Dry Weight Protein Research Articles

Cold-set oat protein isolate--gellan gum binary gels with various microstructures: Fabrication, characterization, formation mechanism, and controlled release properties

Cold-set oat protein isolate (OPI) and gellan gum (GG) binary gels with various microstructures was fabricated with different amounts glucono-δ-lactone (GDL) as a carrier to deliver bioactive compounds. OPI and GG formed gel-like mixture at pH 8 mainly via hydrophobic interactions with a binding constant (Ka) of 3.85 × 104 M−1, while the mixture showed highest storage modulus (G′) with 0.1% GG (w/w, based on the dry weight of protein). Novel binary gels fabricated with 7% OPI (w/v) and 0.1% GG (w/w) (OGG) were then developed through addition of various amounts of GDL. For the gels prepared with 1.5% and 4.0% GDL (w/w, based on the dry weight of protein, pH 7.1 and 6.3, respectively), heterogeneous network formed by co-aggregated OPI and GG with a small amount of small GG particles dispersed within large aqueous pores were fabricated mainly through hydrophobic interactions. For OGG-3 (9.0% GDL, w/w) and OGG-4 (20.0% GDL, w/w), the final pH was 5.1 and 4.1 that around or lower than OPI's isoelectric point, hydrogen bonding and electrostatic attractive forces were developed between two polymers since OPI contained neat or positive charges, resulting in a compact coupled OPI-GG network structure. Heterogeneous network with small GG particles dispersed in pores allowed OGG-2 (4.0% GDL, w/w) had comparable good gel hardness to the gel formed with 9.0% GDL (w/w, OGG-3) with coupled microstructure, whereas OGG-3 showed a better ability to restrict the swelling induced release of riboflavin in SGF, and allowed sustainable release of riboflavin in SIF. Therefore, OPI-GG binary gels with various microstructures prepared by simple acidification method at ambient temperature have great potential to be used as delivery systems for heat-sensitive bioactive compounds in food and non-food applications.

Variation in size and chemical composition of seeds from the seagrass Zostera marina—Ecological implications

Seed size correlates with several plant traits spanning from seedling emergence depth or survival to seed dispersal potential. The ecological importance of seed size has been widely recognised for terrestrial plants, but few studies address this for marine angiosperms. With focus on the seagrass Zostera marina, we (1) relate seed size (length, diameter, fresh and dry weights) to its main reserves: starch, proteins and minerals, (2) quantify inter- and intra-specific population differences in seed size and composition, and (3) determine the effect of size on seed dispersal. We found that the seed size variation originated mostly from differences within rather than between populations. Seed dry weight (DW) was the most variable morphological characteristic across populations (0.64–6.03mg DW). DW was positively correlated with the amount of reserves (p<0.001). An eelgrass seed contained on average 52% DW starch, 13% DW proteins and 4% DW minerals. Interestingly, the relative contents of minerals and proteins were higher in smaller seeds, whereas starch content of seeds >2mg DW remained constant. Seed settling velocity, a proxy for seed dispersal, increased with DW from 1.4 to 8.6cms−1. Seeds of different quality may disperse differently: heavy seeds stay close to the parent plant and contain relatively more carbon to compensate for low light regime in the adults’ shadow, whereas smaller seeds spread further and contain relatively high nutrient content to establish rapidly in more open areas. Intraspecific seed size variations in the seagrass Z. marina may therefore assure both patch maintenance and colonisation of new areas.

Nutrition Composition and Analysis of Medicinal Herbal Potential of Horsfieldia glabra Warb. Seeds

Horsfieldia glabra Warb. is a locally consumed plant indigenous to Chiang Rai Province, Thailand and of late, there has been considerable interest in evaluating its health benefits. The aim of this study was to investigate H. glabra Warb. seeds in order to assess their nutritional properties and its potential as a medicinal herb. In terms of nutritional assessment, the experiment found that H. glabra Warb. seed extract contained 68.24 g per 100 g dry weight of lipids, 7.80 g per 100 g dry weight of protein, 14.20 g per 100 g dry weight of carbohydrates, 5.04 g per 100 g dry weight of crude fiber, 1.41 g per 100 g dry weight of ash and 6.827 kcal per 1 g dry weight of energy. The analysis of its potential as a medicinal herbal determined the antioxidant activity and Minimum Inhibitory Concentration (MIC) of Staphylococcus aureus , Pseudomonas aeruginosa and Escherichia coli . The results revealed that H. glabra Warb. seed extraction displayed antioxidant activity (62.01 ± 3.99% DPPH inhibition activity) with a IC50 value of 0.358 ± 0.02 mg/ml. Experiments investigating MIC determined that the extract exhibited the minimum inhibitory concentration of S. aureus (15.625 mg/ml) with 8.00 ± 1.73 mm clear zone. Whereas Streptomycin concentration of 30 mg/ml inhibited 9.00 ± 2.00 mm clear zone. GC-MS analysis of H. glabra Warb. seeds determined that the major compounds were α -resorcinol (40.769%) and 4-vinylphenol (23.761%).

Screening and Evaluation of Some Green Algal Strains (Chlorophyceae) Isolated from Freshwater and Soda Lakes for Biofuel Production

Microalgae are photosynthetic microorganisms that can produce lipids, proteins and carbohydrates in large amounts and within short periods of time and these can be processed into both biofuels and other useful commercial products. Due to this reason microalgae are considered as a potential source of renewable energy; and one of the most important decisions in obtaining oil from microalgae is the choice of species. In this study, the potential of Chlorophyceae species isolated from freshwater and soda lakes in Hungary and Romania (Central Europe) were characterized and evaluated by determining their biomass accumulation, lipid productivity, fatty acid profiles, and biodiesel properties besides protein and carbohydrate productivity. Out of nine strains tested, three accumulated more than 40% dry weight of protein, four accumulated more than 30% dry weight of carbohydrate and the strain Chlorella vulgaris LC8 accumulated high lipid content (42.1% ± 2.6%) with a favorable C16-C18 fatty acid profile (77.4%) as well as suitable biodiesel properties of high cetane number (57.3), low viscosity (4.7 mm2/s), lower iodine number (75.18 g I2/100 g), relative cloud point (8.8 °C) and negative cold filter plugging point (−6.5 °C). Hence the new strain, Chlorella vulgaris LC8 has potential as a feedstock for the production of excellent quality biodiesel.

179 - Assessment of Catalytic Activity and Oxidation-Reduction Potential of Custom-Synthesized Cerium Oxide Nanoparticles in Cell-Free Systems and Tissue

A procedure is described for the preparation of a large quantity of functionally active iron-sulfur protein (adrenodoxin) crystals from bovine adrenal cortex. The preparation was found to be homogeneous on ultracentrifugation and on disc electrophoresis. It contains 150 ngatoms of iron per mg dry weight of protein and its absorbance ratio at 414 nm/276 nm in the oxidized form is 0.86.

177 - Redox-Directed Suppression of Malignant Cell Invasion in a Three-Dimensional Skin Reconstruct Model of Metastatic Melanoma

A procedure is described for the preparation of a large quantity of functionally active iron-sulfur protein (adrenodoxin) crystals from bovine adrenal cortex. The preparation was found to be homogeneous on ultracentrifugation and on disc electrophoresis. It contains 150 ngatoms of iron per mg dry weight of protein and its absorbance ratio at 414 nm/276 nm in the oxidized form is 0.86.

Bayberry ( Myrica rubra Sieb. et Zucc.) kernel: A new protein source

Bayberry ( Myrica rubra Sieb. et Zucc.) kernel protein isolate (BKPI) was isolated from bayberry kernel defatted flour (BKDF) by isoelectric precipitation. BKPI was evaluated for chemical composition and selected functional properties with defatted kernel flour as reference. BKPI contained over 90% dry weight (DW) of protein versus 60.5% DW of protein in BKDF. It possessed a well-balanced amino acid composition according to the FAO/WHO reference except for a low content of lysine. BKPI had a solubility profile similar to that of BKDF, with minimum solubility observed at pH 4.0 and maximum solubility at pH 12.0. BKPI exhibited minimum foaming capacity (FC) (31.1%) and maximum foaming stability (FS) (72.7%) at pH 4.0. Minimum emulsifying capacity (EC) and emulsifying stability (ES) of BKPI and BKDF were observed at pH 4.0. BKPI had a least gelation concentration of (LGC) of 6% (w/v) at pH 4.0. Results indicated that bayberry kernel has potential to be exploited as a new protein source in China.

96/00200 Study of hydrogen-donor solvent in the NEDOL process

The refractive indices of orthorhombic and monoclinic crystals of β-lactoglobulin have been measured by microscope interferometry and found to be 1.4536 ± 0.0015 and 1.4765 ± 0.0015 respectively, these values being for a particular orientation of the light electric vector relative to the crystal axes. Combining these values with data4 on the dry weight of protein per unit volume of crystals, the specific refraction increments of orthorhombic and monoclinic crystals are calculated to be 0.00196 ± 0.00003 and 0.00191 ± 0.00002 respectively. The values are in fairly good agreement with that of 0.00182 found8 for dilute solutions of β-lactoglobulin. This conclusion is not altered when the birefringence of the crystals, which has also been measured, is taken into account. Both types of crystal approximate in behaviour to uniaxial crystals with birefringence values of 0.00086 ± 0.00003 and about 0.0036 for orthorhombic and monoclinic crystals respectively.

96/00195 RTDS: A continuous, rapid, thermal synthesis method

The refractive indices of orthorhombic and monoclinic crystals of β-lactoglobulin have been measured by microscope interferometry and found to be 1.4536 ± 0.0015 and 1.4765 ± 0.0015 respectively, these values being for a particular orientation of the light electric vector relative to the crystal axes. Combining these values with data4 on the dry weight of protein per unit volume of crystals, the specific refraction increments of orthorhombic and monoclinic crystals are calculated to be 0.00196 ± 0.00003 and 0.00191 ± 0.00002 respectively. The values are in fairly good agreement with that of 0.00182 found8 for dilute solutions of β-lactoglobulin. This conclusion is not altered when the birefringence of the crystals, which has also been measured, is taken into account. Both types of crystal approximate in behaviour to uniaxial crystals with birefringence values of 0.00086 ± 0.00003 and about 0.0036 for orthorhombic and monoclinic crystals respectively.

95/00197 How to manage the oil price risk

The refractive indices of isoionic crystals of a α-chymotrypsinogen have been measured by microscope interferometry employing two procedures. In principle, the index-values are deduced from measurement of optical path of crystal relative to mother liquor by combining this value with measurements first on an air-bubble3,4 squeezed to the same thickness as the crystal, and second, on the crystal located inside an airbubble. The two principle refractive indices are 1.483 ± 0.003 and 1.486 ± 0.001 by method 1, and 1.480 ± 0.001 and 1.482 ± 0.001 by method 2. Separate measurements of birefringence by the polarizing microscope gave a value of 0.0039 ± 0.00005. The crystals are orthorhombic; it was not possible to measure the third refractive index. Combining these values with data5 on the dry weight of protein per unit volume of crystal, the principal specific refraction increments are on average 0.00192 and 0.00195. These values are in fairly good agreement with the value of 0.00185 for dilute solutions of α-chymotrypsinogen.

Low‐temperature glass transition in proteins

AbstractThe viscoelastic properties of solid samples (crystals, amorphous films) of hen egg white lysozyme, bovine serum albumin, and sperm whale myoglobin were studied in the temperature range of 100–300 K at different hydration levels. Decreasing the temperature was shown to cause a steplike increase in the Young's modulus of highly hydrated protein samples (with water content exceeding 0.3 g/g dry weight of protein) in the temperature range of 237–251 K, followed by a large increase in the modulus in the broad temperature interval of 240–130 K, which we refer to as a mechanical glass transition.Soaking the samples in 50% glycerol solution completely removed the steplike transition without significantly affecting the glass transition. The apparent activation energy determined from the frequency dependence of the glass‐transition temperature was found to be 18 kcal/mol for wet lysozyme crystals. Lowering the humidity causes both the change of the Young's modulus in response to the transition and the activation energy to decrease. The thermal expansion coefficient of amorphous protein films also indicates the glass transition at 150–170 K. The data presented suggest that the glass transition in hydrated samples is located in the surface layer of proteins and related to the immobilization of the protein groups and strongly bound water.

Improved purification of bovine adrenal iron-sulfur protein

A procedure is described for the preparation of a large quantity of functionally active iron-sulfur protein (adrenodoxin) crystals from bovine adrenal cortex. The preparation was found to be homogeneous on ultracentrifugation and on disc electrophoresis. It contains 150 ngatoms of iron per mg dry weight of protein and its absorbance ratio at 414 nm/276 nm in the oxidized form is 0.86.

The specific refraction increment of crystalline protein: II. α-Chymotrypsinogen

The refractive indices of isoionic crystals of a α-chymotrypsinogen have been measured by microscope interferometry employing two procedures. In principle, the index-values are deduced from measurement of optical path of crystal relative to mother liquor by combining this value with measurements first on an air-bubble 3,4 squeezed to the same thickness as the crystal, and second, on the crystal located inside an airbubble. The two principle refractive indices are 1.483 ± 0.003 and 1.486 ± 0.001 by method 1, and 1.480 ± 0.001 and 1.482 ± 0.001 by method 2. Separate measurements of birefringence by the polarizing microscope gave a value of 0.0039 ± 0.00005. The crystals are orthorhombic; it was not possible to measure the third refractive index. Combining these values with data 5 on the dry weight of protein per unit volume of crystal, the principal specific refraction increments are on average 0.00192 and 0.00195. These values are in fairly good agreement with the value of 0.00185 for dilute solutions of α-chymotrypsinogen.

Cell interferometry and the specific refraction increment of crystalline proteins: I. β-lactoglobulin

The refractive indices of orthorhombic and monoclinic crystals of β-lactoglobulin have been measured by microscope interferometry and found to be 1.4536 ± 0.0015 and 1.4765 ± 0.0015 respectively, these values being for a particular orientation of the light electric vector relative to the crystal axes. Combining these values with data 4 on the dry weight of protein per unit volume of crystals, the specific refraction increments of orthorhombic and monoclinic crystals are calculated to be 0.00196 ± 0.00003 and 0.00191 ± 0.00002 respectively. The values are in fairly good agreement with that of 0.00182 found 8 for dilute solutions of β-lactoglobulin. This conclusion is not altered when the birefringence of the crystals, which has also been measured, is taken into account. Both types of crystal approximate in behaviour to uniaxial crystals with birefringence values of 0.00086 ± 0.00003 and about 0.0036 for orthorhombic and monoclinic crystals respectively.

The Snail's Foot as a Langmuir Trough

THE importance of the surface film of protein on stationary or slowly moving bodies of water as a food for small aquatic animals had apparently not been realized until the recent work of Goldacre1, who made film-pressure measurements on ponds, lakes and rivers and found on all of them unimolecular layers of protein in higher or lower states of compression. A concomitant study of the behaviour of small aquatic animals led him to the conclusion that they ate this protein in large amounts. Observations of the movements of dust particles in a film during its ingurgitation by a tadpole indicated that this animal might well eat its own dry weight of protein, spread as a monolayer at the air–water interface, in one day.