Dehydration Time Research Articles

Cryopreservation of Arum palaestinum plant callus as a strategy for mitigating extinction risks

Arum palaestinum is a wild perennial plant commonly known as "Al-Loof" in Jordan. Due to overharvesting, climate change, and increasing demand, its natural populations are threatened with extinction. Cryopreservation, an effective method for conserving plant material at ultra-low temperatures, is explored for A. palaestinum calli. We investigated the applicability of encapsulation-vitrification (using different plant vitrification solutions (PVS) and incubation times), encapsulation-dehydration (using sucrose or sorbitol at different concentrations and dehydration times), and the v-cryoplate (using different pre-culture times and temperatures) techniques. In the encapsulation-vitrification experiment, a notable 82.4 % regrowth rate was achieved by desiccating calli in plant vitrification solution 2 (PVS2) for 10 minutes at 25 °C. The encapsulation-dehydration technique resulted in an 82.6 % regrowth rate by incubating calli for one day in low sucrose levels (0.1 M sucrose) following one hour of air dehydration, where the moisture content of the beads was 30 %. The moisture content of the beads decreased from 81 % before chemical and air dehydration to 71 % after 0 hours of air dehydration combined with chemical dehydration using 0.1 M sucrose or sorbitol. It further dropped to 30–34 % after one day of chemical dehydration with 0.1 M sucrose and 1 hour of air dehydration. The v-cryoplate technique successfully conserved calli, showing impressive survival and regrowth percentages (96.8 %) when the callus was pre-cultured with 0.3 M sucrose for three days at 5 °C. Temperature during pre-culture significantly influenced regrowth percentages in the v-cryoplate technique. The study establishes promising cryopreservation protocols for A. palaestinum calli, offering a means to conserve germplasm and contribute to environmental and biodiversity protection by reintroducing endangered plants to their native habitats.

Conventionally cooked and UV-A light dehydrated beef jerky: Effects on physicochemical properties

This study compared beef jerky produced by conventional cooking and UV-A light dehydration. The analyses included the isopiestic method, colorimetric analysis, electron microscopy, infrared spectroscopy, and microbial inactivation studies. The primary criterion was a water activity (aw) value of < 0.85 to optimize UV-A dehydration time, taking 4.5 h to achieve this level. UV-A light dehydration resulted in significantly less browning compared to conventional cooking, yielding a duller, less red product (P < 0.05). Electron microscopy showed that UV-A light dehydration maintained a more uniform microstructure, while conventional cooking caused more structural deffects. Microbial inactivation studies demonstrated the antimicrobial effect of UV-A light by reducing accessible water (aw < 0.85). The hygroscopicity of UV-A light dehydrated jerky was similar to conventionally cooked jerky. Overall, UV-A light-dehydrated beef jerky had similar characteristics to conventionally cooked jerky but with notable differences that could appeal to specific consumer preferences.

Effects of dehydration time on performances of polyamidoamine-epichlorohydrin resin and its modified soybean-based adhesive

Soybean-based adhesive has been commercialized in the wood industry owing to its several advantages, such as no formaldehyde, good bonding properties, and renewability. However, the large-scale application of soybean-based adhesive is greatly limited by its significantly higher cost than urea-formaldehyde resin. Thus, in this study, a cost-effective polyamidoamine-epichlorohydrin (PAE) resin with improved crosslinking efficiency to soybean meal was prepared from branched polyamidoamine (PAA) with reduced dehydration time at high temperatures. Test results from GPC, FTIR and NMR analyses showed that traditional PAA synthesis involving 3-h dehydration time at 180 °C resulted in over-branching of PAA resin and poor crosslinking efficiency of PAE resin and decreased water resistance of obtained soybean-based adhesive. PAA resin synthesized at appropriate dehydration time (1 h) remained sufficient secondary amine groups for being grafted by epichlorohydrin to form effective PAE resin with more azetidinium groups. As a result, the water resistance of soybean-based adhesive crosslinked by the optimal PAE-1 resin prepared from 1 h-dehydrated PAA-1 significantly improved by 42.9 % compared with that of soybean-based adhesive crosslinked by traditional PAE resin, attributing to forming denser and stronger crosslinking networks after thermally cured. Consequently, this optimal PAE-1 could reduce the cost of soybean-based adhesive due to decreasing 16.7 wt% of PAE dosage without compromising bonding property and the energy consumption of PAA/PAE synthesis. Therefore, an appropriate decrease in the dehydration time of PAA resin at a high temperature provides an effective, economical, and energy-saving strategy to improve the bonding property of soybean-based adhesives.

Experimental Study on the Characteristics of Camellia oleifera Fruit Shell Explosion by Hot Air Drying

The shell explosion by hot air drying is a critical step in the processing of Camellia oleifera fruit (COF), which directly affects the degree of the shell explosion, and the separation effect of Camellia oleifera seed and Camellia oleifera shell after the shell explosion of COF. To reveal the characteristics of the COF shell explosion, a hot air drying device was designed based on mass conservation and drying principles. The physical characteristics of COF and the evolution of drying parameters were thoroughly analyzed with a combination method of drying analysis and experimental. Moreover, under the conditions of air temperature 50–70 °C, relative humidity 20–50%, and air velocity 1.3–1.9 m/s, the internal relationship between COF shell explosion formation through hot air drying and the hot air drying medium was systematically investigated by response surface methodology, and a prediction model for the shell explosion rate of COF by hot air drying was constructed using statistical methods. Results demonstrated that decreasing the relative humidity and increasing the temperature and air velocity of the drying medium could reduce the dehydration time of COF. The moisture content of Camellia oleifera shell was found to be 177.45% d.b. (dry basis) at the initial cracking stage of COF. Furthermore, at temperatures ranging from 50 to 70 °C Deff values of COF were estimated to be within the range of 0.915 × 10−9 to 1.782 × 10−9 m2/s. Similarly, at relative humidity levels of 20 to 50%, Deff values ranged from 1.226 × 10−9 to 1.501 × 10−9 m2/s. At an air velocity of 1.3 to 1.9 m/s, Deff values ranged from 0.956 × 10−9 to 1.501 × 10−9 m2/s. The measured values of the shell explosion rate were in close agreement with that calculated using the fitted model, with a correlation coefficient of 0.997 and a root mean square error of 0.9743. This study will provide a theoretical basis for optimizing the shell explosion process and improving shell explosion rate of COF by hot air drying.

Developing a simple and rapid method for cell-specific transcriptome analysis through laser microdissection: insights from citrus rind with broader implications

BackgroundWith the rapid development of single-cell sequencing technology, histological studies are no longer limited to conventional homogenized tissues. Laser microdissection enables the accurate isolation of specific tissues or cells, and when combined with next-generation sequencing, it can reveal important biological processes at the cellular level. However, traditional laser microdissection techniques have often been complicated and time-consuming, and the quality of the RNA extracted from the collected samples has been inconsistent, limiting follow-up studies. Therefore, an improved, simple, and efficient laser microdissection method is urgently needed.ResultsWe omitted the sample fixation and cryoprotectant addition steps. Instead, fresh samples were embedded in Optimal Cutting Temperature medium within 1.5 ml centrifuge tube caps, rapidly frozen with liquid nitrogen, and immediately subjected to cryosectioning. A series of section thicknesses of citrus rind were tested for RNA extraction, which showed that 18 μm thickness yielded the highest quality RNA. By shortening the dehydration time to one minute per ethanol gradient and omitting the tissue clearing step, the resulting efficient dehydration and preserved morphology ensured high-quality RNA extraction. We also propose a set of laser microdissection parameters by adjusting the laser power to optimal values, reducing the aperture size, and lowering the pulse frequency. Both the epidermal and subepidermal cells from the citrus rind were collected, and RNA extraction was completed within nine hours. Using this efficient method, the transcriptome sequencing of the isolated tissues generated high-quality data with average Q30 values and mapping rates exceeding 91%. Moreover, the transcriptome analysis revealed significant differences between the cell layers, further confirming the effectiveness of our isolation approach.ConclusionsWe developed a simple and rapid laser microdissection method and demonstrated its effectiveness through a study based on citrus rind, from which we generated high-quality transcriptomic data. This fast and efficient method of cell isolation, combined with transcriptome sequencing not only contributes to precise histological studies at the cellular level in citrus but also provides a promising approach for cell-specific transcriptome analysis in a broader range of other plant tissues.

Developing Effective Radio Frequency Vacuum Drying Processes for Moutan Cortex: Effect on Moisture Migration, Drying Kinetics, Physicochemical Quality, and Microstructure.

This study aims to maximize the post-harvest quality of Moutan Cortex and reduce energy consumption. Radio frequency vacuum (RFV) technology was used to dehydrate Moutan Cortex in this study to investigate the effects of different drying temperatures, plate spacing, and vacuum degree on the drying kinetics, physicochemical quality, and microstructure of Moutan Cortex. The results showed that RFV drying shortened the dehydration time of the Moutan Cortex by 10.71-28.57% and increased the drying rate by 15.79-54.39% compared to hot-air drying. The best color (∆E = 6.08 ± 0.28, BI = 26.97 ± 0.98) and relatively high retention of polysaccharides, total phenolics, total flavonoids, antioxidant properties, paeonol, gallic acid, paeoniflorin, and benzoylpaeoniflorin contents were observed in the dried products of Moutan Cortex at a drying temperature of 50 °C, spacing of 90 mm, and vacuum of 0.025 MPa. Analyzing the microstructure, it was found that RFV drying could effectively inhibit the shrinkage and collapse of the cellular structure, and a regular and loose honeycomb pore structure appeared inside the samples, which contributed to the rapid migration of the internal moisture. This study can provide a theoretical reference basis for the selection and application of industrialized processing methods of high-quality Moutan Cortex.

Effect of ultrasound combined with chemical pretreatment as an innovative non-thermal technology on the drying process, quality properties and texture of cherry subjected to radio frequency vacuum drying

To obtain high-quality cherry products, ultrasound (US) combined with five chemical pretreatment techniques were used on cherry prior to radio frequency vacuum drying (RFV), including carboxymethyl cellulose coating (CMC), cellulase (CE), ethanol (EA), isomaltooligosaccharide (IMO), and potassium carbonate + ethyl oleate (PC + AEEO). The effect of different pretreatments (US-CMC, US-CE, US-EA, US-IMO, US-(PC + AEEO)) on the drying characteristics, quality properties, texture, and sensory evaluation of cherries was evaluated. Results showed that the dehydration time and energy consumption were decreased by 4.17 − 20.83 % and 3.22 − 19.34 %, respectively, and the contents of individual sugars, soluble solid, total phenolics (TPC), natural active substances, total flavonoids (TFC), and antioxidant properties (DPPH, ABTS and FRAP) were significantly increased after US combined with five chemical treatments (P < 0.05). Moreover, the pretreatment played important role in improving texture properties and surface color retention in the dried cherries. According to the sensory evaluation analysis, the dehydrated cherries pretreated with US-CMC exhibited the highest overall acceptance, texture, crispness, color, and sweet taste showed lower off-odor, bitter taste and sour taste compared to control and other pretreatments. The findings indicate that US-CMC pretreatment is a promising technique for increasing physicochemical qualities and dehydration rate of samples, which provides a novel strategy to processing of dried cherry.

Understanding the evolution of moisture during isothermal dehydration of glutinous rice through global sensitivity analysis

This study examined the effect of layer thickness and temperature on the evolution of moisture during the isothermal dehydration of glutinous rice. To analyse the moisture evolution, empirical models and secondary models (SM) were employed. Global sensitivity analysis (GSA) was used to estimate the importance of the experimental parameters on the developed SM. According to the dehydration curves, the increase in temperature and reduction in the layer thickness significantly shortened (P<0.05) the dehydration time of glutinous rice. The effective diffusivity, activation energy, and Gibb-free energy were 2.0×10−12m2/s to 2.53×10−11m2/s, 43.03 kJmol−1 to 51.05 kJmol−1, and 145.10 kJmol−1 to 155.85 kJmol−1respectively. The Page and Logarithmic models are suitably considered in evaluating the dehydration kinetics of the glutinous rice with a high coefficient of determination (R2) values of >0.9989. The SM aptly described moisture evolution with higher accuracy of R2=0.9843. The GSA shows that the variation in the SM output is primarily driven by the variation in the input parameters with low reliance on its interaction with other parameters, indicating that the SM can play a significant role in the optimization of the industrial dehydration process with a wide range of applications in the agricultural production system.

Optimizing the preparation of paraffin sections from stallion testes.

The preparation of paraffin sections is an important experimental technique in animal histological research, and key factors that determine the quality of a section include the dehydration time, waxing time, and drying temperature of the paraffin section. Paraffin sections obtained from testis tissue of adult horses exhibited higher quality with clear tissue structure and complete cell morphology after they underwent gradient dehydration for 6 hours, were immersed in wax for 60 minutes, and were dried in a 75-degree oven for 15 minutes. The detailed, optimized procedures that are developed in the current study may simplify histological experiments and research on equine testes.

Vacuum frying of parsnip slices: Optimization by taguchi and response surface methodology and modeling the kinetics of water loss

We examined the optimization feasibility of frying conditions at 3 phases to produce crisp fried parsnip slices. In the first phase, the time of ultrasound-assisted osmotic dehydration, time of pre-drying by microwave, and frying pressure were considered as response-affecting factors and Taguchi technique effectively used in analyzing multiple parameters. The impact of process parameters (frying time, thermal driving force, & slice thickness) over the quality fried features parsnip slices (crispness, oil uptake, & optical features) was examined in the second phase. Cooling was performed in different conditions in the third phase. The vacuum frying’s optimal condition to produce fried parsnip slices was determined (parsnip slice thickness of 4.553 mm, ultrasound-assisted osmotic dehydration (immersed for 60 min in fructose solution), frying at 56.273 °C thermal driving force (146.2 °C) for 2.746 min at 70.1 frying pressure (kPa), & removing surface oil by centrifuging at 1200 rpm for 4 min). In this setting, the breaking force, oil uptake, and total color difference were predicted to be 12.217 %, 21.524 N, and 13.394, respectively. The impact of optimum frying conditions on the frying kinetics of parsnip slices was investigated. According to the findings, the model of Midilli et al. was considered the best.

Effect of ultrasound‐assisted osmotic dehydration on the drying characteristics and quality properties of goji

AbstractThe waxy layer on the surface of the goji fruit increases the dehydration time. In this study, the novel use of ultrasound pretreatment (10, 20, and 30 min) assisted with osmotic dehydration was utilized to improve drying efficiency and product quality of goji. The results showed that goji treated with ultrasound‐assisted osmotic dehydration lost more water and gained more solids during osmotic dehydration than goji treated with osmotic dehydration only. Furthermore, the ultrasound‐assisted osmotic dehydration pretreatment method shortened the drying time for freezing drying goji and lowered the water activity of the dried goji. This may be due to the destruction of the wax layer on the surface of the goji by ultrasound. The rehydration rate of the goji treated with ultrasound for 20 min was significantly higher than that of the samples dried by osmosis dehydration only. The application of ultrasound‐assisted osmotic dehydration resulted in the best color and the highest glutathione and total free amino acid content of goji, especially the taurine. Besides the above, the antioxidant capacity of ultrasound‐assisted osmotic dehydration‐treated goji was enhanced, with the highest 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radical scavenging capacity and ferric reducing antioxidant power (FRAP) values for the samples in the 20‐min ultrasound‐assisted group. The results demonstrate that ultrasound‐assisted osmotic dehydration not only reduces the drying time of goji but also enhances its product quality.Practical applicationsThis study explored the effects of different ultrasound‐assisted osmotic dehydration methods on the drying efficiency and quality of freeze‐dried goji. The findings provide a scientific basis for improving goji drying engineering and offer a potential strategy for enhancing goji quality.

Effect of indoor dehydration on the chemical composition of Marselan grapes in Heyang of China.

Marselan is a red wine grape variety with great brewing prospects. The aim of this study was to investigate the effect of postharvest indoor dehydration on the quality of Marselan grapes. For two consecutive years, the harvested grapes were dehydrated naturally indoors (24-28°C). Fresh grapes were used as a control, and dehydrated samples were taken every 7 days during the period of dehydration until ending at day 28. Dehydration treatment increased degrees Brix, reducing sugars, glycerol, and malic acid. On day 7, there was an increase in protocatechuic acid, p-coumaric acid, and total tannin of 26.00%-27.73%, 11.43%-52.52%, and 39.74%-70.45%, respectively. With increasing dehydration time, total phenols, total flavonoids and total flavanols in the skins were decreased by 17.05%-38.13%, 24.32%-57.38%, and 17.05%-59.48%, respectively, with an increase in pH, citric acid, and ascorbic acid contents of grape juice by 7.66%-21.43%, 100%-137.50%, and 61.29%-258.82%, respectively. On day 21, the esters were increased by 1.10-1.75 factors. Partial least square-discriminant analysis result of volatile compounds showed that ethyl acetate, 1-propanol, 1-propanol, 2-methyl-, 1-hexanol, and 1-butanol, 3-methyl- were the predominant characteristic flavor compounds during dehydration of Marselan grapes. The effect of indoor dehydration on Marselan grape quality offered application value for China's later dehydration wine production.

Impact of heat stress on thermal balance, hydration and cortical response among outdoor workers in hot environment- an exploratory report from North East India.

The objective of our study was to assess the impact of heat stress on hydration and cognition among outdoor workers in hot environment. Area heat stress assessments were measured using Quest Temp WBGT monitor. Sweat rate for dehydration and reaction time for acute cognitive processing were recorded using standard procedures. Heat stress measurements ranged from 23.8 °C- 42 °C. More than 50 % of the workers had high sweat rate (>1.2 L/h) when exposed to high environmental temperatures. Positive correlation was obtained between WBGT, sweat rate and reaction time which indicates that hyperthermia has an impact on neural network processing. Heart rate and reaction time also increased with rise in WBGT and heavy physical activity. There was impairment of cognitive functions (reaction time) under heat stress conditions. Hence, reaction time can be used to assess the short-term impact of heat stress on neural modulation and will help to plan effective intervention strategies to reduce morbidity and mortality among workers.

Physical and Chemical Properties of Convective- and Microwave-Dried Blackberry Fruits Grown Using Organic Procedures.

This study aimed to evaluate the effect of convective and microwave drying on the bioactive-compounds content of blackberry (Rubus fruticosus) fruits, as well as drying parameters and energy consumption. The fruit was dehydrated in a convective dehydrator at a temperature of 50 °C and 70 °C and in a microwave oven at power levels of 90 W, 180 W and 240 W. The highest amount of anthocyanins, polyphenols and antioxidant capacity were obtained in blackberry fruits that were microwave dried at 90 W and 180 W (46.3-52.5 and 51.8-83.5 mg 100 g-1 dm of total anthocyanins, 296.3-255.8 and 418.4-502.2 mg 100 g-1 dm of total phenolics, and 1.20-1.51 and 1.45-2.35 mmol TE 100 g-1 dm of antioxidant capacity for 90 W and 180 W models, respectively). It turned out that microwave dehydration shortened the processing time and lowered the energy consumption compared to convective drying (a significantly reduced drying time of 92-99% with microwave dehydration). Blackberry fruits dehydrated at 240 W showed the shortest dehydration time (59-67 min), minimal energy consumption (0.23 kWh) and the most efficient diffusion (1.48-1.66 × 10-8 m2 s-1).

Cryopreservation and assessment of genetic fidelity Acorus calamus Linn., an endangered medicinal plant

BACKGROUND: Acorus calamus Linn. is a medicinally valuable monocot plant belonging to the family Acoraceae. Over-exploitation and unscientific approach towards harvesting to fulfill an everincreasing demand have placed it in the endangered list of species. OBJECTIVE: To develop vitrification-based cryopreservation protocols for A. calamus shoot tips, using conventional vitrification and V cryo-plate. MATERIALS AND METHODS: Shoot tips (2 mm in size) were cryopreserved with the above techniques by optimizing various parameters such as preculture duration, sucrose concentration in the preculture medium, and PVS2 dehydration time. Regenerated plantlets obtained post-cryopreservation were evaluated by random amplified polymorphic DNA (RAPD) to test their genetic fidelity. RESULTS: The highest regrowth of 88.3% after PVS2 exposure of 60 min was achieved with V cryo-plate as compared to 75% after 90 min of PVS2 exposure using conventional vitrification. After cryopreservation, shoot tips developed into complete plantlets in 28 days on regrowth medium (0.5 mg L-1 BAP, 0.3 mg L-1 GA3, and 0.3 mg L-1 ascorbic acid). RAPD analysis revealed 100% monomorphism in all cryo-storage derived regenerants and in vitro donor (120-days-old) plants. CONCLUSION: Shoot tips of A. calamus that were cryopreserved had 88.3% regrowth using V cryo-plate technique and the regerants retained genetic fidelity.

Waste Lime Earthwork Management Using Drone and BIM Technology for Construction Projects: The Case Study of Urban Development Project

Recently, there has been a recognized need to use waste lime landfills for land reclamation projects. Waste lime earthwork is more challenging than general earthwork operations due to potential health and safety hazards and significant changes in earthwork volume. There has been substantial research undertaken on the role of advanced construction technologies in general earthwork; however, their potential in hazardous waste lime environments for earthwork management is yet to be explored. This research proposes a methodology that integrates drone and BIM construction technology for effective and efficient hazardous waste lime earthwork management for construction projects. Drones are used for surveying, providing as-built information, and BIM to model, process, and evaluate the progress of waste lime earthwork. Volume change analyses are conducted using BIM to calculate dehydration time due to the ripple effect of waste lime for cost-efficient earthwork haulage. The case study provides evidence that the proposed method using advanced construction technologies improves productivity, safety, cost control, and better project management for earthwork related to hazardous waste materials.

An effective cryobanking approach preserving the genetic, physiological and phytochemical stability of Polyscias filicifolia Bailey hairy roots

Cryopreservation procedures can affect the physiological and genetic stability of stored samples, as well as their biosynthetic potential, which is particularly important for medicinal plants; as such, it is necessary to refine a number of factors to ensure the effective long-term storage of plant cells. The article describes an effective method of cryopreservation of Polyscias filicifolia hairy roots. Briefly, hairy roots were subjected to osmotic dehydration (OD) with or without subsequent air dehydration (AD; for three to six hours) for cryobanking in liquid nitrogen. After regeneration, genetic stability was assessed using Inter Simple Sequence Repeats (ISSRs) and Start Codon Targeted (SCoT) markers, together with nuclear DNA content, survival rate and biomass growth. In addition, chlorogenic (CGA) and oleanolic acid (OA) yields were determined using HPLC-UV-Vis, and the extract profiled by HPLC-PDA-ESI-HRMS, and the antioxidant potential of the treated root extracts was assessed. OD alone was found to be insufficient for cryopreservation; it was necessary to precede it with AD. The highest survival (93%), and biomass growth (up to 3-fold), were noted for roots subjected to OD preceded by six-hour AD; however, AD had a detrimental effect on the genetic stability of roots when applied for five or six hours. Longer dehydration times correlated with greater CGA biosynthesis. Further, CGA content was enhanced to 2.6 mg g−1 dry weight (DW) at six months post regeneration and 2.2 mg g−1 at 12 months. OA yield was not affected by the cryopreservation conditions. HPLC-PDA-ESI-HRMS analysis confirmed that the main component was CGA, accompanied by ferulic acid derivatives, 3,5-O-dicaffeoylquinic acid (isochlorogenic acid A) and 5-p-coumaroylquinic acid. Interestingly, the profile of biosynthesized compounds in the roots did not change during cultivation for up to 12 months. The highest antioxidant activity, determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric-reducing antioxidant power (FRAP) assay, was noted for the extract from the OD variant, which also demonstrated the highest total phenolic content. Our findings indicate that OD followed by four-hour AD provides the best protection for hairy root meristems with regard to genetic stability, reliable growth and secondary metabolite biosynthesis capabilities.

Effect of Sonication and Edible Coating on Total Phenolic Content, Antioxidant Capacity, and Physical Characteristics of Infrared-Dried Sweet Cherries

This research studied the influence of combined ultrasonic (40 kHz, 150 W, for 3 min) and 0.2% xanthan gum (XG), guar gum (GG), and wild sage seed gum (WG) coating pretreatments on total phenolic content, antioxidant activity, drying time, effective water diffusivity coefficient ( D eff ), rehydration ratio (RR), total color difference ( Δ E ), and surface shrinkage (SS) of infrared-dried sweet cherries. The ultrasonic pretreatment increased the water transfer rate and water diffusivity during infrared drying and decreased the drying time of fresh sweet cherries. The edible coating enhanced the total phenolic content, antioxidant activity, dehydration time, and RR and decreased the D eff , Δ E , and SS values of infrared-dried sweet cherries. The highest value of total phenolic content (3469.7 μg galic acid/g dry) was recorded for pretreated sweet cherry samples by GG. The mean antioxidant activities for uncoated, XG-coated, GG-coated, and WG-coated sweet cherries were 35.64, 59.88, 54.38, and 61.19%, respectively. In this study, the sweet cherry D eff varied from 2.23 × 10 − 9 m2/s (for untreated cherries) to 5.00 × 10 − 9 m2/s (for sonicated and uncoated cherries). The experimental data for the drying curves were fitted to various single-layer equations, and the Page equation using the experimental constants best described the drying rate of sweet cherries. The mean Δ E values for uncoated, XG-coated, GG-coated, and WG-coated sweet cherries were 15.11, 9.91, 8.74, and 10.69, respectively.

The Effect of Dehydration on Tooth Color: A Prospective In Vivo Study.

Introduction The influence of dehydration on tooth shade constitutes a significant aspect, making it a pivotal area of study, particularly within the field of restorative dentistry. This prospective study was done to analyze, using a spectrophotometer, how dehydration affects the shade of the teeth. Materials and methods Twenty-five participants were recruited in this prospective study that took place in the Dental Care Center of Saint Joseph University of Beirut (Lebanon) between October 2022 and January 2023. The inclusion criteria for this study primarily comprised four intact maxillary incisors. On the other hand, damage, cavities, restorations, and staining served as exclusion criteria. The VITA Easyshade Advance (Vident,Brea,CA) spectrophotometer was used to record the measurements. The measures of L (which represents darkness to lightness), a (which represents greenness to redness), and b (which represents blueness to yellowness)were registered at the center of each tooth's labial surface at baseline and then at 10-minute intervals for 30 minutes while the teeth were dehydrating due to the placement of a rubber dam. The color difference (ΔE) was later calculated using L*a*b* measures, with the perceptibility threshold set at ΔE00=0.8. Statistical analyses were performed using the Friedman test, the Bonferroni post hoc test, and the Wilcoxon signed-rank test. Results The different color changes represented byΔE(ΔE1, ΔE2, and ΔE3) were found to be significantly higher than the perceptibility threshold of 0.8 (p<0.001). A statistically significant difference was found between ΔE1 and ΔE3 (p<0.05). Moreover, a statistically significant difference was found between L0, L10, L20, and L30 (p<0.001). Statistically significant differences (p<0.05) exist between the means of L0 and L20, the means of L0 and L30, the means of L10 and L20, and the means of L10 and L30. Conclusion This study showed that dehydration affected the shade of the teeth: Lightness increased, and therefore, the teeth appeared whiter. Dentists should consider the hydration status of the teeth when evaluating color for treatments, as dehydration can significantly affect shade matching: the more the dehydration time elapses, the more the color difference compared to the baseline increases.

Intrinsic Molecular Mechanisms of Transformation between Isomeric Intermediates Formed at Different Stages of Cysteine-Xylose Maillard Reaction Model through Dehydration.

2-Threityl-thiazolidine-4-carboxylic acid (TTCA) and Amadori rearrangement product (ARP), the isomeric intermediates derived from the cysteine-xylose (Cys-Xyl) Maillard reaction model, possessed the ability to produce similar flavor profile during the thermal process, but the flavor formation or browning rate of heated TTCA was significantly lower than that of ARP. Macroscopically, the yield of TTCA reached the maximum when the moisture content of the reaction system just dropped to nearly 0% during the thermal reaction-vacuum dehydration process. During the subsequent dynamic intramolecular dehydration process, the reaction remained at an early stage of the Maillard reaction, and TTCA was the main intermediate. Thereinto, the water activity of the samples decreased with the increased dehydration time. From a molecular perspective, the dissipation of free water promoted the conversion of combined water to immobilized water and free water, increasing the intramolecular dehydration. Instantaneous high-temperature dehydration during the spray drying process revealed a higher efficiency than the thermal reaction-vacuum dehydration process, which facilitated the specific conversion of substrates to intermediates (TTCA, ARP). The loss of free water and immobilized water was a key driving force for the direct formation of TTCA/ARP, regulating the formation stages of MRIs. The increase of the inlet air temperature could alter the ratio of TTCA and ARP at the equilibrium state.