饲料中抗营养因子的作用

抗营养物质即指组成天然饲料的植物原料的正常代谢或饲料在消化利用过程中产生的具有降低营养价值的物质。它们或者代表某种特有的代谢形式或营养物质的存在方式,或者代表一种保护植物本身结构组成形式或繁殖因子的途径。     

饲料中的抗营养因子及其灭活

抗营养因子普遍存在于植物性饲料中,主要包括蛋白酶抑制因子,植物凝集素、非淀粉多糖、植酸、单宁、糖苷、游离棉酚、抗维生素因子、脲酶等,目前主要通过物理、化学和生物学方法对其进行灭活和钝化,对饲料中抗营养因子的种类、性质、抗营养机理及灭活方法作一综述。     

饲料原料中抗营养因子的研究进展

抗营养因子几乎存在于所有的植物性饲料原料中,饲料中的抗营养因子影响营养物质在动物体内消化利用,同时诱发动物营养代谢性疾病.介绍了抗营养因子的定义及分类、理化性质、含量及分布,阐述了其抗营养作用机制,归纳了其检测方法以及消除方法,同时展望了抗营养因子未来的研究方向.     

饲料中的抗营养因子及处理方法

饲料是动物生产的物质基础。现今在配合饲料中90％以上韵组分为植物性饲料,植物性饲料都含有一种或多种抗营养因子。抗营养因子不但影响了饲料的营养价值和适口性,而且给动物的健康生长和生产带来了很大的危害。众所周知我国既是人口大国又是饲料生产大国,人畜争粮,饲料     

大豆中营养因子和抗营养因子研究进展

大豆中含有抗营养因子和营养因子,营养因子包括大豆磷脂、大豆异黄酮等,抗营养因子包括蛋白酶抑制因子、抗原蛋白、凝集素、植酸等,大豆低聚糖和皂甙具有营养和抗营养双重作用。对大豆中的营养因子和抗营养因子的生理功能,对动物的营养及危害作用进行了论述。     

油茶籽饼中抗营养因子的研究

本文对传统方法生产的油茶麸饼，油菜籽壳，油茶籽仁和油茶籽中的几种抗营养因子进行了测定分析。结果表明：他们都不同程度地含有丹宁、茶皂素和生物碱等抗营养因子，茶皂素、丹宁、生物碱含量最高的分别为油茶麸饼、油茶籽壳、油茶麸饼。并对这些抗营养因子的抗营养作用进行了讨论，还提出了去除这些抗营养因子的方法。     

蚕豆中抗营养因子的研究

对蚕豆中所含的一些对人体有害的物质(抗营养因子)进行了总结分析。并介绍了一些常用的方法来降低蚕豆抗营养因子对人体健康造成的不利影响。     

魔芋飞粉中抗营养因子的去除研究

以魔芋飞粉为原料,采取酸洗一步法支队了其中抗营养因子三甲胺、生物碱及单宁,比较了处理前后的魔芋飞粉的营养成分及氨基酸组成,为魔芋飞粉开发成为牲畜饲料提供了一条新途径。     

大豆抗营养因子钝化失活速度的研究

对不同热处理条件下,大豆不同抗营养因子的钝化失活速度进行研究。结果表明,在脲酶完全失活条件下,胰蛋白酶抑制素仍残留一定活性。因此在大豆加工中以脲酶做为抗营养因子失活指标不能全面反映大豆及其制品中抗营养因子的失活状况。     

Assessment of nutritional compounds and antinutritional factors in pea (Pisum sativum) seeds

The nutrient and antinutritional factor content of 18 pea lines was studied. The following levels were found: non‐protein nitrogen 5.2–10.2 g kg^?1 DM, protein nitrogen 35.3–42.4 g kg^?1 DM, lysine 50.7–76.3 g kg^?1 protein DM, histidine 17.8–24.8 g kg^?1 protein DM, tyrosine 22.6–30.0 g kg^?1 protein DM, protein 25.9–31.9% DM, in vitro protein digestibility 89.3–95.6%, vitamin B₁ 5.9–10.3 mg kg^?1 DM, vitamin B₂ 1.1–3.7 mg kg^?1 DM, sucrose 11.6–25.4 g kg^?1 DM, raffinose 4.1–10.3 g kg^?1 DM, stachyose 10.7–26.7 g kg^?1 DM, verbascose 0.0–26.7 g kg^?1 DM, total α‐galactosides 22.6–63.4 g kg^?1 DM, trypsin inhibitor activity 0.8–8.4 TIU mg^?1 DM, inositol hexaphosphate 2.3–6.5 g kg^?1 DM, inositol pentaphosphate 0.1–1.8 g kg^?1 DM and total inositol phosphates 2.8–7.1 g kg^?1 DM. Peas with yellow cotyledons had the highest trypsin inhibitor activities, those with light green cotyledons had the highest lysine contents, and those with dark green cotyledons were the richest in vitamins B₁ and B₂. Peas with brown testae had the lowest verbascose and sucrose contents, while they were the richest in inositol hexaphosphate. Smaller peas were characterised by the highest protein nitrogen contents as well as the highest contents of vitamins B₁ and B₂, verbascose and inositol pentaphosphate. Peas of medium size showed the lowest verbascose, α‐galactoside and vitamin B₂ contents. Bigger peas showed the lowest inositol pentaphosphate contents. © 2003 Society of Chemical Industry     

大豆发芽过程中抗营养因子的变化

大豆蛋白存在着胰蛋白酶抑制因子和凝集素等抗营养因子,影响人类对其的利用。文中采用分光光度法和免疫火箭电泳法测定了发芽过程中东农42、东农823、71434、40567、黑农40五个大豆品种中胰蛋白酶抑制因子和凝集素的含量变化。结果发现:发芽能明显改变大豆中抗营养因子的含量,不同品种的抗营养因子变化程度不同,5种大豆在发芽过程中显示出较为一致的总体趋势。发芽温度对大豆中胰蛋白酶抑制因子的含量有影响。证实在萌发的大豆中存在可失活大豆抗营养因子的内源酶。     

Composition,toxic and antinutritional factors of newly developed cultivars of Brazilian soybean (Glycine max)

Five different recently released Brazilian soybean cultivars (Bays, BR-10, Rio Balsas, Serido and Tropical) were compared for their proximate analyses and presence of antinutritional or toxic factors. As expected, the seeds are rich in proteins, varying from 360·7 to 485·4 g kg⁻¹ flour, and they also have a high amount of fat (from 183·0 to 215·3 g kg⁻¹ flour). Crude extracts from seeds of Bays, BR-10, Serido and Tropical were highly toxic to mice within 1–12 h, depending on the administration route (intraperitoneal, intramuscular or subcutaneous) and dose used while Rio Balsas was not. These acute effects were very similar to those produced by the soytoxin, a neurotoxin that has been recently purified from the commercial soybean sold in Brazil. The amount of trypsin inhibited in the presence of crude extracts ranged from 28·5 to 62·5 g kg⁻¹ flour. Urease was also present and the seed lectin agglutinated preferentially rabbit erythrocytes. A heat treatment at 92°C for 1 min destroyed completely the toxic activity while the haemagglutinating and trypsin inhibitor activities were abolished within 5 min. At these conditions urease was still active. Due to its high protein content, lack of soytoxin, and low levels of trypsin inhibitor, lectin, and urease it is suggested that Rio Balsas could be an alternative for breeding programmes aimed to improve the nutritional quality of soybeans. ©1997 SCI     

Effect of Germination on Chemical Composition,Biochemical Constituents and Antinutritional Factors of Soya Bean (Glycine max) Seeds

The published scientific data concerning the effects of germination on chemical composition, biochemical constituents and anti-nutritional factors of soya bean are reviewed. The amino acid profile did not change to a great extent; only a noticeable increase in aspartic acid was observed whereas there was a gradual decrease in the available lysine level and lipid content as germination progressed. Both the total protein content and the nonprotein nitrogen increased after 5 days of germination. Dietary fibres are partially degraded in germinated seeds. Germinated soya bean is an excellent source of ascorbic acid and riboflavin. Niacin contents increased distinctly after germination. Germination induced a reduction in lipase inhibitor activity. The galactosyl oligosaccharides drastically decreased in germinated seeds. After 4 days of germination, the activity of certain lectins decreased to 4% of that of ungerminated soya beans. The phytic acid in the seeds was degraded by the phytase activated during germination, thus increasing the availability of the minerals present in the germinated seeds. Germination can degrade both Kunitz soya bean trypsin inhibitor and the major Bowman–Birk soya bean trypsin inhibitor; the degradation is enhanced, if germination process lasts more than 4 days. © 1997 SCI.     

豆类植物凝集素抗营养机理研究

植物凝集素是植物在长期进化过程中形成抵御病虫害和动物消化主要成分之一,因此对动物具有较强抗营养作用;该文介绍豆类植物凝集素,并阐述其抗营养机理。     

Some physicochemical and antinutritional properties of raw flours and protein isolates from Mucuna pruriens (velvet bean) and Canavalia ensiformis (jack bean)

The legumes Canavalia ensiformis and Mucuna pruriens are underexploited in tropical Mexico. Their seeds have good nutritional potential, but contain antinutritional factors. Physicochemical and antinutritional properties were determined for raw flours (RF) and protein isolates (PI) produced from these legumes. Protein content in the PI was 737 g kg^–1 for C. ensiformis and 666 g kg^–1 for M. pruriens. Protein isolation improved in vitro digestibility, while maintaining high lysine levels and adequate sulphur amino acids content. Antinutritional factors such as cyanogenic glucosides, cyanide precursors from hydrolysis, tannins and trypsin inhibitors were lower in the PIs than in the RFs. The reduction in canavanine levels, a structural analogue of arginine, in the C. ensiformis PI was noteworthy. These PIs thus have potential applications in the development of new food ingredients in tropical regions using processes that improve nutritional value.     

Protein concentrate from Jatropha curcas screw‐pressed seed cake and toxic and antinutritional factors in protein concentrate

BACKGROUND: Jatropha curcas seeds are highly toxic to livestock. The presence of phorbol esters and antinutrients such as trypsin inhibitor, lectin and phytate and the high level of shells in the seed cake prevent its use in animal diets. Using the principle of isoelectric precipitation, the conditions for preparation of the protein concentrate from oil‐containing seed cake and defatted seed cake were optimised and the contents of phorbol esters and antinutrients were determined. RESULTS: The recovery of protein concentrate was highest when the proteins from the seed cakes were solubilised at pH 11 for 1 h at 60 °C and the precipitation of these proteins was done by lowering the pH to 4. Under these conditions, over 53% of the total proteins present in the seed cakes were recovered in the protein concentrates. The protein contents in the protein concentrates obtained from the oil‐containing seed cake and defatted seed cake were 760 and 820 g kg^?1 respectively. Substantial amounts of phorbol esters were present in the protein concentrates (0.86–1.48 mg g^?1). Trypsin inhibitor was present at an approximately tenfold higher level in the protein concentrates than in the seed cakes. Lectin and phytate were also present at high levels, but their levels were lower than in the seed cakes. Tannins were present in negligible amounts. CONCLUSION: To make the protein concentrate from Jatropha seed cake fit for use as an ingredient in livestock feed, phorbol esters must be removed and trypsin inhibitor and lectin inactivated by heat treatment. The adverse effects of phytate could be mitigated by addition of phytase in the diet. Copyright © 2008 Society of Chemical Industry