Rehydration Kinetics Research Articles

Thermoanalytical study of protein state during rehydration and rehydration kinetics in osmotically dehydrated pork meat (Longissimus dorsi): Insights from Peleg and Weibull models

Osmotically dehydrated pork meat (Longissimus dorsi), in the molasses, was used in the aim to study the protein state during rehydration. Protein state and rehydration kinetics are crucial for obtaining the desired meat product quality. The thermoanalytical techniques were employed to follow protein state and kinetics of rehydration. Obtained kinetic parameters were Peleg's rate constant (k1), 34.43, 6.23, and 10.15 (min (kg d.m.)(kg water)−1) and Peleg's capacity constant (k2), 0.726, 1.243, and 0.860 at 20, 30, and 40 °C, respectively. Parameters of Weibull's model, α, β (min), at 20 °C were 34.4; 0.86, at 30 °C were 6.24; 1.24, at 40 °C were 10.15; 0.86. From obtained enthalpies (ΔHd) and temperatures (Td) of meat proteins denaturation, it was found that proteins were partly denatured and gradually lost their structure and thermal stability during rehydration. Rehydration kinetic parameters indicated that most efficient rehydration was found to be at the 40 °C.

Quality variation analysis and rehydration kinetics modeling of yuba subjecting to three different drying process

This study investigated the effects of hot air drying (HAD), microwave vacuum drying (MVD), and vacuum frying drying (VFD) on the quality of yuba and utilized mathematical models (Peleg model, Weibull equation, first-order kinetic model, and exponential association model) to explore the rehydration kinetics of yuba. The results indicated that, compared to HAD, MVD significantly increased yuba's L* value and sensory score, while VFD notably reduced the cooking loss rate and enhanced moisture retention. Significant changes were observed in the texture of yuba before and after cooking, with distinct differences noted under microscopic observation, and a pronounced change in protein secondary structure. The Peleg model can effectively fit the rehydration processes of HAD and VFD yuba, while the first-order kinetic model can effectively fit the rehydration processes of MVD yuba. This study provides a valuable reference for yuba's drying method and rehydration Kinetics model.

Low-moisture extruded mung bean protein isolate and wheat gluten: Structure, techno-functional characteristics and establishment of rehydration kinetics of the products

Low-moisture extruded products provide excellent shelf-life and stability, making the exploration of new formulations with various proteins highly valuable. This study prepared and compared products with different ratios of mung bean protein isolate (MPI) to wheat gluten (WG) (10:0, 9:1, 8:2, 7:3, 6:4, and 5:5). Results showed significant improvements (P < 0.05) in L∗-value and product quality with increasing WG ratios, peaking at an MPI/WG ratio of 7:3. Increased WG also enhanced protein cross-linking aggregation, as evidenced by changes in particle size, secondary structure, and fluorescence spectra. However, excessive WG (MPI/WG = 6:4) adversely affected product structure and techno-functional characteristics. Rehydration kinetics were best described by the Peleg model, with rehydrated products showing decreased hardness (291.25 N) and chewiness (227.45 N), but increased tensile resistance (P < 0.05). Eleven quadratic polynomial equations were developed to predict color and techno-functional characteristics based on WG percentage (0–50%). The findings provide a theoretical basis for expanding the application of MPI in new low-moisture extruded products.

Seasonality in embolism resistance and hydraulic capacitance jointly mediate hydraulic safety in branches and leaves of oriental cork oak (Quercus variabilis Bl.).

Seasonality in temperate regions is prominent during the era of increased climatic variability. A hydraulic trait that can adjust to seasonally changing climatic conditions is crucial for tree safety. However, little attention has been paid to the intraspecific seasonality of drought-related traits and hydraulic safety of keystone forest trees. We examined seasonal variations in the key morphological and physiological traits as well as multiple hydraulic safety margins (SMs) at the branch and leaf levels in oriental cork oak (Quercus variabilis Bl.), which is predominant in Chinese temperate forests. Pneumatic measurements indicated that, as seasons progressed, the water potential at which 50% of branch embolisms occur (P50_branch) decreased from -3.34 to -4.23MPa, with a coefficient of variation (CV) of 9.08%. Sapwood capacitance ranged from 48.19 to 248.08kgm-3MPa-1, peaking in autumn and reaching minimum in winter (CV 60.58%). Rehydration kinetics confirmed higher leaf embolism vulnerability (P50_leaf) in spring and autumn than those in summer, with values ranging from -1.06 to -3.02MPa (CV 39.85%). All leaf pressure-volume (PV) traits shifted with growth, with CVs ranging from 6.95% to 46.69%. Sapwood density had significant negative correlations with P50_branch and hydraulic capacitance for elastic water storage, whereas leaf mass per area was linearly associated with PV traits but not with P50_leaf. Furthermore, the branch typical SMs (difference between branch midday water potential and P50_branch) were consistently >1.84MPa, and vulnerability segmentation was prevalent throughout, implying a plausible hydraulic foundation for the dominance of Q. variabilis. Diverse hydraulic response patterns existed across seasons, leading to positive SMs mediated by the aforementioned physiological traits. Although Q. variabilis exhibits a high level of hydraulic safety, its susceptibility to sudden summer droughts may increase due to global climate change.

Suitable Model for Rehydration of Dried Red Beets: Effect of Solid-to-Liquid Ratio on Rehydration Characteristics

Rehydration of food products was carried out in various amounts of liquid. The effects of the solid-to-liquid ratio on rehydration characteristics of dried red beets were investigated. Six values of the solid-to-liquid ratio (1:20, 1:15, 1:10, 1:5, 1:3, and 1:1) were taken into consideration. Red beets cubes (10 mm) were dried in a forced convection (2 m/s; 60 °C) and then rehydrated in distilled water at a temperature of 20 °C. The kinetics of mass gain, dry matter loss, water gain, moisture content increase, and volume increase were modeled using the empirical Peleg model which parameters have physical meanings. Equations were formulated to make the Peleg model parameters dependent on the solid-to-liquid ratio. The obtained results indicated that the amount of rehydrating water influenced the values of the model parameters and the course of dried red beets rehydration and helped explain the rehydration kinetics. The Peleg model can be recommended for describing the kinetics of mass gain (R2 = 0.9662–0.9895), dry matter loss (R2 = 0.7042–0.9881), water gain (R2 = 0.9732–0.9913), moisture content increase (R2 = 0.9770–0.9929), and volume increase (R2 = 0.9374–0.9847) during the rehydration of dried red beet cubes at all considered values of the solid-to-liquid ratio.

Energy analysis, mass transfer, and rehydration kinetics of okra dried using evacuated tube solar dryer

ABSTRACT Okra (Abelmoschus esculentus L.), like most fruits and vegetables, deteriorates quickly after harvesting due to its high moisture content and respiration rate. To preserve it and mitigate the post-harvest losses, a developed evacuated tube solar dryer (ETSD) with heat pipes was used to dry fresh okra. Thermal profiling of the ETSD was carried out to investigate the range of temperature gain inside the drying chamber. The effect of different blanching temperatures, viz. 70, 80, and 90°C, on drying characteristics and physical properties like color, water activity, and rehydration kinetics of okra were investigated. The energy efficiency of the collector ranged from 13.21% to 42.67%. Similarly, the convective mass transfer coefficient was calculated and ranged from 3.41 × 10−07 to 8.57 × 10−07 m/s. The okra blanched at 80°C, showing maximum greenness retention and lower water activity. The rehydration ratio was 6.05, 7.19, 7.73, and 7.41 for control, and okra blanched at 70, 80, and 90°C. The rehydration kinetics were analyzed using four distinct models: Peleg, Weibull, exponential, and first order. The Weibull model demonstrated the most accurate fit to the data. It is suggested that okra blanched at 80°C and dried under ETSD gives better retention of color and a higher mass transfer and rehydration rate.

Mechanistic understanding of the improved drying characteristics and quality attributes of lily (Lilium lancifolium Thunb.) by modified microstructure after pulsed electric field (PEF) pretreatment

The effects of the non-thermal (pulsed electric field, PEF) and thermal pretreatment (vacuum steam pulsed blanching, VSPB) on the drying kinetics, quality attributes, and multi-dimensional microstructure of lily scales were investigated. The results indicate that both PEF and VSPB pretreatments improved the drying rate compared to untreated lily scales. Specifically, PEF pretreatment reduced the drying time by 29.58 % − 43.60 %, while VSPB achieved a 46.91 % reduction in drying time. PEF treatment facilitated the enhanced leaching of phenols and flavonoids compared to VSPB treated samples, thereby increasing antioxidant activity. The rehydration ratio of the dried lilies was improved with PEF and VSPB treatment, which closely related to the microstructure. Weibull distribution and Page model demonstrated excellent fit for the drying and rehydration kinetics of lily scales, respectively (R2 > 0.993). The analysis of multi-dimensional microstructure and ultrastructure confirmed the variations in moisture migration and phytochemical contents among different treatments. Consequently, this study offers insights into the technological support for the potential of non-thermal pretreatment in fruits and vegetables.

Innovative hybrid strategy for quality improvement of Goji tea: ultrasonic-ethyl oleate pretreatment combined with heat pump drying.

Goji berries, renowned for their nutritional benefits, are traditionally dried to extend shelf life and preserve quality. However, conventional drying methods often result in uneven drying, color loss and reduced rehydration capacity. This study investigates an innovative hybrid strategy combining ultrasonic-ethyl oleate (US+AEEO) pretreatment with heat pump drying (HPD) to enhance the drying process of Goji berries. Fresh Goji berries underwent US+AEEO pretreatment, which significantly disrupted the waxy layer, enhancing drying efficiency and water infiltration during rehydration. Compared to freeze drying (FD), HPD combined with US+AEEO pretreatment resulted in higher retention of total polyphenol content (TPC) and total flavonoid content (TFC) in the Goji soaking soup. Specifically, the HPD-US+AEEO samples exhibited the highest TPC and TFC levels, significantly outperforming FD samples. Additionally, the DPPH and ABTS antioxidant assays demonstrated higher scavenging activities in HPD-US+AEEO samples. The rehydration kinetics revealed that HPD samples had a superior rehydration rate and final moisture content compared to FD samples. Low-field nuclear magnetic resonance and magnetic resonance imaging analyses confirmed enhanced water distribution and higher mobility in HPD-US+AEEO samples. Scanning electron microscopy indicated a more porous structure in US+AEEO-treated samples, facilitating better water absorption and functional component retention. The combination of US+AEEO pretreatment with HPD significantly improves the drying process of Goji berries, enhancing nutrient retention, color preservation and rehydration properties. This innovative drying method offers a promising solution for producing high-quality dried Goji berries, benefiting both the food industry and health-conscious consumers. © 2024 Society of Chemical Industry.

Microwave-vacuum drying: Modeling validation of drying and rehydration kinetics, moisture diffusivity and physicochemical properties of dried dragon fruit slices

This study investigated the drying of dragon fruit slices with varying samples (0.5 cm, 1 cm, and 1.5 cm) using a microwave-vacuum dryer at power levels of 400 W, 600 W, and 800 W, under a vacuum pressure of 600 mm Hg. The comprehensive assessment included drying kinetics, effective moisture diffusivity (Deff), rehydration behavior, color changes, and ascorbic acid content. Results indicated a substantial moisture content reduction from an initial 614.28% to an average of 7.14% (dry basis) post-microwave vacuum drying. The Wang and Singh model proved most suitable, exhibiting high R2 values and low RMSE values, providing accurate insights into the drying process. Dragon fruit samples showed Deff values from 4.381 × 10−3 to 4.084 × 10−2 cm2/min, increasing with microwave power level. Rehydration, modeled by the Peleg model, revealed that the highest power level had the highest R2 and lowest RMSE values. Notably, 1.5 cm slices at 400 W exhibited minimal color change (18.32) and retained the most ascorbic acid (6.94 mg/100 g). This study offers valuable insights into dragon fruit drying, highlighting its impact on moisture content, modeling, and product quality.

Kinetic and artificial neural network modeling of dried black beauty eggplant (Solanum melongenaL.) slices during rehydration

AbstractThis paper targeted to investigate rehydration characteristics of dehydrated black beauty eggplant (which was dried under sun, by hot air, microwave, and infrared) at 25, 50, and 75°C, and to analyze rehydration ratio (RR) by artificial neural network (ANN) approach. RRs of both microwave‐processed specimens (between 5.66 and 7.91) and sun‐dried ones (between 5.38 and 6.37) were always greater than the others, at all rehydration temperatures. Rehydration temperature had an enhancing effect on RRs, and the image that closely resembled the fresh sample was captured in the microwave‐dried rehydrated samples. Nearly 180–240 min was adequate for rehydration of all slices. Zeroth‐ and first‐order kinetic models, Peleg, Peppas, and two‐term exponential decay models, as well as a new rational model were tested to describe rehydration kinetics. Two‐term equation was almost superior with high R2 (between 0.9734 and 0.9994) and the lowest root mean square error (RMSE) and χ2. Novel recommended mathematical expression was also successful (R2: 0.9679–0.9989, χ2: 0.0051–0.0975, RMSE: 0.0191–0.0866). Regarding relationship between actual and predicted RRs and performance indices of ANN equation, overall R and R2 were recorded as follows: 0.9975–0.9950 (sun‐dried) &gt; 0.99642–0.9929 (hot air‐dried) &gt; 0.9955–0.9911 (infrared‐dried) &gt; 0.9907–0.9815 (microwave‐dried), respectively. The proposed ANN model and novel mathematical formula not only offer a considerable potential in predicting rehydration patterns and developing rehydration protocols in food production sector, but also contribute to save energy by completely understanding the process and optimizing conditions.Practical applicationsThe eggplant is a cherished vegetable often dried, providing a velvety texture and rich taste in Anatolian recipes. In Anatolia, colorful vegetables are strung together on strings, adorning traditional houses, and serving as a testament to the region's deep‐rooted cultural heritage. The Turkic people in Central Asia demonstrated remarkable skill in preserving plants by carefully drying leaves, stems, or roots. The process of rehydration entails the addition of water to dehydrated eggplant slices in order to restore their initial dimensions and attributes for being consumed. This investigation integrates the utilization of ANNs to simulate the rehydration procedures of eggplant. This simulation can be employed for the purpose of quality control and standardization within the food sector. Hence, food manufacturers can anticipate the rehydration characteristics of their products across various production batches and conditions, thereby guaranteeing adherence to quality benchmarks.

The interplay between trehalose and dextran as spray drying precursors for cationic liposomes

Successful oral delivery of liposomes requires formulations designed to withstand harsh gastrointestinal conditions, e.g., by converting to solid-state followed by loading into gastro-resistant delivery devices. The hypothesis was that the use of dextran-trehalose mixtures for spray drying would improve the rehydration kinetics of dried liposomes. The objectives were to determine the protective capacity of trehalose-dextran dehydration precursors and to increase the concentration of liposomes in the dry formulation volume. The study successfully demonstrated that 8.5% dextran combined with 76.5% trehalose protected CAF®04 liposomes during drying, with the liposome content maintained at 15% of the dry powder. Accordingly, the rehydration kinetics were slightly improved in formulations containing up to 8.5% dextran in the dry powder volume. Additionally, a 2.4-fold increase in lipid concentration (3 mM vs 7.245 mM) was achieved for spray dried CAF®04 liposomes. Ultimately, this study demonstrates the significance of trehalose as a primary carrier during spray drying of CAF®04 liposomes and highlights the advantage of incorporating small amounts of dextran to tune rehydration kinetics of spray-dried liposomes.

Effect of different drying methods on the rehydration kinetics, physiochemical and functional properties of unripe plantain (Musa parasidiaca) flour

Plantain (Musa parasidiaca) is a perishable fruit that needs to be processed into flour to extend its shelflife. It is therefore essential to develop specifications for drying Musa parasidiaca pulp to obtain high quality flour and reduce wastage. The study specifically examined functional properties such as bulk density, least gelation concentration, swelling power, oil absorption capacity, tapped density and pH of the unripe Musa parasidiaca flour. Additionally, the proximate composition such as moisture content, ash, crude protein, crude fibre carbohydrate and crude fat were also investigated. The results showed that the method of drying has a significant effect on the carbohydrate and moisture content of the unripe Musa parasidiaca flour. As regard to the crude protein, it was revealed that there were no significant differences between microwave dried (3.75 %) and sun dried (3.84 %) flours. Bulk density of the unripe Musa parasidiaca flour samples dried in the microwave dryer (MD), sun drying (SD) and oven dryer (OD) were 0.66 g/mL, 0.60 g/mL and 0.77 g/mL respectively. It was observed that all the three methods of drying significantly impacted on the bulk density of the unripe Musa parasidiaca flour. There were also marked differences in the rehydration ratios (RR), and the moisture diffusivities of the various Musa parasidiaca flours. The study concludes that the colour of the MD unripe Musa parasidiaca flour was significantly different from that of the SD unripe Musa parasidiaca flour.

Effect of different pre-treatments on rehydration kinetics of solar and hot-air dried Fuji apple slices

The present study demonstrates the effect of direct solar drying (DSD) and hot air drying (HAD) on the quality attributes of Fuji apple slices. DSD samples took a longer time (150–180 min) to dry and simultaneously reached higher equilibrium moisture content at the end of rehydration than HAD samples. DSD samples have higher rehydration ability, dry matter holding capacity, and water absorption capacity than HAD samples. Among several empirical models, the Weibull model is the best fit with higher R2 (0.9977), lower root mean square (0.0029), and chi-square error (0.0031) for describing the rehydration kinetics. Rehydrated HAD samples showed better color characteristics than DSD in terms of overall color change, chroma, and hue angle values. Whereas the hardness and chewiness of rehydrated DSD samples were better than HAD samples because of higher dry matter holding capacity in DSD. Apart from color retention, the DSD samples showed better rehydration capacity and a good texture upon rehydration than HAD slices.

Effect of salt pretreatments on physico-chemical, cooking and rehydration kinetics of instant rice.

The online version contains supplementary material available at 10.1007/s13197-023-05877-y.

Effect of pulsed electric field pretreatment on mass transfer during hot air drying: Drying and rehydration properties of sweet potato

In this study, to investigate the effects of various pulsed electric field (PEF) strengths (0.5–2.5 kV/cm) on drying sweet potato, drying kinetics, mass transfer rate, rehydration kinetics, and microstructure of sweet potato during hot air drying were observed. After pretreatment of PEF, electric conductivity, and Z- index were increased as the strengths of PEF increased. The drying time was approximately 420 min for PEF at 1.5 kV/cm - 2.5 kV/cm and was almost 500 min for control group and the maximum values for moisture diffusivity and mass transfer was observed in 2.5 kV/cm. The shrinkage ratio and microstructure of sweet potatoes did not differ among groups; however, parenchyma cell membranes were empty and disrupted by PEF. The rehydration time decreased as the PEF strength increased, similar to the trend in drying times. PEF pretreatment resolves long-term hot air drying side effects such as quality deterioration and time requirements.

Drying and Rehydration Characteristics of Microwave Dried Mytilus edulis

Rehydration is a critical factor in the processing and consumption of dried food products. This study investigated the kinetics of microwave drying and rehydration of blue mussels (Mytilus edulis) in the range of 140 - 350 W power levels and 20 - 40°C temperatures, respectively. The drying data were utilized to calculate effective diffusivity coefficients (Deff) and activation energy (EA), while rehydration rates and time were also determined. Mathematical modeling was employed to describe the drying and rehydration processes, and the performance of different models was evaluated. The drying process took between 13 - 4.5 minutes, while rehydration was concluded within 360 - 480 minutes. The Deff values ranged from 1.22 - 3.91×10-7 m2/s, and the EA was calculated as 11.417 kW/kg. Rehydration rates resulted in 0.000061 - 0.000126 g/g×min at the highest 40°C and 0.000018 - 0.000032 g/g×min at the lowest 20°C. The drying and rehydration processes were best described by the Alibas model among 11 models and the Two-Term Exponential model among 2 models, respectively. Overall, this study aims to provide valuable insights into the kinetics of microwave drying and rehydration of blue mussels, which can help optimize the processing and preservation of dried food products before consumption.

Rehydration Kinetics of Dehydrated Vegetables Pre-Treated By Ohmic-Blanching

Rehydration Kinetics of Dehydrated Vegetables Pre-Treated By Ohmic-Blanching

Effect of Biopolymer Dip-Coating Pretreatments as a Non-Thermal Green Technology on Physicochemical Characteristics, Drying, and Rehydration Kinetics of Santa Maria Pears

This research was conducted to determine the influences of biopolymer dip-coating pretreatments as a non-thermal green technology on the drying behavior, retention of bioactive compounds, and quality properties of pears. The fresh pears were washed, peeled, and diced into cubes of 5 × 5 mm with a 2 mm thickness and were dipped into 0.3% (w/v) solutions of sodium alginate (SA), pectin (PC), xanthan gum (XG), Arabic gum (AG), and gelatin (GE) before hot air drying (70 °C, 2.0 m/s). The weight loss of samples during drying was recorded online, and the moisture ratio (MR) and drying rate were plotted against drying time. Biopolymers significantly decreased the drying time (maximum 33.33% by SA) compared with uncoated samples except for XG. Moisture diffusion coefficients were determined according to Fick’s second law of diffusion by plotting LnMR against drying time, and a linear regression analysis was applied to the data for the determination of moisture diffusion coefficients which ranged from 2.332 to 3.256 × 10−9 m2/s. The molecular transport of momentum, heat, and mass were determined from Newton’s law of viscosity, Fourier’s law, and Fick’s law, respectively. The results indicated that the friction drag force, convective heat, and mass transfer coefficients were 6.104 × 10−6 N, 76.55 W/m2·K, and 0.0636 m/s, respectively. Mathematical modeling showed the suitability of the Midilli and Kucuk and the Peleg models for the prediction of drying and rehydration processes, respectively. Thermal conductivity, specific heat, and density of coated samples ranged from 0.559–0.579 (W/m·K), 3735–3859 (J/kg·K), and 850.90–883.26 (Kg/m3), respectively. The porosity was reduced due to the penetration of biopolymers into the cellular matrix of samples. The highest total polyphenol content and antioxidant activity belonged to the AG samples. The biopolymers covering the surface of samples produced a protection layer against the loss of bioactive compounds. Biopolymers can be successfully used as a non-thermal green process for improving the drying and quality characteristics of pears at the industrial level.

Freeze-Dried Cooked Chickpeas: Considering a Suitable Alternative to Prepare Tasty Reconstituted Dishes.

The current trend in food consumption is toward convenience, i.e., fast food. The present work aims to study the potential of incorporating freeze-dried cooked chickpeas into a complex and traditional dish in Spanish gastronomy, such as Cocido, which has this legume as the main ingredient. Cocido is a two-course meal: a thin-noodle soup and a mix of chickpeas, several vegetables, and meat portions. The textural properties, sensory qualities, and rehydration kinetics of chickpeas of three Spanish varieties were investigated to select the most suitable cooking conditions to obtain freeze-dried chickpeas of easy rehydration whilst maintaining an adequate sensory quality for the preparation of the traditional dish. The sensory quality of various vegetables and meat portions, cooked under different conditions, was evaluated after freeze-drying and rehydration. It was possible to reproduce the sensory quality of the traditional dish after rehydration with water, heating to boiling in a microwave oven for 5 min, and resting for 10 min. Therefore, it is possible to commercialize complex dishes based on pulses and other cooked and freeze-dried ingredients as reconstituted meals with a wide nutrient profile. Nevertheless, additional research is required on the shelf life, together with other economic and marketing issues such as design of a proper packaging, that would allow consumption as a two-course meal.

Linking stem rehydration kinetics to hydraulic traits using a novel method and mechanistic model.

Despite the recognized importance of hydraulic capacitance as a mechanism used by plants to maintain hydraulic functioning during high transpiration, characterizing the dynamics of capacitance remains a challenge. We used a novel 'two-balance method' to investigate relationships between stem rehydration kinetics and other hydraulic traits in multiple tree species, and we developed a model to explore stem rehydration kinetics further. We found that: (1) rehydration time constants and the amount of water uptake occurring during rehydration differed significantly across species; (2) time constants did not change with declining water potential (Ψ), while water uptake increased at lower Ψ in some species; (3) longer time constants were associated with lower wood density, higher capacitance and less negative stem pressures causing 50 % loss of hydraulic conductivity (P50); (4) greater water uptake occurred in stems with lower wood density and less negative P50 values; and (5) the model could estimate the total hydraulic resistance of the rehydration path, which cannot be measured directly. Overall, the two-balance method can be used to examine rehydration dynamics quickly and thoroughly in detached woody stems. This method has the potential to improve our understanding of how capacitance functions across tree species, which is an often-overlooked component of whole-plant hydraulics.