodynamic performance remained stable. Full article

In recent years, microwave and ultrasound technology has been under extensive development in drying technologies. Researchers are constantly searching for improved solutions or alternatives to hot air drying. The goal of this work was to determine the intermittent action of ultrasound and microwaves on convective drying. An examination of five specific cases of stationary and nonstationary drying processes was conducted. The evolution of moisture content and drying rate over process time was discussed, and the average drying rate and time, drying constant, effective diffusion coefficient, and specific energy consumption were also compared. To identify the differences between the dried products, the quality characteristics such as: water activity, color, shrinkage, rehydration, polyphenol content, odor, and flavor of apples were analyzed. The results indicate that intermittent drying provides a good alternative to convective drying, including when combined with microwave and ultrasound treatments. Applying microwaves or ultrasound intermittently resulted in an increase in the effective diffusion coefficient (by 68%) and drying rate (by 117%) and a reduction in drying time (by 53%), compared to convective drying. This processing method resulted in lower energy consumption by up to 13% and well-preserved quality attributes—this could be very promising for the production of healthy, ready-to-eat apple snacks. Full article

The milling process is a critical technological step that regulates wheat flour characteristics and ultimately determines end-product quality. This study systematically evaluated the effects of three key milling parameter adjustments in a laboratory-scale roller mill—double sifting (2S), double break milling (2BM), and increased roll gap (IRG)—on the physicochemical properties of wheat flour and the quality of microwave freeze-dried non-fried instant noodles. The results demonstrated that milling processes significantly influenced the particle size and composition of flour. The 2BM-IRG process increased the volume mean diameter of flour to 86.38 μm, while significantly improving flour extraction rate (69.80%), protein content (10.98%), and ash content (0.54%). In contrast, the 2S process significantly reduced the volume mean diameter (65.27 μm). These changes in flour properties directly affected noodle quality—noodles made from 2BM-IRG flour exhibited the highest rehydration ratio but also the greatest cooking loss, along with the lowest expected glycaemic index (eGI); noodles produced from 2S flour showed the highest hardness, while the 2BM process endowed noodles with superior elasticity. A correlation analysis revealed that the digestibility characteristics of noodles (eGI) were predominantly and significantly influenced by flour protein and ash content (p < 0.01), while also being significantly affected by particle size (p < 0.05). The study confirmed distinct quality trade-offs between different milling strategies. Therefore, by optimizing combinations of break milling and sifting processes, it is possible to develop specialized flour tailored for specific quality requirements. Full article