[Application of microwave vacuum drying with process management in extract drying of personalized traditional Chinese medicine preparations].

Extracts are important intermediates in the production of traditional Chinese medicines preparations. The drying effect of extracts will directly affect the subsequent production process and the quality of the preparation. To meet the requirements of high drug loading, short time consumption, and simple production process of personalized traditional Chinese medicine preparations, this study explored the application of multi-program microwave vacuum drying process in the extract drying of personalized traditional Chinese medicine preparations. The influencing factors of microwave vacuum drying process were investigated for 5 excipients and 40 prescriptions. Taking the feasibility of drying, drying rate, drying time, and dried extract status as indicators, this study investigated the feeding requirements of microwave vacuum drying. With the dried extract status as the evaluation indicator, the three drying programs(A, B, and C) were compared to obtain the optimal drying condition. The experimental results showed that the optimal feeding conditions for microwave vacuum drying were material layer thickness of 2 cm and C program(a total of 7 drying processes), which solved the problem of easy scorching in microwave drying with process management. Furthermore, the preset moisture content of the dried extract in microwave drying should be 4%-5%, so that the dried extract of traditional Chinese medicine preparation had uniform quality, complete drying, and no scorching. This study lays a foundation for the application of microwave drying in the production of traditional Chinese medicine preparations, promoting the high-quality development of personalized traditional Chinese medicine preparations.

[Mechanisms of changes of active components in Chinese medicinal materials during drying: a review].

Drying is an indispensable processing step for Chinese medicinal materials after harvesting. It often leads to significant changes in the active components of these materials, thus impacting their medicinal values. Understanding the mechanisms behind the changes during the drying process is of great importance for regulating the transformation of key active components. Therefore, this paper reviews the available studies and comprehensively expounds the mechanisms underlying the changes in active components during the drying process. The aim is to offer insights for the development of regulatory strategies and the improvement of drying techniques for Chinese medicinal materials.

Upcycling Romaine lettuce outer leaves by infrared blanching and hot air drying.

Romaine lettuce outer leaves, as opposed to the more commonly marketed heart, are typically discarded and present an opportunity for upcycling as dried powders. Duquesne Romaine lettuce was evaluated to quantify and compare quality attributes of fresh outer and heart leaves, dried powders following hot air drying, and dried powders following an infrared (IR) blanching pretreatment before drying. Attributes measured for fresh leaves included moisture, water activity (Aw), color, total soluble phenolics (TSP), and antioxidant capacity (AC). Drying kinetics and time/energy saving through IR blanching were evaluated. Attributes measured for dried powders included moisture, Aw, color, true density, water vapor isotherms, TSP, AC, cadmium (Cd) content, and pesticide residues. TSP, AC, Cd, and pesticide residues were higher, whereas moisture content and Aw were lower in fresh outer versus heart leaves. Hot air drying reduced TSP and AC to 63.6% and 35.2% of fresh values, respectively, whereas IR blanching further reduced TSP and AC to 37.3% and 25.4% in outer leave powders. On the other hand, TSP and AC increased 237% and 151%, respectively, for unblanched heart powders. Higher increase of TSP than AC in heart leaf powder may indicate synthesis of phenolic compounds activated by abiotic stresses such as cutting and high temperatures at the initial drying stage. IR blanching resulted in significant time/energy savings for drying of outer leaves. Microbial loads were substantially reduced during drying, although microbial population on outer leaves were more resistant. Safe to eat outer leaf Romaine lettuce powders can be produced, assuming appropriate agricultural practices.

A data-driven approach to improve coffee drying: Combining environmental sensors and chemical analysis.

The study introduces a methodology that utilizes data-driven approaches to optimize coffee drying operations. This is achieved through the integration of ambient sensor data and chemical analysis. This statement underscores the significance of temperature regulation, humidity levels, and light intensity within the context of coffee production. There exists a positive correlation between elevated temperatures and increased rates of drying, but humidity has a role in determining the duration of the drying process and the preservation of aromatic compounds. The significance of light intensity in dry processing is also crucial, since excessive exposure can compromise both the taste and quality of the product. The findings of chemical investigations demonstrate a correlation between environmental factors and the composition of coffee. Specifically, increased temperatures are associated with higher quantities of caffeine, while the concentration of chlorogenic acid is influenced by humidity levels. The research additionally underscores the variations in sensory characteristics among various processing techniques, underscoring the significance of procedure choice in attaining desirable taste profiles. The integration of weather monitoring, chemical analysis, and sensory assessments is a robust approach to augmenting quality control within the coffee sector, thereby facilitating the provision of great coffee products to discerning consumers.

Drying strategies of spent coffee grounds using refractance window method.

The objective of this study was to evaluate, during the drying of spent coffee grounds, the application of pretreatments with ethanol and the application of ultrasound assisting the refractive window (RW) drying, and to compare with convective drying by hot air (AC). The effect on the kinetics parameters of the Fick and Page models were evaluated, as well as on the content of total phenolics and antioxidant capacity. For AC drying, samples of spent ground coffee were prepared in the form of fixed rectangular beds 0.7 cm high, which were placed on polyester sheets and pretreated up to 10 times sprayed with ethanol, then dried by AC at 80 °C and 0.8 m/s. For RW drying, the samples prepared in the same way as for AC were used. For this case, the application of ethanol as pretreatment and the use of ultrasound during process were tested. As results, regardless of the conditions applied, drying by RW was up to 50 % faster, evidenced in the highest values of effective diffusivity (from the Fick model) and the kinetic parameter (from the Page model). Regarding the treatments applied and their effect on the drying kinetics, any treatment had a significant effect on AC drying. On the contrary, the strategies applied in RW drying had significant effects, both the application of pretreatment with ethanol as well as the application of ultrasound assisting the process accelerated the drying kinetics. However, the treatment with ethanol and RW drying was the one that best preserved the phenolic compounds and the antioxidant capacity in the samples. Therefore, these strategies could be a good option to improve RW drying by accelerating the process and preserving the bioactive compounds in the spent coffee grounds for subsequent utilization.

Strength development and self-desiccation of saline cemented paste backfill.

Given that many mines around the world are located in areas where fresh water is scarce, and companies are being held to increasingly stringent sustainability and environmental responsibility standards, many mines are looking to use locally available saline groundwater or seawater as mixing water in cemented paste backfill (CPB). However, the impacts of this decision on key engineering properties of CPB (e.g. strength and self-desiccation) that affect its mechanical stability need to be better understood to allow confident selection of this practical and more sustainable solution. Thus, the effect of mixing water salinity and binder type on the strength (unconfined compressive strength, UCS) development and self-desiccation (measured by suction and volumetric water content) of CPB is explored in this research. NaCl concentrations from 0 to 300 g/L were used in CPB made with silica tailings and Portland cement type I (PC). Concentrations of 10 and 35 g/L were found to moderately increase UCS, while a concentration of 100 g/L had comparable UCS to non-saline CPB and a concentration of 300 g/L was found to significantly decrease UCS over all curing times. The overall trend is 10 g/L > 35 g/L > 0 g/L > 100 g/L > 300 g/L. The UCS of the 60-day-old CPB with a NaCl of 300 g/L is significantly lower, registering a 26% decrease compared to the UCS of the 60-day-old CPB without salt. In contrast, the UCS of the 60-day-old CPBs containing 10 g/L and 35 g/L of salt exhibits a notable improvement, being 15% and 10% higher, respectively, than the UCS of the 60-day-old CPB without salt. Water content and suction monitoring were conducted up to 28 days of curing time, and it was found that suction only slightly contributed to UCS gain of the saline CPB, and high salt contents (100 and 300 g/L) significantly inhibited the self-desiccation ability of CPB due to inhibition of cement hydration by the excessive amount of salt. The increase in strength of both saline and non-saline samples was attributed primarily to the increase in cement hydration products, while the increased strength of the samples with salinities of 10 and 35 g/L was mainly attributed to the enhancement of the binder hydration due to the low amount of salt and the presence of Friedel's salt in the pores. The effect of PC replacement by 25 to 75% with slag on CPB with 35 g/L mixing water salinity was also studied. Slag replacement of 50% and higher resulted in significantly higher UCS over most curing times. Suction likely moderately contributed to UCS of the saline CPB with slag, in addition to the presence of Friedel's salt in the pores and the acceleration of cement and slag hydration by the presence of NaCl.

Effects of ultrasonic power on drying kinetics and product quality of licorice extract during ultrasound-assisted vacuum drying.

BACKGROUND: Licorice extract is an important raw material for food additives and medicine. The quality of licorice extract is dictated by the drying process. The commonly used drying methods of licorice extract are not efficient in obtaining high-quality products so alternative techniques need to be developed and researched. In this study, ultrasound-assisted vacuum drying (UAVD) was first utilized to improve drying efficiency and produce a higher-quality product. The changes in water mobility of licorice extract during drying were characterized using low-field nuclear magnetic resonance. In addition, the effects of ultrasonic power on the drying dynamics, the contents of liquiritin and glycyrrhizic acid, the antioxidant capacity and the microstructure formation of licorice extract during the whole drying process were investigated. RESULTS: The drying times for licorice extract to reach equilibrium moisture content were reduced by 9.09-69.70% with UAVD at 40-200 W compared with that without ultrasonic treatment (0 W). Moreover, the proportions of bound water and semi-bound water in fresh concentrate were 3.75% and 96.25%. It was also found that high ultrasonic power promoted the flow of water and the formation of porous structure in licorice extract, which led to the improvement of drying efficiency. The contents of liquiritin (2.444%) and glycyrrhizic acid (6.514%) were retained to a large degree in the dried product at an ultrasonic power of 80 W. The DPPH inhibition rate of UAVD samples with different ultrasonic powers ranged from 84.07 ± 0.46% to 90.65 ± 0.22%. CONCLUSION: UAVD has the advantages of high efficiency and low energy consumption, which may be an alternative technology for vacuum drying widely used in industry. © 2024 Society of Chemical Industry.

Effect of microwave-vacuum drying on the physicochemical properties of a functional tomato snack bar.

BACKGROUND: Tomato is an indispensable ingredient of the Mediterranean diet. Reformulation of traditional Mediterranean products to increase the adherence of consumers is becoming popular. In this study, a tomato snack bar enriched with olive powder and pea protein was developed by using microwave-vacuum drying. Formulations also included tomato powder (TP) and low-methoxylated pectin (LMP) as a structuring agent. RESULTS: The moisture content of microwave-vacuum-dried samples varied in the range 13.6-19.8% and water activity (aw ) values were ~0.6. LMP and TP concentrations affected the color of microwave-vacuum-dried samples. However, the color mainly changed in conventionally dried samples due to browning. In microwave-vacuum-dried samples, lycopene content decreased with increasing LMP, but increased with increasing TP. Textural properties of microwave-vacuum-dried snack bars increased with increasing LMP and TP. CONCLUSION: Both texture and Fourier transform infrared spectroscopy results indicated that there was a network formation due to the contribution of protein and pectin; however, the type of interaction was highly dependent on the drying mechanism. Nuclear magnetic resonance relaxometry data showed that microwave-vacuum-dried samples had a more uniform water distribution. Besides its time and energy efficiency, microwave-vacuum drying improved the color and textural properties of tomato snack bars compared to conventionally dried ones. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

[Application prospect of reaction engineering approach in studying drying behavior of single droplet during spray drying of traditional Chinese medicine].

Spray drying technology is one of the most commonly used unit operations in the production of traditional Chinese medicine(TCM) preparations, offering advantages such as short drying time and uniform product quality. However, due to the properties of TCM extracts, such as high viscosity, strong hygroscopicity, and poor flowability, there is limited scope to solve the problems of wall adhesion and clumping in spray drying from the macroscopic perspective of pharmaceutical production. Therefore, it has become a trend to study and optimize the spray drying process from the microscopic point of view by investigating single droplet evaporation behavior. Based on the reaction engineering approach(REA), the single droplet drying system, as a novel method for studying droplets, collects parameter data on individual TCM droplets during the drying process and uses the REA to process the data and establish predictive models. This approach is crucial for understanding the mechanism of TCM spray drying. This paper summarized and analyzed the cha-racteristics of various single droplet systems, the application of REA in single droplet drying systems, and its significance in optimizing the process, predicting drying states, and shortening the development cycle in the field of TCM spray drying, and looked ahead to the prospects of this method, including the introduction of new parameters and imaging techniques, aiming to provide a reference for further research in the field of TCM spray drying.

QbD-Guided Traditional Chinese Medicine Manufacturing Process: Development and Optimization of Fluid-Bed Granulation and Drying Processes for Xiaochaihu Capsules.

Traditional methods of producing Xiaochaihu (XCH) capsules, a traditional Chinese medicine, are time-consuming, costly, and labor-intensive, which is not conductive to modernizing TCM. To address the challenges, new fluid-bed granulation and drying processes with water as the binder were developed and optimized guided by the principles of Quality by Design (QbD) in this study. Ishikawa diagram was applied to conduct a preliminary risk assessment, followed by 6-factor definitive screening design (DSD) serving as a QbD statistical tool to develop and optimize the new processes. Multiple potential factors and interactions were studied with a small number of experiments using the DSD. This study identified critical process parameters (CPPs), established quadratic regression models to reveal CPP-critical quality attributes (CQAs) connections within the DSD framework, and defined a dependable design space. Processes conducted by parameter combinations in the design space produced qualified granules with production yield and raw material utilization higher than 90% and moisture content lower than 4%. Furthermore, quantitative analysis of baicalin of all the granules ensured qualified contents of active pharmaceutical ingredient. The newly developed processes for XCH capsules, with advantages of shorter time, environmental friendliness, and decreased cost, exemplify the effective application of QbD and design of experiments (DoE) methodologies in the modernization of TCM manufacturing processes.

Influence of Pre-Treatment and Drying Methods on the Quality of Dried Carrot Properties as Snacks.

The aim of the current research was to evaluate the effect of pre-treatment and drying methods on the properties of dried carrots. Carrots were blanched (B) (1 or 3 min) or osmotic dehydrated (OD) (15 or 30 min) and dried by either convection (CD), microwave-convection (MW-CD), microwave-vacuum (MVD), or freeze-drying (FD). FD carrots showed the highest dry matter content (93.6-95.8%) and the lowest water activity (0.24-0.38). MVD carrots had lower dry matter content (79.5-95.8%) and two times more water activity (0.447-0.637) than FD. The highest color difference (∆E) in relation to raw material was noted in MVD samples (22-35) and the smallest in CD and FD (7-18), mainly due to the increase in brightness of the dried carrot. In general dried MCD carrot samples were characterized by the highest max force (hardness) (21.6-42.5 N; on average 34.7 N) in the breaking test and the lowest hardness was observed in the CD (10.8 N) ones. Pre-treatment and drying caused a significant decrease in the content of carotenoids (2.0-2.7 times) and chlorophyll (2.7-4.5 times) compared to the fresh carrot but a retention or increase in the total content of phenolics and antioxidant activity, especially in microwave-vacuum-dried carrots with an increase of even 2.7-2.9 times compared to raw material. High phenolic content (195.6-277.4 mg GA/100 g d.m.) was found in pre-osmotic dehydrated samples, and lower phenolic content was found in blanched samples (110.7-189.6 mg GA/100 g d.m.). Significantly, the highest average antioxidant activity was found in microwave-vacuum-dried samples (228.9 µmol Trolox/100 g d.m.). The results of this study indicate that microwave-vacuum-drying as an alternative to freeze-drying, including in combination with thermal or osmotic treatment, is very promising for the production of dried carrot snacks.

Undifferentiated Cells of Tessaria absinthioides with High Nutritional Value and Health-Promoting Phytochemicals. An Approach Based on Plant Cellular Agriculture.

In vitro cultures of undifferentiated plant cells of Tessaria absinthioides, a native herb popularly recognized and used for its health benefits, were studied as potential food supplements. These tissues were incubated under two light conditions, and the biomass obtained was freeze-dried and oven-dried. To evaluate their nutritional value, their physicochemical and functional properties were determined. Although in some cases there were significant differences in the results according to the drying methodology applied, all these tissues presented a high proportion of proteins (23.6-28.3%), a low percentage of fats (< 2%) constituted mainly by phytosterols, and a significant amount of crude fibers (6.9-9.0%) and ashes (> 10%). In addition, the freeze-dried calli resulted in a product with better functional properties. On the other hand, their phytochemical profiles and antioxidant capacity were studied and compared with tissues from wild specimens and with green tea and chamomile as reference extracts.

Enhanced treatment of sludge drying condensate by A/O-MBR process: Microbial activity and community structure.

With the rapid increase of sludge production from sewage treatment plants, the treatment of sludge drying condensate rich in a large amount of pollutants urgently needs to be addressed. Due to the unique characteristics of sludge drying condensate (high ammonia nitrogen and COD concentration), there are almost no reports on biological treatment methods specifically targeting sludge drying condensate. In this study, A/O-MBR process was proposed for sludge drying condensate treatment and the effects of ammonia nitrogen loads, alkalinity and aeration intensity were explored. Experimental results show that under the ammonia nitrogen load of 0.35 kg NH4+-N/(m3·d) and the aeration intensity of 0.5 m3/(m2·min), the removal rate of COD and NH4+-N could reach 94% and 99.86% with the addition of alkalinity (m(NaHCO3): m(NH4+-N) = 7:1), respectively. The distribution of living and dead microbial cells in the activated sludge of three reactors also proved that the supplement of alkalinity in the influent can ensure the feasible living conditions for microorganisms. In addition to traditional nitrifying bacteria, through the supplementation of alkalinity and the reduction of aeration intensity, the system had also domesticated high abundance heterogeneous nitrification aerobic denitrification (HN-AD) and aerobic denitrification bacteria (both more than 10% of the total bacterial count). The denitrification process of sludge drying condensate was simplified and the denitrification efficiency was greatly improved. The findings of this study could provide important theoretical guidance for the biological treatment process of sludge drying condensate.

Use of coconut sugar as an alternative agent in osmotic dehydration of strawberries.

This study aimed to evaluate coconut sugar (CS) as an alternative osmotic agent to sucrose for the osmotic dehydration (OD) of strawberries. OD was performed by immersing strawberries cut into 13.6 ± 0.4 mm edge cubes in osmotic solutions of CS or sucrose, at two different concentrations (40% and 60%, w/w), with and without application of vacuum (AV) in the first 20 min of the process. The total OD time was 300 min. Evaluations of the kinetics of solid gain (SG), water loss (WL), and weight reduction (WR) were performed at 30, 60, 120, 180, 240, and 300 min. SG, WL, and WR increased over the OD time and showed values of up to 7.94%, 63.40%, and 55.94%, respectively. AV increased WL, WR, shrinkage, pH, and total color difference and decreased anthocyanin, ascorbic acid (AA), phenolic, and antioxidant contents. The higher concentration led to higher SG, WL, WR, shrinkage, hardness, and lower moisture content, water activity, anthocyanin, AA, phenolic, and antioxidant contents. The use of CS instead of sucrose had little influence on strawberry properties, except pH and color responses. The optimal treatment was using a 60% CS solution without AV, showing a very distinct color change, hardness increased by approximately 4.5 times and maintenance of acidity, anthocyanins, AA, total phenolics, and antioxidants of 38.0%, 39.6%, 11.8%, 30.0%, 31.1%, and 30.3%, respectively, compared to fresh strawberries. PRACTICAL APPLICATION: Osmotic dehydration of fruit is a process traditionally carried out using sucrose. However, increasing health concerns have made consumers seek alternative sugars to sucrose. The use of coconut sugar made it possible to produce osmo-dehydrated strawberries different from the traditional one, maintaining product quality and process efficiency.

Freeze-drying pretreatment of watermelon peel to improve the efficiency of pectin extraction: RSM optimization, extraction mechanism, and characterization.

This study assessed the processing parameters and mechanism of pectin extraction and pectin qualities from freeze-dried (FD) pretreatment watermelon peel. The optimal extraction conditions for the highest pectin yield (21.83 %) were a liquid/solid ratio (w/w) of 29, pH of 1.8, ultrasonic power of 573 W, and ultrasonic time of 43 min. Compared to hot-air dried (HD) method, the extraction of pectin from FD watermelon peel was facilitated by the increased cross-sectional areas of cells, transfer rate of extracting solution, mass transfer rate, and reduced rehydration time during the extraction. HD pectin (HDP) exhibited browning, whereas FD pectin (FDP) displayed bright brownish-yellow coloration. Furthermore, the L* value of pectin from FDP was significantly higher and a* and b* values were significantly lower than pectin from HDP (P < 0.05). Additionally, the moisture, ash and protein contents of FDP were significantly higher than those in HDP (P < 0.05). Structural characterization demonstrated FDP as a low-methoxy acetylated pectin, with significantly lower degree of methoxylation and molecular weight compared to that of HDP (P < 0.05). Besides, FDP demonstrated significantly superior emulsification performance compared to HDP (P < 0.05). These findings suggest FD as a potent, efficient, and time-saving technology for drying fresh watermelon peel for pectin preparation.

[Current research status and application prospect of numerical simulation in traditional Chinese medicine drying].

With the rapid development of computer technology, numerical simulation has gradually become an important method to study drying process and improve drying equipment. Using computer to simulate the drying process of traditional Chinese medicine(TCM) is characterized by intuitiveness, scientificity, and low cost, which serves as an auxiliary means for technical innovation in TCM drying. This paper summarizes the theories of different drying methods and the research status of numerical simulation in drying, introduces the modeling methods and software of numerical simulation, and expounds the significance of numerical simulation modeling in shortening the research and development cycle, improving drying equipment, and optimizing drying parameters. However, the current numerical simulation method for drying process has problems, such as low accuracy, lack of quantitative indicators for the control of simulation results on the process, and insufficient in-depth research on the mechanism of drug quality changes. Furthermore, this paper put forward the application prospect of numerical simulation in TCM drying, providing reference for the further study of numerical simulation in this field.

Drying kinetics and quality dynamics of ultrasound-assisted dried selenium-enriched germinated black rice.

Black rice is a functional food due to its higher protein, fiber, iron, antioxidant compounds, and other health benefits than traditional rice. The ultrasonic (US) pretreatments (10, 20, and 50 min) followed by hot-air drying (50, 60, and 70 °C) were applied to study the drying kinetics, mathematical modeling, thermodynamics, microstructure, bioactive profile, volatile compounds and to lock the nutritional composition of selenium-enriched germinated black rice (SeGBR). Ultrasonic-treated samples exhibited a 20.5% reduced drying time than control ones. The Hii model accurately describes the drying kinetics of SeGBR with the highest R2 (>0.997 to 1.00) among the fifteen studied models. The activation energy values in US-SeGBR varied from 3.97 to 13.90 kJ/mol, while the specific energy consumption ranged from 6.45 to 12.32 kWh/kg, which was lower than untreated. The obtained thermodynamic attributes of dried black rice revealed that the process was endothermic and non-spontaneous. Gallic acid, kaempferol, and cyanidin 3-glucoside were present in high concentrations in phenolics, flavonoids, and anthocyanins, respectively. The HS-SPME-GC-MS investigation detected and quantified 55 volatile compounds. The US-treated SeGBR had more volatile compounds, which may stimulate the release of more flavorful substances. The scanning electronic micrograph shows that the US-treated samples absorbed high water through several micro-cavities. Selenium concentration was significantly higher in US-treated samples at 50 °C than in control samples. In conclusion, ultrasound-assisted hot-air drying accelerated drying and improved SeGBR quality, which is crucial for the food industry and global promotion of this healthiest rice variety.

Quality of bee pollen submitted to drying, pasteurization, and high-pressure processing - A comparative approach.

Bee Pollen is a valuable and useful natural food product that can be used for different purposes, among which medical ones. This matrix is deemed a superfood because of its chemical composition, which is rich in nutrients and possesses significant bioactivities, including antioxidant and microbiological properties. Nevertheless, the storage conditions and processing methods must be optimized to maintain their properties and maximise their application. This work investigates the best bee pollen conservation process and its impact on individual constituents. Monofloral bee pollen was analysed for 30 and 60 days after three different storage processes (drying, pasteurization, and high-pressure pasteurization). The results showed a decrease mainly in fatty acid and amino acid content for the dried samples. The best results were obtained with high-pressure pasteurization, maintaining the proteins, amino acids and lipids characteristics of pollen and the lowest microbial contamination.

Metabolomics analysis reveals metabolite changes during freeze-drying and oven-drying of Angelica dahurica.

Angelica dahurica (Angelica dahurica Fisch. ex Hoffm.) is widely used as a traditional Chinese medicine and the secondary metabolites have significant pharmacological activities. Drying has been shown to be a key factor affecting the coumarin content of Angelica dahurica. However, the underlying mechanism of metabolism is unclear. This study sought to determine the key differential metabolites and metabolic pathways related to this phenomenon. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) based targeted metabolomics analysis was performed on Angelica dahurica that were freeze-drying (- 80 °C/9 h) and oven-drying (60 °C/10 h). Furthermore, the common metabolic pathways of paired comparison groups were performed based on KEEG enrichment analysis. The results showed that 193 metabolites were identified as key differential metabolites, most of which were upregulated under oven drying. It also displayed that many significant contents of PAL pathways were changed. This study revealed the large-scale recombination events of metabolites in Angelica dahurica. First, we identified additional active secondary metabolites apart from coumarins, and volatile oil were significantly accumulated in Angelica dahurica. We further explored the specific metabolite changes and mechanism of the phenomenon of coumarin upregulation caused by temperature rise. These results provide a theoretical reference for future research on the composition and processing method of Angelica dahurica.

Development of FE modeling for hybrid greenhouse dryer for potato chips drying.

In this communication, a combination of heat and mass transfer model was developed using finite element (FE) model to explain the drying performance of the hybrid greenhouse dryer for potato chips. The hybrid greenhouse dryer is integrated with a single-pass solar air heater (SAH). A partial differential equation for a combined set of heat and mass transfer was numerically solved by the FE method. In order to see the spatial moisture distribution within the potato sample, a 3-dimensional FE model was created, and moisture removal takes place from the surface during drying of the products. Lagrange triangle FEs of extremely small size and second-order geometry shape were employed for meshing the geometry of model. Time-dependent study was express the fluctuation in time interval of 0-5 h. The developed model showed the maximum crop and ground temperature are 67.1 and 79.1°C, respectively. Moisture ratio in dry basis is reduced from 1 to 0.005 in 03 h and remains constant at 0.005. Thus, average moisture ratio in dry basis was found as 0.18902. Drying efficiency for the hybrid greenhouse dryer found to be 20.52%, whereas thermal efficiency for SAH was found 54.53%. Relative humidity inside the drying chamber found to be 26.50% in hybrid greenhouse dryer. The predicted versus the experimental results observed that hybrid greenhouse dryer having moderate inside temperature is suitable for crop drying as well as ith sustaining the environmental balance, hybrid greenhouse proves to be most effective.