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1.
Grain yield, chemical composition, protein quality and digestible energy were measured for 18 maize varieties (opaque-2, high oil, waxy hybrids, normal hybrids) cultivated in Yugoslavia. Protein quality assessment was based on amino acid composition, and true protein digestibility, biological value, net protein utilization and utilizable protein as determined in nitrogen balance experiments with rats. The protein concentration in dry matter varied from 8.63–18.81% while the fat concentration varied from 4.45–16.13%. There were only minor differences in ash and crude fibre, while starch and sugar varied inversely to fat and protein concentration. Lysine levels were approximately 30% higher for the opaque-2 varieties compared with normal maize, while leucine levels were about 30% lower. Yields were extremely high for all varieties with the highest value being 10.3 tonnes/ha. Due to the high yields, protein production/ha was high in range of 822–977 kg. This resulted in high yields of amino acids/ha. Protein utilization was very high in the opaque-2 varieties, which had the highest lysine contents. The biological values were close to 80 in these varieties, whereas they were only 60–65 in the normal maize varieties.  相似文献   

2.
The chemical composition and protein quality of two varieties of buckwheat were measured and compared with the values of wheat. The protein quality was based on amino acid composition and true protein digestibility, biological value, net protein utilization, and utilizable protein obtained in N-balance experiments with rats. The protein content in buckwheat was approximately 12% and thus very much the same as in wheat. The fat content in buckwheat was close to 3% whereas the crude fiber concentration was very high (12.7 and 17.8%, respectively, for two varieties). The high fiber content caused a low concentration of soluble carbohydrates with the lowest value of 48.7%. Both buckwheat varieties had a high tannin content (1.76 and 1.54%, respectively). The protein quality was very high, with biological values above 90%. This can be explained by a high concentration of most essential amino acids, especially lysine, threonine, tryptophan, and the sulphur-containing amino acids. However, due to the high contents of crude fiber and tannin, the true protein digestibility was slightly below 80%.  相似文献   

3.
Chemical analyses and feeding experiments using rats were conducted to evaluate the nutritive value of winged bean and other legumes (soyabean, green gram, bambarra nuts, pigeon peas, field beans, cow peas) sources grown in Tanzania. Proximate analyses showed that the composition of winged bean was similar to soyabean, while the composition of the other legumes differed considerably. This was also the case for antinutritional constituents and minerals. As to the amino acid composition, the lysine level was high with the highest value in winged bean (7.5 g/16 g N). However, the concentration of methionine and cystine was low which limits their protein quality. Another important amino acid, threonine, was generally high, especially in winged bean (4.3 g/16 g N). With exception of field bean, true protein digestibility was above 80%, soyabean having the highest value (90.7%). The biological value was also highest in soyabean (76.1%) followed by winged bean (69.9%). Utilizable protein was high in soyabean (28.8%) and somewhat lower in winged bean (23.4%). Energy digestibility was around 80%, soyabean having the highest value of 85.8%. The study findings support the idea that winged bean is a good alternative plant protein source in Tanzania.  相似文献   

4.
The nutritive value of some commercial wheat varieties grown in Pakistan was measured chemically, including amino acid analysis, and biologically in N-balance experiments with growing rats. The protein content ranged from 13.2% in Punjab-83 to 16% in Barani-83. Lysine per 100g protein varied between 2.46 and 2.75%. The available carbohydrate ranged from 67.3 to 74.7%. Iron content was highest in Sonalika while the concentration of zinc and manganese was highest in Sarhad-82. The protein digestibility (TD), biological value (BV) and net protein utilisation (NPU) varied between 92–95%, 56–68% and 53–65% respectively. Level of wheat protein was negatively correlated with available carbohydrate (r=–0.93), lysine per unit protein (r=–0.67) and BV (r=–0.76). The lysine content (g/16gN) of commercial wheat varieties showed a positive correlation (r=+0.95) with the BV. The protein quality was lowered in varieties having higher content of protein.  相似文献   

5.
不同燕麦品种的蛋白质营养品质评价   总被引：3，自引：0，他引：3  
为了解我国燕麦品种的蛋白质营养品质状况,收集了2008-2010年9个产地的54个燕麦品种,采用国际通用的WHO/FAO氨基酸评分模式对其蛋白质营养品质进行评价,并比较了不同产地和不同年份样本间的差异。结果表明,本试验中的燕麦蛋白质含量大多集中在16%～20%,其第一限制性氨基酸为赖氨酸,其次是苏氨酸、含硫氨基酸(蛋氨酸+胱氨酸);必需氨基酸含量占总氨基酸含量的33.14%,接近WHO/FAO推荐的理想蛋白质的必需氨基酸组成模式。不同地区所产燕麦品种的蛋白质品质存在显著差异,从氨基酸评分(AAS)、化学评分(CS)、生物价(BV)等指标可反映出吉林产燕麦的蛋白质营养品质较好,甘肃地区的仅次之,且在粗蛋白含量上更具优势。基于蛋白质营养品质通过聚类分析将所收集的样品分为4类,分类结果与其样品来源有关。  相似文献   

6.
Four oat cultivars adapted for soil and climate conditions in the southern region of Brazil were evaluated for protein nutritive value. Evaluations were done both in vitro and in vivo. In vitro evaluation was done by essential amino acid profile, available lysine, amino acid scoring, and protein digestibility corrected amino acid-scoring (PDCAAS). Nitrogen balance indices and PER were determined in vivo with rats. In all four cultivars (UFP-15, UFP-16, CTC-03, UFRGS-14), lysine was the most limiting amino acid. Available lysine, amino acid score and PDCAAS were highest for cultivar UFRGS-14 and lowest for CTC-03. When compared to casein, only nitrogen retention for UFRGS-14 did not differ statistically (p>0.05); all other indices of protein quality were inferior to casein for the oat cultivars. The oat cultivars tended to be identical among themselves, except for apparent protein digestibility which was significantly higher in the UFRGS-14 and CTC-03 cultivars. On average, the PER values of the oat cultivars were 82% of casein; the net protein utilization was 88% of casein as determined in vivo and 49% by the estimation in vitro (PDCAAS).  相似文献   

7.
Agricultural intensification through the application of mineral fertilizers, the recycling of crop residues and animal manures and through plant breeding are the only means to increase food supply in the poverty ridden West African Sahel, where pearl millet (Pennisetum glaucum (L.) R. Br.) is the dominant staple. Research on the effects of soil amendments on the quality of millet straw and grain is scarce, comparative studies of possible quality differences in traditional landraces versus improved varieties and hybrids are lacking. This paper reports results from 22 landrace populations, 22 improved varieties, six inbred×variety hybrids (IVHs, fertile inbred×open-pollinated varieties) and four topcross hybrids (TCHs, male-sterile line×open-pollinated varieties), whose grains were analyzed for protein concentration and amino acid composition, macro- and micronutrients (total and phytate P, K, Ca, Mg, Zn, Cu), metabolizable energy (ME), fat and β-carotene. At similar yield levels, landraces showed a 2.9 and 3.5% higher protein concentration compared with improved varieties and hybrids without a detrimental effect on protein quality as determined by the relative amount of lysine and threonine. Landrace populations also had the highest fat concentrations and the largest micronutrient densities. However, in-vitro digestibility and ME were (79.8% and 12.2 MJ kg−1 respectively) larger for both groups of hybrids. The concentration of β-carotene was (0.13 μmol kg−1) highest in the improved varieties, but appeared overall too low to significantly contribute to vitamin A nutrition in local diets. While the results of this genotype screening need to be verified in replicated multi-location trial studies, they underline the potential of including landraces in breeding programs to concurrently improve grain yield and grain quality in this area of the world.  相似文献   

8.
In North Vietnam, during winter, shortage of herbage constrains the profitability of dairy farming. The first objective of this study was to evaluate the potential of alternative temperate (C3) forage species, namely common oat ( Avena sativa L.), lop-sided oat ( Avena strigosa Schreb.), Italian ryegrass ( Lolium multiflorum L.) and a commercial forage mixture (Avex), to address the shortage of herbage during winter in the mountain regions of North Vietnam. The second objective was to measure the effects of cultural practices (sowing rate, harvest interval and irrigation level) on yield of dry matter (DM), chemical composition, digestibility of DM and metabolizable energy (ME) concentration of herbage from the best adapted C3 species previously tested (lop-sided oat). Four experiments were conducted. Oat species proved to be the best adapted species and produced the highest annual yield of herbage (7600 kg DM ha−1) with a high nutritive value. Yields of DM of lop-sided oat were not affected by sowing rate of seed but increased as the length of harvest intervals increased from 30 to 45 and 60 d ( P  <   0·001). Crude protein concentration, digestibility of DM and ME concentration decreased as the harvest interval increased ( P  <   0·01). Irrigation increased the yields of DM of lop-sided oats by 1·3 ( P  <   0·05) but had no effect on the nutritive value of herbage. It is concluded that both common oat and lop-sided oat are suitable species to provide herbage in the winter for the mountain regions of North Vietnam.  相似文献   

9.
Three local cultivars of lentil (Lens) seeds (Giza 9, Family 91, and Family 195) as well as one imported Pakistani variety were studied. Moisture, protein, fat, carbohydrate, ash, fiber, thiamine, riboflavin, amino acids and some protein fractions were determined on the unpeeled and peeled seeds. The protein quality was evaluated by determining the protein efficiency ratio, net protein utilization, biological value, and true digestibility coefficient. All components were increased by peeling, except the ash, the fiber content, and the residual nitrogen content of the insoluble protein fraction. The latter was markedly decreased by peeling. Giza 9 lentil seeds were found to contain the highest protein and thiamine contents. They showed the highest protein quality and proved to be nutritionally superior to other varieties. Generally, the three local cultivars were found to be chemically and biologically superior to the imported Pakistani cultivar.  相似文献   

10.
The nutritional value of three pale seeded and one dark seeded variety ofAmaranthus caudatus was studied by chemical analyses and in balance experiments with growing rats. Effects of processing: popping, toasting and flaking were also examined. The pale seeds contained about 14% protein, 10% fat, 2.5% ash, 64% starch and 8% of dietary fibre. The black seeds had a much higher content of fibre (16%). The concentration of essential amino acids were high. Lysine ranged from 5.2–6.0 g/16 g N in the grains, and the limiting amino acids were leucine followed by valine or threonine. The grains contained small amounts of tannin (0.3%) and heat-labile protease inhibitor activity, at levels typical of common cereal grains. Digestibility of protein in the pale seeds was high (87%) and quite unaffected by processing. Protein digestibility of the black seeds was lower, and the digestibility was further reduced by toasting. The biological value of the protein was similar in all products, and very high. The content of minerals varied among varieties and was also affected by processing. Phytate: zinc molar ratios were high in most products, and rats fed the amaranth samples with the lowest zinc contents were in negative zinc balance. In general, femur zinc concentrations were rather low. However, amaranth is an unconventional crop which deserves further attention.  相似文献   

11.
Two varieties of mesta (Hibiscus sabdariffa) seeds were analysed for their proximate composition. Their protein (18.8–22.3%), fat (19.1–22.8%) and dietary fiber (39.5–42.6%) contents were found to be high. The seeds were found to be a good source of minerals like phosphorus, magnesium and calcium. Their lysine and tryptophan contents were also high. Sulphur containing amino acids were limiting in this seed protein and the chemical score of mesta seed protein was 40 and 57 for AMV-2 and Bhimili-1 varieties respectively. Mesta seed oil is rich in unsaturated fatty acids (70%), of which linoleic acid constituted 44%. Weanling rats were fed with 10% mesta seed protein before and after cooking for 4 weeks. Food intake of animals receiving raw mesta seed diets was significantly lower than those receiving cooked mesta seed diets as well as the casein control diet. Protein and dry matter digestibilities of raw and cooked mesta seed diets were lower than that of casein control diet. Cooking improved the food intake, gain in body weight, dry matter and protein digestibility of mesta seed diets. PER and NPU of cooked mesta seed diets were significantly higher than the corresponding raw diets. These results indicate that cooked mesta seed protein is of relatively good quality.  相似文献   

12.
为了筛选适应贵州地区种植的朝天椒品种,以资源圃收集的48份朝天椒种质资源为研究对象,对其粗脂肪、蛋白质、维生素C、辣椒素、粗纤维、干物质等6项品质指标和产量进行测定,并利用隶属函数值法和聚类分析法对所得数据进行综合评价分析。结果表明：48份朝天椒种质资源的品质和产量存在较大差异。其中,粗脂肪含量范围在0.12~0.71 g/100 g之间,平均含量为0.47 g/100 g,品种‘黔辣10号’含量最高;蛋白质含量范围在2.36~3.67 g/100 g之间,平均含量为2.90 g/100 g,品种‘DZ-33’含量最高;维生素C含量范围在48.51~74.64 mg/100 g之间,平均含量为59.07 mg/100 g,品种‘子弹头’含量最高;辣椒素含量范围在6.63~72.54 mg/100 g之间,平均含量为31.49 mg/100 g,品种‘香脆白米椒’含量最高;粗纤维含量范围在2.32%~10.45%之间,平均含量为7.59%,品种‘黔辣18号’含量最高;干物质含量范围在11.12%~20.98%之间,平均含量为15.66%,品种‘单生理想’含量最高;干椒产量范围在189.66~442.81 kg/667 m2之间,平均产量为304.62 kg/667 m2,品种‘2018-70’平均干椒产量最高。6项品质指标的平均隶属度值在0.29~0.75之间,相差0.46,种质资源间差异较大。聚类分析可将48份朝天椒种质资源分为3大类群,第Ⅰ类群包括26份种质资源,占总资源数的54.17%,6项品质指标的平均含量和平均干椒产量都处于居中水平;第Ⅱ类群包括16份种质资源,占总资源数的33.33%,6项品质指标的平均含量都处于最低水平,但平均干椒产量处于最高水平;第Ⅲ类群包括6份种质资源,占总资源数的12.50%,6项品质指标的平均含量都处于最高水平,综合品质表现最好,但平均干椒产量最低。开展朝天椒种质资源品质和产量的综合评价分析,可为朝天椒种质资源的创新利用以及新品种选育奠定基础。  相似文献   

13.
The chemical composition of different varieties of field beans (Vicia faba L.), cowpeas (Vigna unguiculata), groundnuts (Voandzeia subterranea), and sorghum (Sorghum vulgare) were determined. Nutrients analysed in these materials included amino acids, starch, sugar, fibre, minerals and antinutritional factors. All the materials were further tested in balance trials with rats; true protein digestibility (TD), biological value (BV), net protein utilization (NPU) and digestible energy (DE) were evaluated. Based on the chemical analyses as well as on the biological data, the nutritive value of plant materials between species as well as between varieties within species differed considerably. Therefore, more quality evaluation studies along with plant breeding programmes are needed to select the most promising varieties from the nutritional point of view.  相似文献   

14.
The commercial oil cake produced during expeller pressing of maize germ, was extracted with n-hexane and 80 percent ethanol followed by seiving to remove undesirable materials. In defatted maize germ oil cake (DMGOC): protein, starch, fat, crude fiber (CF) and ash were respectively 24.69, 36.55, 5.68, 7.56 and 3.90 percent and they decrease after processing except ash, which increased slightly. It contains better quality protein having only 3 percent zein and 47 percent albumin. Its amino acids like lysine and tryptophan and biological value (BV) were higher than that of whole maize grain, and was comparable with that of the amino acid requirement of preschool children and casein diets both. Its digestible energy (DE) was lower compared with whole maize grain as well as the casein diets. After processing albumin, globulin and zein decreased whereas glutelin and the residual fraction increased. Not much differences were observed in chemical composition and different amino acids, in vitro protein digestibility (IVPD), true digestibility (TD), BV and DE improved after processing.  相似文献   

15.
Chemical analyses and balance trials with rats of 17 foods showed marked differences in protein quality. According to anin vitro procedure true protein digestibility was high (around 90%). The same was also the case for thein vivo values with the exception of two legumes, beans and chick peas, which were digested to a markedly lower degree when compared to thein vitro values. The assumed reason for this is discussed. Due to extensive differences in the amino acid composition of the 17 samples BV varied considerably with the lowest value (45.5) of rice-wheat gluten breakfast cereal. Energy digestibility was generally high. Amino acid digestibility determinedin vivo followed the pattern of the corresponding protein digestibility, although marked differences occurred from one amino acid to another in the same food.  相似文献   

16.
不同类型稻米的蛋白营养价值   总被引：16，自引：0，他引：16  
 选用147个不同稻类、不同粒型及色泽的稻米，分析其粗蛋白含量、蛋白质的氨基酸含量和蛋白质生物价的化学计算值。结果表明：稻米的粗蛋白含量越高，蛋白质的品质越差；籼稻的粗蛋白含量的变幅大，但蛋白质中各氨基酸含量的变化小。粳稻、糯稻则相反；紫黑米蛋白的营养价值最高；大胚米的粗蛋白含量最高，它的蛋白质品质略次于总体水平；香米在蛋白质方面与普通大米无多大差异．  相似文献   

17.
为筛选出适宜在齐齐哈尔地区推广种植的燕麦品种，用基于熵权的灰色关联方法对9个燕麦品种的农艺性状和饲草品质进行综合评价。结果发现，9个品种中，梦龙株高达到120 cm以上，与吉利和摩登差异不显著，但显著高于其他品种(P<0.05);悍马鲜草产量最高(49 395 kg·hm-2),龙牧12号干草产量最高(13 837 kg·hm-2)。9个燕麦品种的可溶性碳水化合物(WSC)、粗蛋白(CP)、粗脂肪(EE)、酸性洗涤纤维(ADF)、中性洗涤纤维(NDF)、粗灰分(ASH)、木质素(ADL)含量和相对牧草质量(RFQ)分别为10.52%～12.55%、6.58%～9.88%、1.96%～2.83%、32.67%～39.52%、59.47%～68.34%、6.99%～10.40%、3.50%～4.47%、85.00～110.67。梦龙、龙牧12号和吉利的CP含量显著低于其他品种(P<0.05);泰克的ASH含量显著高于其他品种(P<0.05);龙牧12号的ADF和NDF含量均显著高于其他品种(P<0.05)。应用灰色关联度法...  相似文献   

18.
Brown and milled rices were prepared from rough rice, and the nutritive value of the rices was studied by chemical analyses and in balance experiments with growing rats. The concentration of essential nutrients decreased with the degree of milling, but the energy density of brown and milled rices was similar. In the highly refined white rice the protein content was reduced to 86% and the mineral content to 23% of corresponding levels in brown rice. The zinc concentration was halved. The amino acid composition was rather unaffected by the degree of milling, but the lysine concentration was slightly lower in white rice than in brown rice. Milling was accompanied by an increase in true protein digestibility and a corresponding decrease in biological value. Thus net protein utilization of the different rices was remarkably uniform. A total of 33% of the utilizable protein and 22% of the digestible energy in brown rice was removed during milling. Rats fed rough, brown and lightly milled rices were unable to maintain their femur zinc concentration; deposition of calcium and phosphorus also appeared to be affected. Factors present in the outer part of the rice kernel interfere strongly with zinc utilization. Phytate and/or fibre are not solely responsible for this effect. Unless rice was milled into highly refined white rice, zinc status of rats was adversely affected. The results suggest that zinc might be a limiting factor in rice-based diets.  相似文献   

19.
The chemical compositions, of raw and treated lupine flour were determined and compared with other plant protein sources. The protein content in the dry matter was 47.7% in untreated seeds ofLupinus mutabilis and about 56% in debittered seeds. The oil-cake contained 65.3% protein. The amino acid analysis showed that lupine protein is characterized by a low level of S-amino acids, the content of which amounts to only 50% of that of the FAO standard reference pattern. The protein quality was measured using the biological tests PER (Protein Efficiency Ratio), NPU (net protein utilization), and BV (biological value) in rats on diets with and without DL-methionine supplementation. PER determinations gave low values for the non-supplemented lupine proteins (1.34, semi-sweet variety; 1.53, water-extracted seeds; 1.19, oil-cake; 3.09, casein), but the PER's were improved by the addition of 0.2% DL-methionine to the diets (3.05, 2.69, 2.81, respectively). Raw as well as processed lupine protein showed an excellent apparent digestibility (80.0–85.8%; casein, 87.1%). The observed NPU and BV values confirmed the importance of methionine supplementation. The true digestibility of 92% was equivalent to that of casein. The complementation effects of mixing lupine protein with proteins from wheat, oat, barley, rice, maize, potato, quinua or fish were investigated by determination of the PER values of the respective mixtures. Feeding lupine protein with cereal proteins resulted in PER values that exceeded by far those of the proteins fed separately (true complementation). This result was not observed for the mixture of potato and lupine. High quality proteins like quinua and fish protein also showed no complementation effect with lupine protein but did improve the quality of the lupine protein to a great extent. The best results could be obtained with combinations of three different plant proteins, in which lupine protein always contributed one third of total protein. These mixtures resulted in PER values equal to those for casein or other animal proteins and may be applied as an economical way to prevent and combat malnutrition.  相似文献   

20.
Nutrient composition and digestibility of stover contribute markedly to the nutritive value of forage maize in cattle feeding. Low stover digestibility limits the quality of whole plant maize silage (WPMS) and should therefore be prevented by optimizing management of WPMS production. A project was carried out to analyse nutrient composition and ruminal nutrient degradability of ensiled stover of nine different current maize varieties, which were planted in 3 years and harvested at three maturity stages (50, 55 and 60% ear dry‐matter [DM] content). Variety and harvest date had a significant impact (p < 0.05) on crude protein (CP) and metabolizable energy content, whereas fibre content and non‐fibre components were not affected by these factors. In contrast, the potential and effective degradability (ED) of organic matter (OM), CP and neutral detergent fibre (NDF) were significantly influenced by variety and harvest date. The ED5 (ED at 5% per hour passage rate) of different varieties ranged from 22.9% to 29.3% for OM, from 66.2% to 71.4% for CP and from 17.3% to 20.5% for NDF. The ED5 of OM, CP and NDF declined significantly by 4.1%, 2.5% and 2.1% units between the second and third maturity stage. Almost all investigated parameters were significantly influenced by year. Significant differences between varieties indicate that there is a potential for improvement of stover degradability through breeding. Harvest ear DM content should not exceed 55%, because nutritive value of ensiled stover declines significantly beyond this value, which could negatively affect WPMS quality in cattle feeding.  相似文献   

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