Determination Of Protein Content Research Articles

Variable selection in near-infrared spectra: Application to quantitative non-destructive determination of protein content in wheat

With the development of information technology, online non-destructive quantitative testing technology for wheat has attracted widespread attention. Protein content is an important indicator for wheat. A near infrared (NIR) spectroscopy system was utilized for the quantitative detection of protein in wheat. Firstly, the spectra of wheat were obtained by the NIR spectroscopy system. Then, variable selection methods were used to optimize the characteristic wavelengths, including competitive adaptive reweighted sampling (CARS), variable combination population analysis (VCPA), Monte Carlo variable combination population analysis (MCVCPA), and automatic weighting variable combination population analysis (AWVCPA). AWVCPA algorithm was effective in eliminating uninformative and inference wavelength variables of NIR spectra and reduced the complexity of quantitative prediction model. The characteristic wavelengths selected by AWVCPA were highly related to the absorbance of protein. Finally, the partial least squares (PLS) was employed to construct quantitative detection models based on different variable selection method. The experimental results showed that the AWVCPA-PLS prediction model is the best among the four tested models. The R2, RMSEP, RPD and RER values of AWVCPA-PLS were 0.9753, 0.0934, 10.15 and 38.54 respectively, indicative of high prediction accuracy and robust performance. This study provides an important theoretical basis for evaluating wheat in food engineering region.

Antioxidant activity, carbohydrates and protein in sorgum (Sorghum bicolor L. Moench) plants as a development of economic functional food materials during the COVID-19 pandemic

This study aims to determine the content of antioxidants, carbohydrates, and protein in Sorghum (Sorghum bicolor L. Moench) as an economically functional food ingredient during the COVID-19 pandemic. The research stages include the manufacture of sorghum seed extract, Antioxidant level testing using the DPPH test, carbohydrate content testing, and protein content determination using the Kjeldahl method, the Kjeldahl method consists of 3 stages, namely: the destruction stage, the distillation stage, and the titration stage. The results showed that Sorghum had an IC50 value of 88.8970 ppm, carbohydrate content of 71.8 g, and protein content of 9.68%. so that sorghum has the potential to develop functional food during the COVID-19 pandemic.

Determination of Protein content in Cheese Products

The high concentration of essential amino acids in cheese contributes to the growth and development of the human body. Despite the presence of a notable amount of saturated and trans-fatty acids, there is no clear evidence relating the consumption of cheese to any disease. The high concentration of calcium in cheese is well known to contribute to the formation and maintenance of strong bones and teeth, but also shows a positive effect on blood pressure and helps in losing weight in combination with low-energy diets. The SMART 6 is a system for rapid moisture and fat determination - in less than 5 minutes. The SMART 6 Moisture and Solids Analyzer uses dual-frequency microwave radiation to quickly analyze any product, wet or dry, in 3 minutes or less. Sprint® is a direct protein measurement system using biochemical protein labeling technology that only binds protein nitrogen. Measurement of total nitrogen can lead to erroneous results when non-protein nitrogen is present. Sprint does not require regular calibration and is easy to operate. Competitive express technologies require constant, costly calibrations and method development for each unique sample due to differences in color, texture and consistency.

Exercise May Promote Skeletal Muscle Hypertrophy via Enhancing Leucine-Sensing: Preliminary Evidence.

Several studies have indicated a positive effect of exercise (especially resistance exercise) on the mTOR signaling that control muscle protein synthesis and muscle remodeling. However, the relationship between exercise, mTOR activation and leucine-sensing requires further clarification. Two month old Sprague-Dawley rats were subjected to aerobic exercise (treadmill running at 20 m/min, 6° incline for 60 min) and resistance exercise (incremental ladder climbing) for 4 weeks. The gastrocnemius muscles were removed for determination of muscle fibers diameter, cross-sectional area (CSA), protein concentration and proteins involved in muscle leucine-sensing and protein synthesis. The results show that 4 weeks of resistance exercise increased the diameter and CSA of gastrocnemius muscle fibers, protein concentration, the phosphorylation of mTOR (Ser2448), 4E-BP1(Thr37/46), p70S6K (Thr389), and the expression of LeuRS, while aerobic exercise just led to a significant increase in protein concentration and the phosphorylation of 4E-BP1(Thr37/46). Moreover, no difference was found for Sestrin2 expression between groups. The current study shows resistance exercise, but not aerobic exercise, may increase muscle protein synthesis and protein deposition, and induces muscle hypertrophy through LeuRS/mTOR signaling pathway. However, further studies are still warranted to clarify the exact effects of vary intensities and durations of aerobic exercise training.

Study of transgen functionality in T2 biotechnological plants of winter wheat on the sign of osmoresistance

Aim. To investigate the functionality of the transgene in the seed generation (T2) of genetically modified winter wheat plants (Triticum aestivum L.) in terms of productivity in conditions of normal and insufficient water supply. Methods. Determination of yield structure and protein content. Results. The indicators of productivity of control and T2 biotechnological plants under normal growing conditions and water deficit are analyzed. The quantitative composition of protein in the conditions before and after osmotic stress and in the period of rehydration was determined. Conclusions. It is shown that under the action of water deficit there is a decrease in productivity for all studied plants. In this case, genetically modified plants had an advantage in the main elements of the crop structure over the original form under both analyzed growing conditions. It was found that under normal conditions of hydration, the amount of protein in the studied plants did not differ significantly. An increase in its content in control plants under the action of osmotic stress was recorded, which may indicate the synthesis of stress response proteins. Decreased protein content during rehydration may indicate the passage of normal metabolic processes.
 Keywords: Triticum aestivum L., biotechnological plants, proline dehydrogenase gene, structural analysis of yield, osmostability.

Synthetic NAC 71-82 Peptides Designed to Produce Fibrils with Different Protofilament Interface Contacts.

Alpha-synucleinopathies are featured by fibrillar inclusions in brain cells. Although α-synuclein fibrils display structural diversity, the origin of this diversity is not fully understood. We used molecular dynamics simulations to design synthetic peptides, based on the NAC 71-82 amino acid fragment of α-synuclein, that govern protofilament contacts and generation of twisted fibrillar polymorphs. Four peptides with structures based on either single or double fragments and capped or non-capped ends were selected for further analysis. We determined the fibrillar yield and the structures from these peptides found in the solution after fibrillisation using protein concentration determination assay and circular dichroism spectroscopy. In addition, we characterised secondary structures formed by individual fibrillar complexes using laser-tweezers Raman spectroscopy. Results suggest less mature fibrils, based on the lower relative β-sheet content for double- than single-fragment peptide fibrils. We confirmed this structural difference by TEM analysis which revealed, in addition to short protofibrils, more elongated, twisted and rod-like fibril structures in non-capped and capped double-fragment peptide systems, respectively. Finally, time-correlated single-photon counting demonstrated a difference in the Thioflavin T fluorescence lifetime profiles upon fibril binding. It could be proposed that this difference originated from morphological differences in the fibril samples. Altogether, these results highlight the potential of using peptide models for the generation of fibrils that share morphological features relevant for disease, e.g., twisted and rod-like polymorphs.

Analysis of Protein and Calcium Content in White Swallow’s Nest Stew (Collacalia Fuchiphaga)

Swallow's nest (Collocalia fuchiphaga) is one of the high export commodities. This is because the bird's nest is considered to be nutritious in terms of health. In this research, using swallow's nest obtained from several swallow buildings in Subur Indah Village, Katingan District, Kuala Central Kalimantan. The purpose of this study was to analyse the protein and calcium content of boiled white bird’s nest (Collacalia Fuchiphaga). Determination of protein content was carried out using the Kjeldahl method while for determination of calcium content using the permanganometric titration method. Based on the results with 3 repetitions each, the protein content was 21.8; 22.92 and 22.15% at 4 hours of boiling then 19.7; 18.1 and 19.05% at 8 hours of boiling. Meanwhile, the determination of the calcium content resulted in 201.5; 198.2 and 205.6 mg / 100 g calcium at 4 hours of boiling and 182.5; 178.8 and 175.6 mg / 100 g calcium. The conclusion in this study is that the longer it takes to boil a swallow's nest, the less protein and calcium content is obtained

Monoclonal antibodies to hemagglutinin of influenza A/H7N3 virus (Orthomyxoviridae: Alphainfluenzavirus: Influenza A virus)

Variants of influenza virus A/H7 have the same high pandemic potential as A/H5. However, the information about the antigenic structure of H7 hemagglutinin (НА) is considerably inferior in quantitative terms to similar data for H5 НА.The aims of the study were development and characterization of the monoclonal antibodies (MAbs) panel for HA subtype H7 of the influenza A virus. Viruses were accumulated in 10-day-old chicken embryos. Purification and concentration of the virus, determination of protein concentration, preparation of MAbs and ascitic fluids, hemagglutination and hemagglutination inhibition (HI) tests, assessment of antibodies' activity in indirect enzyme-linked immunosorbent assay (ELISA), as well as determination of MAbs isotypes and neutralization reaction (NR) were carried out by standard methods. The obtained MAbs to А/mallard/Netherlands/12/2000 (H7N3) strain were studied in HI test with a set of strains of different years of isolation belonging to different evolutionary groups. MAbs had a reduced reactivity compared to the immunogen-virus for all the studied strains. Cross-interaction of MAbs 9E11 and 9G12 in HI test with influenza A/H15 virus has been observed. Influenza A agent with H7 HA variant could serve as a potential cause of a future pandemic. Development of the MAbs panel for subtype H7 HA is an urgent task for both veterinary medicine and public health. The obtained MAbs can be used not only for epitope mapping of the H7 HA molecule (currently insufficiently studied) and as reagents for diagnostic assays, but also for determining common («universal») epitopes in HA of different strains of this subtype.

Determination of protein concentration in downstream biomanufacturing processes by in-line index of refraction.

Protein concentration determination is a necessary in-process control for the downstream operations within biomanufacturing. As production transitions from batch mode to an integrated continuous bioprocess paradigm, there is a growing need to move protein concentration quantitation from off-line to in-line analysis. One solution to fulfill this process analytical technology need is an in-line index of refraction (IoR) sensor to measure protein concentration in real time. Here the performance of an IoR sensor is evaluated through a series of experiments to assess linear response, buffer matrix effects, dynamic range, sensor-to-sensor variability, and the limits of detection and quantitation. The performance of the sensor was also tested in two bioprocessing scenarios, ultrafiltration and capture chromatography. The implementation of this in-line IoR sensor for real-time protein concentration analysis and monitoring has the potential to improve continuous bioprocess manufacturing.

PENETAPAN KADAR PROTEIN PADA SUSU KENTAL MANIS DAN SUSU UHT (ULTRA HIGH TEMPERATURE) MENGGUNAKAN METODE KJELDAHL

Accordingto SNI, Ultra High Temperature (UHT) milki sobtained by sterilizing milk at a minimum of 135oC for two seconds with or without the addition of permitted fooding redients and food additives and packaged a septically. Sweetened Condensed Milk (SCM) is obtained from fresh milk whose water content is reduced by heating at least 100oC and added with sucrose sugar or a mixture of sucrose and dextrose sugar and then partially evaporates the water until it be comes thick. This study aims to determine the protein content of UHT and SCM milk has met the requirements set bythe Indonesian National Standard (SNI). The samples tested were 2 brandsof UHT milkand 2 brands of SCM. Determination of protein content was carried out by the Kjeldahl method in accordance with the Indonesian National Standard (SNI) procedure and work equipment for the Kjeldahl method. The test resultss how that the protein contentof UHT A milkis 2.86% and UHT B milkis 3.34%, this has metthe protein content requirements of SNI 01–2971–1998, which is at least 2.7%. The results of the teston SCM A that were tested contained a protein contentof 6.74% and SCM B of 6.54%, these results reached the minimum limit of protein contentstated in SNI 01-2971-1998, which is at least 6.5%.

Fast determination of lipid and protein content in green coffee beans from different origins using NIR spectroscopy and chemometrics

The chemical compounds including lipid and protein in green coffee beans are important indicators of the final quality of the coffee products, which are usually determined by time-consuming and destructive chemical methods. Therefore, a fast and reliable method was attempted to exploit by near-infrared (NIR) spectroscopy combined with partial least squares (PLS) regression for the determination of lipid and protein in green coffee beans from different origins. Orthogonal signal correction (OSC) and several traditional spectral pretreatment methods were compared during the PLS regression model building process. Important variables selection was further achieved based on the regression coefficients (β). The results showed that the 1st and 2nd derivative reduced the model quality, while OSC, MSC, and SNV pretreatment enhanced the model quality. The quality of PLS models was significantly improved after important variable selection. Especially, OSC-PLS models were the most robust for protein and lipid prediction with the best performance indicators (R2p>0.982, RPD > 7.55, RMSEcv <0.101, RMSEP < 0.106). The excellent performance showed that the NIR technique together with PLS regression could be applied as a substitute way to determine the protein and lipid content in green coffee beans.

Multi-Environmental Evaluation of Protein Content and Yield Stability among Tropical Soybean Genotypes Using GGE Biplot Analysis

The yield and protein performance in a soybean genotype result from its interaction with the prevailing environmental conditions. This makes selecting the best genotypes under varied target production environments more complex. This study’s objectives were to determine protein content and protein stability of 30 elite soybean genotypes in major soybean-growing areas of Uganda, assess the yield performance and stability in soybeans and determine the relationship between the protein content and grain yield in soybeans. The genotypes were planted in a randomized complete block design of three replications for six seasons across eight locations in Uganda. Genotype and genotype-by-environment (GGE) biplot analyses classified the test locations into three mega-environments for soybean protein and grain yields. Genotype NII X GC 20.3 had the highest mean protein content of 43.0%, and BSPS 48A-9-2 and BSPS 48A-28 were superior for the mean grain yield (1207 kg ha−1). Bulindi was the most discriminating and representative test environment for soybean yield. A weak and negative correlation (r = −0.1**, d.f. = 29) was detected between the protein content (%) and yield (kg ha−1). The highest-yielding genotypes BSPS 48A-9-2, BSPS 48A-31, and Nam II × GC 44.2 are recommended for further evaluation under farmers’ production conditions for selection and release as new soybean varieties in Uganda.

Determination of soluble wheat protein fractions using the Bradford assay

AbstractBackground and objectivesDetermination of different grain protein fractions in wheat cultivars is an important task in analyzing bread baking quality. In many laboratories, the Bradford assay is used to determine protein concentrations in solutions. In any protein assay (including Bradford), the ideal protein to use as a standard is the purified protein being assayed. In the absence of such an absolute reference, protein another protein must be selected as a relative standard such as bovine serum albumin (BSA) which is widely used. The aim of this work was to find conversion factors for BSA to determine correct albumin–globulin, gliadin, and glutenin concentrations, because these purified wheat grain protein fractions are mostly not available to be used for calibration purposes.FindingsIn case of BSA calibration, gluten concentration was underestimated (50%–54%) compared to calibration with the respective purified wheat proteins (65%–70%) in extracts of wheat grain samples. This result is explained with the different amino acid composition of BSA and wheat protein fractions leading to a more intense signal with BSA in the Bradford assay. Calibration of the Bradford assay using BSA as well as purified wheat protein fractions allowed to calculate the conversion factors of 2.11 for BSA/albumin–globulin, 4.25 for BSA/gliadin, and 3.42 for BSA/glutenin. Application of these conversion factors proved to accurately adjust protein concentrations of wheat fractions originating from ten cultivars, determined with BSA calibration of the Bradford assay.ConclusionsBSA calibration of the Bradford assay in combination with the conversion factors can be used to determine protein concentration of wheat grain fractions.Significance and noveltyFindings of this study make a contribution toward the correction of a common method, to provide a basis for better comparability of research results from different laboratories.

Comparison of PLSR, MLR, SVM regression methods for determination of crude protein and carbohydrate content in stored wheat using near Infrared spectroscopy

Aim of the study was to predict quality parameters namely protein and carbohydrate content of wheat grain stored for one year at 4 °C and 21 °C using Near Infrared spectroscopy (NIRS) and Chemometrics. The spectra of grains were measured in reflectance mode using lab made filter based pre dispersive NIRS ranging from wavelength 750 nm to 2580 nm. NIR Wavelengths were divided into two sets for all the stored samples depending on its correlation with factors. The reference data and NIR data were analysed by principal component analysis (PCA) scores, partial last squared regression (PLSR) model, Multiple Regression Analysis (MLR) and Support Vector Machine Regression (SVMR). First four factors were sufficient to develop regression models for the above mentioned methods. Prediction performance was compared on the basis of the coefficient of correlation (R2) and Root Mean Square Error (RMSE) for the calibration and validation sets. R2 values for prediction of protein content from PLSR model were 0.955, 0.997 for 4 °C Wavelength Set I and II and 0.903, 0.989 for 21 °C Wavelength Set I and II. For the prediction of carbohydrate content 0.978, 0.951 and 0.946, 0.974 were the R2 values for the 4 °C and 21 °C wheat samples Set I and Set II respectively. MLR model also gave R2 values greater than 0.9 for all the samples. Wavelengths with high β correlation coefficients were defined. SVMR predicted the protein content and carbohydrate content with good accuracy. SVMR and PLS results. All the models developed showed good accuracy for successful prediction of protein and carbohydrate content of stored wheat grains with PLSR and SVMR giving the best results. This study showed that near infrared spectroscopy has potential to distinguish wheat grains stored under different conditions.

High cytotoxicity of betulin towards fish and murine fibroblasts: Is betulin safe for nonneoplastic cells?

BackgroundBetulin, a natural pentacyclic triterpene with the lupane structure that is present in significant amounts in the outer bark of birch, is known for its broad array of biological and pharmacological properties. Betulin has attracted attention as a potential, natural-origin antimicrobial substance. The literature describes it as selectively toxic to neoplastic cells but safe for normal cells.The research aim was to evaluate the basal cytotoxicity of betulin towards fish (BF-2) and murine (NIH/3T3) fibroblasts. We used four colorimetric tests that provide a preliminary evaluation of possible mechanisms of the cytotoxicity of a compound to assess the degree of the toxicity of betulin after 24, 48 and 72 h of incubation with cells: the MTT assay (mitochondrial activity assessment), the NRU assay (lysosomal membrane integrity assessment), the LDH assay (cellular membrane integrity assessment) and the SRB assay (total cellular protein content determination).ResultsThe results revealed an exceptionally high sensitivity of mitochondria to the effect of betulin, with the other endpoints being less sensitive. Although murine fibroblasts were more vulnerable to the toxic effect of betulin than fish fibroblasts, the betulin CC50 values for both cell lines were comparable with analogous IC50 values determined by other researchers in studies involving cancerous cells.ConclusionsThe results indicate the need to verify the claim about the selective toxicity of betulin towards malignant cells and to conduct safety/toxicity tests before any potential therapeutic use of betulin in veterinary medicine.

Synthetisation of an affinity matrix (Procainamide Sepharose Cl-6b) for brain cholinesterase purification and separation source from Monopterus albus

Affinity chromatography for acetylcholinesterase; AChE namely Procainamide Sepharose CL-6B was synthesised through the coupling method between soluble procainamide hydrochloride immobilised by a cross-linked agarose size exclusion, sepharose CL-6B. 1, 4-butanediol diglycidyl ether plays a role in building up a productive and rigid connecting of a biospecific ligand (Procainamide hydrochloride) to an insoluble matrix (Sephacryl CL-6B). Local freshwater eel brain was extracted and centrifuge at high speed. The supernatant was collected, and seven different volumes were separately loaded on to the column for isocratic purification where 12 fractions were collected at the end of elution stage. This study shows 1000 μL of extractant; considered as the maximum volume to load onto the column. Lastly, a stepwise elution was performed with five different concentrations of NaCl, and each of 1 mL fraction was collected then assay for determination of enzyme activity and protein content. The data shows AChE was successfully purified with percentage recovery of 38 % after 21 purification fold. Kinetic study strengthens the data where the efficient coefficient ratio of ATCi was much higher compared to PTCi and BTCi at 3.03, 2.67 and 1.52 Vmax⋅Km −1, respectively, prove that the collected fraction predominantly contained with AChE, which is a targeted enzyme to be used as a sensitive biosensor to detect the presence of carbamate and organophosphate contamination in the environment.

The Xenopus spindle is as dense as the surrounding cytoplasm.

The mitotic spindle is a self-organizing molecular machine, where hundreds of different molecules continuously interact to maintain a dynamic steady state. While our understanding of key molecular players in spindle assembly is significant, it is still largely unknown how the spindle's material properties emerge from molecular interactions. Here, we use correlative fluorescence imaging and label-free three-dimensional optical diffraction tomography (ODT) to measure the Xenopus spindle's mass density distribution. While the spindle has been commonly referred to as a denser phase of the cytoplasm, we find that it has the same density as its surrounding, which makes it neutrally buoyant. Molecular perturbations suggest that spindle mass density can be modulated by tuning microtubule nucleation and dynamics. Together, ODT provides direct, unbiased, and quantitative information of the spindle's emergent physical properties-essential to advance predictive frameworks of spindle assembly and function.

A Comprehensive Workflow for the Analysis of Bio-Macromolecular Supplements: Case Study of 20 Whey Protein Products

The presence of bio-macromolecules as major ingredients is a primary factor in marketing many biologically derived macromolecular supplements. Workflows for analyzing these supplements for quality assurance, adulteration, and other supply-chain difficulties must include a qualitative assessment of small-molecule and macromolecular components; however, no such integrated protocol has been reported for these bio-macromolecular supplements. Twenty whey protein supplements were analyzed using an integrated workflow to identify protein content, protein adulteration, inorganic elemental content, and macromolecular and small-molecule profiles. Orthogonal analytical methods were employed, including NMR profiling, LC-DAD-QToF analysis of small-molecule components, ICP-MS analysis of inorganic elements, determination of total protein content by a Bradford assay, SDS-PAGE protein profiling, and bottom-up shotgun proteomic analysis using LC-MS-MS. All 20 supplements showed a reduced protein content compared to the claimed content but no evidence of adulteration with protein from an unclaimed source. Many supplements included unlabeled small-molecule additives (but nontoxic) and significant deviations in metal content, highlighting the importance of both macromolecular and small-molecule analysis in the comprehensive profiling of macromolecular supplements. An orthogonal, integrated workflow allowed the detection of crucial product characteristics that would have remained unidentified using traditional workflows involving either analysis of small-molecule nutritional supplements or protein analysis.

Terahertz spectroscopy combined with data dimensionality reduction algorithms for quantitative analysis of protein content in soybeans

Protein content in soybean is a key determinant of its nutritional and economic value. The paper investigated the feasibility of terahertz (THz) spectroscopy and dimensionality reduction algorithms for the determination of protein content in soybean. First of all, the THz sample spectrum was data processed by pre-processing or dimensionality reduction algorithms. Secondly, by calibration set, using partial least squares regression (PLSR), genetic algorithms-support vector regression (GA-SVR), grey wolf optimizer-support vector regression (GWO-SVR) and back propagation neural network (BPNN) were respectively used to model protein content determination. Afterwards, the model was validated by the prediction set. Ultimately, the BPNN model combined with linear discriminant analysis (LDA) for related coefficient of prediction set (Rp), root mean square error of prediction set (RMSEP), relative standard deviation (RSD), the time required for the operation was respectively 0.9677, 1.2467%, 3.3664%, and 53.51 s. The experimental results showed that the rapid and accurate quantitative determination of protein in soybean using THz spectroscopy is feasible after a suitable dimensionality reduction algorithm.

Good Old-Fashioned Protein Concentration Determination by Amino Acid Analysis.

Although a lot of new methods for protein concentration determination have been developed and established the last years, the amino acid analysis has still this relevance within proteomics for multiple reasons especially in the quantitative protein analysis. Amino acid analysis enables indirectly both the protein and peptide concentration determination which are essential for using the same amounts for comparative quantitative experiments. Moreover, the quantity and quality of synthetic peptides can be verified. The method itself is robust in comparison with colorimetric assays, especially when detergents or chaotropes are present in the sample buffer. Furthermore, it is highly sensitive. Nevertheless, amino acid analysis needs a certain experience to be set up and is time-consuming compared to other protein concentration determination techniques.