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This study aimed to investigate the possibility of extracting protein from chicken feathers. We conducted our research in a controlled laboratory environment, where we carefully washed feathers collected from white broiler chickens. The feathers were ground and hydrolyzed using a 1:10 ratio of 0.2 eq/L of standard sodium hydroxide (NaOH) solution and 28.5 % sodium hydrosulfite (NaHSO3) solutions. The hydrolyzed solution was further processed in a 90 °C water bath for 6 h using a rotor stirrer. After this, the solution was neutralized with 99 % acetic acid (CH3COOH) and filtered. The filtrate was dialyzed with distilled water in a cellophane membrane bag for 24 h. Following dialysis, we obtained two samples of the dried and ground protein. The first sample was subjected to physicochemical analysis, while the second sample was treated with 5 % H2O2 before analysis. Our analysis, conducted using the Kjeldahl and liquid chromatography methods, revealed that 68–78 % of proteins were synthesized. The study of free amino acids found that the highest indicator, which belongs to 38–40 % of cysteine, asparagine, glutamine, and tryptophan in the protein, failed because of alkaline hydrolysis. However, samples 1 and 2 of the protein containing 17 free amino acids were comparable, further validating our findings.

In this study, we examined whether the combustion method, which is simple and rapid, can be used as an alternative to the conventional Kjeldahl method for nitrogen determination of food additives in Japan's Specifications and Standards for Food Additives. We compared the nitrogen contents from the combustion method and Kjeldahl method using six food additives: Casein, Sodium Casein, Caramel III, Carob Bean Gum, Thaumatin, and Macrophomopsis Gum. As a result, the combustion method was validated as an alternative method to the Kjeldahl method without changing the current specifications. [ABSTRACT FROM AUTHOR]

The oil and carbohydrates contained in the Moringa oleifera seeds (MO) are two parameters that inhibit its coagulant potential. Oil extraction and protein purification are therefore necessary to improve its performance. The extraction process to recover the maximum oil yield was carried out using the solvent chloroform: ethanol C: E in a ratio (3:1). At a temperature of 100°C, the yield was higher than 44%. Purification was carried out by salting-in the protein with 1 M NaCl combined with ethanol precipitation and heat treatment. Analysis of the protein powder by the Kjeldahl method revealed 92% pure protein and 14% nitrogen; energy dispersive X-ray (EDX) analysis revealed high percentages of carbon (45%) and oxygen (39%). Scanning electron microscopy (SEM) showed a porous surface, and X-ray diffraction identified a crystalline phase of protein. The isoelectric point of Moringa oleifera protein (MOP) is in the range of pH 6.5–7.5 and its zeta potential varies between −19 mv and + 25.49 mV. It indicates a lower level of dispersion stability, implying a high capacity for protein agglomeration and flocculation. By reducing the zeta potential of water from −16 mv to −1.18 mv after treatment without modifying its pH, the Moringa protein has proven its ability to destabilise organic colloids. Moringa protein as a coagulat aid is effective for high turbidity wastewater with removal up to 86.78% and DOC removal up to 56.52%. The study reveals that coagulation with Moringa protein is a cost-effective alternative since it reduces the quantity of coagulant and time required for wastewater treatment. [ABSTRACT FROM AUTHOR]

The possibility of formulating nitrogen, phosphorus and potassium (NPK) biofertilizer from ashes of waste organic materials such as chicken feathers, bone and banana peels is investigated in this study by first subjecting the agricultural waste to 80-250 heat in a muffle furnace to produce ash. Kjeldatherm block digestion unit, UV spectrophotometer, and flame photometers, respectively helped in measuring the concentrations of N, P and K inherent in the fertilizer precursors as well as in 5 formulated blends (i.e., A, B, C, D & E). It was discovered that NPK in the single substrate and blends favorably compared with standard NPK 20:10:10 chemical fertilizer to some extent. Among single material fertilizer sources, feather ash with 0.179:1:0.134 NPK and bone ash with 0.009:1:0.021 NPK had the closest nutrient content with the standard, showing potential promise. On the other hand, Blend E is the same as the standard, followed by Blend A, B, D and C, which are hierarchically close in elemental composition to the standard. The choice of these biofertilizers is dependent on their nutrient compositions, the type of crops to be grown, and the soil mineral requirements. Most importantly, different NPK ratio organic fertilizers produced in this study can competitively be produced in a large scale to address huge costs associated with the NPK 20:10:10 standard commercial fertilizer. Blend E (NPK 20:10:10) can be formulated locally by farmers in rural areas easily using this particular agricultural residue or a host of other confirmed farm wastes.

The design of case studies for ideological and political education in courses is one of the important tasks of constructing a virtual teaching and research platform. This paper aims at the Kjeldahl method and carries out a diversified and integrated innovative case design of ideological and political education. Centering on the formation of students' core chemical literacy, the teaching content and links are designed from four modules: subject concept, scientific thinking, exploratory innovation, and attitudes and values, and integrated into the BOPPPS classroom-teaching model. This design effectively enhances the high-level, innovative, and challenging nature of the course, implicitly integrate ideological and political elements into the teaching process. This teaching design achieves the teaching goal of integrating knowledge transmission, ability cultivation, and value leadership. [ABSTRACT FROM AUTHOR]

Objective:The aim of this study is to determine the total protein and free amino acid content of Artemisia abrotanum L. in two different periods, the pre-blooming and blooming periods.Methods:The Dumas and Kjeldahl methods were applied comparatively to determine the total protein amount. In addition, after the sample was extracted with water:methanol (80:20) containing 0.1% formic acid, free amino acids were determined in liquid chromatography-mass spectrometer.Results:By using the Dumas method, the % nitrogen content was found to be 2.10 and 2.20, in the pre-blooming and blooming period samples. The results obtained by applying the Kjeldahl method are 2.16 and 2.25, respectively. The total protein content was calculated from the nitrogen content of the plant by using a nitrogen conversion factor of 6.25. The total free amino acid content in the pre-blooming and blooming period was found to 453.41 and 606.18 mg/100 g dried plant respectively.Conclusion:Since the total protein and free amino acid content of Artemisia abrotanum L. is higher during the blooming period, it should be preferred to be harvested during this period.

Objective: The aim of this study is to determine the total protein and free amino acid content of Artemisia abrotanum L. in two different periods, the pre-blooming and blooming periods. Methods: The Dumas and Kjeldahl methods were applied comparatively to determine the total protein amount. In addition, after the sample was extracted with water:methanol (80:20) containing 0.1% formic acid, free amino acids were determined in liquid chromatography-mass spectrometer. Results: By using the Dumas method, the % nitrogen content was found to be 2.10 and 2.20, in the pre-blooming and blooming period samples. The results obtained by applying the Kjeldahl method are 2.16 and 2.25, respectively. The total protein content was calculated from the nitrogen content of the plant by using a nitrogen conversion factor of 6.25. The total free amino acid content in the pre-blooming and blooming period was found to 453.41 and 606.18 mg/100 g dried plant respectively. Conclusion: Since the total protein and free amino acid content of Artemisia abrotanum L. is higher during the blooming period, it should be preferred to be harvested during this period. [ABSTRACT FROM AUTHOR]

Proteins are the second most essential macromolecules after nucleic acids. This article aimed at the comparative analysis of extraction methods and nutritional benefits of milk and dairy products. Proteins form the body mass and perform several crucial tasks that include acting as a catalyst and carrying out different metabolic reactions in the body. Furthermore, protein acts as a transporter, transmits nerve impulses, provides mechanical support or immune protection, and controls growth. Several sources of proteins are present, but milk holds an important place due to its biological activities. The considerable health benefits of milk and its products are due to proteins. Yoghurt and cheese have significant importance among milk products. Proteins of milk and its products can be extracted by pH adjustment through homogenisation, centrifugation, and deproteinisation. There are several techniques for identifying and quantifying milk and product proteins. The Kjeldahl and spectrophotometric methods are the most widely used methods for quantifying proteins in milk and its products. Furthermore, these techniques include electrophoresis and chromatographic methods, including native gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), urea-PAGE, capillary electrophoresis, and isoelectric focusing. A few are chromatographic methods like reverse-phase high-performance liquid chromatography (RP-HPLC), size exclusion chromatography, and ion-exchange chromatography. Each technique has its advantages as well as disadvantages. The selection of the process depends upon the type of protein. The extracted proteins from milk and its products have many health or therapeutic effects that exhibit antimicrobial, antiproliferative, antioxidant, antihypertensive, anticancer, antiviral, and immunomodulatory effects. Yoghurt has prime importance among milk products because of its therapeutic effects and more protein.

Proteins are the second most essential macromolecules after nucleic acids. This article aimed at the comparative analysis of extraction methods and nutritional benefits of milk and dairy products. Proteins form the body mass and perform several crucial tasks that include acting as a catalyst and carrying out different metabolic reactions in the body. Furthermore, protein acts as a transporter, transmits nerve impulses, provides mechanical support or immune protection, and controls growth. Several sources of proteins are present, but milk holds an important place due to its biological activities. The considerable health benefits of milk and its products are due to proteins. Yoghurt and cheese have significant importance among milk products. Proteins of milk and its products can be extracted by pH adjustment through homogenisation, centrifugation, and deproteinisation. There are several techniques for identifying and quantifying milk and product proteins. The Kjeldahl and spectrophotometric methods are the most widely used methods for quantifying proteins in milk and its products. Furthermore, these techniques include electrophoresis and chromatographic methods, including native gel electrophoresis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), urea-PAGE, capillary electrophoresis, and isoelectric focusing. A few are chromatographic methods like reverse-phase high-performance liquid chromatography (RP-HPLC), size exclusion chromatography, and ion-exchange chromatography. Each technique has its advantages as well as disadvantages. The selection of the process depends upon the type of protein. The extracted proteins from milk and its products have many health or therapeutic effects that exhibit antimicrobial, antiproliferative, antioxidant, antihypertensive, anticancer, antiviral, and immunomodulatory effects. Yoghurt has prime importance among milk products because of its therapeutic effects and more protein. [ABSTRACT FROM AUTHOR]

[Display omitted] • N quantification by NIRS in stem and root of B. juncea is achieved for first time. • Diverse germplasm collections allowed rapid and reliable NIRS calibration. • The developed NIRS equations displayed the best prediction performance. Brassica juncea depends heavily on nitrogen (N) fertilizers for growth and accumulation of seed protein. However, it is an inefficient mobilizer of applied N which leads to accumulation of excess N in the soil, posing environmental risks. Hence, it is imperative to systematically examine spatial–temporal pattern of crop N to efficiently manage N application. The Kjeldahl method is commonly used to estimate N status of crops but it is a destructive method that entails the use of perilous and expensive chemicals. Near-infrared reflectance spectroscopy (NIRS) offers a safe, accurate, and non-destructive alternative for large-scale screening of seed metabolites. Currently, no NIRS model exists to quickly estimate N content in shoots and roots from large germplasm sets in any rapeseed-mustard crop. Developing such a model is essential to breed for enhanced nitrogen use efficiency (NUE). We used 738 shoot and 346 root samples from a B. juncea diversity set to construct the NIRS models. A diverse range of genetic variation in N content was recorded in the stem (0.21–6.61%) and root (0.15–3.04%) tissues of the crop raised on two different N levels (N0 and N100). Modified partial least squares (MPLS) method was employed to establish a regression equation linking reference N values with spectral changes. The developed models exhibited strong associations with reference values, with RSQ values of 0.884 for stem and 0.645 for roots. Furthermore, external validation confirms the reliability of the developed models. The developed models have strong predictive capabilities for rapid and reliable N estimation in various tissues of B. juncea plants. [ABSTRACT FROM AUTHOR]

Modification of cotton with 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) has been studied extensively and can be operated by means of exhaustion, cold pad-batch, and continuous and pad-steam methods. Most of the research addresses the cationization of cotton fabric after bleaching or mercerization, or during the mercerization process. In our studies, we performed a comparison of the cationization effects on raw, enzymatic, and alkali-scoured cotton knitted fabrics applying CHPTAC according to the exhaustion method. The charge density of the cotton surface was measured using a Muetek Particle Charge Detector and a “back titration” method with polyelectrolytes. These results were compared with the nitrogen content in the samples, K/S measurements of tested samples after dyeing with anionic dye (Acid Yellow 194), and other physicochemical parameters such as weight loss, whiteness, and wettability.

The method based on the determination of the amount of active amino groups using o-Phthaldialdehyde (OPA method) can be applied in practice to assess accurately the degree of proteolysis in cheeses. The work establishes that the OPA method gives results that strictly correlate (R2 > 0.80, p < 0.01) with the results of assessing the degree of proteolysis by the Kjeldahl method. The results of the OPA method, expressed in the absorption intensity of the colored sample at a wavelength of 340 nm (OD340), can be converted to the content of soluble nitrogenous substances in cheese (WSN), using the calibration relationship between these indicators.The accuracy of the calibration relationship between WSN and OD340 can be increased (R2 > 0.91, p< 0.01) when using the OPA method in relation to a homogeneous group of cheeses produced by the same technology using the same type of milk clotting enzyme and lactic acid starter culture and having a similar shape of the molecular mass distribution of proteolysis products.The OPA method can be used to assess the content of proteolysis products, which form cheese flavor, in EMС. The results of assessing the degree of proteolysis by the OPA method (OD340) are proportional to both the total content of soluble nitrogen and the proportion of nitrogenous substances in it with a mass of less than 0.5 kDa, which make the greatest contribution to the formation of cheese flavor.The advantage of using the OPA method for assessing proteolysis in cheeses and EMC instead of the Kjeldahl method is a simpler measurement procedure and the possibility of studying more samples in less time.

Protein is one of the most abundant substances in plants and plays a major role in human health hence standardization of its analytical quantification method is essential. Various methods for protein quantification exist, such as Kjeldahl, Bradford, Lowry, bicinchoninic acid assay (BCA), Biuret, and total amino acid content methods. These methods are widely applied; however, the development of the rapid and efficient method is the need of the time hence the objective of this research was to analyze and comparing compare the modification of the Kjeldahl method for the determination of protein content in oilseed crops. The study was performed to improve the sample preparation method (processing and digestion) for protein quantification. Generally, the method initially requires homogenization of grains to a fine flour, which involves time and increases the risk of sample cross-contamination and partial loss of oil from the sample during grinding. Moreover at times, it becomes challenging to homogenize oil seeds to fine flour due to high oil content. However, in the present research, the whole grain was digested in place of grounded flour to accomplish quick protein quantification and compared it with the flour matrix of different oil seeds. To further reduce the digestion time and avoid frothing, we have used the modified digestion mixture. The developed method was statistically validated using analysis of variance (ANOVA), Pearson correlation reliability test, paired T-test, and different types of plot analysis. The validation of the sample preparation method in protein quantification demonstrated non-significant differences that the protein content from whole grain of all the five oilseed crops shows 100% non-significant results compared with the flour matrix in both the digestion mixtures. The developed novel method could be used to prepare the sample for protein analysis and reduces the overall analysis time while ensuring the accuracy of the results.

For long-flame coal, the content of the basic elements in the organic mass (carbon, hydrogen, nitrogen, sulfur, and oxygen) is determined. Standard chemical methods are employed: accelerated determination of carbon and hydrogen; the Kjeldahl method for nitrogen; and the Eschka method for total sulfur. Their content is also determined by an instrumental method. The results are subjected to statistical analysis; the data from chemical and instrumental analysis are compared. For all the elements, the discrepancy is insignificant; the dispersion is uniform; and the results obtained by the methods may be regarded as equally accurate. On that basis, chemical coal analysis may be replaced by instrumental analysis, with considerable savings of time. [ABSTRACT FROM AUTHOR]

BACKGROUND By measuring the nitrogen content in plant fruits, the growth status of plants can be grasped and important information for improving the yield of high-quality fruits can be provided. At present, the traditional Kjeldahl method is used to determine nitrogen in plant fruits. The main steps are digestion, distillation and titration. The digestion time of traditional method is 90 minutes, and the titration and distillation time is 10-20 minutes. The determination process is complicated and produces errors, which is not suitable for the analysis of large amounts of plant fruits. OBJECTIVES To shorten the analysis and determination time of total nitrogen in plant fruit samples, improve work efficiency, avoid artificial errors, and solve the problems of sample splashing and white smoke escaping during digestion. METHODS A graphite digestion instrument was used for digestion. Concentrated sulfuric acid and a catalyst were added, the reflux plug was capped, and an automatic nitrogen determination instrument was used for analysis. RESULTS The sample did not splash and the white smoke did not escape. The digestion time was 50 minutes and the distillation time was 3 minutes. The reagent consumption was reduced by 2mL. The relative error and relative standard deviation were less than 5%. CONCLUSIONS The established method meets the needs of the laboratory to quickly and accurately detect total nitrogen in large amounts of plant samples. It has been applied in the detailed survey project of the China geological survey bidding project and the detailed investigation of the soil pollution status of agricultural land in Hebei Province.

Background and Objectives: Melamine is an organic nitrogen used as an adulterant to increase nitrogen and protein contents in milks. Enzyme-linked immunosorbent assay has verified as a good alternative for rapid screening of melamine and other food additives instead of the laborious chromatography techniques. Materials and Methods: In the present study, MaxSignal enzyme-linked immunosorbent assay kit was used to screen melamine in 30 samples, including milks, infant formulas, chocolates, tea whiteners and pet foods. The kit was based on a competitive colorimetric enzyme-linked immunosorbent assay. Results: Melamine was detected in the range of 0.05-0.69 ppm in infant formula/milk powder samples and 0.001-0.042 ppm in liquid milk samples, which were under the set limits of Codex Alimentarius, 2012. Codex Alimentarius Commission adopted a maximum melamine level of 1 ppm for powdered infant formulas and of 2.5 ppm for other foods and animal foods. The commission has now set a maximum limit of 0.15 ppm for melamine in liquid milks. Further protein analyses of milk and infant formula samples were also carried out to verify the presence of melamine. Conclusions: It has been seen that enzyme-linked immunosorbent assay could effectively be used as a screening tool for detecting melamine in a wide range of food samples. Whereas, complementary techniques such as high-performance liquid chromatography, gas chromatography/mass spectrometry can be adopted as verification methods for regulatory compliance. [ABSTRACT FROM AUTHOR]

Abstract Background Cassia sophera Linn is a medicinally important plant belonging to the family of Caesalpiniaceae. The whole part of the plant is used as traditional folk medicine and is reported to possess analgesic, anticonvulsant, antioxidant, anti-inflammatory, hepatoprotective, and antiasthmatic activity. The present communication attempt is to evaluate fatty acids from different parts of the plant by GC-MS spectrophotometer and total protein content by the Kjeldahl method and to quantify some active constituents, i.e., alkaloid, saponin, and flavonoid. Results From fatty acid compositions of the petroleum ether extract of leaves, stems, flowers, and seeds of this plant grown in Bangladesh, 22 compounds from leaves, 8 compounds from stems, 9 compounds from flowers, and 12 compounds from seeds were identified. The main fatty acid was arachidic acid (38.66%) from leaves. Linoleic acid (40.12% and 42.40%) was found mainly from stems and seeds, whereas from flowers, it was docosadienoic acid (27.14%). Conclusion The findings from the present study showed that the protein content for seeds has higher value (19.20%) than other parts of the plant. Also the present investigation showed that different parts of the plant contain phytochemicals in appreciable quantities in the form of flavonoids, alkaloids, and saponins. The flavonoid and alkaloid content of leaves showed higher value. But the stem part showed higher saponin content than other parts of the plant.

Copyright of Journal of Food & Dairy Sciences is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Protein scarcity is the most vital cause of long-lasting diseases and even untimely deaths in some developing nations. The application of protein in food is advantageous from the point of view of non-toxicity, biocompatibility, and dietary benefits. This study aimed to determine the protein contents of the sprouts of Vigna radiates (mung beans), Lens culinaris (lentils), and Cicer arietinum (chickpeas) using the Kjeldahl and Lowry methods. The results obtained from the Kjeldahl method identified protein concentrations of 2.54, 2.63, and 2.19%, whereas the Lowry method results identified protein concentrations of 2.96%, 4.10%, and 1.6% in mung beans, lentils, and chickpeas, respectively. In both the methods, lentils were found to have the highest amount of protein followed by mung beans and chickpeas. Both the Kjeldahl and Lowry methods demonstrated good protein values and low variation in the protein amount in the analyzed samples. Furthermore, the methods had greater sensitivity and comparable experimental variability. The outcomes revealed that assays can be applied for protein analysis in legumes. In the context of a lack of suitable standard procedures for evaluating legumes’ compositions, the present study is suitable for food control laboratories. In addition, the studied samples represent a significant source of protein and can be used to fulfil the daily requirements for protein intake and other food applications.

Being attractive for insects, non-genetically modified rapeseed is valuable for maintaining environmental biodiversity. Primarily, the rapeseed is an important industrial crop which is used for production of vegetable oil. Oil extraction from rapeseeds results in the generation of substantial amounts of rapeseed meal which is used either as a protein rich feed additive or as a source for preparation of protein containing ingredients for food industry. Both applications require frequent evaluation of protein content. Although Kjeldahl method is considered standard, it is not appropriate for routine evaluation of protein content in protein extracts. The aim of the study was to evaluate suitability of biuret and Bradford methods for protein quantification in rapeseed meal extracts. After consecutive triple extraction of proteins with water, 5% NaCl, 70% ethyl alcohol and 0.1 N NaOH, protein evaluation of each albumin, globulin, prolamin and glutelin extraction aliquot demonstrated overall lower protein content by Bradford method compared to biuret method. The most pronounced differences in protein content were observed with prolamin fraction where three fold higher protein concentrations in each extraction aliquot was observed when biuret method was applied for the evaluation. Comparative quantification of the total protein of each of the four fractions followed a similar trend of lower protein content evaluation by Bradford method. Overall results indicated biuret method as more suitable for protein quantification in rapeseed meal extracts which was confirmed by comparison with data obtained by Kjeldahl method.

In the summer of 2005 and 2010, moss samples were collected from 72 sampling sites evenly distributed all over the territory of Republic of North Macedonia. Kjeldahl method was used to determine the nitrogen content in the samples. Descriptive statistics and distribution maps were prepared. Data obtained from these two surveys were compared, and additional comparison was done with data obtained from similar studies in the South-Eastern European countries and Finland as a clean area. The median value of N content in the samples collected in 2005 is 1.21%, varies from 0.70% to 1.54%, while the content of N in samples collected in 2010 ranges between 0.68% and 1.75% with the median value of 1.06%. High contents of N were found in the Northern and Central parts of the country mainly as a result of agricultural activities, industry and traffic. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Kjeldahl and combustion (Dumas) methods are the main methods used to determine total nitrogen (TKN and TCN) content in agriculture biomass. However, the results obtained using these methods differ because of differences in their underlying principles. Herein, we used these two methods to determine the total nitrogen content in 1 179 crop residues (rice straw, wheat straw, corn stover, rape stalk, cotton stalk) from China, and systematically analyzed and compared in total nitrogen content and their distributions in the collected crop residues by different types with these two methods. Seven common distributions (Normal, Lognormal, Gamma, Weibull, Exponential, Laplace, Lorentz) were used to determine the data distribution types of TKN and TCN in different crop residues. The correlation between the two methods was explored using ordinary least squares regression (OLS), orthogonal regression (Orth), and least median square regression (LMS). Finally, the research reviewed the correlation between different biomass (food, flowers, grass, soil, crop, crop residues, sewage sludge and animal manure, etc.) results of two methods for measuring nitrogen content. The results showed: The distributions of nitrogen content were non-normal distributions in different crop residues. The total TKN and TCN contents were the same distributions in rice straw, wheat straw, rape stalk and total crop residues which approximately followed Lognormal, Gamma, Lognormal and Lognormal respectively. The median method was recommended for data statistics, and results from low to high were: 1) TKN: wheat straw (5.66 ± 1.07 g/kg), rape stalk (7.10 ± 1.87 g/kg), rice straw (8.20 ± 1.42 g/kg), corn stover (8.82 ± 2.23 g/kg), cotton stalk (10.42 ± 1.45 g/kg); 2) TCN: wheat straw (6.17 ± 1.17 g/kg), rape stalk (8.50 ± 2.45 g/kg), rice straw (8.59 ± 1.45 g/kg), corn stover (10.10 ± 1.91 g/kg), cotton stalk (11.75 ± 1.48 g/kg). It was found that TKN was significantly lower than TCN in all types of crop residues (P < 0.05). TKN and TCN values were also significantly different among wheat straw, cotton stalk and other crop residues (P < 0.05). Although the fitting efficiencies of OLS, Orth and LMS were the same on the determination coefficient (R2) scale, the fitting results were different. LMS was recommended because it reduced the effect of outliers compared with three methods, observed from kernel density – scatter plots. Five types of crop residues and the total had different fitting result between TKN and TCN. The correlation between TKN and TCN for total crop residues was quantified as the LMS equation. In addition, there was a gap of the linear relationships between TKN and TCN in different types of biomass. The slope of plant biomass was generally lower than that of animal manure, whose potential reason was different forms and contents of nitrogen in different biomass (ammonium nitrogen, nitrate nitrogen, nitrite nitrogen, heterocyclic nitrogen, and nucleic acid nitrogen, etc.). The results may provide extensive and reliable data for reference from large sample size, and methods support for the scientific utilization of nitrogen in crop residues. [ABSTRACT FROM AUTHOR]

BACKGROUND: By measuring the nitrogen content in plant fruits, the growth status of plants can be grasped and important information for improving the yield of high-quality fruits can be provided. At present, the traditional Kjeldahl method is used to determine nitrogen in plant fruits. The main steps are digestion, distillation and titration. The digestion time of traditional method is 90 minutes, and the titration and distillation time is 10-20 minutes. The determination process is complicated and produces errors, which is not suitable for the analysis of large amounts of plant fruits. OBJECTIVES: To shorten the analysis and determination time of total nitrogen in plant fruit samples, improve work efficiency, avoid artificial errors, and solve the problems of sample splashing and white smoke escaping during digestion. METHODS: A graphite digestion instrument was used for digestion. Concentrated sulfuric acid and a catalyst were added, the reflux plug was capped, and an automatic nitrogen determination instrument was used for analysis. RESULTS: The sample did not splash and the white smoke did not escape. The digestion time was 50 minutes and the distillation time was 3 minutes. The reagent consumption was reduced by 2mL. The relative error and relative standard deviation were less than 5%. CONCLUSIONS: The established method meets the needs of the laboratory to quickly and accurately detect total nitrogen in large amounts of plant samples. It has been applied in the detailed survey project of the China geological survey bidding project and the detailed investigation of the soil pollution status of agricultural land in Hebei Province. [ABSTRACT FROM AUTHOR]

Glanders is a contagious and fatal disease of horses, donkeys, and mules, caused by infection with the bacterium Burkholderia mallei. The pathogen causes nodules and ulcerations in the upper respiratory tract and lungs. Glanders is transmissible to humans by direct contact with diseased animals or with infected or contaminated material. In the untreated acute disease, the mortality rate can reach 95% within 3 weeks Malein PPD - the diagnostic product contain max 2mg/ml Burkholderia mallei. The amount of protein in the biological product "Malein PPD" is measured as nitrogen from protein molecule, applying the Kjeldahl (method determination of nitrogen by sulphuric acid digestion). The validation study aims to demonstrate the determination of the protein of the Malein PPD, by sulphuric acid digestion, it is an appropriate analytical method, reproducible and meets the quality requirements of diagnostic reagents. The paper establishes the performance characteristics of the method considered and identify the factors that influence these characteristics. The method for determining the concentration of protein, by the Kjeldahl method is considered valid if the results obtained for each validation parameter are within the admissibility criteria.The validation procedure includes details on protocol working to determine the protein of the Malein PPD, validation criteria, experimental results, mathematical calculations.

The physicochemical properties of the novel original anxiolytic GML-1 drug substance were studied, analytical techniques for it were developed, and its main pharmacopoeial quality parameters were determined using IR spectroscopy, UV spectrophotometry, HPLC, and the Kjeldahl method. [ABSTRACT FROM AUTHOR]

The majority of dry pet food currently on the market is produced using fresh meats (FMs) and especially meat meals (MMs) as the main protein source. The transport and storage conditions of the raw materials, together with thermal and mechanical treatments in the case of MMs, may result in undesirable alterations of food products and their protein content. This study was conducted to analyze the protein component of three different kinds of raw materials used for dry pet food production, i.e., chicken, pork, and salmon. The quantitative analysis of the protein component was determined using the traditional Kjeldahl method and near-infrared (NIR) spectroscopy, and an alternative method, i.e., the Bradford assay, while the qualitative analysis was performed through SDS-PAGE, followed by Coomassie Blue staining. The amino acid (AA) profile was also evaluated by quadrupole time-of-flight liquid chromatography/mass spectrometry (Q-TOF LC/MS). In addition, the digestibility was tested through in vitro gastric and small intestine digestion simulation. Statistical analysis was performed by the Student’s t-test, and data are reported as mean ± SEM, n = 10 (p < 0.05). The results showed that the MMs are lower in quality compared to FMs, both in terms of protein bioavailability and digestibility, having a lower soluble protein (SP) content (chicken MM = 8.6 g SP/100 g dry sample; pork MM = 6.2 g SP/100 g dry sample; salmon MM = 7.9 g SP/100 g dry sample) compared to FMs (chicken FM = 14.6 g SP/100 g dry sample; pork FM = 15.1 g SP/100 g dry sample; salmon FM = 13.7 g SP/100 g dry sample). FMs appear, therefore, to be higher-quality ingredients for pet food production. Moreover, the Bradford assay proved to be a quick and simple method to better estimate protein bioavailability in the raw materials used for dry pet food production, thanks to its correlation with the in vitro digestibility.

The deterioration of natural resources in agricultural activities, has motivated the search for new alternatives to enrich the soil with macro and micro nutrients sustainably, for the benefit of future generations, just as you think about the conservation and maintenance of water, avoiding eutrophication problems by the accumulation of fertilizers (nitrates and nitrites) leached and deposited in natural sources, for this purpose they have been measured several agro ecological options that provide proper nutrition and a delicate ecological balance; in this investigation at field level in maize cultivation and different states it applied dose of azolla as a natural source of nitrogen to enrich the soil in the canton Cevallos, Tungurahua province. Anabaena floors of the town, based on the state of azolla and the level established for such preparation, the states of azolla. Six mixtures were prepared substrates azolla studied were: Dry A1 and A2 in the fresh state; the doses were established in relation to the volume of azolla against soil volume used: (0.5: 1) (0.75: 1) and (1: 1). The data collected were plant height and percentage of nitrogen in dry matter at 15, 30, 60 and 90 days. All this in order to establish the amount of nitrogen contributed by azolla as biofertilizer in growing corn. The best results were presented at the A1D3 (azolla dry-Dose 1: 1) treatment given plant height 15.02 cm at 15 days, 35.88 cm 30 days, 53.22 cm 60 66.12 days and 90 days; to 0.54% nitrogen percentage at 15 days, 0.90% at 30 days, 1.68% at 60 days and 2.08% after 90 days. In conclusion, the use of Azolla as a bio-fertilizer rich in nitrogen is feasible, as has been demonstrated in this research that the corn plant benefits from the contribution of this material, improving sustainable agricultural practices. It is recommended to expand this research in the same crop or other commercially important crops until the end of its production cycle, to report the results of these.

In this work, the nitrogen conversion factor in eggs Coturnix coturnix L. (Japanese quail), was determined. 850 eggs of Coturnix coturnix L. were analyzed, the maximum precipitation and extraction pH was determined by the Kjeldahl method, at different acidic and basic pH. The protein conversion factors found for white and yolk were 6.33 and 6.30 respectively. These results justify its consumption compared to other food sources, high in protein in the human diet. [ABSTRACT FROM AUTHOR]

This work is oriented to elaborate pasta enriched with micro-encapsulated anchovy protein (Engraulis ringens), with the idea of innovate nutritiously with an already existing product, evaluating the acceptability of consumers at three different protein concentrations (5%, 10% and 15%), using quality parameters of a product in terms of taste, color, aroma and texture, and under a hedonic scale. The Kjeldahl (1883) method was used for the determination of proteins and the Duncan (1951) test for the sensory analysis. The final goal is to determine how the preferences of the consumers vary when adding this type of "extra nutritional contributions" in the pastas. In the sensory analysis, a panel of 24 people participated, concluding that the trial with 5% of anchovy protein added was the best evaluated or the one with greater acceptance: its attributes were the closest to the elaboration of an ideal paste and its rejection was lower compared to the other two trials. [ABSTRACT FROM AUTHOR]

The nitrogen content in winter wheat from various crops grown organically or conventionally was determined by instrumental photon activation analysis. The method utilizes measurement of the annihilation gamma line at 511 keV from the short-lived photoactivation product 13N, corrected for interference contributions from other positron emitting nuclides. Results compared well to those obtained by the Kjeldahl method. A positive impact of conventional agriculture on higher crude protein content in grain was found. Analysis of whole kernels and their germination and growth after irradiation were also tested. [ABSTRACT FROM AUTHOR]

Remote sensing is the method of acquiring and recording of information about an object without the direct contact. Hyper spectral imaging is the technique to collect and process the information in a narrow and continuous spectral band that was obtained over the electromagnetic spectrum. Hyper spectral satellite data of wheat crop was taken for this study from Airborne Visible Infrared Imaging Spectrometer (AVIRIS) sensor with appropriate longitudes and latitudes from earth explorer site. The vegetation indices used for this study are Normalized Difference Vegetation Index (NDVI) and Vegetation Index Green (VIG). The estimation of these indices has been done on the first derivative of the reflectance obtained from the field. The Protein and Nitrogen values were calculated using satellite data and these values were correlated with experimental analysis using Kjeldahl method. [ABSTRACT FROM AUTHOR]