The evaluation of the protein quality of soybean products by short-term bioassays in adult human subjects

The protein quality of soybean products was determined by a short nitrogen balance index (NBI) assay with 15 adult males. In the first study, a textured vegetable protein (TVP) was tested alone and in a 50:50 mixture with ground beef. Protein was fed at 0.2, 0.4 and 0.6 g/kg body weight/day with a constant energy intake. The protein quality (NBI) was then calculated by regression analysis of nitrogen absorbed to nitrogen retained. The NBI of beef (0.91) and of the mixture (0.87) were similar; however, the protein quality of TVP fed alone (0.77) was significantly lower. In the second study, carried out at an intake level of 0.6 g protein/kg/day, supplementation of the TVP with 0.5% DL-methionine improved nitrogen retention, but the values obtained did not reach statistical significance. Meat alone, or the 50:50 mixture fed at an equivalent protein intake, gave similar nitrogen retention values, both of which differed significantly from those obtained when TVP was fed alone. The addition of wheat gluten, used as a source of methionine, to the TVP: meat mixture, produced nitrogen retention values below those obtained with the 50:50 beef:TVP blend. Ten men participated in another trial, this time to determine the protein quality of a soybean protein isolate, which gave an NBI value of 0.91, indicating the high quality of the protein tested. Comparison of the protein quality values obtained by the short-term NBI assay revealed these were essentially the same as those reported by other workers using the conventional long-term approach.     

Effect of animal protein supplementation and energy on the protein quality of diets based on rice and beans in adult males

Four short nitrogen balance index studies were carried out in adult subjects to evaluate the biological quality of a mixture based on rice and beans, and also to measure the effect of animal protein and/or energy supplementation on the nutritive value of the mixture. In the first study, rice supplied 60% and beans, 40% of the protein's diet, which was administered at an energy level of 45.5 kcal/kg/day of metabolizable energy. A regression coefficient of 0.76 +/- 0.11 was found between ingested nitrogen and nitrogen balance, and a value for nitrogen maintenance of 96.2 +/- 13.7 mg/kg/day. When this same diet was administered in the second study at a 51.2 kcal/kg/day of metabolizable energy, the regression coefficient was 0.80 +/- 0.13, and that of nitrogen for maintenance, 90.1 +/- 8.7 mg/kg/day, without differences being significant (P less than 0.05) for any of the two measures. In the third study, 10% of the mixture's protein was substituted by milk protein, and given at a level of 45.2 kcal/kg/day of metabolizable energy. In this case, the regression coefficient found was 0.96 +/- 0.08, and that of nitrogen for maintenance, 78.6 +/- 10.2 mg/kg/day. These values do differ significantly (P less than 0.05) from those found in the two previous studies. When the diet of the third study was administered to the same subjects at a level of 48.9 kcal/kg/day of metabolizable energy, the regression coefficient of the equation was 0.86 +/- 0.17, and that for maintenance nitrogen, 82.4 +/- 10.2 mg/kg/day. These values are statistically equal to those found in the third study and do differ significantly from those of the first two studies. Information indicates that the supplementary effect of protein and milk occurs mainly at the digestive level. It is therefore concluded that when rice and beans are consumed jointly, in the adequate proportions, they constitute an excellent-quality food for adult humans.     

Biological vs. Chemical evaluation of toxicity and protein quality of cottonseed meals

Summary 1. Toxicological evaluation of 68 cottonseed meals in rats failed to show a direct correlation between their toxicity and their free, total or combined gossypol content. The common practice of considering the free gossypol content of cottonseed meal as a yardstick for its toxicity is questioned. 2. There was poor correlation between biologically evaluated protein quality of cottonseed meals and their nitrogen solubility in 0.02N sodium hydroxide. Application of this chemical test for indicating the protein quality of cottonseed meals is likewise questioned on the basis of existing evidence. Presented at the Conference on Cottonseed Meal Quality as Related to Processing, Southern Regional Research Laboratory, New Orleans, La., January 24–25, 1955.     

Chemical composition and biological quality of defatted hazelnut flour

The results of the chemical composition and biological quality of deffated hazel nut flour are shown. The samples analyzed contained significant amounts of proteins (19%) comparable to legume flour, higher than cereals and lower than deffated oleaginous flours. The oil extracted from the seed was analyzed and the average results obtained were the following: Refraction index, 1.47; saponification No. 184.8; iodine No. 85.0. The average composition of the fatty acids obtained by gas liquid chromatography was: Palmitic acid 2.3% Palmitoleic acid 37.0% Stearic acid 0.5% Oleic acid 39.5% Linoleic acid 6.9% Linolenic acid 1.1% Eicosanoic acid 2.3% Eicosaenoic acid 4.6% Docosenoic acid 3.4% Tetraeicosanoic acid 0.3% These results indicate a good-quality oil due to the low content of linolenic acid. The nutritive value of the deffated meal measured in the rats gave a net protein ratio (NPR) of 3.58, lower than the corresponding casein value (4.10). The true protein digestibility measured in the rat gave a value of 7.3%, compared to 95% for casein. The amounts of iron and phosphorous are comparatively lower than those reported for rape-seed meal and sunflower meal.     

Chemical composition and nutritive value of the protein of Amaranthus quintensis

An account is given of some considerations concerning the chemical recognition and evaluation by biological methods of the quality of the flour obtained from Amaranthus quitensis seeds, submitted to grinding and sifting. The protein content of the flour (21.70g/100g) can be considered as very important, as well as that of the available lysine (5.20g/16gN). The calcium content was also remarkable (500mg/100g), and the starch ratio reached 45.00g/100g. The amount of nitrates found was 20.00mg/100g, which is an acceptable limit. The research for organic nitro compounds was negative. As for the biologic quality of the protein, the experiments revealed that it has quite an acceptable availability, as demonstrated by the following values: NPU = 42.50 +/- 6.10, D = 68.50 +/- 5.30, VB = 62, NPR = 2.10 +/- 1.80 and RNPR = 42.     

A new alternative for estimating recommendations of protein intake in humans. Protein requirements of an adult population fed with a diet based on rice and beans

This paper proposes a new approach to estimate the protein needs of a population; recommendations are also made on the protein intake of adults fed diets based on rice and beans. For this purpose, the nitrogen balance data previously reported for 40 adult human subjects who had participated in 160 nitrogen balance periods fed diets based on rice and beans, with and without animal protein and/or energy supplementation were used. The proposed method is based on the curvilinear response between nitrogen intake and its nitrogen balance. The second degree equation describing the relationship between nitrogen balance and intake is calculated. Using the mathematical concept of the first and second derivatives, the point of inflexion is obtained, and interpreted as that condition wherein the individual utilizes with maximum efficacy the ingested nitrogen; nitrogen ingestion, which corresponds to that point, is therefore taken as the dietary nitrogen recommendation for the individual. When the values obtained by means of the quadratic equation are compared to those obtained by the traditional linear equation, values were found to be statistically equal (p less than 0.05) for both calculation methods. The recommended protein intake of an adult population fed a diet based on rice and beans was 0.80 and 0.77 g/kg/day for the quadratic approach, and for the conventional method, respectively. When this diet was supplemented with 10% milk protein and with the same energy level, the calculated values were 0.64 and 0.71 g protein/kg/day for both methods, in this same order. The essential amino acid intake and absorption values were also calculated from the protein levels recommended by both methods to be in nitrogen balance, from a diet based on rice and beans. Findings revealed, in all cases, that the intakes of each and all essential amino acids met those levels indicated by FAO/WHO, with the exception of isoleucine and the sulphur-containing amino acids, which apparently limit the quality of the diet.     

Uptake and balance of labelled fertilizer nitrogen by potatoes

Potatoes have a shallow rooting system. This can seriously affect the efficient use of fertilizer N. During two consecutive years, 1985 and 1986, a study was conducted on a commercial field to investigate the uptake of labelled N by potatoes under the recommended N rate and existing agricultural practices. The fertilizer efficiency, fertilizer distribution within the plant and soil and the total fertilizer balance were made using¹⁵NH₄ ¹⁵NO₃ 3.63 At. %¹⁵N excess. The recovery of the applied N-fertilizer in the whole plant was 25 and 56% for 1985 and 1986, respectively. The % Ndff and % Ndfs ranged between 30–40% and 60–70% respectively in both years. An important amount of fertilizer N was left in the soil after harvest. It reached 44 and 34% in 1985 and 1986, respectively.The total balance of the applied fertilizer N showed that up to 31 and 10% of the fertilizer N was lost during 1985 and 1986, respectively. The differences between the two growing seasons were mainly related to the method and timing of fertilizer N application and to the amount of rainfall.     

Chemical composition, starch digestibility and antioxidant capacity of tortilla made with a blend of quality protein maize and black bean

Tortilla and beans are the basic components in the diet of people in the urban and rural areas of Mexico. Quality protein maize is suggested for tortilla preparation because it presents an increase in lysine and tryptophan levels. Beans contain important amounts of dietary fiber. The objective of this study was to prepare tortilla with bean and assesses the chemical composition, starch digestibility and antioxidant capacity using a quality protein maize variety. Tortilla with bean had higher protein, ash, dietary fiber and resistant starch content, and lower digestible starch than control tortilla. The hydrolysis rate (60 to 50%) and the predicted glycemic index (88 to 80) of tortilla decreased with the addition of bean in the blend. Extractable polyphenols and proanthocyanidins were higher in the tortilla with bean than control tortilla. This pattern produced higher antioxidant capacity of tortilla with bean (17.6 μmol Trolox eq/g) than control tortilla (7.8 μmol Trolox eq/g). The addition of bean to tortilla modified the starch digestibility and antioxidant characteristics of tortilla, obtaining a product with nutraceutical characteristics.     

Identification of the composition of the raw material in surgical sutures in evaluation of their quality

A method for identifying nonabsorbable surgical sutures (SS) for inclusion in GOST R 543005-2008 “Surgical Suture Materials. General Specifications. Testing Methods” was developed as a result of analyzing published data and experiments with domestic and foreign suture materials. In addition to determining the basic functional indexes, it is also necessary to identify the composition of the raw materials of SS in different types of tests — technical acceptance, identification, certification, etc., for supplying the country’s medical institutions with high-quality suture materials.     

The chemical composition and protein quality of amaranth grain germ plasm in Guatemala

The present research was carried out for the purpose of collecting part of the germ plasm of grain amaranth in Guatemala, as well as to evaluate it in terms of yield, chemical composition and nutritive value. A total of 27 Guatemalan selections, one from Mexico and seven from Peru were planted in June 1982 in 7.5 m2 experimental plots replicated four times. The harvest seed was utilized for analysis of protein, ether extract, crude fiber, tannin content and trypsin inhibitors, as well as for NPR assays. A group of five pooled samples was made based on protein content for amino acid analyses; 10 samples were selected for a second NPR and protein digestibility assay. A preliminary assay on amino acid supplementation of raw grain flour is also reported. The selections were significantly different in grain yield. In general, selections which flowered at a short height and were harvested also at short height, tended to yield more seed. Findings revealed a negative relationship between plant height and grain yield, but a positive relationship between plant height and dry vegetable residue. Protein content of the grain averaged 15.0% with values ranging from 12.8 to 17.4%. Fat content varied from 5.6 to 10.6% with an average of 8.4%. Amaranth grain with a higher protein content contained greater amounts of amino acids on a weight basis, but when these were expressed on a nitrogen basis, differences disappeared. Based on the FAO/WHO amino acid reference pattern, grain amaranth protein was deficient in sulfur amino acids. Although the biological trial corroborated this deficiency, more studies should be undertaken. The NPR values of the samples from Peru averaged 2.30, the one from Mexico 2.04 and those from Guatemala, 2.36. Protein digestibility was 80, 82 and 74%, respectively. The data suggest that there is sufficient variability to select materials of a higher chemical composition, nutritive value, and yield.     

Plasma cholesteryl ester transfer protein and lipoprotein levels during treatment of growth hormone-deficient adult humans

The incidence of atherosclerosis is increased in growth hormone (GH) deficient-individuals. Nonetheless, the antiatherogenic benefits of GH replacement therapy remain uncertain. In this study the effect of human recombinant growth hormone (hrGH) replacement therapy administered to GH-deficient adults on the plasma cholesteryl ester transfer protein (CETP) concentration and activity was analyzed. These findings were related to changes in the concentrations of the plasma lipoproteins. The hrGH was administered for 12 mon to human GH-deficient patients (n=13; 8 men, 5 women). During the study plasma lipoproteins were separated by ultracentrifugation, and plasma cholesterol esterification rate (CER), endogenous CETP activity, and CETP concentration were measured. GH replacement therapy transiently (at 3 mon) lowered plasma concentration of CETP and low density lipoprotein-cholesterol (LDL-C) and raised total triglycerides. Furthermore, hrGH permanently increased both the plasma lipoprotein(a) [Lp(a)] concentration, which is known as atherogenic, and the proportion of cholesteryl ester in the high density lipoprotein₂ (HDL₂) particles, which is potentially atheroprotective. The simultaneous decrease of the plasma CETP and LDL-C concentrations elicited by hrGH indicated a close relationship between LDL metabolism and the regulation of the CETP gene expression. Endogenous CETP activity and the CER were not modified because these parameters are regulated in opposite ways by plasma levels of triglycerides; that is, CER increased and CETP decreased.     

A new approach to genetic alteration of soybean protein composition and quality

Although soybeans produce high-quality meal, modern animal and fish production systems often require synthetic essential amino acid supplements to fortify feed rations. However, biotechnology may enable development of soybeans with naturally adequate levels of certain essential amino acids for advanced feed formulations. One approach involves genetic manipulation of glycinin (11S) and β-conglycinin (7S) contents, the principal components of soybean storage proteins. Because 11S contains more cysteine and methionine than 7S protein, a higher 11S:7S ratio could lead to beneficial changes in the nutritional quality of soybean meal. Although genotypic variation for 11S:7S may be low among soybean [Glycine max (L.) Merr.] germplasm, ratios ranging from 1.7–4.9 were observed among accessions of the wild ancestor of cultivated soybean (Glycine soja Sieb, and Zucc.). Thus, wild soybean germplasm was evaluated as a potential source of genes that govern protein synthesis that may have been lost during the domestication of G. max. Change in the amount of 11S protein accounts for a significant portion of the genotypic variation in protein concentration and composition among wild soybeans. Strong positive correlation exists between the 11S:7S ratio and methionine or cysteine concentration of total protein. Moderate positive associations were found for threonine or tyrosine. A moderate negative correlation was found between lysine and 11S:7S. No association was found for leucine and phenylalanine or for total essential amino acid concentration. Based on these data, G. soja may contain a different complement of genes that influence expression of 11S and 7S proteins than G. max germplasm. Thus, through interspecific hybridization, wild soybeans may be a useful genetic resource for the further improvement of protein quality in cultivated soybeans.     

混煤质量评价方法的研究与应用

建立在传统的单种煤基础上的配煤炼焦理论难以适应现代煤源状况,必须依据中国煤炭分类的原则和商品煤反射率分布图来确定炼焦煤的黏结性和结焦性,鉴别其混煤的程度,正确评价混煤的性质及其在炼焦配煤中的作用,通过小焦炉炼焦,制定合适的配煤方案。试验表明,合理利用混煤配煤炼焦,可以消除混煤对炼焦配煤的不利因素,生产出高质量的焦炭,满足高炉生产的要求。     

Effects of different thermal treatments and storage on the proximate composition and protein quality in canned tuna

The purpose of this project was to study the modifications in nutrient composition, amino acid content, and protein quality of white tuna preserves after each of the thermal treatments involved in the canning process. Also the influence that a three years storage period at room temperature has on the nutritional quality of canned tuna was studied. The biological assays used for the study of the protein utilization were carried out on Wistar rats, fed on semi-synthetic diets for 12 days varying only the protein source, casein or tuna provided as follows: raw, cooked in brine, steamed, sterilized tuna, and canned tuna stored for three years. The sterilization process and storage time led to a great increase in the lipid content of the canned tuna and to a porcentual decrease in protein, and moisture content. Amino acid composition of canned and cooked tuna did not show great modifications compared to raw tuna. Neither protein digestibility nor biological value of the cooked, canned, and stored tuna showed any deterioration. The protein quality of white tuna meat preserves has been compared with preserves made up of red and white tuna meat.     

Simulation of the nitrogen balance in the soil and a winter wheat crop

A simulation model for winter wheat growth, crop nitrogen dynamics and soil nitrogen supply was tested against experimental data. When simulations of dry matter production agreed with measurements, nitrogen uptake was simulated accurately. The total amount of soil mineral nitrogen as well as the distribution of mineral nitrogen over the various soil layers were generally simulated well, except for experiments in which fertilizer was applied late in spring. In these experiments, applied nitrogen disappeared because it could not be accounted for by the model. Some explanations for this disappearance are briefly discussed.     

Watershed nitrogen export model related to changing nitrogen balance and hydrology in the Changjiang River basin

Rivers play a key role in linking between terrestrial and aquatic ecosystems, and are becoming important sinks of nitrogen (N). However, quantifying N export from terrestrial ecosystems to rivers at large scales is still challenging, due to the heterogeneous characteristics of watersheds in hydrology, land use, geology, climatology, etc. N export from terrestrial ecosystems to rivers is basically controlled by N balances and driven by hydrological processes. Here a model of watershed export coefficient (E _ws ) of dissolved inorganic nitrogen (DIN) is proposed to describe the dynamic processes of DIN export to the river from non-point sources (NPS), with emphasis on the changing N balance and hydrology in the Changjiang River basin during the period 1970–2003. We found a significant relationship between E _ws and the relative N surplus degree, which can predict the variation of E _ws in the basin. Our study shows that E _ws increased from 0.11 to 0.61 across the whole basin during the period, indicating E _ws was dynamic rather than static through time. The amounts of NPS-DIN export to the river (W _NPS ) increased from 0.22 × 10³ to 4.54 × 10³ kg km^?2 year^?1 in response to the increasing watershed N surplus during 1970–2003. The quick increase of W _NPS and E _ws demonstrate the diminishing capacity of terrestrial ecosystems to retain N as N surplus increased as a direct result of human activities. Our research helps researchers and policy makers to understand the mechanism of river N level in response to watershed N balance and hydrology processes.     

The transformations and balance of nitrogen in Japanese paddy fields

Research on the transformations and balance of nitrogen in Japanese paddy field is reviewed. During the past decade substantial progress has been made in estimating more accurate nitrogen balance. However, available data do not provide reliable assessments of nitrogen losses or gains, especially of biological nitrogen fixation, denitrification and leaching. Accordingly, data obtainable now permit only a partial accounting of the nitrogen balance in flooded paddy soils. Accurate estimates on inputs and outputs of nitrogen are required. The problems in estimating these gains and losses are discussed, and the need for more nitrogen balance studies in the field is emphasized.     

臭氧低温氧化烟气脱硝过程中的氮平衡试验研究

臭氧氧化污染物协同脱除技术利用臭氧的强氧化性,将烟气中溶解度较低的NO _x 、Hg、VOCs等多种污染物氧化为高价态或易溶解的形式,并结合尾部湿法喷淋系统实现污染物的同时脱除。由于其具有温度窗口低、脱硝效率高、反应速率快及改造难度小等优点,在工业锅炉、窑炉及非电行业得到广泛应用。但是在此过程中的污染物实际转化路径,尤其是氮氧化物的输入/输出平衡,目前还未有详细的验证试验支撑。因此本文针对典型臭氧氧化脱硝过程,对污染物脱除过程中的氮氧化物输入/输出平衡及氮元素流向进行了分析试验。试验结果表明,气相输入的NO经过臭氧氧化耦合湿法喷淋后逐渐转化为液相中硝酸根和亚硝酸根离子。在不同O₃/NO摩尔比下,气相氮元素的减少量均以液相中硝酸根及亚硝酸根的增加量存在,不存在其他含氮形式。同时,吸收浆液中硝酸盐及亚硝酸盐的转化率也与烟气中NO _x 脱除率相匹配。在NO/SO₂同时氧化条件下,调节O₃/NO摩尔比,结合湿法喷淋系统可以实现NO _x /SO₂的协同高效脱除,同时系统满足氮元素输入/输出平衡,为臭氧氧化污染物协同脱除技术的工程应用推广提供了依据。     

炼焦煤质量的综合评价体系及方法研究

基于层次分析法评价炼焦煤质量体系,通过建立炼焦煤质量的综合评价体系,对炼焦煤各项指标进行了赋值,并对汾西矿业集团的炼焦煤产品进行了有效评价。