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1.
Food Chem ; 303: 125386, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31473454

RESUMO

The present work investigated the influences of ultrahigh pressure (UHP), ultrasound (US) and their combination (UHP-US) as pretreatments on properties of vacuum-freeze dried strawberry slices. During vacuum-freeze drying, drying duration and total energy consumption of UHP sample, US sample and UHP-US sample was decreased. After the UHP or US pretreatments, a* value (redness), antioxidative substances (total anthocyanin content, total flavonoid content, total phenolic content, diphenyl picrylhydrazyl (DPPH), hydroxyl (-OH) radical-scavenging assay), hardness and cross-section areas of matrix in the dried slices were significantly (P < 0.05) increased. Transverse relaxation times and peak area corresponding to free water in the pretreated samples were obviously decreased, indicating lower mobility in the pretreated samples. As compared with UHP or US individually, UHP in combination with US increased those parameters more pronouncedly. Therefore, UHP and US are promising techniques for the vacuum-freeze drying processing of strawberry products.


Assuntos
Dessecação , Conservação de Alimentos/métodos , Fragaria/química , Frutas/química , Pressão , Ondas Ultrassônicas , Antocianinas/análise , Antioxidantes/análise , Antioxidantes/química , Cor , Flavonoides/análise , Liofilização , Frutas/efeitos da radiação , Fenóis/análise , Vácuo
2.
Nature ; 574(7776): 90-94, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31578485

RESUMO

Groundwater is the world's largest freshwater resource and is critically important for irrigation, and hence for global food security1-3. Already, unsustainable groundwater pumping exceeds recharge from precipitation and rivers4, leading to substantial drops in the levels of groundwater and losses of groundwater from its storage, especially in intensively irrigated regions5-7. When groundwater levels drop, discharges from groundwater to streams decline, reverse in direction or even stop completely, thereby decreasing streamflow, with potentially devastating effects on aquatic ecosystems. Here we link declines in the levels of groundwater that result from groundwater pumping to decreases in streamflow globally, and estimate where and when environmentally critical streamflows-which are required to maintain healthy ecosystems-will no longer be sustained. We estimate that, by 2050, environmental flow limits will be reached for approximately 42 to 79 per cent of the watersheds in which there is groundwater pumping worldwide, and that this will generally occur before substantial losses in groundwater storage are experienced. Only a small decline in groundwater level is needed to affect streamflow, making our estimates uncertain for streams near a transition to reversed groundwater discharge. However, for many areas, groundwater pumping rates are high and environmental flow limits are known to be severely exceeded. Compared to surface-water use, the effects of groundwater pumping are markedly delayed. Our results thus reveal the current and future environmental legacy of groundwater use.


Assuntos
Mapeamento Geográfico , Água Subterrânea/análise , Chuva , Rios/química , Movimentos da Água , Abastecimento de Água/métodos , Irrigação Agrícola/métodos , Organismos Aquáticos , Mudança Climática , Dessecação , Secas/estatística & dados numéricos , Ecossistema , Água Doce/análise , Internacionalidade , Modelos Teóricos
3.
Zhongguo Zhong Yao Za Zhi ; 44(15): 3195-3202, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31602872

RESUMO

Dry granulation technology is a great innovation in granulation technology,which saves many intermediate links and reduces many intermediate costs. It is closely related to the characteristics of materials,dry granulation equipment and process. Dry granulation technology is a systematic engineering science covering many technical fields. The process of dry granulation involves complex mathematical model mechanisms of temperature field,pressure field and velocity field,closely related to the characteristics of materials and drying equipment. However,due to the late start of research on dry granulation technology of traditional Chinese medicine,basic research is still weak. The research on dry granulation technology has achieved great results in the fields of food,chemical industry,agriculture and forestry,showing great reference significance. The advantage of dry granulation of traditional Chinese medicine is that it can be directly granulated by adding an appropriate amount of auxiliary materials in the extract powder of traditional Chinese medicine,without the need of wetting,mixing,drying and other processes. The process is simple and can effectively guarantee the quality of traditional Chinese medicine. The granules obtained by the dry granulation technique are important intermediates for preparing the solid preparations of traditional Chinese medicines,which would directly affect the subsequent molding process and the quality of the preparation products. Therefore,based on the characteristics of dry granulation method in traditional Chinese medicine and by referring to the advanced research results of dry granulation technology in other fields,we would discuss the research ideas of dry granulation in traditional Chinese medicine in terms of the mechanism of dry granulation equipment,technology,on-line detection technology and mathematical model of dry granulation process,hoping to provide reference for the research of dry granulation method in traditional Chinese medicine.


Assuntos
Dessecação , Medicina Tradicional Chinesa , Tecnologia Farmacêutica , Medicamentos de Ervas Chinesas , Modelos Teóricos , Pós , Controle de Qualidade
4.
Zhongguo Zhong Yao Za Zhi ; 44(15): 3281-3286, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31602884

RESUMO

Decoction pieces are important raw materials in the production of traditional Chinese medicine( TCM),and their quality could directly affect the clinical efficacy and medication safety. Research on the production and processing technology of TCM is the basis for the normalization and standardization of Chinese medicine decoction pieces. At present,the production and processing standards for Scutellaria baicalensis pieces are non-regulated,lacking data foundation. In this study,with baicalin,baicalein,wogonoside and wogonin contents as evaluation indicators,single factor experiment was designed to optimize the softening,drying and cutting processes of S. baicalensis,providing a basis for the standardization of their production and processing. The effects of different softening,drying and cutting processes on the contents of the main components in S. baicalensis were comprehensively analyzed by the summation of relative differences. RESULTS:: showed that the contents of the four components and comprehensive indexes were affected by different softening methods and drying temperatures. The content of wogonin in boiling method was higher than that in boiling with cold water,and the content of glycosides in 70 ℃ drying condition was higher than that in other groups. The content of baicalin was significantly affected by different cutting thicknesses,but not by comprehensive index. Eventually,the optimal preparation process for S. baicalensis was determined as follows: boiled in boiling water for 20 min,cut into thin slices( 1-2 mm),and then dried at 70 ℃ in blast drier. This process was close to the actual production,practical and feasible and meanwhile,it was of great significance to improve the quality of S. baicalensis pieces.


Assuntos
Medicamentos de Ervas Chinesas/normas , Scutellaria baicalensis/química , Dessecação , Flavonoides/análise , Medicina Tradicional Chinesa , Controle de Qualidade
5.
Environ Monit Assess ; 191(10): 607, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31485756

RESUMO

The geochemical fractions of heavy metals in sediments are crucial indexes for their mobility and bioavailability evaluations. However, different drying processes of sediment pretreatment could change metal geochemical fractions, especially for Hg, which is potentially volatile. In this study, the influence of pretreatment methods including oven-drying, air-drying, freeze-drying, and fresh sediments on the analysis of Hg fractions in sediments was investigated. Results showed that remarkable differences of Hg concentration were observed between fresh sediments and dried pretreatment sediments (P < 0.05). Briefly, the concentrations of the water-soluble and human stomach acid-soluble fractions in oven-dried and air-dried sediments generally showed significant increasing trends compared with those in the fresh sediments, while the organo-chelated fraction exhibited significant decreasing trends. The cause of this phenomenon was primarily the oxidation of organic matter, aging process, and the diffusion of Hg into micropores. The significant loss was also observed at elemental Hg fraction due to its volatilization effect. The freeze-drying posed minor influence on changes of Hg fraction analysis compared with oven-drying and air-drying. Moreover, the total Hg concentrations in pretreated sediments showed a decline of varying degrees compared with those in fresh sediments ascribing to the volatilization of elemental Hg. Finally, Pearson correlation analysis further confirmed that freeze-drying could minimize the errors of the Hg fraction analysis in sediments.


Assuntos
Dessecação , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Mercúrio/análise , Disponibilidade Biológica , Poluentes do Solo/análise , Volatilização
6.
Eur J Pharm Biopharm ; 144: 79-90, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31499162

RESUMO

Despite the fact that solid dispersions are gaining momentum, the number of polymers that have been used as a carrier during the past 50 years is rather limited. Recently, the poly(2-alkyl-2-oxazoline) (PAOx) polymer class profiled itself as a versatile platform for a wide variety of applications in drug delivery, including their use as amorphous solid dispersion (ASD) carrier. The aim of this study was to investigate the potential of poly(2-ethyl-2-oxazoline) (PEtOx) by applying a benchmark approach with well-known, commercially available carriers (i.e. polyvinylpyrrolidone (PVP) K30, poly(vinylpyrrolidone-co-vinyl acetate) (PVP-VA) 64 and hydroxypropylmethylcellulose (HPMC)). For this purpose, itraconazole (ITC) and fenofibrate (FFB) were selected as poorly water-soluble model drugs. The four polymers were compared by establishing their supersaturation maintaining potential and by investigating their capability as carrier for ASDs with high drug loadings. Spray drying, as well as hot melt extrusion and cryo-milling were implemented as ASD manufacturing technologies for comparative evaluation. For each manufacturing technique, the formulations with the highest possible drug loadings were tested with respect to in vitro drug release kinetics. This study indicates that PEtOx is able to maintain supersaturation of the drugs to a similar extent as the commercially available polymers and that ASDs with comparable drug loadings can be manufactured. The results of the in vitro dissolution tests reveal that high drug release can be obtained for PEtOx formulations. Overall, proof-of-concept is provided for the potential of PEtOx for drug formulation purposes.


Assuntos
Portadores de Fármacos/química , Poliaminas/química , Solubilidade/efeitos dos fármacos , Química Farmacêutica/métodos , Cristalização/métodos , Dessecação/métodos , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos/efeitos dos fármacos , Derivados da Hipromelose/química , Polímeros/química , Povidona/química , Pirrolidinas/química , Compostos de Vinila/química
7.
Biol Res ; 52(1): 46, 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434576

RESUMO

BACKGROUND: One of the most extreme environments on our planet is the Maritime Antarctic territory, due to its low-water availability, which restricts the development of plants. Sanionia uncinata Hedw. (Amblystegiaceae), the main colonizer of the Maritime Antarctic, has effective mechanisms to tolerate this environment. It has been described that the tolerance to desiccation is mediated by the hormone abscisic acid (ABA), antioxidants systems, accumulation of compatible solutes and proteins of the late embryogenesis abundant (LEA). However, to date, these mechanisms have not been described in S. uncinata. Therefore, in this work, we postulate that the tolerance to desiccation in the Antarctic moss S. uncinata is mediated by the accumulation of ABA, the osmolytes proline and glycine betaine, and dehydrins (an LEA class 11 proteins). To demonstrate our hypothesis, S. uncinata was subjected to desiccation for 24 h (loss in 95% of water content), and the effects on its physiological, photosynthetic, antioxidant and biochemical parameters were determined. RESULTS: Our results showed an accumulation of ABA in response to water loss, and the activation of protective responses that involves an increment in levels of proline and glycine betaine, an increment in the activity of antioxidant enzymes such as SOD, CAT, APX and POD, and the accumulation of dehydrins proteins. CONCLUSION: The results showed, suggest that S. uncinata is a  desiccation-tolerant moss, property mediated by high cellular plasticity regulated by ABA.


Assuntos
Antioxidantes/análise , Bryopsida/fisiologia , Dessecação , Fotossíntese/fisiologia , Adaptação Fisiológica , Regiões Antárticas , Bryopsida/química , Bryopsida/classificação , Fatores de Tempo
8.
Pharm Res ; 36(10): 142, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31376020

RESUMO

BACKGROUND: With the recent approval of the first small interfering RNA (siRNA) therapeutic formulated as nanoparticles, there is increased incentive for establishing the factors of importance for the design of stable solid dosage forms of such complex nanomedicines. METHODS: The aims of this study were: (i) to identify factors of importance for the design of spray-dried siRNA-loaded lipidoid-poly(DL-lactic-co-glycolic acid) hybrid nanoparticles (LPNs), and (ii) to evaluate their influence on the resulting powders by using a quality-by-design approach. Critical formulation and process parameters were linked to critical quality attributes (CQAs) using design of experiments, and an optimal operating space (OOS) was identified. RESULTS: A series of CQAs were identified based on the quality target product profile. The loading (ratio of LPNs to the total solid content) and the feedstock concentration were determined as critical parameters, which were optimized systematically. Mannitol was chosen as stabilizing excipient due to the low water content of the resulting powders. The loading negatively affected the colloidal stability of the LPNs, whereas feedstock concentration correlated positively with the powder particle size. The optimal mannitol-based solid formulation, defined from the OOS, displayed a loading of 5% (w/w), mass median aerodynamic diameter of 3.3 ± 0.2 µm, yield of 60.6 ± 6.6%, and a size ratio of 1.15 ± 0.03. Dispersed micro-embedded LPNs had preserved physicochemical characteristics as well as in vitro siRNA release profile and gene silencing, as compared to non-spray-dried LPNs. CONCLUSION: The optimal solid dosage forms represent robust formulations suitable for higher scale-up manufacturing.


Assuntos
Dessecação/métodos , Lipídeos/química , Nanopartículas/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico/química , RNA Interferente Pequeno/química , Administração por Inalação , Animais , Composição de Medicamentos , Excipientes/química , Inativação Gênica , Técnicas de Transferência de Genes , Manitol/química , Camundongos , Nanomedicina , Tamanho da Partícula , Pós , Células RAW 264.7 , RNA Interferente Pequeno/administração & dosagem , Solubilidade , Solventes/química
9.
Eur J Pharm Biopharm ; 143: 61-69, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31445157

RESUMO

Localized aerosol delivery of gene therapies is a promising treatment of severe pulmonary diseases including lung cancer, cystic fibrosis, COPD and asthma. The administration of drugs by inhalation features multiple benefits including an enhanced patient acceptability and compliance. The application of a spray dried powder formulation has advantages over solutions due to their increased stability and shelf life. Furthermore, optimal sizes of the powder can be obtained by spray drying to allow a deep lung deposition. The present study optimized the parameters involved with spray drying polyplexes formed by polyethylenimine (PEI) and nucleic acids in inert excipients to generate a nano-embedded microparticle (NEM) powder with appropriate aerodynamic diameter. Furthermore, the effects of the excipient matrix used to generate the NEM powder on the biological activity of the nucleic acid and the ability to recover the embedded nanoparticles was investigated. The study showed that bioactivity and nucleic acid integrity was preserved after spray drying, and that polyplexes could be reconstituted from the dry powders made with trehalose but not mannitol as a stabilizer. Scanning electron microscopy (SEM) showed trehalose formulations that formed fused, lightly corrugated spherical particles in the range between 1 and 5 µm, while mannitol formulations had smooth surfaces and consisted of more defined particles. After redispersion of the microparticles in water, polyplex dispersions are obtained that are comparable to the initial formulations before spray drying. Cellular uptake and transfection studies conducted in lung adenocarcinoma cells show that redispersed trehalose particles performed similar to or better than polyplexes that were not spray dried. A method for quantifying polymer and nucleic acid loss following spray drying was developed in order to ensure that equal nucleic acid amounts were used in all in vitro experiments. The results confirm that spray dried NEM formulations containing nucleic acids can be prepared with characteristics known to be optimal for inhalation therapy.


Assuntos
Nanopartículas/química , Ácidos Nucleicos/química , Polietilenoimina/química , Pós/química , Células A549 , Administração por Inalação , Aerossóis/química , Varredura Diferencial de Calorimetria/métodos , Linhagem Celular Tumoral , Química Farmacêutica/métodos , Dessecação/métodos , Excipientes/química , Humanos , Manitol/química , Microscopia Eletrônica de Varredura/métodos , Tamanho da Partícula , Trealose/química
10.
Food Chem ; 300: 125195, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31326676

RESUMO

Presence of pungent gingerols in ginger oleoresin makes it an ideal natural flavoring candidate for the food industry. The study reports its incorporation for synergistic enhancement of flavor and nutraceutical portfolio of candied mango. The process is systematically optimized at bench-scale for gingerols infusion and subsequent candying treatment in a range of hypo and hypertonic osmotic solutions for critical transport properties. After that, optimization of the drying process and the scale-up study was conducted with a 200 folds increase in the batch size. Collated effects of multistep optimization resulted in 85.6, 76.8, 60.2% retention in ß-carotene, total phenolics, Vitamin C, respectively, along with minor color difference and significant improvement in sensory scores over fresh mango. Mass transfer and quality parameters were comparable in both scales, implying excellent repeatability and scalability of the process. Compared with a similar commercial product, substantial improvement in quality characteristics along with 376.7% reduction in overall processing time was achieved.


Assuntos
Doces , Catecóis/química , Álcoois Graxos/química , Aromatizantes/química , Indústria de Processamento de Alimentos/métodos , Mangifera/química , Ácido Ascórbico/análise , Ácido Ascórbico/química , Cor , Dessecação/métodos , Suplementos Nutricionais/análise , Qualidade dos Alimentos , Frutas/química , Gengibre/química , Humanos , Fenóis/análise , Fenóis/química , Paladar , beta Caroteno/análise , beta Caroteno/química
11.
J Food Sci ; 84(7): 1682-1691, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31287569

RESUMO

Microwave vacuum drying as compared to conventional vacuum drying has evinced advantages regarding drying time, while comparable product characteristics were achieved when drying sensitive biological material. Due to the volumetric microwave input, a time reduction of up to 90% is possible. When drying viscous liquids, a foamed structure that remains stable during drying exhibits further advantages as the diffusion-limited third drying step is enhanced by the porous structure. As foams not only have to be thermally resistant during microwave vacuum processing, but also withstand the vacuum, a specific process for foam drying by microwaves under low pressure conditions was developed. Foam formation and stabilization was achieved by using a synergistic mixture of proteins and carbohydrates; Lactobacillus paracasei ssp. paracasei F19 (L. paracasei) served as a model sensitive substance. Investigation of surface activity and foaming properties as a function of L. paracasei concentration revealed a significant positive contribution of the bacterial cells. It was shown that L. paracasei directly adsorbed at the air-water interface. Besides, a structuring of the liquid lamellae was assumed. Moreover, drying time was reduced to at least 50% compared to microwave vacuum drying without foaming. It was further observed that the slight loss in survival was mainly due to the relatively high moisture content and high vacuum levels at the beginning of the process. However, foaming, vacuum application, and final drying, respectively, did not affect viability of the bacterial cells. Thus, by incorporation of lactic acid bacteria into foam structures, drying can be carried out in a fraction of time, and further results in high-product quality. PRACTICAL APPLICATION: The application of continuous foam drying offers an efficient and energy-saving alternative to the currently applied techniques for the processing of sensitive material. The process could be applied for the preservation of starter cultures and probiotics as well as in the pharmaceutical industry, when sensitive material such as therapeutic proteins is dried. This process is especially suitable for freezing-sensitive and thermolabile substances.


Assuntos
Dessecação/métodos , Lactobacillus paracasei/química , Preservação Biológica/métodos , Probióticos/química , Dessecação/instrumentação , Micro-Ondas , Preservação Biológica/instrumentação , Vácuo
12.
AAPS PharmSciTech ; 20(7): 255, 2019 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-31321570

RESUMO

The main principles of green chemistry and engineering were extended to pharmaceutical formulations to prepare eco-friendly surfactant-free dry emulsion tablets (SFDETs) devoid of solvents or synthetic surfactants. Surfactant-free emulsions were stabilized by in situ cyclodextrins/sweet almond oil inclusion complexes and assessed for creaming stability. Formulation variables' effects on the emulsion droplet size and tadalafil solubility were studied using 22 × 3 factorial design. The emulsions exhibited nanometric and micrometric droplet sizes. The optimized nanoemulsion was loaded with tadalafil, morphologically evaluated, and utilized for preparing lyophilized SFDETs using different gelatin/Pearlitol® ratios. The tablets were characterized and the selected formulation was subjected to storage for 6 months. The emulsions prepared using ß-cyclodextrin or higher concentrations of α-cyclodextrin showed little or no phase separation. Statistical analysis revealed significant influence of cyclodextrin type and amount on droplet size, while cyclodextrin type and oil volume exhibited significant effect on drug solubility. Morphological examination revealed non-aggregated spherical emulsion droplets. The prepared tablets showed satisfactory mechanical strength, short disintegration times, and enhanced drug dissolution. The selected tablet formulation (gelatin/Pearlitol®, 4:2 w/w) showed acceptable stability at 25°C/60% relative humidity. An overall conclusion claims that the absence of surfactants is expected to minimize the proposed tablets' in vivo toxicity and environmental concerns.


Assuntos
Ciclodextrinas/química , Emulsões/química , Tensoativos/química , Comprimidos , Tadalafila/química , Dessecação , Liberação Controlada de Fármacos , Liofilização , Umidade , Solventes
13.
Zhongguo Zhong Yao Za Zhi ; 44(10): 1974-1977, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355549

RESUMO

The aim of this paper was to compare the influence of freeze-drying and sun-drying on six main nucleosides and nucleobases of Cordyceps sinensis by HPLC. Hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were reference substances. HPLC analysis was performed on a GL Inertsustain AQ-C_(18) column( 4. 6 mm×250 mm,5 µm),with mobile phase consisting of water( A)-acetonitrile( B) at the flow rate of 1. 0 mL·min~(-1)( 0-10 min,0-1% B; 10-65 min,1%-3% B). The detection wavelength was 260 nm,the column temperature was controlled at 30 ℃,and the injection volume was 5 µL. The linear ranges of hypoxanthine,xanthine,uridine,inosine,guanosine and adenosine were 1. 025-20. 50( r = 0. 999 8),0. 545-10. 90( r = 0. 999 9),4. 051-81. 02( r = 0. 999 8),4. 044-80. 88( r= 0. 999 9),2. 075-41. 50( r= 0. 999 9),4. 032-80. 64( r = 0. 999 9) mg·L~(-1),respectively. The average recoveries of them( n = 6)were as follows: 102. 3%( RSD 2. 1%),101. 1%( RSD 2. 4%),97. 80%( RSD 1. 7%),101. 8%( RSD 1. 8%),98. 90%( RSD2. 0%) and 98. 10%( RSD 1. 4%),respectively. Each sample was processed by freeze-drying and sun-drying so as to compare the difference between the two drying methods. The contents of six index ingredients were significantly different between freeze-drying and sun-drying sample of C. sinensis. The total contents of six index ingredients in sun-drying sample were higher than that in the corresponding freeze-drying sample. This research results provide the scientific basis for the drying methods and quality evaluation of C. sinensis.


Assuntos
Cordyceps/química , Dessecação , Liofilização , Nucleosídeos/análise , Cromatografia Líquida de Alta Pressão
14.
Zhongguo Zhong Yao Za Zhi ; 44(10): 1983-1988, 2019 May.
Artigo em Chinês | MEDLINE | ID: mdl-31355551

RESUMO

In this study,the protein in different Cordyceps samples,which include fresh sample( S1),22 ℃ drying sample( S2),37 ℃ drying sample( S3) and 60 ℃ drying sample( S4),were analyzed by sodium dodecylsupinate-polyacrylamide gel electrophoresis( SDS-PAGE) and two-dimensional electrophoresis( 2-DE). The total protein contents in Cordyceps samples were from 1. 655-4. 493 mg·g~(-1) and the protein contents in fresh sample was the highest. The results of SDS-PAGE showed that the mainly ranges of protein molecular weight of Cordyces samples were 10-100 kDa and the numbers of protein bands were 28 to 41,the fresh sample had the maximum number of protein bands. The 2-DE profiles were analyzed by PDQuest software. The resulted indicated that 488-876 protein spots were detected in different Cordyceps samples and the isoelectric point( pI) was distributed between 4. 5 and 6. 5,the protein molecular weight was distributed in 10-20 kDa and 25-100 kDa,the fresh sample had the maximum number of protein spots. Therefore,the drying process could decrease contents and species of protein in Cordyceps,and the different drying conditions had different effects on protein. These results provide a reference for improving the drying process of Cordyceps.


Assuntos
Cordyceps/química , Dessecação/métodos , Proteínas Fúngicas/análise , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Peso Molecular
15.
Soft Matter ; 15(30): 6190-6199, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328216

RESUMO

The evaporation of colloidal solutions is frequently observed in nature and in everyday life. The investigation of the mechanisms taking place during the desiccation of biological fluids is currently a scientific challenge with potential biomedical and industrial applications. In the last few decades, seminal works have been performed mostly on dried droplets of saliva, urine and plasma. However, the full understanding of the drying process in biocolloids is far from being achieved and, notably, the impact of solute properties on the morphological characteristics of the evaporating droplets, such as colloid segregation, skin formation and crack pattern development, is still to be elucidated. For this purpose, the use of model colloidal solutions, whose rheological behavior is more easily deducible, could represent a significant boost. In this work, we compare the drying of droplets of whey proteins and casein micelles, the two main milk protein classes, to that of dispersions of silica particles and polymer-coated silica particles, respectively. The mechanical behavior of such biological colloids and model silica dispersions was investigated through the analysis of crack formation, and the measurements of their mechanical properties using indentation testing. The study reveals numerous analogies between dairy and the corresponding model systems, thus confirming the latter as a plausible powerful tool to highlight the signature of the matter at the molecular scale during the drying process.


Assuntos
Caseínas/química , Laticínios/análise , Dessecação , Micelas , Proteínas do Soro do Leite/química , Fenômenos Mecânicos , Modelos Químicos , Reologia
16.
J Food Sci ; 84(8): 2181-2189, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31355452

RESUMO

This study was conducted to optimize a process of cold plasma pretreatment for hot-air drying on corn kernels. Effects of plasma pretreatment time (30, 40, 50 s), plasma pretreatment power (300, 400, 500 W) and drying temperature (37.5, 45, 52.5 °C) on drying time and drying rate during this process were investigated. Polynomial equations were established through a three-factor and three-level Box-Behnken design and used to evaluate the optimal operational conditions for the drying process. The optimal pretreatment conditions were drying temperature at 52.5 °C, plasma pretreatment time of 50 s and plasma pretreatment power of 500 W, and the corresponding drying rate and drying time were 3.6163 (g/g h-1 ) and 1.29 hr, respectively. The AFM images showed that cold plasma pretreatment can change the topography of the treated surface with some micro-holes, which explain how the plasma pretreatment can improve the drying process. PRACTICAL APPLICATION: Cold plasma pretreatment can improve the efficiency of corn kernels drying. Furthermore, it has potential application for reducing energy consumption in drying. Cold plasma pretreatment could be potentially applied in grain drying.


Assuntos
Dessecação/métodos , Manipulação de Alimentos/métodos , Gases em Plasma/farmacologia , Sementes/química , Zea mays/efeitos dos fármacos , Sementes/efeitos dos fármacos , Temperatura Ambiente , Zea mays/química
17.
J Sci Food Agric ; 99(14): 6572-6581, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31325328

RESUMO

BACKGROUND: As a pretreatment before drying, the purpose of osmotic dehydration (OD) is to reduce the initial water content of samples and shorten the drying time. When OD is combined with pulse vacuum, the mass transfer is enhanced. Furthermore, the properties of materials, which affect the absorption and dissipation of microwaves, can be changed by OD. In this work, pulsed vacuum osmotic dehydration (PVOD) with sucrose solution was adopted before microwave freeze-drying (MFD). The effects of PVOD on the drying characteristics and quality of dried products were studied. RESULTS: Results showed that the unfrozen water content was increased by PVOD, which made the dielectric constant and loss factor of Chinese yam larger than that of untreated samples, and the difference amplified with the increasing temperature. Thus, the shortened drying time (up to 38.5%) and increased average drying rate (up to 16.8%) were achieved by MFD combined with PVOD. While in traditional freeze-drying, PVOD resulted in slightly shortened drying time but decreased drying rate. The mechanism of PVOD on improving drying rate of MFD was analyzed from the perspective of unfrozen water content and dielectric properties. Furthermore, the quality assessments indicated that PVOD treatment retained a better color and improved the total phenolic content of dried yams compared to untreated and dried samples. CONCLUSION: PVOD using sucrose solution was an effective method to change the characteristics of yam, enhancing the MFD rate and improving the product qualities. © 2019 Society of Chemical Industry.


Assuntos
Dessecação/métodos , Dioscorea/química , Conservação de Alimentos/métodos , Tubérculos/química , Água/análise , Cor , Dessecação/instrumentação , Conservação de Alimentos/instrumentação , Liofilização , Micro-Ondas , Osmose , Fenóis/análise
18.
Food Chem ; 299: 125117, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31288164

RESUMO

This work evaluated nutritional and organoleptic properties of murta, a Chilean native berry, impregnated with Lactobacillus casei var. rhamnosus and dehydrated by different methods: freeze- (FD), convective- (CD) and vacuum- (VD) drying. Scanning electron microscopy revealed that L. casei localized at the peduncle and near the peduncle of the impregnated fruit. Murta enriched with probiotics contained higher L. casei viable counts after dehydration with FD compared to CD and VD methods. Overall, drying resulted in a decrease in crude fibre and phenolic compounds, which was attributed to L. casei metabolic activity suggesting that murta berries could act as prebiotics for L. casei. Among drying methods, L. casei enriched FD murta presented less alterations in the microstructure, less drying-induced damage and obtained a higher sensory acceptability score than CD and VD murta. Taken together, these results will contribute to the development of functional foods from regional products improving local economy.


Assuntos
Frutas/química , Lactobacillus rhamnosus , Myrtaceae/química , Chile , Dessecação , Fibras na Dieta/análise , Liofilização , Frutas/microbiologia , Humanos , Lactobacillus rhamnosus/crescimento & desenvolvimento , Myrtaceae/microbiologia , Fenóis/análise , Prebióticos , Probióticos , Sensação , Vácuo
19.
Food Chem ; 298: 125079, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31260959

RESUMO

Citral-in-water emulsions were prepared with two different essential oil concentrations of 2.5 and 5.0% (w/w), then spray-dried in the presence of the same amount of maltodextrins (20%). The microcapsules were prepared with two different emulsifier compositions: monolayer microcapsules (ML) stabilized by sodium caseinate alone and layer-by-layer microcapsules (LBL) stabilized by sodium caseinate and pectin. The encapsulation efficiency was higher for LBL microcapsules (e.g. 99.6 ±â€¯0.4% for 2.5% citral) than that for ML ones (e.g. 78.6 ±â€¯0.6% for 2.5% citral) which confirm that the additional pectin layer was able to protect citral during the spray-drying process whatever citral concentration. Furthermore, our results showed that the antibacterial activity of the obtained microcapsules significantly depends on both citral concentration and interfacial membrane composition. The presence of two layers surrounding the citral droplets may result in a progressive and controlled release of the encapsulated citral.


Assuntos
Emulsões/química , Monoterpenos/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Cápsulas/química , Caseínas/química , Dessecação , Listeria/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Óleos Voláteis/química , Tamanho da Partícula , Pectinas/química , Polissacarídeos/química , Staphylococcus aureus/efeitos dos fármacos
20.
Food Chem ; 299: 125122, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31288165

RESUMO

To ease the mass exchange in fruit tissues, cutting and blanching are traditionally performed. However, recently, unconventional methods such as sonication are becoming more popular, which cause several alterations of physical and chemical properties as well as microstructure changes. The aim of this work was to evaluate the distribution of water inside the cranberry fruits, microstructural changes and sugars content, following traditional and sonication pre-treatments in osmotic solutions. TD-NMR spectroscopy was used to measure the transverse relaxation time (T2) and intensity of proton pools in different cellular compartments. The microstructure of the samples was evaluated by SEM microscopy, sugars content by HPLC and sucrose melting temperature and enthalpy by DSC. Different pre-treatments appeared to promote microstructure alterations and loss of water from vacuole and cytoplasm/extracellular space, more pronounced in cut and blanched samples. Cutting and blanching followed by osmotic dehydration with assisted sonication eased sucrose penetration into the tissue.


Assuntos
Conservação de Alimentos/métodos , Frutas/química , Açúcares/análise , Vaccinium macrocarpon/química , Água/metabolismo , Varredura Diferencial de Calorimetria , Dessecação , Frutas/ultraestrutura , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Osmose , Sonicação , Sacarose/análise , Temperatura Ambiente , Vaccinium macrocarpon/ultraestrutura
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