抗营养因子的抗营养作用

抗营养因子普遍存在于植物性饲料中,主要包括蛋白质抑制剂,植物凝集素等。根据抗营养因子与不同营养素拮抗的特点,可将其抗营养作用分为降低蛋白质利用率,降低能量利用率,降低矿物质,微量元素利用率和降低维生素利用率等。     

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。     

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。     

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     

饲料原料中植酸的研究进展

植酸是肌醇磷酸酯的混合物,是谷物籽粒中磷酸盐的主要储存形式,是对畜禽营养物质消化影响较大的抗营养因子。简要介绍了植酸的理化特性、含量及存在形式,阐述了其抗营养作用以及在其他领域的使用价值,归纳了植酸的检测方法,分析了植酸酶正常或超量添加对植酸降解的影响,同时展望了植酸未来发展的方向等。     

稻米中抗营养因子的研究进展

植酸是稻米的天然组分，是稻谷种子生长和活动所必需的。在稻谷的生长过程中，不仅对灌浆十分有利，而且对稻谷成分的形成和工艺品质也有很大的促进作用，但是对人类营养而言，植酸是一种抗营养物质，植酸可与钙、锌、铁等物质螯合，降低钙、锌、铁等的生理利用率；植酸还能与蛋白质等形成不溶性复合物，降低氨基酸的利用率；一些消化酶的作用也受到植酸的抑制，从而影响到蛋白质、淀粉、脂肪的利用率。     

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生理功能

一直以来,人们利用各种方法去除蚕豆中所含的原花青素、植酸、凝集素、蛋白酶抑制剂等被认为是不利于营养吸收的物质,但随着人们生活状况的改善,营养过剩引起了各类慢性疾病,例如糖尿病、高血压、高血脂等等。近期的研究表明,蚕豆中的这些抗营养因子具有诸如抗氧化、抗肿瘤、降血糖、预防肥胖等生理功能,适量摄入有利于人体健康,需要人们对其进行新的评价和开发利用。      

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     

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。     

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     

ACE抑制肽的研究进展

随着高血压患者的大幅增加和人们对健康的重视,血管紧张素转换酶(ACE)抑制肽作为有效的降血压多肽,又因无毒副作用,使其成为近些年的研究热点。文章综述了ACE抑制肽的作用机理和研究历史,从植物及动物方面介绍了多肽的来源,并阐述了直接酶解法、发酵法、固相合成法制备ACE抑制肽方法,以及从体外活性检测和体内活性检测介绍ACE抑制肽检测方法,希望为ACE抑制肽的深入研究提供依据。     

Biochemical and nutritional evaluation of Jatropha protein isolate prepared by steam injection heating for reduction of toxic and antinutritional factors

BACKGROUND: Jatropha kernel contains 400–600 g oil kg^?1, and the cake obtained after oil extraction is rich in protein. The use of Jatropha cake/meal in food or feed is limited owing to the presence of toxic and antinutritional constituents. The main objective of the present study was to prepare protein isolates with reduced toxic and antinutritional factors and improved nutritional quality. RESULTS: The yield of protein isolates was 70–77%, with a protein content of 955–970 g kg^?1. The trypsin inhibitor activity was reduced by 90–97% and the phytate, tannin and saponin contents were reduced by 90, 85 and 98% respectively in the isolates, while phorbol esters and cyanogenic glucosides decreased to undetectable levels. The chemical scores for the meals and isolates were similar; methionine and cystine were the limiting amino acids. The in vitro digestibility and calculated nutritional indices (essential amino acid index, predicted biological value, nutritional index and computed protein efficiency ratio) of the protein isolates were higher than those of the meals. Protein quality as indicated by the protein digestibility‐corrected amino acid score was 1.0. CONCLUSION: Jatropha protein isolate prepared by steam injection has markedly reduced toxic and antinutritional constituents and hence has great potential as a rich source of protein. Copyright © 2008 Society of Chemical Industry     

Nutrient contents,rumen protein degradability and antinutritional factors in some colour- and white-flowering cultivars of Vicia faba beans

Six colour-flowering (Scirocco, Alfred, Carola, Condor, Tina and Herz Freya) and six white-flowering (Caspar, Albatros, Gloria, Tyrol, Vasco and Cresta) cultivars of Vicia faba were studied. The crude protein contents of colour- and white-flowering cultivars were 267±13·6 and 283±18·8 g kg⁻¹, respectively, which did not differ significantly at P<0·05. The levels of lipids, crude fibre, starch and ash varied from 14 to 22 g kg⁻¹, 88 to 143 g kg⁻¹, 407 to 485 g kg⁻¹ and 32 to 42 g kg⁻¹, respectively. The calculated organic matter digestibility (OMD) and metabolisable energy (ME) of the white-flowering cultivars were significantly higher (P<0·001) than those of the colour-flowering cultivars (OMD: 889·1±26·6 g kg⁻¹ vs 797·5±17·1 g kg⁻¹; ME: 13·97±0·49 vs 12·30±0·34 MJ kg⁻¹). In all cultivars, sulphur amino acids were lower than adequate concentration when compared with recommended amino acid pattern of FAO/WHO/UNO reference protein for a 2–5-year-old child. The in vitro rumen nitrogen degradability of colour-flowering cultivars was significantly lower (P<0·01) compared to that of white-flowering cultivars (71·4±9·3% vs 88·0±11·1%). Amongst colour-flowering varieties, the contents of total phenols (TP), tannins (T) and condensed tannins (CT) were highest in Alfred (28·3, 21·0 and 35·4 g kg⁻¹, respectively). The contents of TP and T were similar (about 15 and 10 g kg⁻¹, respectively) in Carola, Tina and Herz Freya, and the CT were in the order: Condor>Herz Freya>Carola. The CT were not detected in white-flowering varieties, T were virtually absent and TP were extremely low (4·0–4·9 g kg⁻¹). The activities of other antinutritional factors (white- and colour-flowering cultivars, respectively: trypsin inhibitor activity 3·05±0·34 and 1·85±0·09 mg trypsin inhibited g⁻¹; lectin 27·2±9·4 and 27·1±5·1 mg ml⁻¹ assay medium producing haemagglutination; phytate 15·0±2·7 and 16·6±2·3 g kg⁻¹) were very low. A strong negative correlation (r=-0·92, P<0·001) between tannins and in vitro rumen protein degradability was observed which suggested that tannins have adverse effect on protein degradability. Similarly negative correlations between tannin levels and metabolisable energy (r=-0·89; P<0·001) and organic matter digestibility (r=-0·89; P<0·001) were observed. The correlation coefficient between trypsin inhibitor activity and tannins was negative and highly significant (r=-0·88, P<0·001), whereas between tannins and saponins it was significantly positive (r=0·96, P<0·001). ©1997 SCI