Study on the Effect of Different Drying Methods on the Proximate, Nutritional and Mineral Composition of Clarias gariepinus (Catfish)

Aim: This study investigated the effect of modern drying methods on the proximate, nutritional, and mineral composition of Clarias gariepinus in Port Harcourt, Nigeria. Methods: Fresh C. gariepinus were purchased from Mile 3 Market in Port Harcourt, Rivers State. Samples were dissected using a sharp knife, intestinal components, and gills were removed and the edible portion was washed properly and rinsed with distilled water. Samples were treated in four groups: fresh, smoking using firewood, electric drying (200oC), and non-electric drying (200oC for 30 minutes) methods. Samples were blended using mortar and pestle into powder and kept in an air-tight container prior to analyses. Results: The proximate composition of C. gariepinus revealed that crude protein concentration was in the following proportions; electric drying method (52.16+0.01%), non-electric drying method (43.40+0.00%), smoking method (32.72+0.00%) and fresh (23.01+0.00%). The lipid content of smoked and electric-dried C. gariepinus was significantly (p<0.05) higher compared to the fresh sample. However, there was no significant difference between the lipid content of fresh C. gariepinus sample and non-electric dried sample. The carbohydrate content increased in the smoking and electric drying methods but decreased in the non-electric drying method. The ash content increased only in the smoking method but decreased in both the electric dryer and non-electric dryer methods. Fresh samples had the highest moisture content (74.03+0.00%) while the least was observed in the electric dried sample (38.84+0.00%). The percent anti-nutrient composition of C. gariepinus showed that smoked samples had the highest flavonoid concentration (3.252±0.00%) which was not significantly higher (p>0.05) than the flavonoid content of electric dried C. gariepinus (2.89±0.33). The levels of selected minerals showed varying concentrations of potassium, sodium and calcium for the various processing methods. Conclusion: Modern drying methods had a significant effect on the proximate component, flavonoids, and oxalate composition of C. gariepinus. Electric drying method showed to be a better method of drying Clarias gariepinus compared to other drying methods.

Study on drying methods and harvesting time of Gynura divaricata leaf based on main active constituents / 中国药房

OBJECTIVE To determ ine the contents of main active constituents in Gynura divaricata leaf with different drying methods and at different harvesting time ，so as to confirm the best drying method and harvesting time. METHODS G. divaricata leaf with different drying methods [drying in the shade ，drying in the sun ，oven drying （60℃，70℃，80℃），microwave drying and freeze drying] and different harvesting time （March to October ）were prepared. The content of water-soluble extract was determined by hot dip method. The contents of total flavonoids and polysaccharides were determined by ultraviolet-visible spectrophotometry. The content of astragalin was determined by HPLC. Analytic hierarchy process was used for comprehensive analysis. RESULTS The time of drying in the shade ，drying in the sun ，drying at 60 ℃，drying at 70 ℃，drying at 80 ℃， microwave drying and freeze drying were 7 d，5 d，8 h，5 h，3.5 h，6 min and 1 d respectively. The average contents of water-soluble extract in G. divaricata leaf were 55.98％，60.78％，52.33％，49.54％，46.87％，59.70％ and 58.24％；those of total flavonoids were 3.27％，3.22％，1.99％，1.70％，1.31％，3.92％ and 2.28％；those of polysaccharides were 4.70％，6.09％， 6.48％，5.45％，5.74％，5.76％ and 7.15％；those of astragalin were 0.48％，0.46％，0.24％，0.23％，0.20％，0.48％，0.29％. The comprehensive score of microwave drying was the highest ，being 0.996 3. The average contents of water-soluble extract from March to October were 41.50％，40.57％，39.16％，40.65％，40.68％，43.30％，45.19％ and 40.12％；those of total flavonoids were 2.24％，2.81％，3.87％，3.92％，3.82％，3.93％，3.66％ and 3.25％；those of polysaccharides were 4.41％，4.61％， 4.98％，5.26％，5.75％，5.94％，5.32％ and 4.47％；those of astragalin were 0.20％，0.21％，0.25％，0.26％，0.25％，0.24％， 0.25％ and 0.21％，respectively. The comprehensive scores of samples collected from May to September exceeded 0.92，and the comprehensive score in August was the highest （0.988 6）. CONCLUSIONS Microwave-dried Gynura divaricata leaf has the best quality ，and the best harvesting time is from May to September.

Effects and evaluation of different processing and drying methods on components in Paeoniae Radix Alba / 中国中药杂志

The present study evaluates different processing and drying methods and investigates their effects on the chemical components in Paeoniae Radix Alba via content determination. The fresh medicinal materials of Paeoniae Radix Alba collected from Bozhou of Anhui province were processed(boiled and peeled) and dried(hot air-dried, infrared-dried, and microwave-dried) at different temperatures(40, 50, 60 and 70 ℃), and the 11 components(monoterpene glycosides, polyphenols, tannin, and benzoic acid) in Paeoniae Radix Alba were determined by ultra-performance liquid chromatography coupled to triple quadrupole with electrospray tandem mass spectrometry(UPLC-TQ-MS). Then the compounds in processed and dried samples were analyzed by partial least squares discriminant analysis(PLS-DA) and orthogonal partial least squares discriminant analysis(OPLS-DA), and the contribution rates of differential components were evaluated by variable important in projection(VIP). The results indicated that the samples obtained by different processing and drying methods could be distinguished. Albiflorin, gallic acid, 1,2,3,4,6-pentakis-O-galloyl-β-D-glucose, and benzoic acid were the common differential components in boiled Paeoniae Radix Alba. Benzoic acid was the common differential component in peeled Paeoniae Radix Alba. Gallic acid was the common differential component in Paeoniae Radix Alba dried by different methods. The samples could not be distinguished after drying at different temperatures due to the lack of common differential components. This study is expected to provide a reference for the selection of processing and drying methods and the optimization of processing parameters.

Effect of drying methods on the powder and compaction properties of microcrystalline cellulose derived from Gossypium herbaceum

The effect of drying method, a process variable, on the powder and compaction properties of microcrystalline cellulose (MCC) obtained from the partial acid hydrolysis of bleached alpha (α) cellulose content of matured linters of Gossypium herbaceum (GH) was investigated. A portion of the wet MCC obtained was fluid bed dried at 60 ± 1 ºC, inlet air of 30 m3 min-1 for 3 h (coded MCC-GossF). The second portion was lyophilized at - 45 ± 2 ºC for 6 h (coded MCC-GossL). The physicochemical, scanning electron micrographs, X ray diffraction patterns and micromeritic properties of the derived MCCs were determined using standard methods. The cohesiveness and compactibility of the powders were investigated using Kawakita model while the deformation and compressibility pattern were determined using Heckel model. Avicel® PH 102 (AV-102) was used as comparing standard. Ash values of < 2%, pH (6.54 ± 0.23 to 6.58 ± 0.08), degree of polymerization, DP (231.50) was obtained. MCC-GossF had higher moisture content, swellability, better flow indices, and lesser porosity than MCC-GossL. Kawakita model demonstrated good consolidation and compactibility for both powders. Compacts of MCC-GossL were significantly (p < 0.05) harder than those of MCC-GossF. Heckel analysis demonstrated good compressibility and deformation pattern that was comparable with AV-102. Compacts of MCC-GossL had better mechanical and tablet compression properties than MCC-GossF

Effects of three drying methods on the physical properties and drug delivery in chitosan microspheres / 华西口腔医学杂志

OBJECTIVE@#The purpose of this study is to investigate the effects of different drying methods on the physical properties and drug delivery of chitosan microspheres.@*METHODS@#Three types of drying methods were utilized, including air drying and freeze drying after freezing at -20 ℃ (slow cooling) and at -80 ℃ (fast cooling). The physical properties of microspheres were characterized. Utilizing bovine serum albumin (BSA) as the model drug, the in-vitro release behaviors of drug-loaded beads were investigated.@*RESULTS@#By comparing the physical properties of the different drying methods, the microspheres' diameters, porosities, and surface area were observed to increase successively from air drying and slow cooling to fast cooling, whereas the pore size and the swelling and degradation rates varied. The drug-loading experiments revealed that the loading capacity of air-dried microspheres was the lowest and the release rate was the slowest. Although the loading capacity of fast cooling microspheres was high, an obvious burst release was observed. The loading capacity of slow cooling microspheres was similar to that of the fast cooling microspheres and the loaded BSA can be released continuously.@*CONCLUSIONS@#The results indicate that different drying methods can affect the physical properties of chitosan microspheres, which further influence drug loading and release.

Effects of different drying methods on active constituents of root bark and root of Polygala tenuifolia / 中草药

Objective To investigate the effects of different drying methods on composition and content of five active constituents in root bark and root of Polgala tenuifoliaroot. Methods The contents of polygalaxanthone III, 3,6’-disinapoyl sucrose, polygalacic acid, senegenin, and tenuifolin in root bark and root from different drying samples were determined by HPLC. Then the data analysis was performed by ANOVA and TOPSIS methods. Results There is a difference in the order of drying methods for bark and root of P. tenuifoliaroot. For P. tenuifoliaroot root bark, the order of different drying methods was microwave drying > 60 ℃ hot-air drying > 50 ℃ hot-air drying > 70 ℃ hot-air drying > freeze-drying > 40 ℃ hot-air drying > shade drying > sun drying; For P. tenuifolia root, the different drying methods were sorted by microwave drying > 60 ℃ hot-air drying > shade drying > sun drying > 50 ℃ hot-air drying > 40 ℃ hot-air drying > 70 ℃ hot-air drying > freeze-drying. Conclusion Combined with the production practice, this study suggests that microwave drying and hot-air drying at 60 ℃ are suitable drying methods for P. tenuifoliaroot bark and root, providing a basis for the determination of drying methods for the origin processing of P. tenuifolia.

Total phenolics, antioxidant capacity, colour and drying characteristics of date fruit dried with different methods

Abstract Date slices were dried with the three drying methods convective (60, 70 and 80 °C), microwave (120 W) and freeze drying to determine drying characteristics and to compare the dried fruit quality. All colour parameters changed depending on the drying method and colours closest to the fresh sample were obtained with freeze drying. It is interesting to note that the total phenolic content and antioxidant capacity in each sample rose when looked at in relation to the fresh sample. In particular, microwave-dried samples were recorded as having the highest total phenolic content and the highest antioxidant capacity. To explain the drying kinetics of the date slices, nine thin-layer drying models were also attempted. Based on statistical tests, the model developed by Midilli et al. model was found to be the best model for convective and microwave drying, but the Two Term model was the best for freeze drying. This study shows that microwave drying can produce high quality date slices with the additional advantage of reduced drying times compared to convective and freeze drying.

Effects of different drying methods on content of bioactive component and antioxidant activity in Lycium ruthenicum / 中国中药杂志

To compare the appearances, tastes, contents of bioactive components and antioxidant activity of Lyceum ruthenicum under different drying methods, so as to direct its production practice. The folin-phenol colorimetric method, UV, extinction coefficient method and DPPH, as well as fluorescence recovery after photobleaching (FRAP) method to determine the contents of polyphenols, proanthocyanidins, total anthocyanin and antioxidant activity under different drying methods： vacuum freeze drying, low-temperature oven drying and air drying for L. ruthenicum. The results showed that the drying methods had certain effects on its appearances, tastes, contents of bioactive components and antioxidant activity. The appearances and tastes were best after the L. ruthenicum was dried by vacuum freeze drying, with significantly lower moisture than air drying method. The contents of total polyphenols, anthocyanin and proanthocyanidins were highest by air-drying but lowest by low temperature oven drying in L. ruthenicum. The scavenging ability to DPPH was strongest by freeze-drying and lowest by low temperature oven drying, while the antioxidant activity was strongest by air-drying in the FRAT method. In addition, the appearances and tastes were poor in air drying, with higher moisture but highest contents of the three bioactive components. Therefore, the drying methods for L. ruthenicum shall be comprehensively considered.

Study on the drying method of the luminal machine / 中国实用护理杂志

Objective To investigate the method of the operation of the tube type,improve the drying efficiency,and control the occurrence of infection in hospital,reduce the energy consumption.Methods Devices with full automatic washing machine washing out the lumen of 600 pieces were divided into control group and two experimental group by random digital table method each group was 200 pieces,respectively,and using dumped water before drying,luminal devices placed in different position and different container among the three groups in 90 ℃ drying 30 minutes after lumen devices to compare the drying effect.Results At the dry temperature 90℃,the same drying time of 30 minutes,the rate of drying qualified of the experimental group 2 was 100.0％ (200/200),which was higher than 82.5％ (165/200) of the experimental group 1,the difference was statistically significant (x2=38.356,P ＜ 0.05);and also higher than 21％ (42/200) of the control group,the difference was statistically significant (x2=261.157,P ＜ 0.05).Conclusions The new drying operation method can improve the drying efficiency of the tube type,and control the risk of inffection in the hospital.

Effects of different drying methods on quality of Gastrodiae Rhizoma / 中国中药杂志

Different drying methods, including drying in the sun, sulphur fumigation, hot air drying, microwave drying, infrared drying and various coupling techniques,were used to dry fresh Gastrodiae Rhizoma. Characteristics, extracts and the contents of active components of all samples were compared to investigate the effects of different drying methods on quality of Gastrodiae Rhizoma. The results showed that the characteristics of the samples would be better with use of sulphur fumigation, hot air drying, and hot air-microwave drying. Different drying methods had little effects on extracts. Among them, the extract content was higher after hot air drying. The stilbene glycosides would transformation and the contents of Gastrodiae Rhizoma polysaccharides would decline with use of sulphur fumigation, microwave drying and infrared drying. In the comprehensive analysis of characteristics, content of active components, production cost and other factors, hot air drying or hot air-microwave drying was recommended as the first choice.

Influence of different drying methods on steroidal saponins and homoisoflavonoids in Ophiopogon japonicus / 中国中药杂志

To study the influence of three different drying methods (including 50 ℃-drying, 80 ℃-drying and －70 ℃-freeze-drying methods) on steroidal saponins and homoisoflavonoids in Ophiopogon japonicus,a HPLC-DAD-ELSD-MSn method was investigated to screen and identify the differential components. Through comparing the HPLC chromatograms with that of fresh O. japonicus, 50 ℃-drying medicine was similar with fresh medicine whereas the other two drying methods had great influence on the components of O. japonicus. In this study, 36 differential components were screened, among which 24 constituents(13 homoisoflavonoids and 11 steroidal saponins) were identified via HPLC-LTQ-Orbitrap MS.As a result, it was revealed that different drying methods had significant influences on the components of steroidal saponins and homoisoflavonoids. Among them, 50 ℃-drying method was the most suitable drying approach when the stability of components, cost and practicability were considered.

Effects of Different Drying Methods on Composition and Antioxidative Activities of Volatile Oils fromCymbopogon Citrates / 中国中医药信息杂志

Objective To discuss the effects of different drying methods on composition and antioxidative activities of the volatile oil fromCymbopogon citrates; To optimize the best drying method for Cymbopogon citrates. MethodsCymbopogon citrates was dried by drying in the sun, drying in the shade and oven drying at 40℃. Volatile oil was extracted by steam distillation. Chemical constituents in the volatile oil were analyzed by GC-MS and the antioxidative activities were determined by ferric reducing antioxidant power (FRAP method).Results Extraction rate of the volatile oil fromCymbopogon citratesunder the environment of freshness, sun drying, shade drying and oven drying at 40℃ were 0.25%, 1.21%, 1.19% and 1.17%, respectively; after dried by different methods, main constituents and antioxidative activities of the volatile oil fromCymbopogon citrates were basically same. Conclusion Different drying methods have little influence on composition and antioxidative activities of the volatile oil fromCymbopogon citrates. Oven drying at 40℃ was the best way to dryCymbopogon citrates.

Effect of different drying methods on ginsenosides in flower of Panax ginseng and Panax quinquefolius / 中草药

Objective: To select the reasonable post-processing methods after harvest of the flower of Panax ginseng (FPG) and Panax quinquefolius (FPQ). The present study evaluated the effect of different drying methods on the quality of FPG and FPQ based on the contents of 14 ginsenosides. Methods: The contents of 14 ginsenosides were quantified by HPLC including ginsenosides Rg1, Re, Rb1, Rc, Rb2, Rb3, Rd and their corresponding malonyl-ginsenosides (m-Rg1, m-Re, m-Rb1, m-Rc, m-Rb2, m-Rb3, and m-Rd). Results: The contents of 14 ginsenosides were highest by oven drying at 40℃, followed by freeze drying, microwave drying, and infrared drying, and decreased with the increased temperature. The contents of malonyl-ginsenosides obviously decreased with reaching a high temperature (> 100℃). The decrement of malonyl-ginsenosides and the variation of corresponding ginsenosides was not equivalent, and the total content of 14 ginsenosides was also reduced. Conclusion: Oven drying at 40℃ is a suitable drying method for keeping the content of original ginsenosides, and oven drying at high temperature (> 100℃) can prompt the transformation into rare ginsenosides. Different drying methods can be selected according to different purposes in clinical application.

The Effect of Different Drying Methods on the Phytochemicals and Radical Scavenging Activity of Ceylon Cinnamon (Cinnamomum zeylanicum) Plant Parts.

Aim: The research aimed at ascertaining whether the different drying methods and plant parts have effect on the radical scavenging activity and phytochemical properties of cinnamon as an herb/spice. Methodology: Fresh samples of the cinnamon (Cinnamomum zeylanicum) was collected at the Aburi Botanical Gardens, Ghana. Some of the samples were sun, oven, room and freeze dried. The dried and fresh samples were extracted with methanol and water and the extract analyzed. Results: Only the sun dried samples had the total phenolic and total flavonoid been degraded compared to the fresh sample. The flavonoid and phenolic contents and the DPPH radical scavenging activity were significantly expressed in different amounts in the root, stem, leaf and seed. Conclusion: Generally, the drying influenced the phytochemical contents which are major contribution to the radical scavenging activity of the cinnamon.

Morphology, Functional and Pasting Properties of Ginger Starches Prepared by Four Different Drying Methods.

Aim: This study aims at providing information on the morphology, physico-chemical and pasting properties of the ginger starches prepared by air drying, oven drying, freeze drying and microwave drying methods with a view to improving their utilization. Place and Duration of Study: Department of Pharmaceutics and Pharmaceutical Technology, Olabisi Onabanjo University, Nigeria and Department of Pharmaceutics, University of Ibadan, Nigeria between March 2013 and February 2014 Methodology: Starch was isolated from the rhizomes of Zingiber officinale and dried by oven, freeze drying, air drying and microwave drying methods. They were studied for their composition, morphological, functional and pasting properties Result: The residual protein content of the four starches was slightly different averaging 5.06%. The residual protein of air dried starch was the lowest and that freeze dried starch was the highest. There was no significant variation in the saponin and tannin contents of the dried samples. The amylose content of the ginger starches ranged between 20.7% and 22.1%.The rank order of the amylose content was microwave dried >freeze dried> air dried>oven dried. Drying methods had a significant effect (P<0.0001) on the solubility index and swelling capacity of the dried samples investigated. The rank order of the swelling capacity of the ginger starches was freeze dried<air dried<oven dried<microwave dried. A higher solubility index was observed among the oven-dried sample and the microwave sample compared to freeze dried and air dried samples. X-ray fluorimetric (XRF) analysis of the different starch powders showed the presence of iron, copper and zinc in trace amounts; and the absence of heavy metals like lead and mercury. All the four dried samples have fairly good flow. Significant differences were observed in individual pasting parameters of the ginger starches especially in peak viscosity, trough viscosity, final viscosity and setback viscosity. Peak viscosity was found to be lowest for freeze dried starch (300.42RVU) and highest for oven dried starch (324.25RVU). The rank order of the final viscosity was oven dried > microwave dried > air dried>freeze dried. Conclusion: This study revealed that the physicochemical as well as the pasting properties of the ginger starches prepared by the four drying methods make them to be considered as excellent resource with possible applications in many food and pharmaceutical processing. The results also showed that difference in drying methods during processing has an effect on composition and pasting properties of ginger starch.

Analysis of two drying methods on the yield and activity of sulfated polysaccharides extracted from Halymenia sp (Rhodophyceae) / Análise de dois métodos de secagem sobre o rendimento e atividade de polissacarídeos sulfatados extraídos da rodofícea Halymenia sp

Sulfated polysaccharides (SPs) have attracted growing interest for various biotechnological applications. We evaluated the efficiency of two methods of drying SPs (M I and II) extracted from Halymenia sp Rhodophyceae in order to compare the yield, purification and anticoagulant activity. The total SPs (TSPs) were first extracted with papain in 100 mM sodium acetate (pH 5.0) containing cysteine and EDTA (5 mM). The TSPs obtained were dried in an oven (M I) or lyophilized (M II) and then examined by ion exchange chromatography (DEAE-cellulose) using the NaCl gradient technique. The fractions were analyzed by 0.5% agarose gel electrophoresis and the in vitro anticoagulant activity was evaluated by the activated partial thromboplastin time test using normal human plasma and compared to heparin (HEP) (193.00 IU mg-1). There was a difference in TSP yield of 19.05% and similar chromatographic SP profiles. Electrophoresis revealed fractions with distinct resolutions. The fractions eluted with 0.75 M of salt (M I and II) were the most active, measuring 27.40 and 72.66 IU mg-1, respectively, when compared to HEP. Therefore, obtaining SP with anticoagulant activity from Halymenia sp. is more efficient by freeze-drying.

Os polissacarídeos sulfatados (PS) têm despertado interesse crescente para diversas aplicações em biotecnologia. Avaliou-se a eficiência de duas metodologias de secagem de PSs (M I e II) extraídos da rodofícea Halymenia sp. a fim de se comparar o rendimento, a purificação e a atividade anticoagulante. Inicialmente, os PS totais (PSTs) foram extraídos com papaína em tampão acetato de sódio 100 mM (pH 5,0) contendo cisteína e EDTA (5 mM). Os PSTs foram secados em estufa (M I) ou liofilizados (M II), seguido por cromatografia de troca iônica (DEAE-celulose) utilizando um gradiente de NaCl. As frações foram analisadas por eletroforese em gel de agarose a 0,5% e a atividade anticoagulante "in vitro" avaliada por meio do teste do tempo de tromboplastina parcial ativada usando plasma humano normal e comparadas à heparina (HEP) (193.00 UI mg-1). Verificaram-se diferença no rendimento de PSTs (19,05%) e semelhantes perfis cromatográficos de PS, revelando, por eletroforese, frações de PS distintas em grau de resolução entre os métodos. As frações eluídas com 0,75 M de sal (M I e II) foram as mais ativas, com valores de atividade da ordem de 27,40 e 72,66 UI mg-1, respectivamente, em relação à HEP. Portanto, a secagem por liofilização seria uma forma mais eficaz na obtenção de PSs com atividade anticoagulante de Halymenia sp.

Study of Drying Methods of Forsythia Suspense Leaves / 中国中医药信息杂志

Objective Better drying methods of Forsythia suspense leaves was studied to provide some basis for the development and utilization of Forsythia suspense leaves. Methods A RP-HPLC method was used on XTerraTMRP8 (3.9 mm?150 mm, 5 ?m) column with acetonitrile-0.1% acetic acid solution (12 : 88) as mobile phase for forsythoside. The detection wavelength of forsythoside was at 328 nm and detection temperature was 30 ℃. Results The contents of forsythoside was higher when dry, microwave drying, absorbent paper drying, steaming 2～10 min, cooking 2～10 min was used to deal with Forsythia suspense leaves. The contents of forsythoside was lower when dried, drying, infrared drying, vacuum drying was used to deal with Forsythia suspense leaves. Conclusion Steaming 2～10 min, cooking 2～ 10 min is more appropriate for drying of Forsythia suspense leaves, when factors of the contents of forsythoside, the cost and ease of operation were considerd.

Influências da variação sazonal e tipos de secagem nas características da droga vegetal - raízes de Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae) / Influence of seasonal variation and drying on root’s characteristics derived from Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae)

Analisou-se a variação sazonal e a influência de diferentes tipos de secagem (sol, sombra e estufa) no teor de saponinas e nas características físico-químicas da droga vegetal - raízes de Pfaffia glomerata (Spreng.) Pedersen (Amaranthaceae). A avaliação sazonal apontou a ocorrência de diferenças significativas nos teores de extrativos (maior no inverno: 61,1 por cento±1,9), saponinas totais (maior no inverno: 17,1±0,2 por cento), e entre cinzas totais (maiores no inverno e primavera: 6,5±0,4 e 6,5±1,0 por cento, respectivamente) e cinzas insolúveis em ácido(maiores no verão e outono: 0,57±0,11 e 0,44±0,18 por cento, repectivamente). Quanto à variação sazonal do teor de saponinas, o valor do lote colhido no inverno foi maior do que nas outras estações, confirmando o conceito geral de maior ocorrência de ativos em órgãos subterrâneos no inverno. Quanto à influência dos métodos de secagem, o lote seco ao sol forneceu maior teor de extrativos (61,2±2,3 por cento) do que os lotes secos na sombra e em estufa, contradizendo a regra geral de que a radiação solar degrada os ativos vegetais. Esse mesmo perfil de dados ocorreu com relação ao teor de saponinas, pois o lote seco ao sol mostrou maior valor(15,4 por cento) do que daqueles secos na sombra ou em estufa (14,4 e 11,6 por cento, respectivamente). Desta forma, verificou-se que, de fato, ocorre variação sazonal nas raízes de P. glomerata, particularmente, no que diz respeito aos teoes de extrativos, cinzas e saponinas totais, sendo que essas variações indicam maior concentração de ativos nos períodos de inverno e primavera. Dentre os métodos de secagem testados, o emprego do sol parece favorecer os teores de saponinas e de extrativos, embora tal conclusão mereça ser melhor investigada.

The seasonal variation and the influence of drying (sun, shadow and hot-house greenhouse) were analysed in relation to the total saponin content and physicochemical characteristics. The seasonal evaluation detected significant differences in the parameters of extractable matter (larger in winter: 61.1 percent±1.9), total saponin content (larger in winter; 17.1±0.2 percent) and between total ash (larger in winter and spring; 6.5±0.4 and 6.5±1.0 percent, respectively) and acid-insoluble ash (larger in summer and autumn; 0.57±0.11 and 0.44±0.18 percent, respectively). In relation to the seasonal variation of total saponin content, the value of the sample collected in winter was larger than in other seasons, confirming the general rule that the largest content of substances in underground organs occurred in winter. In relation to the influence of drying methods, the sample dried at the sun presented a larger value of extractable matter (61.2±2.3 percent) than those dried on shadow and in hot-house greenhouse, contradicting the general rule that the sun radiation would degrade natural substances. The same profile was found in relation to the total saponin content, because the sample dried at the sun showed a larger value (15.4 percent) than those dried on shadow or in hot-house (14.4 and 11.6 percent, respectively). However, these conclusions have to be more investigated.