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1.
Mar Drugs ; 17(8)2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31374944

RESUMO

Microalgae are considered as excellent candidates for bioactive compounds, yet microalgal residues remaining after the extraction of one or two compounds are usually discarded, which is not economical. This study demonstrates the alkaline extraction of proteins from Chlorella pyrenoidosa residue after lipid and pigment extractions, and their functional properties. Single-factor experiments and response surface methodology were used to obtain the optimal conditions for protein extraction. Based on our results, a maximum protein yield of 722.70 mg/g, was obtained under the following extraction conditions: sodium hydroxide concentration 7.90%, extraction temperature 70.00 °C, extraction time 34.80 min, and microalgal residue concentration 8.20 mg/mL. The molecular weight of microalgal residue protein isolate (MRPI) was mainly distributed at the regions of 0.18-0.50 kDa, 0.50-1.50 kDa, and 1.50-5.00 kDa. The essential amino acid content was greater than the values recommended by FAO/WHO standards; a high essential amino acid index value (1.49) was another good indication that MRPI is suitable for human consumption. Moreover, MRPI exhibited excellent emulsifying properties and antioxidant activity, which suggests it may be useful as an emulsifying agent and antioxidant. These findings could improve the extraction methods of functional protein from microalgal residue and add value to microalgae-based bioactive compound production processes.


Assuntos
Chlorella/química , Microalgas/química , Extratos Vegetais/farmacologia , Proteínas de Plantas/farmacologia , Sequência de Aminoácidos , Aminoácidos Essenciais/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsificantes/farmacologia , Alimento Funcional , Lipídeos/isolamento & purificação , Peso Molecular , Estresse Oxidativo/efeitos dos fármacos , Pigmentos Biológicos/isolamento & purificação , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Hidróxido de Sódio/química , Temperatura Ambiente
2.
Ecotoxicol Environ Saf ; 183: 109553, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416012

RESUMO

In the present work, the production of bioemulsifier (BE) by a lactic acid bacterium (LAB) grown at 25 °C in lactic whey-based media for 24 h was evaluated. Maximum production was detected in a medium containing yeast extract, peptone and lactic whey (LAPLW medium), with a yield of 270 mg L-1. The BE proved to be more innocuous for Caco-2 cells, used as a toxicological indicator, than the non-ionic surfactant Triton X-100. In addition, the microbial product presented higher stability to changes in temperature (37 °C to 100 °C), pH (2-10), and salt concentration (5% and 20%, w/v) than the synthetic surfactant. Regarding emulsifying capacity tested against different hydrophobic substrates (kerosene, motor oil, diesel, sunflower oil, and grape oil), the BE displayed E24 values similar to or even better than those of Triton X-100. Finally, Triton X-100 caused irreversible modifications on the giant unilamellar vesicles (used as model membrane system), promoting the solubilization of the lipid bilayers. Nevertheless, BE induced temporary modifications of the membrane, which is associated with incorporation of the bioproduct in the outer layer. These results demonstrate the role of BE in biological processes, including reversible changes in microbial membranes to enhance the access to hydrophobic substrates.


Assuntos
Biotecnologia/métodos , Emulsificantes/isolamento & purificação , Enterococcus/metabolismo , Ácido Láctico/metabolismo , Soro do Leite/metabolismo , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Emulsificantes/metabolismo , Emulsificantes/toxicidade , Emulsões , Humanos , Interações Hidrofóbicas e Hidrofílicas , Octoxinol/química , Petróleo/metabolismo , Óleos Vegetais/metabolismo , Temperatura Ambiente
3.
Int J Mol Sci ; 20(13)2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31269636

RESUMO

Marine microorganisms represent a reservoir of new promising secondary metabolites. Surface-active proteins with good emulsification activity can be isolated from fungal species that inhabit the marine environment and can be promising candidates for different biotechnological applications. In this study a novel surface-active protein, named Sap-Pc, was purified from a marine strain of Penicillium chrysogenum. The effect of salt concentration and temperature on protein production was analyzed, and a purification method was set up. The purified protein, identified as Pc13g06930, was annotated as a hypothetical protein. It was able to form emulsions, which were stable for at least one month, with an emulsification index comparable to that of other known surface-active proteins. The surface tension reduction was analyzed as function of protein concentration and a critical micellar concentration of 2 µM was determined. At neutral or alkaline pH, secondary structure changes were monitored over time, concurrently with the appearance of protein precipitation. Formation of amyloid-like fibrils of SAP-Pc was demonstrated by spectroscopic and microscopic analyses. Moreover, the effect of protein concentration, a parameter affecting kinetics of fibril formation, was investigated and an on-pathway involvement of micellar aggregates during the fibril formation process was suggested.


Assuntos
Proteínas Fúngicas/química , Penicillium chrysogenum/química , Tensoativos/química , Amiloide/química , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsões/química , Proteínas Fúngicas/isolamento & purificação , Concentração de Íons de Hidrogênio , Micelas , Tensão Superficial , Tensoativos/isolamento & purificação , Temperatura Ambiente
4.
J Agric Food Chem ; 67(23): 6551-6558, 2019 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-31099556

RESUMO

Unicellular microalgae are a valuable source of macro- and micronutrients. They contain, for example, proteins that are potentially useful as new emulsifiers. The aim of this study was to investigate the emulsifying properties of a less-refined lyophilized crude water-soluble extract (WSE), obtained from the heterotrophically cultivated microalga Chlorella protothecoides. Interfacial tension measurements indicated that mainly the proteins in the extract showed interfacial activity. O/W emulsions were prepared by high-pressure homogenization (1 000 bar, 3 passes) with 5.0 wt % of oil and 2.5 wt % of protein from Chlorella protothecoides, resulting in emulsions having a volume-based mean droplet diameter of d43 ≤ 1 µm and being stable for at least 7 days. Two different stress tests showed that ( i) protein-stabilized emulsions were resistant to very high salt concentrations (up to 500 mM NaCl), and ( ii) emulsions were stable over a very broad pH range of 2-9, with only minor changes in the particle size d43 (e.g. with an increase of only 300 nm when the pH was lowered from 5 to 4) compared to whey protein-stabilized emulsions. All WSE emulsions had monomodal particle size distributions and were macro- and microscopically stable during a storage of up to 7 days. The results indicate that the WSE of Chlorella protothecoides has remarkably good emulsifying properties and might be of use as a new emulsifier in various applications in which emulsions are exposed to a broad range of ionic strengths and pH values.


Assuntos
Chlorella/química , Emulsificantes/química , Microalgas/química , Extratos Vegetais/química , Emulsificantes/isolamento & purificação , Emulsões/química , Emulsões/isolamento & purificação , Concentração Osmolar , Extratos Vegetais/isolamento & purificação , Água/química
5.
J Food Sci ; 84(5): 1023-1034, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30997934

RESUMO

Protein isolates were recovered from scallop (Patinopecten yessoensis) gonads to develop a novel functional matrix by investigating their physiochemical and functional properties. Scallop gonad protein isolates (SGPIs) were prepared from degreased scallop gonads (DSGs) by an alkali extraction and isoelectric solubilization/precipitation (ISP) process. The protein compositions of the SGPIs were mainly vitellogenin and beta-actin with molecular weights of 266 and 42 kDa, respectively, as determined using Nano-liquid chromatography-mass/mass (Nano-LC-MS/MS). After the ISP process, the protein solubility of the SGPIs was significantly improved, and the surface hydrophobicity of SGPIs intensely increased by 1.1-fold, which were attributed to the exposure of aromatic residues such as phenylalanine, tyrosine, and tryptophan. However, the content of total/reactive sulfhydryl in SGPIs was decreased compared with that of DSGs. Meanwhile, the ISP process caused partial protein unfolding, as indicated by circular dichroism analysis, which exhibited a remarkable rise in the ß-sheet content with a parallel decline in the α-helix and random coil contents (P < 0.05). SGPIs exhibited a better oil absorption capacity and foaming property than both DSGs and soybean protein isolates (SPIs). Moreover, the emulsifying capacity of SGPIs was greatly enhanced by the ISP process, which was superior to the effect of commercial SPIs and was ascribed to its favorable solubility as well as surface characteristics. PRACTICAL APPLICATION: During the processing of scallop (Patinopecten yessoensis) adductors, scallop gonad, a high-protein part, is usually discarded as processing by-products despite its edibility. In recent years, scallop gonads are regarded as good sources to develop protein matrices due to their high protein content and numerous nutrients. In this study, scallop gonad protein isolates (SGPIs) were isolated by isoelectric solubilization/precipitation (ISP) process. The preferable solubility, foaming property coupled with high emulsifying property of SGPIs indicated that the SGPIs could be potentially utilized as a good protein emulsifier and additives in production of kamaboko gels, hamburger patties, sausages, and pet foods.


Assuntos
Emulsificantes/química , Emulsões , Aditivos Alimentares/química , Gônadas/química , Pectinidae/química , Proteínas/química , Alimentos Marinhos , Animais , Cromatografia Líquida , Emulsificantes/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Tecnologia de Alimentos/métodos , Géis/química , Humanos , Proteínas/isolamento & purificação , Solubilidade , Espectrometria de Massas em Tandem
6.
J Sci Food Agric ; 99(5): 2375-2383, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30357828

RESUMO

BACKGROUND: Sodium caseinate (SC) is not considered suitable for use as an emulsifier in organic processed food in the food industry because of the use of prohibited synthetic chemical substances during its production. Casein mixture preparation (CMP), one of the permissible substances specified in the regulations, was isolated from organic milk using citric acid and dibasic potassium phosphate for organic processed foods. RESULTS: To compare CMP and SC, model emulsions stabilized with each substance were prepared at various concentrations and their physicochemical properties were analyzed. The emulsions' stability was determined using Turbiscan under various environmental stresses. The zeta potential of SC and CPM showed a high surface charge (≤ 30 mV) at all protein concentrations. Because the concentration of the protein preparation increased to 0.75% (w/v), the particle size of the CMP emulsion decreased with the surface load increased as much as that of SC. The CMP and SC emulsions were stable at neutral pH and room temperature. However, at acidic pH and high temperature, both emulsions were destabilized by creaming and flocculation and increased the creaming migration rates. CONCLUSION: Overall, our data suggest the use of CMP as an emulsifier substitute for SC in organic processed foods. © 2018 Society of Chemical Industry.


Assuntos
Caseínas/química , Emulsificantes/química , Proteínas do Leite/química , Leite/química , Animais , Caseínas/isolamento & purificação , Bovinos , Emulsificantes/isolamento & purificação , Alimentos Orgânicos/análise , Temperatura Alta , Concentração de Íons de Hidrogênio , Proteínas do Leite/isolamento & purificação , Tamanho da Partícula
7.
Int J Biol Macromol ; 124: 1167-1176, 2019 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-30521924

RESUMO

In this study, physicochemical, interfacial and emulsifying properties of Retama reatam and guar galactomannans were comparatively investigated. The results showed that Retama reatam galactomannan is mainly composed of total carbohydrates (95.52%) and lower protein contents (0.87%). The sugars identified were mannose (Man) and galactose (Gal), with a Man:Gal ratio of 1.85 compared to guar gum (1.83). The results of thermal properties indicated were transition temperature (Tg) and melting temperature (Tm) very similar to those of the guar gum. Moreover, results also revealed that there is no significant difference in terms of equilibrium interfacial tension of Retama reatam gum at 10 and 20°C. Moreover, preliminary tests show that stable oil-in-water nanoemulsions may be formulated using Retama reatam gum. Therefore, measurement of mean oil droplet diameter d after heating at 80°C, shows that stable nanoemulsions may be formulated using Retama reatam galactomannan. Further in vivo experiments confirmed that Retama reatam gum can reduce the glycemic index of starchy foods and inhibit the surge of postprandial blood glucose level.


Assuntos
Cosméticos/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Emulsificantes/química , Fabaceae/química , Hipoglicemiantes/farmacologia , Mananas/farmacologia , Animais , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Cosméticos/química , Cosméticos/isolamento & purificação , Diabetes Mellitus Experimental/sangue , Emulsificantes/isolamento & purificação , Emulsões , Galactanos/química , Galactose/química , Galactose/isolamento & purificação , Hipoglicemiantes/química , Hipoglicemiantes/isolamento & purificação , Mananas/química , Mananas/isolamento & purificação , Manose/química , Manose/isolamento & purificação , Camundongos , Transição de Fase , Gomas Vegetais/química , Sementes/química , Temperatura Ambiente
8.
Food Funct ; 10(1): 49-60, 2019 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-30566165

RESUMO

Emulsion-based delivery systems were structured by using scallop gonad protein isolates (SGPIs) as novel food-grade emulsifiers. The effects of carrier oil, including the long chain triglycerides (LCT) and medium chain triglycerides (MCT), on the bioaccessibility and cellular uptake of ß-carotene (BC) were investigated. Both LCT and MCT delivery systems remained stable at pH 7-8 but aggregated at lower pH values (3-6) according to the results of light scattering and microscopy measurements. LCT droplets fabricated within SGPIs were digested and released more slowly than MCT droplets during the simulated gastrointestinal tract digestion. The LCT emulsion showed higher BC bioaccessibility (65.5%) than the MCT emulsion (23.1%) as a result of the greater solubilization of BC in mixed micelles fabricated from long-chain fatty acids. Moreover, the LCT emulsion produced higher cellular uptake of BC as compared with the MCT emulsion in intestinal epithelial cells. These results demonstrated that SGPIs could be used as novel food-grade emulsifiers to protect lipophilic bioactive compounds in emulsion-based delivery systems, in which LCT is more suitable to encapsulate and deliver BC than MCT.


Assuntos
Emulsificantes/química , Gônadas/química , Pectinidae/química , Proteínas/química , Triglicerídeos/química , beta Caroteno/química , beta Caroteno/farmacologia , Animais , Disponibilidade Biológica , Células CACO-2 , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Emulsificantes/isolamento & purificação , Emulsões/química , Emulsões/metabolismo , Emulsões/farmacologia , Feminino , Humanos , Proteínas/isolamento & purificação , beta Caroteno/metabolismo
9.
Food Chem ; 244: 197-205, 2018 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-29120771

RESUMO

Effects of HCl, H2SO4, HNO3, citric acid, and acetic acid on the yield, structure, and emulsifying properties of potato pectins were investigated. Results showed that the highest yield (14.34%) was obtained using citric acid, followed by HNO3 (9.83%), HCl (9.72%), H2SO4 (8.38%), and acetic acid (4.08%). The degrees of methylation (37.45%) and acetylation (15.38%), protein content (6.97%), and molecular weight (3.207 × 105 g/mol) were the highest for pectin extracted using acetic acid, and (galactose + arabinose)/rhamnose was 33.34, indicating that it had a highly branched rhamnogalacturonan I domain. Fourier transform infrared spectroscopy showed a specific absorbance peak at 1064 cm-1, which corresponds to the acetyl groups in potato pectins. SEM showed that all potato pectins are morphologically different. The emulsifying activity (EA, 44.97%-47.71%) and emulsion stability (ES, 36.54%-46.00%) of the pectins were influenced by acid types, and were higher than those of commercial citrus and apple pectin.


Assuntos
Emulsificantes/química , Emulsificantes/isolamento & purificação , Pectinas/química , Pectinas/isolamento & purificação , Solanum tuberosum/química , Concentração de Íons de Hidrogênio , Peso Molecular
10.
Food Chem ; 242: 139-146, 2018 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-29037669

RESUMO

There is no information on the chemical composition of camelina seed lecithin; therefore, the objective of this study was to investigate the chemical composition and emulsifying properties of lecithin recovered from camelina seed oil by water (WDCL) and enzymatic degumming (EDCL) using phospholipase A1 (PLA1). The lecithin obtained by both WDLC and EDLC was rich in phosphatidylinositol (PI), and contents were 37.8 and 25.2wt%, respectively. Lecithin recovered by enzymatic degumming contained more lysophospholipids compared to water degumming. The saturated fatty acid content of the EDCL was significantly higher than that of the WDCL. Emulsions stabilized using EDCL resulted in the highest stability when deionized water was used as the aqueous phase (original pH); however, at pH=7.5, emulsions stabilized using EDCL and WDCL were less stable compared to the emulsion stabilized with soy lecithin. Results showed that camelina seed lecithin is a promising alternative PI-rich emulsifier for various food applications.


Assuntos
Camellia/química , Emulsificantes/química , Ácidos Graxos/química , Lecitinas/química , Emulsificantes/isolamento & purificação , Emulsões/química , Ácidos Graxos/isolamento & purificação , Lecitinas/isolamento & purificação , Fosfolipases A1/química , Sementes/química
11.
Food Res Int ; 99(Pt 3): 971-978, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28865623

RESUMO

A protein extract from the brown seaweed Himanthalia elongata (Linnaeus) S. F. Gray was prepared and its functional properties, colour and amino acid composition were assessed for its potential future use by the food industry. The total content of amino acids was determined as 54.02±0.46gaminoacids/kg dry weight, with high levels of the essential amino acids lysine and methionine. SDS-PAGE showed 5 protein bands with molecular weights of 71.6, 53.7, 43.3, 36.4 and 27.1kDa. The water holding capacity and oil holding capacity were determined as 10.27±0.09gH2O/g and 8.1±0.07goil/g respectively. Foaming activity and stability were higher at alkaline pH values. The emulsifying capacity and stability of the extract varied depending on the pH and oil used. These results demonstrate the potential use of Himanthalia elongata protein extract in the food industry.


Assuntos
Emulsificantes/farmacologia , Aditivos Alimentares/farmacologia , Feófitas/química , Proteínas de Plantas/farmacologia , Alga Marinha/química , Sequência de Aminoácidos , Cor , Emulsificantes/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Indústria Alimentícia/métodos , Proteínas de Plantas/isolamento & purificação , Solubilidade
12.
World J Microbiol Biotechnol ; 33(8): 161, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28755169

RESUMO

This study describes a novel and efficient alasan-like bioemulsifier produced by Pseudomonas stutzeri NJtech 11-1, which was isolated from the Shengli Oilfield. The strain was found to produce a new and interesting emulsion stabilizer. The crude bioemulsifier showed super stability with 50% salinity and broad pH 3-10. The emulsion index (EI24) was increased to 100% after heating from 45 to 95 °C and the emulsion could be stable for at least 30 days. The yield of Ps-bioemulsifier (pure bioemulsifier) was 0.68 ± 0.05 mg mL-1. The Ps-bioemulsifier was composed of carbohydrates (80 ± 2.6%) and proteins (9.5 ± 0.5%). A low concentration (0.2 mg mL-1) of the Ps-bioemulsifier was obtained maximum emulsifying activity at pH 7.1 and its emulsifying activity strengthened by suitable salinity. Furthermore, Ps-bioemulsifier could also emulsify cyclohexane, hexadecane, kerosene, xylene hydrocarbons efficiently. Therefore, the Ps-bioemulsifier showed emulsifying characteristics which make it a good candidate for potential applications in bioremediation and microbial enhanced oil recovery.


Assuntos
Emulsificantes/isolamento & purificação , Emulsificantes/metabolismo , Pseudomonas stutzeri/metabolismo , Alcanos/metabolismo , Biodegradação Ambiental , Metabolismo dos Carboidratos , Cicloexanos/metabolismo , Endopeptidase K , Hidrocarbonetos/metabolismo , Concentração de Íons de Hidrogênio/efeitos dos fármacos , Querosene , Petróleo/metabolismo , Filogenia , Proteínas/metabolismo , Pseudomonas stutzeri/classificação , Pseudomonas stutzeri/crescimento & desenvolvimento , Pseudomonas stutzeri/isolamento & purificação , Salinidade , Temperatura Ambiente , Viscosidade
13.
J Agric Food Chem ; 65(20): 4153-4160, 2017 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-28453286

RESUMO

The interfacial and emulsion-forming properties of sugar beet extract (Beta vulgaris L.) were examined and compared to a Quillaja extract that is widely used within the food industry. We investigated the influence of extract concentration on surface activity at oil-water and air-water interfaces and on the formation of oil-in-water emulsions (10% w/w, pH 7). Sugar beet extract reduced the interfacial tension up to 38% at the oil-water interface, and the surface tension up to 33% at the air-water surface. The generated emulsions were negatively charged (ζ ≈ -46 mV) and had the smallest particle sizes (d43) of ∼1.3 µm at a low emulsifier-to-oil ratio of 0.75:10. Applying lower or higher extract concentrations increased the mean particle sizes. The smallest emulsions were formed at an optimum homogenization pressure of 69 MPa. Higher homogenization pressures led to increased particle sizes. Overall, sugar beet extract showed high surface activity. Furthermore, the formation of small emulsion droplets was successful; however, the droplets were bigger compared to those from the Quillaja extract. These results indicate sugar beet as an effective natural emulsifier that may be utilized for a variety of food and beverage applications.


Assuntos
Beta vulgaris/química , Extratos Vegetais/química , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsões/química , Manipulação de Alimentos , Tamanho da Partícula , Extratos Vegetais/isolamento & purificação , Quillaja/química
14.
Sci Rep ; 7: 41193, 2017 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-28117455

RESUMO

Acidobacteria have been described as one of the most abundant and ubiquitous bacterial phyla in soil. However, factors contributing to this ecological success are not well elucidated mainly due to difficulties in bacterial isolation. Acidobacteria may be able to survive for long periods in soil due to protection provided by secreted extracellular polymeric substances that include exopolysaccharides (EPSs). Here we present the first study to characterize EPSs derived from two strains of Acidobacteria from subdivision 1 belonging to Granulicella sp. EPS are unique heteropolysaccharides containing mannose, glucose, galactose and xylose as major components, and are modified with carboxyl and methoxyl functional groups that we characterized by Fourier transform infrared (FTIR) spectroscopy. Both EPS compounds we identified can efficiently emulsify various oils (sunflower seed, diesel, and liquid paraffin) and hydrocarbons (toluene and hexane). Moreover, the emulsions are more thermostable over time than those of commercialized xanthan. Acidobacterial EPS can now be explored as a source of biopolymers that may be attractive and valuable for industrial applications due to their natural origin, sustainability, biodegradability and low toxicity.


Assuntos
Acidobacteria/química , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Biopolímeros , Emulsificantes/química , Emulsificantes/isolamento & purificação , Emulsões/química , Monossacarídeos/química , Reologia , Microbiologia do Solo
15.
J Sci Food Agric ; 97(3): 882-888, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27198121

RESUMO

BACKGROUND: Alfalfa is considered a potential feedstock for biofuels; co-products with value-added uses would enhance process viability. This work evaluated dried alfalfa leaves for protein production and describes the functional properties of the protein. RESULTS: Dried alfalfa leaves contained 260 g kg-1 dry basis (DB) crude protein, with albumins being the major fraction (260 g kg-1 of total protein). Alkali solubilization for 2 h at 50 °C, acid precipitation, dialysis, and freeze-drying produced a protein concentrate (600 g kg-1 DB crude protein). Alfalfa leaf protein concentrate showed moderate solubility (maximum 500 g kg-1 soluble protein from pH 5.5 to 10), excellent emulsifying properties (activity 158-219 m2 g-1 protein, stability 17-49 min) and minimal loss of solubility during heating at pH ≥ 7.0. CONCLUSIONS: It is technically feasible to extract protein with desirable emulsifying and heat stability properties from dried alfalfa leaves; however, the dried form may not be a practical starting material for protein production, given the difficulty of achieving high yields and high-purity protein product. © 2016 Society of Chemical Industry.


Assuntos
Produção Agrícola , Produtos Agrícolas/química , Emulsificantes/isolamento & purificação , Aditivos Alimentares/isolamento & purificação , Medicago sativa/química , Folhas de Planta/química , Proteínas de Vegetais Comestíveis/isolamento & purificação , Precipitação Química , Diálise , Emulsificantes/química , Estudos de Viabilidade , Aditivos Alimentares/química , Liofilização , Temperatura Alta/efeitos adversos , Concentração de Íons de Hidrogênio , Meio-Oeste dos Estados Unidos , Tamanho da Partícula , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Proteínas de Vegetais Comestíveis/química , Caules de Planta/química , Estabilidade Proteica , Solubilidade , Água/análise
16.
Int J Biol Macromol ; 95: 1179-1189, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27825823

RESUMO

Speckled Sugar bean protein (0-4%) was used to stabilize sunflower oil in water emulsion (30% oil). To investigate the effect of other components on emulsion properties different salt concentrations (0-0.5M) and pH (3-7) were used. For this purpose, zeta potential, oil droplet size, adsorbed protein, non-adsorbed protein, viscosity, emulsifying capacity, emulsion stability and creaming rate were evaluated. Results showed that protein concentration was the most effective variable affected emulsions characteristics followed by protein-pH interaction as the second effective term. Salt somehow influenced emulsion properties but it had no negative effect on emulsifying capacity, emulsion stability or creaming rate. FTIR spectroscopy revealed that protein fractions with higher sheet secondary structure had better adsorption on oil droplets; while, fractions with helix subunit as the predominant secondary structure had the lowest adsorption capacity. At the end, emulsion properties were optimized based on the different independent and dependent variables. Results confirmed that Speckled Sugar bean protein was resistant to aggregation at high ionic strength. As a result, this protein could perform well as an emulsifier at different pH values.


Assuntos
Emulsificantes/química , Phaseolus/química , Óleos Vegetais/química , Proteínas de Plantas/química , Cloreto de Sódio/química , Água/química , Adsorção , Emulsificantes/isolamento & purificação , Emulsões , Análise Fatorial , Tecnologia de Alimentos , Humanos , Concentração de Íons de Hidrogênio , Concentração Osmolar , Proteínas de Plantas/isolamento & purificação , Estrutura Secundária de Proteína , Óleo de Girassol , Viscosidade
17.
Int J Biol Macromol ; 93(Pt A): 1240-1252, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27693832

RESUMO

Plant polysaccharides are widely used in food industry as thickening and gelling agents and these attributes largely depend on their thermal, emulsifying and rheological properties. As known, the extraction methods always bring about the diversification of property and functions of polysaccharides. Thus, the Vaccinium bracteatum Thunb leaves polysaccharides (VBTLP) were sequentially extracted using hot buffer (HBSS), chelating agent (CHSS), dilute alkaline (DASS) and concentrated alkaline (CASS). The thermal, emulsifying and rheological properties of VBTLP were investigated in the present study. Within the range of 20-225°C, CHSS showed the highest peak temperature, whereas HBSS displayed the highest endothermic enthalpy and highest emulsifying activity, while, CASS showed the longest emulsifying stability. The VBTLP solutions exhibited non-Newtonian shear-thinning behavior within the concentrations of 0.6-2.5%. The apparent viscosity of VBTLP solution decreased under following conditions: acidic pH (4.0), alkaline pH (10.0), in the presence of Ca2+ and at high temperature, while it increased in the presence of Na+ and at freezing conditions. The modulus G' and G″ of VBTLP solutions were increased with increasing oscillation frequency, and the crossover frequency shifted to lower values when the polysaccharide content increased. The above results of thermal, emulsifying and rheological properties of VBTLPs supplied the basis for V. bracteatum leaves in potential industrial applications of foods.


Assuntos
Emulsificantes/química , Emulsificantes/isolamento & purificação , Folhas de Planta/química , Polissacarídeos/química , Polissacarídeos/isolamento & purificação , Reologia , Vaccinium myrtillus/química , Concentração de Íons de Hidrogênio , Cloreto de Sódio/química , Temperatura Ambiente , Viscosidade
18.
Carbohydr Polym ; 153: 518-525, 2016 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-27561524

RESUMO

Pressurized liquid extraction (PLE) was utilized to extract sulfated polysaccharides (fucoidan) from brown seaweed Saccharina japonica. Various conditions of temperature (80-200°C), pressure (5-100bar), and solvents (water, 0.1% sodium hydroxide, 0.1% formic acid, 70% ethanol, 50% ethanol, and 25% ethanol) were assessed; the best crude fucoidan (CF) yield was 8.23%, obtained from 140°C and 50bar (sodium hydroxide). Compositional analysis, FT-IR, molecular weight, monosaccharides, TGA, UV-vis, XRD, and elemental analysis confirm that extracted polysaccharides revealed the features of fucoidan. Fucose was the main monosaccharide present in CF obtained by various solvent systems. All CF showed antioxidant activities as measured by DPPH radical and ABTS(+) radical scavenging. CF demonstrates good emulsion-stabilizing capacities, especially with vegetable oils. This study demonstrates that PLE is an efficacious method for enhancing the yield of polysaccharides from S. japonica and that it could be a potential source of natural antioxidants and emulsifiers.


Assuntos
Antioxidantes/química , Emulsificantes/química , Extração Líquido-Líquido/métodos , Polissacarídeos/química , Alga Marinha/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Emulsificantes/isolamento & purificação , Emulsificantes/farmacologia , Emulsões/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/farmacologia , Pressão , Solventes , Sulfatos/química , Sulfatos/isolamento & purificação , Sulfatos/farmacologia , Temperatura Ambiente
19.
Carbohydr Polym ; 143: 100-7, 2016 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-27083348

RESUMO

The operational parameters involved in microwave-assisted extraction (MAE) of jujube polysaccharide including microwave power, water to raw material ratio and extraction temperature and time were optimized by RSM. MAE at 400W, 75°C, 60 min, using 30 g water/g powdered jujube was the best condition for maximum yield (9.02%) of polysaccharide. Two novel water-soluble polysaccharides (JCP-1 and JCP-2) with average molecular weights of 9.1×10(4)-1.5×10(5)Da in term of the symmetrical narrow peaks were identified using the analytical purification procedures. The JCP-1 and JCP-2 mainly composed of glucose, arabinose, galactose and rhamnose in molar ratios of 1.4:2.1:4.2:0.9 and 1.2:1.8:4.1:1.1, respectively. The use of 1.5% JCP-1 led to a high emulsifying stability (95.5%) in a model oil-in-water type emulsion with a reduced surface tension (44.1 mN/m) and droplet size (1.32 µm), and an increased apparent viscosity (0.13 Pas) during 21-day cold storage. The antioxidant activities were increased in dose-dependent manners (25-200 µg/mL).


Assuntos
Emulsificantes/química , Depuradores de Radicais Livres/química , Micro-Ondas , Polissacarídeos/química , Ziziphus/química , Fracionamento Químico , Emulsificantes/isolamento & purificação , Depuradores de Radicais Livres/isolamento & purificação , Calefação/métodos , Polissacarídeos/isolamento & purificação , Tensão Superficial , Viscosidade
20.
Carbohydr Polym ; 140: 59-65, 2016 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-26876828

RESUMO

Microwave assisted extraction technique was used to extract pectin from sour orange peel. Box-Behnken design was used to study the effect of irradiation time, microwave power and pH on the yield and degree of esterification (DE) of pectin. The results showed that the optimum conditions for the highest yield of pectin (29.1%) were obtained at pH of 1.50, microwave power of 700W, and irradiation time of 3min. DE values of pectin ranged from 1.7% to 37.5%, indicating that the obtained pectin was low in methoxyl. Under optimal conditions, the galacturonic acid content and emulsifying activity were 71.0±0.8% and 40.7%, respectively. In addition, the emulsion stability value ranged from 72.1% to 83.4%. Viscosity measurement revealed that the solutions of pectin at low concentrations showed nearly Newtonian flow behavior, and as the concentration increased, pseudoplastic flow became dominant.


Assuntos
Fracionamento Químico/métodos , Fenômenos Químicos , Citrus/química , Micro-Ondas , Pectinas/química , Pectinas/isolamento & purificação , Emulsificantes/química , Emulsificantes/isolamento & purificação , Frutas/química , Ácidos Hexurônicos/análise , Viscosidade
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