Effect of different drying methods on drying characteristics, appearance and active components of Belamcandae Rhizoma / 中国中药杂志

In order to explore the effect of different drying methods(drying-in-the-shade, sun-drying, and hot air drying) on appearance characteristics, internal structure and composition of Belamcandae Rhizoma, so as to provide a theoretical basis for screening out suitable drying methods for primary processing. In this study, the Belamcandae Rhizoma's dynamic changes of the moisture content ratio and drying rate with different drying time under different drying methods, as well as the effects of different drying methods on the appearance, drying rate, density, ash, extractives and the contents of six flavonoids(mangiferin, tectoridin, iridin, tectorigenin, irigenin, irisflorentin) were compared. The results showed that fresh Belamcandae Rhizoma consumed the longest time to reach the water balance point by traditional dry drying in the shade, whiche was about 311 h; that by sun drying was 19.3%, which was shorter than drying in the shade; both drying curves were smoother. The section color of the sun drying samples was the closest to that of fresh samples, but the interior is full of holes, with a low density and loose structure. Hot air drying(40, 60, 80 ℃) could save about 27% to 88% of the drying time, which was greatly shorter, with less pores, a larger density and compact structure. Compared with the traditional drying method, the drying rate of hot air drying was reduced by 13.7%. Ash was affected by temperature, the drying conditions under 40 ℃ and below were not significantly different from those of conventional drying. The ash content decreased by 7.73% to 18.5% compared with conventional drying at 60,80 ℃. After conventional drying and 40 ℃ hot air drying, the contents of tectoridin and iridin(glycosides) in the samples were significantly higher than those in 60,80 ℃ hot air drying, while the contents of tectorigenin, irigenin and irisflorentin(aglycones) dried at 60 ℃ were the best. Therefore, considering comprehensive appearance characteristics and content of medicinal ingredients, traditional Chinese medicinal materials after 60 ℃ hot air drying show a solid texture, tight internal structure, good appearance, appropriate reduction of toxic parasides and higher aglycone content.

Effect of different pretreatment methods on far-infrared drying characteristics and polysaccharides of Lycium barbarum / 中草药

Objective: To shorten the drying time of Lycium barbarum, increase its shelf life, improve the quality of dried L. barbarum products, and provide technical support for the development of wolfberry drying industry. Methods: Using L. barbarum as experiment material, after being permeated, ultrasonic treating, blanching, ultrasonic treating + permeation and ultrasonic treating + blanchting, far infrared drying test was carried out. The effects of different pretreatment methods on the far-infrared drying characteristics of L. barbarum were studied. Weibull distribution function was used to fit the drying process. The quality and microstructure of dried L. barbarum products were analyzed. Results: After being pretreated, the drying time of L. barbarum was significantly reduced, the drying rate was increased; Compared with L. barbarum without pretreatment before pre-dried, drying time after blanching pretreatment shortened 27.5%, the moisture ratio of the material decreased fastest, and drying rate was the highest. Weibull distribution function can simulate the far infrared drying process of L. barbarum under different pretreatment conditions. The range of r2 and χ2 was 0.991 73-0.999 15 and 8.13 41 × 10-5-8.846 79 × 10-4. The drying characteristics described by scale parameter (α) and shape parameter (β) were consistent with those in the drying characteristic curve. The dried product pretreated with ultrasound + permeation had the smallest color difference (6.756 4) compared with the fresh sample. The polysaccharide content inside the material (991.27 mg/g•DW) was the highest; The microstructure of the dry product obtained by the ultrasound + penetration group had the most voids, and the drying treatment had the least damage to its surface. Conclusion: Ultrasonic and osmotic pretreatment of L. barbarum before drying can not only shorten the drying time, but also improve the quality of its dried products.

Effects of fresh-cut on drying rate and quality of Panax notoginseng / 中国中药杂志

To study the effects of fresh-cut drying methods on the appearance and internal components of Panax notoginseng, and explore the feasibility of fresh-cut drying methods of P. notoginseng, so as to provide more effective processing methods for the production of P. notoginseng slices and Chinese patent medicines. In this study, we have compared the effects of 6 different drying methods on drying time, drying rate, density, appearance and internal components of P. notoginseng roots. It takes about 453 h to dry by whole-root drying in the sun, with a long constant speed period and a slow drying rate, the time of whole-root drying at 50 ℃ was shortened by 61.6% compared with whole-root drying in the sun, which resulted in the decrease of density and poor appearance of the medicinal material with hollow and crack appeared in the xylem, while the drying time of fresh-cut drying method was reduced by 61.82% to 91.58% and the drying rate increased greatly, due to the relatively slow drying process in the sun or in the shade after fresh-cut, salting-out and whitening appeared on the surface, and the internal components were all decreased to some extent. The drying time of fresh-cut drying at 50 ℃ was 91.58% and 68.83% shorter than that of whole-root drying in the sun and at 50 ℃, respectively. When drying at 50 ℃ after fresh-cut, the appearance and content of internal components of the medicinal materials were better, the appearance was yellowish green, the cut sections were clear with uniform pore distribution, and the content of saponin components was increased by 7.24% compared with that of the whole-root drying at 50 ℃, When drying at 40 ℃, the surface of slices has salting-out and whitening spots, and the loss of dencichine and total sugar was large, but at 60 ℃, this high temperature made the rate of dehydration of slices was extremely fast, which led to severe cracking and fragmentation, and the loss of total sugar and alcohol extract was large. By vacuum freeze drying after fresh-cut, the structure of medicinal materials slices was loose, the density was greatly reduced, and the appearance was different from those recorded in traditional books. The contents of total saponin components and dencichine were increased by 16.51% and 22.54%, respectively, compared with traditional whole-root drying. The fresh-cut process method is feasible in the production of P. notoginseng slices. In production, it is recommended that drying at 50 ℃ after fresh-cut can make the medicinal materials better in appearance and content of internal components, which is convenient for the subsequent processing and industrial feeding extraction. For the purpose of internal contents, it is better to adopt freeze-drying after fresh-cut processing method.

Optimization of processing method for Lonicera macranthoides of Guizhou by multi-index evaluation / 中草药

Objective To investigate the effects of different processing methods on the appearance, quality components and processing efficiency of Lonicera macranthoides that produced in Guizhou Province, in order to provide basis for the optimization of processing methods. Methods Eleven processing methods were used such as the traditional method group (sun drying, sun drying after steaming, drying in shade, and drying in shade after steaming), constant temperature drying group (50, 60, 70, and 80 ℃) and variable temperature drying group (50→60 ℃, 50→70 ℃, 50→80 ℃). Then the indicators such as color, aroma, moisture, total ash, acid insoluble ash, chlorogenic acid, total saponins, processing time, and drying rate were measured. Results According to all the indicators, the comprehensive correlation degree of the 50 ℃ and the variable temperature drying method was between 0.94 and 0.96, which was much higher than other methods, and the comprehensive correlation degree of 50→60 ℃ degrees was the highest, reaching 0.959 8. Conclusion In conclusion variable temperature drying method is a better processing method for L. macranthoides. This method can be used as an important technical means for large-scale processing.

Vacuum pulsed drying characteristics of Lycii Fructus based on Weibull distribution model / 中草药

Objective To mitigate Lycii Fructus surface crust and save drying time during drying process, vacuum pulsed drying technology was applied to dry Lycii Fructus so as to investigate moisture diffusion regulation and build the drying model. Methods The effect of different drying temperature (50, 55, 60, and 65 ℃), vacuum pressure holding time (5, 10, 20, and 30 min), and atmosphere pressure holding time (2, 4, and 8 min) on drying characteristics, moisture diffusion coefficients and drying activation energy was explored in vacuum pulsed drying process. Weibull model distribution was used to simulate and analyze Lycii Fructus drying curves. Results All the drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had significant influence on drying time. When drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time was 60 ℃, 4 min, and 10 min, respectively, the minimum drying time was achieved to be 284 min. Weibull distribution model can be well described the vacuum pulsed drying process of Lycii Fructus. The scale parameter was related to drying time and decreased as drying temperature increased. The drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had little influence on the shape parameter. The shape parameter was associated with drying method. The moisture diffusion coefficient and activation energy were calculated to be 2.02 × 10-8-3.56 × 10-8 m2/s and 36.27 kJ/mol, respectively. Conclusion Weibull distribution model can well describe the moisture diffusion regulation of vacuum pulsed drying process of Lycii Fructus. The drying result had a great significance for predicting, controlling and optimizing drying process. On the other hand, the research could provide technical basis for industrial drying of Lycii Fructus by vacuum pulsed drying technology.

Comparison of Polysaccharide and Dendrobine Content in Hejiang Dendrobium nobile at Different Harvesting Time / 中国药房

OBJECTIVE:To determine quality indexes of Hejiang Dendrobium nobile at different harvesting time and months,and to provide scientific reference for reasonable harvesting period of Hejiang D.nobile.METHODS:The stem of annual,biennial and triennial D.nobile were collected.The drying rate,the contents of polysaccharides (colorimetry),dendrobine (GC) and total alkaloids (colorimetry),effective component total rate (dendrobine×drying rate) were measured.Biennial D.nobile were collected in autumn and winter (Oct.of the second year-Mar.of the third year,15th day a month) to determine drying rate,the contents of polysaccharides and dendrobine.RESULTS:The drying rate,the contents of polysaccharides and effective component total rate were higher than annual and triennial D.nobile.The content of total alkaloids and dendrobine were in descending order:annual D.nobile (0.52％,0.48％) ＞biennial D.nobile(0.48％,0.44％) ＞triennial D.nobile (0.32％,0.22％).From Oct.of the second year to Mar.of the third year,the drying rate of biennial D.nobile was increasing month by month;the contents of polysaccharides and dendrobine increased firstly and then decreased;the content of polysaccharide was the highest in Feb.(17.32％),and the content of dendrobine reached the highest level in Dec.(0.51％).CONCLUSIONS:The optimal harvesting period is biennial Hejiang D.nobile in Dec.and Jan.(third years before flowering),considering flowering characteristics,drying rate,the contents of polysaccharide and dendrobine.

Drying kinetics and mathematical modeling of Erzhi Pills during hot-air drying process / 中草药

Objective: To study the change rule of water content in the drying process of hot air drying of thin layer drying characteristic and model research, and to provide reference for improving the quality of Erzhi Pills (EP). Methods: The moisture ratio, drying rate of dry basis, and drying rate curves along with the change of drying time and relationship between dry basis moisture content and drying rate of EP were studied using a hot air dryer at five levels of drying air temperature in the range of 50-90 ℃. The model was fitted and verified by the empirical model Henderson & Pabis model, Newton model, Page model, Logarithmic model, two term exponential model, Wang & Singh model, Midilli et al. model, etc. Meanwhile, based on Fick's diffusion law, the effective diffusion coefficients of water (Deff) and activation energy value in EP were calculated. Results: The drying curves of EP show that the moisture ratio and drying rate of EP were closely related to the temperature of drying medium, and the moisture of the material decreases with the prolonged drying time. It could be seen from the drying rate curve that the drying rate increased with the increase of hot air temperature, and the migration of moisture was accelerated. By comparing the correlation coefficient (R2), chi-square (χ2) and standard error (RMSE), we could see that the mean value of R2 of model number 7 was the maximum, the χ2 and RMSE mean were the smallest (0.996 86, 2.43 × 10−4, and 1.93 × 10−4), respectively. The results showed that the model number 7 could describe and predict the drying process of the pills. The experimental data had the effective diffusion coefficient (Deff) value of 8.6 × 10−11—3.13 × 10−10 m2/s, and the activation energy (Ea) was 30.97 kJ/mol. Conclusion: The hot air drying process of EP can be modeled and verified. The research provides a new way to explore the drying characteristics and quality of pills.

Drying of pineapple slices in natura and pre-osmodehydrated in inverted sugar / Secagem de fatias de abacaxi in natura e pré-desidratadas osmoticamente em açúcar invertido

This research describes the drying kinetics and compares the convective drying rates of in natura and osmodehydrated pineapple slices in inverted sugar. The effective moisture diffusivity during air drying was estimated using Fick's second law of diffusion. The suitability of a theoretical liquid-diffusion model and seven semi-theoretical mathematical models for use in describing the experimental drying curves was also evaluated. Goodness of fit between experimental and predicted values was based on the root mean square error, mean absolute percentage error, mean bias error, agreement index, residual plot analysis and the principle of parsimony. Osmotic dehydration was conducted in 155, 310, and 465 mL L-1 osmotic solutions, at 40 and 50 ºC for 2 h at 60 rpm. Convective drying was performed in a tray cabinet dryer using heated ambient air at 60 ºC and 1.15 m s-1. Osmotic pretreatment facilitated water removal during the first hours of drying, a trend that was reversed towards the end of the process for samples osmodehydrated at the highest solution concentration. The effect of the osmotic pretreatments on drying rate was negligible at 40 C, but at 50 C the rate of moisture removal was more intense for samples in natura and osmodehydrated at the lowest solution concentration. Effective moisture diffusivity increased with temperature and solution concentration. The single-exponential, three-parameter semi-theoretical drying model gave the best predictions of the drying curves of pineapple slices both in natura and pre-osmodehydrated in inverted sugar.

O trabalho descreve a cinética de secagem e compara as taxas de secagem por convecção de fatias de abacaxi in natura e pré-desidratadas osmoticamente em açúcar invertido. A difusividade efetiva da água no interior do produto durante a secagem foi calculada empregando-se a Segunda Lei de Fick. Avalia, também, o grau de adequação de um modelo teórico de difusão de liquido e de sete modelos semi-teóricos na descrição das curvas experimentais de secagem. A desidratação osmótica foi realizada empregando-se soluções a 155, 310 e 465 mL L-1, a 40 e 50 ºC, sob agitação a 60 rpm e tempo de imersão de 2 h. A secagem por convecção foi feita em secador do tipo gabinete com bandejas, com ar à 60 ºC e 1,15 m s-1. O grau de ajuste dos modelos foi avaliado por meio da raiz do erro quadrático médio, do erro percentual absoluto médio, do viés médio, do índice de ajuste, pela análise da dispersão de resíduos e aplicando-se o princípio da parcimônia. O pré-tratamento osmótico facilitou a remoção de água durante as primeiras horas de secagem, comportamento que se reverteu ao final do processo para amostras desidratadas na solução mais concentrada. O efeito do pré-tratamento osmótico sobre a taxa de secagem foi desprezível a 40 ºC, no entanto, a 50 ºC, a taxa de remoção de água foi mais intensa para amostras in natura e pré-desidratadas nas soluções de menor concentração. A difusividade efetiva aumentou em função de aumentos na temperatura e na concentração da solução. O modelo exponencial simples de três parâmetros foi o que melhor descreveu as curvas de secagem por convecção de fatias de abacaxi in natura e pré-desidratadas osmoticamente em açúcar invertido

Increasing the rate of drying reduces metabolic imbalance, lipid peroxidation and critical water content in radicles of garden pea (Pisum sativum L.)

Orthodox seeds become desiccation-sensitive as they undergo germination. As a result, germinating seeds serve as a model to study desiccation sensitivity in plant tissues. The effects of the rate of drying on the viability, respiratory metabolism and free radical processes were thus studied during dehydration and wet storage of radicles of Pisum sativum. For both drying regimes desiccation could be described by exponential and inverse modified functions. Viability, as assessed by germination capacity and tetrazolium staining, remained at 100% during rapid (< 24 h) desiccation. However, it declined sharply at c. 0.26 g g¹ dm following slow (c. 5 days) drying. Increasing the rate of dehydration thus lowered the critical water content for survival. Rapid desiccation was also associated with higher activities and levels of malate dehydrogenase and the oxidized form of nicotinamide adenine dinucleotide. It was also accompanied by lower hydroperoxide levels and membrane damage. In addition, the activitiy of glutathione reductase was greater during rapid drying. Ageing may have contributed to increased damage during slow dehydration, since viability declined even in wet storage after two weeks. The results presented are consistent with rapid desiccation reducing the accumulation of damage resulting from desiccation-induced aqueous-based deleterious reactions. In addition, they show that radicles are a useful model to study desiccation sensitivity in plant tissues.