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The study was carried out to evaluate the performance of a biomass gasifier as a backup heating source to a solar dryer and to analyze the drying characteristics and the quality attributes of shrimps (Metapenaeus dobsoni) drying in the solar-gasifier hybrid dryer. The coconut shell was used as a biomass feedstock for the operation of a downdraft gasifier to generate producer gas. The shrimp samples were dried in a solar-gasifier hybrid dryer to the final moisture contents of 18% (d.b.), 16% (d.b.), and 17% (d.b.) within 6 h, 9 h, and 6 h under hybrid, solar, and gasifier modes, respectively. The thermal efficiency of the downdraft gasifier was estimated to be 73% and 67.5% for the coconut shell feedstock during hybrid and gasifier modes of operation. Modeling of drying data revealed that page model was the best fit for solar and hybrid modes of operation, whereas Midili model accurately predicted the drying behavior of shrimp in the gasifier mode. Proximate composition of shrimps was not affected by different drying modes. Total volatile basic nitrogen (TVB-N), trimethylamine (TMA), and thiobarbituric acid reactive substance (TBARS) values of shrimps were found to be within the safe limit. The rehydration ratio of dried shrimps for hybrid, solar, and gasifier modes was 2.39, 2.52, and 2.49, respectively. The shrinkage (%) observed under the hybrid, solar, and gasifier modes was 20.71%, 19.95%, and 25.45%, respectively. The drying modes positively affected the color development in shrimps. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve the drying efficiency and quality of purple sweet potatoes after blanching pretreatment, this study employed three methods: hot water blanching (HWB), microwave blanching (MB), and vacuum steam pulsed blanching (VSPB). The impact of different blanching methods on the microstructural parameters and macroscopic performance of purple sweet potatoes was investigated using techniques such as paraffin sectioning, microscopic observation, and image processing. The results indicated that, at the microscopic level, the proportion of large cells after VSPB was significantly higher than that after hot water and MB, being 15.81%, 5.15%, and 25.68%, respectively. At the macroscopic level, samples pretreated with VSPB had the shortest drying time (210 min), the highest rehydration ratio (RR) (3.988), and the best chewiness (2095.44 g). Further studies explored the effects of blanching vacuum degree, blanching time, and blanching frequency on the distribution of various microstructural parameters of purple sweet potato tissue cells. Through nonlinear polynomial fitting, a fitting equation was established between the microstructural parameters after VSPB and the macroscopic RR and browning index. The determination coeffi cients R2 of the established mathematical models and the predicted results were all greater than 0.8. The findings of this study provide an important reference for exploring the mechanism of the impact of VSPB pretreatment on the microstructural parameters and macroscopic performance of purple sweet potatoes and offer a theoretical basis for the design of drying equipment. [ABSTRACT FROM AUTHOR]

Objective: Investigation of optimized rehydration process of dried cuttlefish and its textural changes before and after rehydrating. Methods: The combination rehydration method was conducted by two-step process with alkaline solution first and pure water next, the conditions were optimized based on the rehydration ratio and protein loss. Then the textural properties of dried cuttlefish before and after rehydrating, as well as protein secondary structure, tissue morphology and other related indexes were analyzed. Results: The conditions for alkaline solution treatment of dried cuttlefish were the concentration of sodium carbonate solution 0.50%, 2.0 h of the rehydrating time, 50 ℃ of the rehydrating temperature, the ratio of material to liquid being 1:20 g/mL. On this basis, the optimal conditions for pure water treatment were 1.0 h of the rehydrating time, 50 ℃ of the rehydrating temperature, the ratio of material to liquid being 1:20 g/mL, with the rehydration ratio and protein loss of the rehydrated dried cuttlefish were 261.10%±7.10% and 16.80%±0.74% respectively. The rehydration treatment reduced the hardness, gumminess and chewiness of dried cuttlefish while the springiness increased significantly (P

To improve the drying efficiency and quality of hot air-dried apple slices with blanching pretreatment, this study systematically evaluated the effects of two blanching pretreatments, hot water blanching and vacuum steam pulsed blanching, on the macroscopic drying performance of apple slices. The results indicated that under the conditions of 0.07 MPa vacuum, two blanching cycles, and blanching time of 3 minutes, vacuum steam pulsed blanching significantly enhanced the rehydration rate and textural quality of apple slices while reducing the drying time. Paraffin sectioning, microscopic observation and image processing were used to compare the microstructural changes of apple slices in terms of cell cross-sectional area, perimeter, equivalent diameter, cell roundness, wall roughness factor, and porosity under different branching conditions (temperature and time for hot water blanching; vacuum level, number of cycles, and time for vacuum steam pulsed blanching). The results showed that with the increase in temperature, blanching time and number of blanching cycles, apple cells exhibited changes that accelerated water evaporation during subsequent drying, thus shortening the drying time. Additionally, the relationship between microstructural parameters and rehydration ratio was fitted to a polynomial regression model. The findings of this study provide a theoretical basis for understanding the mechanisms by which vacuum steam pulsed blanching affects the microstructure and quality of dried apple slices.

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cold plasma technology, a non-thermal food processing method, significantly enhances food quality and safety by modifying its physicochemical and nutritional attributes. Additionally, this treatment extends the shelf-life of food products, ensuring prolonged freshness and improved overall quality. The present study systematically examined the effect of cold plasma treatment on various attributes, including moisture content (MC), pH, hardness (H), antioxidant activity (AOA), total phenolic content (TPC), rehydration ratio (Rr), browning index (BI), and color difference (ΔE) in black raisins (BR) and golden raisins (GR). The comprehensive analysis delivers valuable insights into the transformative influences of cold plasma on the physicochemical and nutritional characteristics of these raisin varieties. A Box–Behnken experimental design (BBD) combined with response surface methodology (RSM) was used to determine the optimization of treatment time (5, 10 and 15 min) and voltage (10, 20 and 30 kV). The optimized time and voltage for black raisins was 10 kV with 15 min, whereas, for golden raisins, it was 20 kV with 10 min. Furthermore, the experimentation of shelf-life studies for both raisins illuminated the substantial impact of cold plasma treatment, notably enhancing H, Rr, BI, AOA and TPC. Concurrently, a decline in MC and pH was observed throughout the storage period. Furthermore, plasma treatment improved the quality of raisins by reducing the total mesophilic aerobic bacteria count as compared to untreated ones from 4.65–2.42 to 4.71–2.40 log CFU/g for BR and GR, respectively, and similar results were also noticed in mold and yeast count during the 15 days of storage period. However, Future research of this study should delve into long-term storage effects, scalability for commercial applications, and the underlying mechanisms driving these improvements in raisin quality. [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]

Summary: The global demand for dehydrated onion is on the rise, driven by the increasing consumer preference for ready‐to‐eat convenience foods. This study focused on enhancing the quality and functional properties of dehydrated onion slices (cv. Pusa Shobha) through different pre‐treatment and drying conditions. Fresh onion slices were subjected to pre‐treatment using NaCl (3%, 5% and 7%) and KMS (0.3%, 0.5% and 0.7%) solutions for 10 min, followed by tray drying at 50 °C, 60 °C and 70 °C temperatures for varying durations of 14, 12 and 10 h, respectively. Based on physicochemical and functional properties, onion slices pretreated with 5% NaCl + 0.5% KMS and dehydrated at 60 °C for 12 h retained higher bioactive compounds like total phenols (166.32 mg GAE 100 g−1 DW), total flavonoids (28.94 mg QE g−1 DW), ascorbic acid (12.45 mg 100 g−1 DW), quercetin (172.88 μg g−1 DW) and total antioxidant activity (24.59 μmol TE g−1 DW). Additionally, it maintained superior sensory acceptability with higher pungency (7.15 μmol g−1 DW), dehydration ratio (9.25%), rehydration ratio (5.20%), lower non‐enzymatic browning (0.36) and moisture content (5.75%). Hence, the optimised treatment of 'Pusa Shobha' slices with 5% NaCl + 0.5% KMS, followed by dehydration at 60 °C for 12 h, yields dehydrated onion slices with superior bioactive compounds, sensory acceptability, and enhanced functional properties. The findings of his research offer valuable technology for the food industry, providing a practical and efficient method to produce high‐quality dehydrated onion slices. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of the osmotic effect on the drying and rehydration of paneer. The paneer slices were pre‐treated with salt at seven different concentrations and surface treatments. The osmotic solution and product ratio was taken as 1:4 and the pretreatment time was fixed as 12 h. Weight loss (WL), solute gain (SG), and weight reduction (WR) of paneer were evaluated during osmotic pretreatment. The pretreated paneer was dried at 50°C in a tray dryer. The equilibrium moisture content of dried slices varied from 14.12% to 15.86% and the moisture diffusivity of the osmotic treated samples had a better result with maximum value of 4.76 × 10−8 m2/s. The osmotic pretreatment minimized the drying time of paneer. The Midilli model revealed the best fit for drying paneer slices with R2 value >.99. Rehydration was carried out at three different temperatures at 4, 28, and 100°C. The samples rehydrated at 28°C showed better results in terms of the rehydration ratio with a maximal value of 1.85. In model investigation, the Peleg, Exponential, and Weibull model was found good fit for samples rehydrated at 4, 28, and 100°C. The osmotic pretreatment impacted positively on the quality matrices such as color retention, drying time, nutritional profile, and rehydration ratio of paneer slices. However, the higher osmotic pretreatments above 12% recorded unacceptable salty flavor. Practical applications: The stability of paneer is limited and it requires refrigeration facility to store the paneer which is a frailty factor in supply chain cycle of dairy industries. In current practices, the high‐cost freeze drying technique was used to dry the paneer to make as shelf stable. The conventional drying techniques would not suit for drying the paneer, that alters the characteristics of paneer. The research findings will improve the characteristics of dried paneer in conventional dryer and hence, it is viable to make the shelf stable paneer at low cost. This research would make an alternative approach to manufacture the shelf stable and ready to eat paneer. [ABSTRACT FROM AUTHOR]

The study was done to optimize the steam blanching of shrimp (Metapenaeus dobsoni) for drying purposes. Response surface methodology was used to study the interaction effects of salt concentration and blanching time on drying rate, shrinkage, rehydration ratio, redness index, chewiness, and salt content of shrimp. The optimized steam blanching conditions were salt concentration: 0.5% and blanching time: 2 min. The experimental values were validated with the predicted values using the mean relative percent deviation modulus (%P) for drying rate, shrinkage, rehydration ratio, redness index, chewiness, and salt content of shrimp and was found to be 0.06, 2.62, 2.25, 8.55, 5.45, and 1.72, respectively. [ABSTRACT FROM AUTHOR]

Drying process extends the shelf-life of fresh faba beans and makes them available all year round. Dried and cooked faba beans are used to make a variety of traditional food products. Ultrasonic pretreatment, as a modern food processing technology, can shorten the drying time of fresh legumes and improve the quality and sensory properties of products. So, the present study aimed to analyze the impact of the ultrasonic treatment process (0, 5, 10, and 15 min, 40 kHz, and 150 W) on the mass transfer rate, drying time, and effective moisture diffusivity (Deff) of fresh faba beans. Also, the effect of ultrasonic treatment on textural properties and sensory attributes of cooked faba beans was studied. By using the ultrasonic process, the rate of water extraction from fresh faba beans, and thus their dehydration rate, can be increased. With increasing the duration of ultrasonic pretreatment from 0 to 15 min, the drying time of fresh faba beans decreased from 250 min to 150 min (p 0.9968, and the sum of squared error (SSE) and root mean squared error (RMSE) were also closer to zero compared to other models. The rehydration ratio of dried faba beans (after cooking) significantly increased from 308.4 % to 327.1 % with the extension of processing time from 0 to 15 min (p

Background: Advances in regeneration methods have brought us improved vascular scaffolds with small diameters (φ < 6 mm) for enhancing biological suitability that solve their propensity for causing intimal hyperplasia post‐transplantation. Methods: The correlation between the rehydration ratio of the hydrogel and its material concentration is obtained by adjusting the material ratio of the hydrogel solution. The vascular model with helical structure has been established and analyzed to verify the effect of helical microvascular structure on thrombosis formation by the fluid simulation methods. Then, the helical structure vascular has been fabricated by self‐developed 3D bioprinter, the vascular scaffolds are freeze‐dried and rehydrated in polyethylene glycol (PEG) solution. Results: The experimental results showed that the hybrid hydrogel had a qualified rehydration ratio when the content of gelatin, sodium alginate, and glycerol was 5, 6, and 3 wt%. The established flow channel model can effectively reduce thrombus deposition and improve long‐term patency ratio. After PEG solution modification, the contact angle of the inner wall of the vascular scaffold was less than 30°, showing better hydrophilic characteristics. Conclusion: In study, a small‐diameter inner wall vascular scaffold with better long‐term patency was successfully designed and prepared by wrinkling and PEG modification of the inner wall of the vascular scaffold. This study not only creates small‐diameter vascular scaffolds with helical structure that improves the surface hydrophilicity to reduce the risk of thrombosis but also rekindles confidence in the regeneration of small caliber vascular structures. [ABSTRACT FROM AUTHOR]

Featured Application: A widely used method of food preservation is drying. Unfortunately, apart from the increase in the durability of the raw material and the decrease in its weight and volume, there are also negative changes related to its physical, chemical, and sensory properties. To reduce some unfavorable effects of the drying process, pretreatment can be used. Ultrasonic waves applied before drying in most cases positively affect the changes in food, obtaining high-quality products with changed physical properties. Additionally, ultrasounds have a positive impact on the efficiency of the technological process based on heat and mass transfer, reducing its duration, which results in lower production costs. Therefore, pretreatment using ultrasound is a promising alternative to the thermal pretreatment of raw materials. Beetroots are sources of bioactive compounds and valued pigments such as betalains. The purpose of this study was to determine the influence of ultrasound pretreatment on the beetroot infrared–hot air drying process and the functional properties of the obtained product. In this study, there were two used frequencies—21 and 35 kHz—and three different periods of time—10, 20, and 30 min. Since beetroots are usually subjected to thermal treatment, another aim was to examine the influence of blanching and soaking on the beetroot tissue properties in order to compare traditional and ultrasound-treated methods. As a result of this study, it was found that ultrasound pretreatment changed the dry matter content, water activity, thickness of the tissue, total color difference, and contents of betanin pigments in the beetroot. It was revealed that the drying process is shorter after ultrasound pretreatment using a 21 kHz frequency. Drying tissue exposed to ultrasounds showed a significant increase in the L* parameter; however, the decrease in the a* parameter was caused by a reduced content of betalain pigments. Taking into consideration parameters important from a technological point of view, it was found that the best condition for beetroot pretreatment is 20 min treatment, regardless of the frequency used. [ABSTRACT FROM AUTHOR]

Influences of drying air temperatures on drying time, specific energy consumption as well as product quality of culture asparagus were investigated in hot-air drying. The drying properties of asparagus samples were performed in a laboratory scale convection dryer at three different temperatures. The drying times of asparagus samples were found as 1200, 630 and 510 min for 50, 60 and 70 °C, respectively. In regard to the data obtained, Midilli et al. model is superior to other models to describe drying behavior of asparagus samples. The effective moisture diffusivity values of asparagus samples were calculated between 6.32 ⋅ 10-9-1.62 ⋅ 10-8 m²/s and the activation energy was estimated as 43.59 kJ/mol. The highest rehydration content and the least total color change were found in asparagus slices dried at 50 °C. Energy consumption values for asparagus samples dried at 50, 60 and 70 °C temperatures were obtained as 10.14, 5.32 and 4.31 kWh, respectively. In terms of energy consumption values, the best efficiency among all drying temperatures was obtained at 70 °C. It has been determined that the specific energy consumption decreased with increasing temperature. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to explore the best thawing method for beetroots in freeze-thaw pretreatment. Methods: The frozen beetroots were thawed using different thawing methods （room temperature thawing, running water thawing, refrigeration thawing, microwave thawing, and ultrasonic thawing）, and then the thawed beetroots were subjected to microwave drying. The effects of different thawing methods on the microwave drying time, rehydration ratio, color, betalains content, total phenolic content, and total flavonoids content of microwave-dried beetroots were evaluated. Results: The results showed that refrigeration thawing required the longest thawing time, but the thawing loss rate was the smallest and the rehydration ratio of microwave-dried beetroots was the largest, which was 4.82. Meanwhile, running water thawing could better maintain the color of microwave-dried beetroots. There was no significant difference in microwave drying time among different thawing methods. It was found that the microwave-dried beetroots prepared by ultrasonic thawing showed the highest betacyanins content, and the microwave-dried beetroots obtained by microwave thawing displayed the highest betaxanthins content. Compared with other thawing methods, running water thawing resulted in higher total phenolic content and total flavonoids content of microwave-dried beetroots, which was 8.15 mg GAE/g and 16.50 mg RE/g, respectively. Conclusion: Running water thawing was a more suitable method for the thawing of frozen beetroots, which could provide better physicochemical properties of microwave-dried beetroots.

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 (

Beef cuts were dried by tray drying (TD), microwave drying (MD), and TD+MD. Salting as pre-treatment was carried out with NaCl or NaCl+KCl salts to evaluate the effect of sodium reduction. The beef was divided into nine groups: three were subjected to TD, MD, and TD+MD; for the other six groups, dry salting was applied with 100% NaCl or 50% NaCl + 50% KCl, followed by MD, TD, or TD+MD. Processing times of TD, MD, and TD+MD were about 660, 250, and 300 min, and effective diffusivities (Deff) were 1.33 × 10-8, 3.88 × 10-8, and 3.57 × 10-8 m²/s, respectively. Compared with TD, the MD procedure resulted in significantly harder texture and lower rehydration ratio (p < 0.05). SEM images of dried beef indicated fractures and disruption after TD, while a compact structure was obtained with MD. Both salt types contributed a softer texture in rehydrated MD, but KCl did not change the hardness values of dried meat. MD could have great potential for drying meat by reducing drying time, and KCl could be applied as a substitute for NaCl without adversely affecting the structural quality. [ABSTRACT FROM AUTHOR]

This article explores the drying characteristics of Kachri fruit slices in a heat pump dryer, focusing on the effects of air temperature and pretreatments. Kachri is a fruit found in western Rajasthan, India. The study found that increasing the drying air temperature and using pretreatments such as potassium metabisulfite (KMS) or magnesium oxide (MgO) resulted in higher drying rates. Additionally, higher temperatures and pretreatments led to higher moisture diffusivity and rehydration ratios. These findings are consistent with previous research on drying fruits and vegetables. [Extracted from the article]

In this study, the effect of various drying methods on the rehydration behaviour and mass transfer diffusion coefficients of squid (Loligo vulgaris) is investigated. Drying methods were selected as infrared (IR), ultrasonic pre-treated infrared (US-IR) and microwave (MW). In IR and US-IR method drying temperatures were within 60 - 80 °C and in MW drying the power levels were in between 140 - 350 W. The rehydration process was carried out for all samples in 180 minutes at room temperature with 30-minute weighing intervals. Obtained rehydration data were applied to the mathematical models of Peleg and Two-Term Exponential. The rehydration ratios were changed between 1.78 - 2.50, 1.91 - 2.66 and 2.78 - 3.83 g/g dry matter for IR, US-IR, and MW respectively. Mass transfer diffusion coefficients of effective moisture diffusion (Deff) values were changed between 1.01 × 10-7 - 1.07 × 10-7, 1.02 × 10-7 - 1.08 × 10-7, and 1.12 × 10-7 - 1.22 × 10-7 m²/s, for IR, US-IR, and MW respectively. Peleg and Two-Term Exponential mathematical models showed matched well with the experimental data. In addition, colour values found to be changed particularly in the brightness values due to rehydration process. [ABSTRACT FROM AUTHOR]

Unbalanced drying air and temperature distribution in a dryer is among the major cause of non-uniformity in moisture content of dried food. Thus, the distribution of air and temperature in corner-ended, corner-ended with deflector, curved-ended, and curved-ended with defectors were investigated. Velocities used were 2 m/s, 4 m/s, and 6 m/s while temperatures ranged from 40-60 ° C. The design with lowest deviations in simulated and actual drying parameters was fabricated to dry mushrooms. Results showed that adding deflectors improved drying air and temperature distribution. The corner-ended with deflector dryer configuration was superior to other designs, with 6 m/s and 60 °C being optimal. A mass transfer simulation of the corner-ended with deflectors configuration had moisture evaporate from 1.00-0.11 in 2000 seconds. A comparison of moisture ratios in the two dryers gave R2 = 0.9965, which was acceptable. Drying at 55-60 °C gave the best Lentinan content and rehydration ratio for mushrooms. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The rehydration kinetics is an important element in both the manufacture and consumption of dry goods. The rehydration behavior and effective diffusion coefficients of blue mussels (Mytilus edulis) dried with traditional methods were investigated in this study at various drying and rehydration temperatures, as well as under vacuum and non-vacuum environments. The drying temperatures in the early study were between 60 and 80°C, whereas the rehydration temperatures were between 20 and 40°C. The maximum rehydration rates for mussels were calculated between 0.0094 - 0.0022 g/g × min for the oven drying and between 0.0127 - 0.0070 g/g × min for vacuum oven drying. Vacuum application has been seen to boost the rehydration rate and rehydration ratio by shortening the time it takes to reach rehydration saturation. The compatibility of the obtained rehydration data with the Peleg, Two-Term and Weibull mathematical models was examined and a higher agreement was reached with the Two-Term model for almost all experimental sets. [ABSTRACT FROM AUTHOR]

This study aims to convert raw chickpea (Cicer arietinum L.) into dried chickpea puree powder form using a drum dryer having a high rehydration ratio and for ready-to-use consumption form maintaining its healthy properties. The effects of the drying conditions on the physical, chemical, and rheological properties of chickpea puree powders were investigated. Before drying, raw chickpeas were soaked in water at 25°C for 12 hours and boiled at 100°C for 55 minutes. In the drying process, saturated steam pressures (2, 3, and 4 bar) and drum rotation speeds (2.0, 3.0, 4.0, and 5.0 rpm) were chosen as process variables. The most appropriate process conditions were determined as 3 bar of steam pressure and 2 rpm of drum rotation speed targeting the maximum protein content (30.35±0.18%), maximum rehydration ratio (515±0.01%), and as low as possible browning index (BI)(59.28±4.90) values. It was determined that chickpea puree had the appropriate rheological characteristics when the shear stress and shear rate values for chickpea puree powders with various dry matter contents (%25, %26, %27.5, %30) produced under suitable process parameters were examined. [ABSTRACT FROM AUTHOR]

The present study investigated the effects of infrared and forced convective air at different infrared power levels (300, 400, and 500 W) and hot air temperatures (50, 57, and 65°C) on thin layer drying of rose petals. Infrared drying requires 50%–52% less time as compared with forced convective drying. The initial and final moisture content of rose petals were 84% (w.b.) and 4.5% (w.b.) respectively. The Midilli–Kucuk model gives a superior fit for both the drying methods followed by Avhad and Marchetti, and the Page model. The zero‐order, followed by the first‐order color kinetics model gives the best fitting for L*, a*, and b* values. Moisture diffusivity was increased by infrared power (1.7308 × 10−8 to 4.1495 × 10−8 m2/s) and hot air temperature (9.3715 × 10−9 to 1.1709 × 10−8 m2/s). The activation energy obtained for rose petals in hot air dryers and infrared dryers was 51.09 kJ/mol and 6.50 kW/kg, respectively. Samples dried at 500 W infrared drying for 18 min demonstrated higher retention of color, ascorbic acid (61.03 ± 2.6 mg/100 g), and anthocyanin content (295.75 ± 65.70 mg/100 g) in the rose petals. Practical Applications: Several drying techniques are available, though continuous efforts have been made to improve drying methods in terms of energy efficiency and product quality attributes. The present work has been carried out considering the dearth of information on the influence of infrared power/intensity on drying behavior and product quality of rose petals. Mass and color kinetics has been studied for a better understanding of the process along with rehydration, ascorbic acid and anthocyanin content. Our results showed that the infrared drying has significant industrial importance as it provides an efficient way to dry flowers, preserving their quality and extending their shelf life. [ABSTRACT FROM AUTHOR]

The study was carried out to optimize the drying conditions of shrimp in the hot air‐assisted microwave drying system using response surface methodology. The drying experiments were performed using a Box–Behnken design with air temperature (50–70°C), air velocity (.5–1.5 m/s), and microwave power level (600–1000 W) as independent variables and drying time, water activity, and rehydration ratio as independent variables. The obtained response variables were fitted into the various regression equations to predict a suitable model. The methodology of desired function was applied to indicate 61.74°C air temperature, 922.61 W microwave power, and 1.0 m/s air velocity which offered a reduced drying time of 2.8 h, the water activity of.424 and improved rehydration ratio of 2.51, respectively with a desirability value of.949. The moisture content, drying efficiency, shrinkage, and total color change were determined for the samples obtained under optimized conditions and were observed as 16.5% (w.b), 35.71%, 14.14%, and 16.95 ± 2.14, respectively. Scanning electron microscopy analysis of dried shrimp showed the formation of pores of diameters ranging from 3.17 to 10.6 μm. The process parameters optimized under the study for hot air‐assisted microwave drying can be used for the production of good‐quality dried shrimps. Practical applications: Generally, fish and fish products are dried in the open sun or solar dryers in most developing countries. The traditional methods offer the least process controls with maximum energy and manpower demand to meet the ever‐growing industry requirements with increased awareness of the safety and quality of the dried products. The hot air‐assisted microwave (HAMW) drying system developed under the study could have complete control over the process parameters without compromising the quality of the dried product. The study suggests the HAMW drying system as a potential means of drying technique for large‐scale commercial production of dried shrimps. [ABSTRACT FROM AUTHOR]

Beetroots are sources of bioactive compounds and valued pigments such as betalains. The purpose of this study was to determine the influence of ultrasound pretreatment on the beetroot infrared–hot air drying process and the functional properties of the obtained product. In this study, there were two used frequencies—21 and 35 kHz—and three different periods of time—10, 20, and 30 min. Since beetroots are usually subjected to thermal treatment, another aim was to examine the influence of blanching and soaking on the beetroot tissue properties in order to compare traditional and ultrasound-treated methods. As a result of this study, it was found that ultrasound pretreatment changed the dry matter content, water activity, thickness of the tissue, total color difference, and contents of betanin pigments in the beetroot. It was revealed that the drying process is shorter after ultrasound pretreatment using a 21 kHz frequency. Drying tissue exposed to ultrasounds showed a significant increase in the L* parameter; however, the decrease in the a* parameter was caused by a reduced content of betalain pigments. Taking into consideration parameters important from a technological point of view, it was found that the best condition for beetroot pretreatment is 20 min treatment, regardless of the frequency used.

Quince is a nutritionally important fruit, which is not much appreciated for fresh consumption. Drying of quince is one of the methods which is suited for preserving it against deterioration. In this paper, an experimental investigation was conducted to study the drying kinetics, modeling and quality of quince slices in an air impingement dryer under different drying temperatures, air velocities and relative nozzle-to-product distance (H/D) values. The results indicated that increasing drying air temperature and velocity can reduce the drying time. In addition, the impact of drying temperature on the drying time was more significant than that of the air velocity. It was also observed that the maximum heat and mass transfer occurs at the H/D ratio of 4 as Reynolds number varies between 4000 and 7500. The effective moisture diffusivity of quince slices ranged from 3.04×10-10 to 7.85×10-10 m 2 s -1 and the activation energy of quince slices were 23.570, 24.825 and 33.430 kJ mol-1 at different velocities of air. Based on the results reported in this study, the Midilli model provided the best fit to describe the experimental drying data of quince slices. Furthermore, the results showed that the rehydration ratio of dried slices increased as H/D ratio rose and dropped with increase of the drying temperature and air velocity. Also results of color change of dried samples demonstrated that drying temperature and air velocity significantly affected the overall color change of quince slices, while the interaction between drying temperature and air velocity beside main effect of H/D ratio did not show any statistically significant difference in color change of dried samples. From the point of view of the drying time, rehydration ratio and color change of the dried slices, the optimum drying conditions were proposed. [ABSTRACT FROM AUTHOR]

Objective: This study focuses on optimizing the heat pump drying process of carrot. Methods: On the basis of single factor experiment, Box-Behnken experiment was designed. Color difference, rehydration ratio and β-carotene content were used to study the effects of initial temperature, drying temperature rise and slice thickness on carrot drying quality. The regression equation was established, and the interaction between three independent factors on the response was analyzed. The optimal drying process parameters and the predicted values of carrot heat pump drying were obtained. Finally, the optimal parameters were determined by comparing the experimental results with the predicted values. Results: The optimal process parameters of carrot heat pump drying were as follows: the initial and drying temperature were 54.1 ℃ and 9.25 ℃ respectively, and the slice thickness was 3.8 mm. Under the control of these conditions, the color difference value of carrot was 9.759, the rehydration ratio was 6.196, with the content of β-carotene of 34.378 mg/100 g. The dried product was bright orange red, and the rehydration ratio and the retention of β-carotene were high. Conclusion: Response surface method can determine the best process parameters of carrot heat pump drying, and help to obtain the best quality of carrot dried products.

In this study, apple slices were dried using infrared (IR) and hot air techniques and comprehensively analyzed in terms of drying and product characteristics. The influence of IR power level (450–650 W) and hot air temperature (60–75°C) on mass transfer, color kinetics, product texture, microstructure, and rehydration characteristics was studied. The results indicated that drying time, color change, and energy requirement were lower in IR drying than in hot air drying. Moisture diffusivity was observed to increase with IR power (3.367 × 10−9–5.579 × 10−9 m2/s) and hot air temperature (1.288 × 10−9–2.387 × 10−9 m2/s). The activation energies of apple slices in IR and hot air drying were 11.94 and 21.90 kJ/mol, respectively. IR‐dried apple slices were more crispy, with a porous structure and higher rehydration ability. Experimental data were fitted to nine different thin‐layer drying and four‐color kinetic models using nonlinear regression analysis. The results of regression analysis indicated that the Midilli–Kucuk model is the best model to describe the drying behavior in both techniques. The color characteristics (L, a, and b) can be best explained by the modified color model and total color change by fraction conversion model for both IR and hot air drying of apple slices. This study revealed that IR drying of apple slices results in a better quality product in less time and energy as compared to hot air drying. Practical applications: Drying is a vital food processing and preservation technique based on the principle of reducing the water content of the product. Although several drying techniques are available, there have been continuous efforts to improve drying methods in terms of energy efficiency and product quality attributes. The present work has been carried out considering the dearth of information on the influence of infrared power/intensity on the drying behavior and product quality of apple slices. Mass and color kinetics have been studied for a better understanding of the process, along with texture, microstructure, and rehydration properties. Our results showed that the process is superior, in terms of energy and product quality, as compared to other published work. It is concluded that infrared drying can be effectively used in the dehydration of apple slices on an industrial scale and can be promoted as a healthy alternative to fried snacks. [ABSTRACT FROM AUTHOR]

Introduction Strawberry plays an important role in human health because of its micronutrients and natural antioxidant content. Increasing storage time and decreasing microbial processes, weight and volume, and eventually facilitating export, has bolded the need for drying this product. The most common drying method is sun drying. This technique requires large areas and lengthens the time to complete the process which is undesirable economically. Furthermore, the final product may be contaminated by dust and insects, and the exposure to solar radiation results in color deterioration. In order to improve the quality, traditional sun drying techniques can be replaced by a more rapid and efficient drying method such as hot-air drying. In recent years air impingement technology has got more attention in the field fruit slices drying due to high heat and mass transfer, decreasing drying time and increasing product quality. The objectives of this study were to investigate the effects of drying conditions on the drying kinetics and quality characteristics including the rehydration ratio of the strawberry slices in an air impingement jet dryer. Materials and Methods An air jet impingement dryer with controllable temperature, air velocity, and the relative nozzle-to-product distance (H/D) was used in this study. The experiments were conducted under different temperatures (45, 55, and 65°C), air velocities (6, 9, and 12 m s-1) and H/D ratios (4, 5, 6, 7, and 8). The initial moisture content, effective moisture diffusivity, activation energy, and rehydration ratio were evaluated. Results and Discussion The effects of drying temperature and air velocity on the moisture ratio and the drying rate are shown in Figs 2 and 3. As it can be seen, the moisture ratio of strawberry slices decreased with the increase of drying time. The analysis of variance for drying time indicated that increasing drying temperature and air velocity could reduce the drying time. In addition, the effect of drying temperature on drying time was more significant than that of the air velocity. It is clear that the drying rate decreased with moisture content. There was a rapid decrease in drying rate during the initial period and slow decrease at the later stages of the drying process. It is also found that the drying process generally took place in the falling rate period. It is observed that the moisture ratio decreased as H/D ratio fall. The response of drying time was affected significantly (p < 0.05) by H/D ratio. The effective moisture diffusivity increased with increasing drying temperature and air velocity. Based on the results reported in this study, the Wang and Singh model with the lowest Root Mean Square Error (RMSE=0.02) and the highest Coefficient of determination (R2=0.996) provided the best fit to describe the experimental drying data of strawberry slices. The statistical analysis shows that drying temperature and air velocity have significant (p < 0.01) effect on the rehydration ratio (RR) of slices, while the interaction effect was not significant. The means comparison shows that the RR of dried slices decreased as drying temperature and air velocity rose. H/D ratio significantly (1%) affected rehydration ratio. The means comparisons shows that the rehydration ratio increased when H/D value varied from 4 to 8. Also, the results of color change represented that color change of dried samples decreased with increase of temperature and air velocity and increased with increase of the H/D ratio. Conclusions a) Increasing drying temperature and air velocity dropped the drying time. In addition, the effect of drying temperature on drying time was more significant than that of the air velocity. b) A constant rate period was not observed in drying of strawberry slices and the whole process of strawberry slices was carried out in the falling rate period. c) The moisture ratio decreased as H/D ratio dropped, which in turn resulted in saving drying times. d) The Wang and Singh model was found to be the best model to describe the drying kinetics of strawberry slices. e) The effective moisture diffusivity of strawberry slices ranged from 1.62×10-10 to 3.24×10-10 m2 s-1. f) The values of activation energy of strawberry slices were found to be 12.88, 15.055 and 16.746 kJ mol-1 for air velocities of 6, 9 and 12 m s-1, respectively. g) The rehydration ratio of dried slices dropped as the drying temperature and air velocity rose and increased with increase of the H/D ratio. h) The color change of dried samples decreased with the increase of temperature and air velocity and increased with the increase of the H/D ratio.

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This study presents four models' suitability for the rehydration ratio and moisture content history data during the hydration process of beetroot, sweet potato, and yam. The models are the Akinola et al., the Exponential, the Peleg, and the Weibull models. Rehydration occurred at 27°C for the dehydrated sample slices, which had original dimensions of 25 mm x 25 mm x 3.0 mm. During rehydration, the mass/moisture content history data was recorded for the samples. Regression analysis established that the Akinola et al. Model best fit the rehydration ratio/ mixture content changes vs time history data. The study results show a rapid increase in rehydration in the initial hour of the rehydration process. This increase gradually decreases to a contact equilibrium value. For the yam, sweet potato, and beetroot slices, the rehydration ratio values approached 2.1, 2.1 and 6.5, respectively. This study provides a better understanding of the beetroot, sweet potato, and yam slices' rehydration process. Also, knowledge of the rehydration characteristics of the agro-products will be valuable in the design, operation and optimisation of processing equipment and prediction of water absorption with time. [ABSTRACT FROM AUTHOR]

The present research aimed to evaluate the effect of microwave-assisted conventional drying (hybrid drying) on the physico-chemical and functional characteristics of formulated instant banana-milk powders (IBSPs), and organoleptic attributes of banana-milk shakes during storage. The instant powders were prepared from ripe (IBSP1 (control) and IBSP2) and overripe (IBSP3) bananas using hot-air drying (control) and hybrid (microwave assisted hot-air) drying. The water holding capacity, water solubility index, and viscosity of fresh samples, IBSP1, IBSP2, and IBSP3 were 1.97, 1.53 and 0.60 g/g dry sample, 69.48, 75.21 and 76.62 g/mL and 82.29, 86.29 and 72.55 mPas, respectively. A significant (p < 0.05) increase in moisture content, water activity (aw), acidity, and non-enzymatic browning was observed in all the variants/samples during storage. Among various treatments, the shakes prepared by reconstitution (IBSP: water ratio, 1:4) of IBSP2 formulation rated highest organoleptically (significant, p < 0.05). [ABSTRACT FROM AUTHOR]

Objective: In order to explore the effect of step-down relative humidity drying strategy on the drying characteristics of agricultural products. Methods: Yam slices were selected as the object. The effects of constant humidity drying （relative humidity 15%, 25%, 35%, 45%） and step-down relative humidity drying （relative humidity 45% in the first stage for different times of 10, 20, 30, 60 min and relative humidity 20% in the second stage） on the drying characteristics of yam slices were studied at 60 ℃; The multi-field coupling model was constructed for the simulation of heat and mass transfer; The rehydration ratio and microstructure of the dried product were also measured. Results: ① During constant humidity drying, the drying rate decreased with the increase of relative humidity; However, the drying time of step-down relative humidity drying （45% relative humidity maintained for 20 min and then decreased to 15%） was 8.3% shorter than that of constant humidity drying （relative humidity 15%）. ② The drying rate of yam slices generally increased first and then decreased, The fitting results of drying model showed that it was accurate to describe the changing process of moisture and mass transfer. ③ The rehydration ratio increased first and then decreased with the increase of relative humidity; Under special drying condition of step-down relative humidity drying strategy （relative humidity 45% kept for 20 min and then decreased to 15%）, the yam slices showed honeycomb porous structure, which was good for the mass transfer. Under this condition, the maximum rehydration ratio was 6.85 ± 0.05; Under the drying condition of constant humidity strategy （relative humidity is 20%）, the microstructure of yam sllices begin to shrink and collapse, which led to a lower rehydration rate. Conclusion: During the process of hot air drying, the multi-field coupling model can significantly shorten the drying time, effectively improve the microstructure of materials and improve the rehydration rate of products; The multi-field coupling model can precisely simulate the heat and mass transfer process in yam slices during hot air drying; The research results can provide theoretical basis and technical support for the application and optimization of step-down relative humidity drying strategy.

To explore the effects of vacuum-steam pulsed blanching (VSPB) on drying characteristics and quality attributes of garlic slices, the surface color, texture, peroxidase (POD) activity, total phenolic content, antioxidant capacity (DPPH and FRAP), rehydration ratio and thiosulfinate content under various blanching cycle of times (2, 3, 4, and 5 times) and atmospheric pressure duration (20, 30, 40, and 50 s) were investigated. Results indicated that VSPB treatment can inactive POD completely under all VSPB conditions. The hardness of garlic cloves was reduced after VSPB treatment, while hot air drying increased the firmness of garlic slices. The porosity of the garlic surface evidently declined after VSPB treatment, which hindered the moisture diffusion and thus prolonged the drying time from 3 h to 9 h. The total phenolic content, DPPH and FRAP values of blanched garlic cloves were significantly (p < 0.05) lower than those of the raw garlics. VSPB treatment resulted in undesirable color degradation and thiosulfinate degeneration. The highest rehydration ratio was found for the sample blanched at atmospheric pressure duration of 30 s with the blanching cycle times of 3. The findings in the current work will enhance the better understanding of the effect of VSPB on drying behavior and quality attributes of garlic and may provide clues about on selecting suitable blanching methods for garlic. [ABSTRACT FROM AUTHOR]

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In this research, thin layer drying characteristics, rehydration ratio and effective moisture diffusivity of apple were investigated using microwave dryer which has intermittent and continuous modes. Drying time varied between 25 and 215 minutes and they declined with the rise in microwave power and reduction in pulsing ratio. In an attempt to pick the optimum thin layer models for the drying applications, 8 mathematical models suited to the experimental results. On the grounds of the statistical tests evaluation, Midilli et al model which represent drying characteristics are optimally suited than other models. The highest rehydration ratio was recorded for the samples dried at 100W continuous mode and the lowest ratio at 300W continuous application. Effective moisture diffusivity values were computed by the 2nd law of Fick and changing between 3.04x10-9 and 2.53x10-8 m2 s-1. Consequently, the intermittent microwave method could be used as a favorable drying method for obtaining high-quality fruit slices or processing valuable material and continuous microwave drying can be taken as another drying approach for apple samples.

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Copyright of Food & Machinery is the property of Food & Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Industrially, the use of far-infrared (FIR) as a heat source for drying daylily presents some issues, such as high energy consumption and large loss of nutrients. The use of mid-infrared (MIR) was performed to study the drying of daylily to explore its advantages, with the FIR drying as a comparison. Drying models were established by the drying kinetics, and the changes of nutrition, rehydration ratio (RR) and water migration pattern were researched. The results showed the best-fitting drying model was the Modified Henderson and Pabis model. Under the same temperature, compared with FIR drying, the drying time of MIR drying was shortened by 50%, the effective moisture diffusivity (Deff) was increased by 103%, the drying activation energy (Ea) was reduced by 10%, the reducing sugar and ascorbic acid retention rate was increased by 13.9% and 9.7%, respectively. The MIR drying had better RR and water migration characteristics. [ABSTRACT FROM AUTHOR]