RESUMO
Cooking improves food aroma, but few studies have explored how cooking affects food aromas. Here, aroma changes in mildly salted large yellow croaker (Larimichthys crocea, MSLYC) after steaming, baking, frying, and deep frying was investigated. The raw fish was dominated by fishy notes but after cooking, the aroma became dominated by fatty notes. Nine volatiles, including hexanal, nonanal, (E, Z)-2, 6-nonadienal, (E, E)-2, 4-decadienal, 1-octen-3-ol, linalool, ethyl hexanoate, acetic acid and anethole, were identified as key odor-active compounds using GC-MS, OAV, and omission tests analyses. Changes in the concentrations of key odor-active compounds were mainly due to evaporation, oxidation of linolenic acids, and thermal catalyzed reactions. Interestingly, anethole was the key odor-active compound, providing new insight into the underlying reactions of cooked fish aroma.
Assuntos
Perciformes , Compostos Orgânicos Voláteis , Animais , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Culinária/métodos , Ácidos LinolênicosRESUMO
Tsukamurella sp. strain MH1, capable to use a wide range of n-alkanes as the only carbon source, was isolated from petroleum-contaminated soil (PiteÈti, Romania) and its complete genome was sequenced. The 4,922,396â¯bp genome contains only one circular chromosome with a Gâ¯+â¯C content of 71.12%, much higher than the type strains of this genus (68.4%). Based on the 16S rRNA genes sequence similarity, strain MH1 was taxonomically identified as Tsukamurella carboxydivorans. Genome analyses revealed that strain MH1 is harboring only one gene encoding for the alkB-like hydroxylase, arranged in a complete alkane monooxygenase operon. This is the first complete genome of the specie T. carboxydivorans, which will provide insights into the potential of Tsukamurella sp. MH1 and related strains for bioremediation of petroleum hydrocarbons-contaminated sites and into the environmental role of these bacteria.
Assuntos
Actinomycetales/genética , Alcanos/metabolismo , Genoma Bacteriano , Actinomycetales/crescimento & desenvolvimento , Sequência de Bases , Biodegradação Ambiental , Cromossomos Bacterianos/genética , Família MultigênicaRESUMO
The aim of this study was to prepare α-tocopherol loaded nanoliposomes as carriers of DHA and EPA and to investigate their physicochemical properties, such as peroxide value (PV), volatile compounds (VOCs), particle size, size distribution, zeta potential and morphology of the liposomes. The particle size of liposomes was in the range of 82.4-107.2nm. The highest extent of lipid oxidation was observed at 40°C for 90days, with the lowest PV and propanal levels for a nanoliposome formulation in comparison with the control sample. The zeta potential of the nanoliposomes was decreased during storage. No significant change in the PV and zeta potential of the liposome formulations with α-tocopherol was observed at 4°C after 90days (0.14meq/kg and -43.5mV, respectively). This study demonstrated that incorporation of α-tocopherol into liposomes contributes a significant antioxidant effect on DHA and EPA.
Assuntos
Antioxidantes/química , Ácidos Docosa-Hexaenoicos/química , Ácido Eicosapentaenoico/química , alfa-Tocoferol/química , Química Farmacêutica , Lipossomos/química , Nanopartículas/química , Oxirredução , Tamanho da PartículaRESUMO
The objective of this study was to develop proliposomal formulation and self micro-emulsifying drug delivery system (SMEDDS) for a poorly bioavailable drug, nisoldipine and to compare their in vivo pharmacokinetics. Proliposomes were prepared by thin film hydration method using different lipids such as Soy phosphatidylcholine (SPC), Hydrogenated Soy phosphatidylcholine (HSPC), Dimyristoylphosphatidylcholine (DMPC) and Dimyristoyl phosphatidylglycerol sodium (DMPG), Distearyl phosphatidylcholine (DSPC), and Cholesterol in various ratios. SMEDDS formulations were prepared using varying concentrations of Capmul MCM, Labrasol, Cremophor EL and Tween 80. Both proliposomes and SMEDDS were evaluated for particle size, zeta potential, in vitro drug release, in vitro permeability and in vivo pharmacokinetics. In vitro drug release was carried out in purified water using USP type II dissolution apparatus. In vitro drug permeation was studied using parallel artificial membrane permeation assay (PAMPA) and everted rat intestinal perfusion techniques. In vivo pharmacokinetic studies were conducted in male Sprague-Dawley rats. Among the different formulations, proliposomes with drug:DMPC:cholesterol in the ratio of 1:2:0.5 and SMEDDS with Capmul MCM (13.04% w/w), Labrasol (36.96% w/w), Cremophor EL (34.78% w/w) and Tween 80 (15.22% w/w) demonstrated the desired particle size and zeta potential. Enhanced drug release was observed with proliposomes and SMEDDS compared to pure nisoldipine in purified water after 1h. Nisoldipine permeability across PAMPA and everted rat intestinal perfusion models was significantly higher with proliposomes and SMEDDS. Following single oral administration of proliposomes and SMEDDS, a relative bioavailability of 301.11% and 239.87% respectively, was achieved compared to pure nisoldipine suspension.
Assuntos
Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Lipídeos/química , Nisoldipino/administração & dosagem , Administração Oral , Animais , Disponibilidade Biológica , Química Farmacêutica/métodos , Liberação Controlada de Fármacos , Emulsões , Excipientes/química , Lipossomos , Masculino , Nisoldipino/farmacocinética , Tamanho da Partícula , Permeabilidade , Ratos , Ratos Sprague-Dawley , SolubilidadeRESUMO
During the research and development of new drugs directed at the central nervous system, there is a considerable attrition rate caused by their hampered access to the brain by the blood-brain barrier. Throughout the years, several in vitro models have been developed in an attempt to mimic critical functionalities of the blood-brain barrier and reliably predict the permeability of drug candidates. However, the current challenge lies in developing a model that retains fundamental blood-brain barrier characteristics and simultaneously remains compatible with the high throughput demands of pharmaceutical industries. This review firstly describes the roles of all elements of the neurovascular unit and their influence on drug brain penetration. In vitro models, including non-cell based and cell-based models, and in vivo models are herein presented, with a particular emphasis on their methodological aspects. Lastly, their contribution to the improvement of brain drug delivery strategies and drug transport across the blood-brain barrier is also discussed.