RESUMO
Probiotics are sensitive to external conditions, resulting in low survival rates after being ingested or during food production, transportation and storage. In order to improve the survival rate of Lactobacillus plantarum (LP) during gastrointestinal digestion, storage, and freeze-drying, alginate-whey protein isolate (ALG-WPI) and alginate-pectin-whey protein isolate (ALG-PEC-WPI) composites were employed to encapsulate LP. The encapsulation efficiency of ALG-WPI-LP and ALG-PEC-WPI-LP beads both reached more than 99 %. Scanning electron microscopy (SEM) indicated that dense and rough aggregates were formed on the surface of both composites, and attached LP cells could be observed inside the beads. The ALG-WPI and ALG-PEC-WPI composites can protect the viability of LP in simulated gastric fluid (SGF) and release the probiotics in simulated intestinal fluid (SIF). The storage stability of LP at 4 °C was improved by about 15 % in comparison with bare LP and the survival rates of LP in ALG-WPI-LP and ALG-PEC-WPI-LP powders after freeze-drying were increased by 65.37 % and 72.06 %, respectively. The formation mechanism of ALG-WPI and ALG-PEC-WPI composites was further explored by fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The ALG-WPI and ALG-PEC-WPI composites have great potential to protect and deliver probiotics in food systems.
Assuntos
Lactobacillus plantarum , Probióticos , Alginatos/química , Lactobacillus plantarum/química , Pectinas/química , Probióticos/química , Proteínas do Soro do Leite/químicaRESUMO
Peppermint oil emulsions were prepared by using zein-lecithin-EGCG (Z-L/E) complex nanoparticles as emulsifiers. The preparation conditions of emulsions were optimized via measuring the particle size, surface tension and stability of emulsions, and peppermint oil of 3% (particle size = 375 nm, polydispersity index (PDI) = 0.45), the zein:lecithin ratio of 4:1 (w/w) (particle size = 396 nm), and the zein:EGCG ratio of 10:1 (w/w) (surface tension = 47.32 N/m) was the optimal condition. The rapid stability analysis showed that the instability mechanism of emulsions was ascribed to creaming and stratification, and the stability mechanism of emulsions was explored, indicating that the complex nanoparticles adsorbed on the surface of oil droplets to give Pickering emulsions. Electronic tongue experiments showed that the Z-E/L4:1 stabilized emulsion was distinguished from the other three samples due to its good stability. The electronic nose experiment could distinguish the emulsions with different droplet sizes.
Assuntos
Nanopartículas , Zeína , Emulsões/química , Lecitinas , Mentha piperita , Nanopartículas/química , Tamanho da Partícula , Óleos de Plantas , Água/química , Zeína/químicaRESUMO
Sodium alginate (SA)-pectin (PEC)-whey protein isolate (WPI) complexes were used as an emulsifier to prepare ß-carotene emulsions, and the encapsulation efficiency for ß-carotene was up to 93.08%. The confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM) images showed that the SA-PEC-WPI emulsion had a compact network structure. The SA-PEC-WPI emulsion exhibited shear-thinning behavior and was in a semi-dilute or weak network state. The SA-PEC-WPI stabilized ß-carotene emulsion had better thermal, physical and chemical stability. A small amount of ß-carotene (19.46 ± 1.33%) was released from SA-PEC-WPI stabilized ß-carotene emulsion in simulated gastric digestion, while a large amount of ß-carotene (90.33 ± 1.58%) was released in simulated intestinal digestion. Fourier transform infrared (FTIR) experiments indicated that the formation of SA-PEC-WPI stabilized ß-carotene emulsion was attributed to the electrostatic and hydrogen bonding interactions between WPI and SA or PEC, and the hydrophobic interactions between ß-carotene and WPI. These results can facilitate the design of polysaccharide-protein stabilized emulsions with high encapsulation efficiency and stability for nutraceutical delivery in food and supplement products.
RESUMO
The ovalbumin (OVA)-pectin (PEC)-sodium alginate (SA)-Vitamin D3 (VD3) complex nanoparticles were fabricated by antisolvent precipitation method, and the excellent encapsulation efficiency and loading capacity of VD3 were obtained by 96.6% and 2.8%, respectively. Compared with ternary OVA-PEC-VD3 complexes, the addition of SA with strong negative charge effectively regulated the OVA-PEC complexes and significantly improved the stability of OVA-PEC-SA-VD3 complex nanoparticles with preferable size as small as 126 nm. The storage stability was also investigated after low temperature storage for 31 d, and the particle size of quaternary complexes was increased only 40 nm. In vitro digestion results elucidated that the complex nanoparticles had good stability in the simulated gastric fluid, and almost completely released in the simulated intestinal fluid confirmed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) experiments and scanning electron microscope (SEM) images. The release kinetics study clarified that it was close to Fick release. Fluorescence and Fourier transform infrared spectroscopy (FTIR) experiments showed that quaternary complex nanoparticles were mainly combined by electrostatic, hydrophobic and hydrogen bonding interactions. The novel quaternary protein-polysaccharide complexes have excellent stability and great sustained-release performance for VD3, which may be helpful for the digestion and absorption of vitamin by human body, thus have potential applications in the food and drug industry.
Assuntos
Alginatos , Nanopartículas , Digestão , Humanos , Ovalbumina , PectinasRESUMO
To achieve highly systemic therapeutic efficacy, chemotherapy is combined with photothermal therapy for chemo-photothermal synergistic therapy; however, this strategy suffers from high toxicity and unsatisfactory sensitivity for cancer cells. Herein, we developed a pH- and photothermal-responsive zeolitic imidazolate framework (ZIF-8) compound for loading a dual-drug in the tumor site and improving their curative effects. Since autophagy always accompanies tumor progression and metastasis, there is an unmet need for an anticancer treatment related to the regulation of autophagy. Green tea polyphenols, namely, (-)-epigallocatechin-3-gallate (EGCG) and doxorubicin (DOX), both of which exhibit anticancer activity, were dual-loaded via polydopamine (PDA) coating ZIF-8 (EGCG@ZIF-PDA-PEG-DOX, EZPPD for short) through hierarchical self-assembly. PDA could transfer photothermal energy to increase the temperature under near-infrared (NIR) laser irradiation. Due to its pH-response, EZPPD released EGCG and DOX in the tumor microenvironment, wherein the temperature increased with the help of PDA and NIR laser irradiation. The duo of DOX and EGCG induced autophagic flux and accelerated the formation of autophagosomes. In a mouse HeLa tumor model, photothermal-chemotherapy could ablate the tumor with a significant synergistic effect and potentiate the anticancer efficacy. Thus, the results indicate that EZPPD renders the key traits of a clinically promising candidate to address the challenges associated with synergistic chemotherapy and photothermal utilization in antitumor therapy.
Assuntos
Antibióticos Antineoplásicos/farmacologia , Antioxidantes/farmacologia , Catequina/análogos & derivados , Doxorrubicina/farmacologia , Indóis/química , Polímeros/química , Neoplasias do Colo do Útero/terapia , Zeolitas/química , Animais , Antibióticos Antineoplásicos/síntese química , Antibióticos Antineoplásicos/química , Antioxidantes/síntese química , Antioxidantes/química , Catequina/síntese química , Catequina/química , Catequina/farmacologia , Doxorrubicina/síntese química , Doxorrubicina/química , Feminino , Células HeLa , Humanos , Camundongos , Camundongos Nus , Fototerapia , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologiaRESUMO
This study aimed to characterize the thermophilic fungi in pile-fermentation process of Pu-erh tea. Physicochemical analyses showed that the high temperature and low pH provided optimal conditions for propagation of fungi. A number of fungi, including Blastobotrys adeninivorans, Thermomyces lanuginosus, Rasamsonia emersonii, Aspergillus fumigatus, Rhizomucor pusillus, Rasamsonia byssochlamydoides, Rasamsonia cylindrospora, Aspergillus tubingensis, Aspergillus niger, Candida tropicalis and Fusarium graminearum were isolated as thermophilic fungi under combination of high temperature and acid culture conditions from Pu-erh tea pile-fermentation. The fungal communities were analyzed by PCR-DGGE. Results revealed that those fungi are closely related to Debaryomyces hansenii, Cladosporium cladosporioides, A. tubingensis, R. emersonii, R. pusillus, A. fumigatus and A. niger, and the last four presented as dominant species in the pile process. These four preponderant thermophilic fungi reached the order of magnitude of 10(7), 10(7), 10(7) and 10(6)copies/g dry tea, respectively, measured by real-time quantitative PCR (q-PCR). The results indicate that the thermophilic fungi play an important role in Pu-erh tea pile fermentation.
Assuntos
Fungos/classificação , Fungos/isolamento & purificação , Chá/microbiologia , Eletroforese em Gel de Gradiente Desnaturante , Fermentação , Fungos/genética , Reação em Cadeia da Polimerase , Chá/químicaRESUMO
CONTEXT: Accumulating evidence has suggested favorable effects of fish oil on weight loss in animal experiments; however, findings remain inconsistent in humans. OBJECTS: The meta-analysis was performed to investigate the influence of fish oil on some parameters of body composition in overweight/obese adults. DESIGN: Human randomized, placebo-controlled trials were identified by a systematic search of Embase, PubMed, the Cochrane Library, web of science and reference lists of related reviews and articles. The random-effects model was used to estimate the calculated results. RESULTS: In total, 21 studies with 30 study arms were included in this analysis. Calculated results of the meta-analysis demonstrated that fish oil had no effect on reducing body weight (overall SMD = -0.07, 95% CI -0.21 to 0.07, P = 0.31) and BMI (overall SMD = -0.09, 95% CI -0.22 to 0.03, P = 0.14) whether alone or combined with life modification intervention in overweight/obese subjects. However, waist circumference was significantly reduced (SMD = -0.23, 95% CI -0.40 to -0.06, P = 0.008) in those with fish oil supplementation combined with life modification intervention. Waist hip ratio (WHR) was significantly reduced (overall SMD = -0.52 95% CI -0.76 to -0.27, P < 0.0005) in fish oil supplemented individuals with or without combination life modification intervention. CONCLUSION: Current evidence cannot support an exact anti-obesity role of n-3 polyunsaturated fatty acids (PUFAs) in overweight/obese subjects. However, these subjects may benefit from reducing abdominal fat with fish oil supplementation especially when combined with life modification intervention. Further large-scale and long-term clinical trials are needed to gain definite conclusions.
Assuntos
Fármacos Antiobesidade/uso terapêutico , Óleos de Peixe/uso terapêutico , Obesidade/tratamento farmacológico , Índice de Massa Corporal , Suplementos Nutricionais , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento , Redução de PesoRESUMO
Volatility and flash point for the pseudo-binary mixtures of sunflower seed-based biodiesel+ethanol were measured over the entire composition range. The biodiesel was prepared by the transesterification of sunflower seed oil in supercritical methanol without using any catalyst. The vapor pressures of mixtures of biodiesel+ethanol as a function of temperature were measured by comparative ebulliometry with an inclined ebulliometer. The vapor pressures versus composition at different temperatures and temperatures versus composition at different pressures were obtained from Antoine correlations. It is found that ethanol can adjust effectively the volatility and flash point of the biodiesel. The correlation of the flash points with the vapor pressure data for the pseudo-binary mixtures of biodiesel+ethanol displays agreement with the experimental data obtained by closed cup test.
Assuntos
Fontes Geradoras de Energia , Etanol , Óleos de Plantas , Esterificação , Metanol , Óleo de Girassol , Temperatura , Pressão de Vapor , VolatilizaçãoRESUMO
Vapor pressures and flash points for several mixtures of an aviation fuel with dimethyl carbonate (DMC) or diethyl carbonate (DEC) have been measured, respectively, over the entire composition range. Correlation between the experimental vapor pressures and the equilibrium temperatures by the Antoine equation is performed for each mixture. The bubble-point lines of pressure versus composition at different temperatures and those of temperature versus composition at different pressures are then obtained from the Antoine correlations. It is found that DMC and DEC are the oxygenated hydrocarbon additives that can adjust effectively the volatility and flash point of the aviation fuel. The correlation of the flash points with the vapor pressure data for the pseudo-binary mixtures of the fuel and DMC or DEC gives satisfactory results.