常见豆类制备纳豆的品质比较

对大豆、黑豆、绿豆、褪皮绿豆、红豆、腰豆6种不同种类的豆子进行发酵,检测不同原料对纳豆品质的影响,包括纳豆口味的感官评价、有机营养成分(蛋白质、总氨基酸、粘多糖)、水分含量的测量和纳豆芽孢杆菌的生长曲线测定。结果表明:6种豆类制成的纳豆中,大豆和褪皮绿豆的口味最佳。其中大豆制品在水分、粘多糖和营养物质方面综合品质最佳,而褪皮绿豆的粘多糖成分的含量最高,可作为新一代的纳豆后备材料。     

益康纳豆的研制

益康纳豆是以大豆为原料经纳豆芽孢杆菌发酵制得的健康食品。本文从多种发酵豆制品中分离筛选到一株纳豆激酶活性好的菌株，并对该菌株的形态、生理生化特性、影响固体制备的因素、固体培养物保藏试验以及该菌株纳豆激酶的酶学性质等内容进行了研究。研究表明，经发酵后的纳豆可溶性总氮及多种氨基酸含量明显增高，富含多种生物活性酶，同时也是理想的微生态调节剂。     

纳豆芽孢杆菌发酵产品研究进展

纳豆是日本的传统食品,由纳豆芽孢杆菌发酵制作而成,其分泌的纳豆激酶具有安全性高、溶栓性能力强等特点。近些年来,纳豆芽孢杆菌(Bacillus natto)在食品及农副产物深加工领域应用越来越广泛,生产了多种活性产物并有效地提高了食品的营养特性。纳豆激酶除溶栓外更多最新的功能活性也逐渐被研究者发现,在稳定性及气味改良等方面的改善也有着很大的进步。本文综述了纳豆芽孢杆菌及纳豆激酶的开发及应用现状及存在的瓶颈问题和解决对策等研究进展,以期为纳豆相关食品的开发提供支持。     

纳豆专用新品种中龙小粒豆3号的选育及配套栽培技术

纳豆是营养价值较高的发酵豆制品,吸水能力强、蒸煮特性好、粒形整齐一致的小粒大豆适于纳豆加工.为选育适宜纳豆加工的专用新品种,为发展纳豆健康产业作出积极贡献,也为大豆种质创新提供借鉴,以中龙小粒豆1号为母本,以高蛋白优异种质龙品8807为父本,经有性杂交,育成了适宜加工纳豆的小粒大豆新品种中龙小粒豆3号.该品种百粒重8....     

马克斯克鲁维酵母对纳豆发酵风味的影响和发酵工艺研究

纳豆是一种健康的食品,但具有不容易被人们接受的氨气味,为了提高纳豆风味和口感,降低豆腥味,本研究采用马克斯克鲁维酵母和纳豆芽孢杆菌复合发酵的方式,通过响应面分析法,分别以感官评分和纳豆激酶活性为指标,优化纳豆复合发酵的条件,并进行验证试验.结果显示:马克斯克鲁维酵母和纳豆芽孢杆菌复合发酵的最优条件为马克斯克鲁维酵母和纳...     

纳豆激酶液态发酵工艺的优化

对由纳豆芽孢杆菌(Bacillus natto)液体摇瓶发酵生产纳豆激酶的发酵条件进行优化,并对5L发酵罐放大工艺进行研究。结果表明:以4%(w/v)的可溶性淀粉作为碳源,种龄10 h,接种量3%(v/v),通气量0.5 vvm,发酵罐转速由220 r·min-1提升至700 r·min-1,使发酵罐中溶解氧保持在20%以上,以上条件更有利于纳豆激酶的表达。条件优化后,摇瓶中纳豆激酶的表达量由低于1 000 IU·m L-1,提高到2 051.3 IU·m L-1(以尿激酶活为标准)。     

台湾杂志载文推荐多吃点发酵豆制品

正近日,台湾《康椒》杂志载文介绍有关发酵豆制品的保健作用。纳豆,帮女性安度更年期。纳豆是经过蒸煮后,发酵制成的大豆加工品。大豆的蛋白质因发酵分解,更容易被消化吸收,其中维生素B2的含量比普通大豆多出4倍。研究证实,纳豆中的纳豆激酶能溶解血栓,防止心肌梗死、脑梗死等疾病。此外,纳豆还富含大豆异黄酮、锌、钙、与维生素K,不但能补充雌激素,改善更年期症状,还可以预防骨质疏松。味噌,防癌抗衰老。味噌是黄豆、米曲和食     

高产纳豆激酶突变菌株产酶条件的研究

为了获得最佳产酶条件,通过研究不同碳源(葡萄糖、木糖、麦芽糖、蔗糖、淀粉),氮源(牛肉膏、蛋白胨、大豆蛋白胨、酵母膏、硫酸铵),碳氮浓度比和无机离子组成的培养基发酵,利用纤维蛋白平板法测定纳豆激酶的活性.得到纳豆激酶的最佳产酶条件为:1.5%蛋白胨,1.5%麦芽糖,0.05%硫酸镁,0.2%氯化钙,0.2%磷酸二氢钠和0.1%磷酸氢二钠;碳氮浓度比为1:1.     

纳豆激酶的发酵和纯化方法

对纳豆激酶在菌种选育、发酵条件及分离纯化工艺方面的研究进展作了综述,介绍了提高纳豆激酶产量的多种固、液体发酵条件和菌种选育结果,并归纳了膨胀床吸附、金属螯合双水相亲和纳豆分配、反胶束萃取、磁性微球分离等分离技术在纳豆激酶分离纯化中的应用.     

纳豆保健作用及其栽培新品种选育

本文概述了大豆制品纳豆的功能保健作用，介绍了适宜加工纳豆的大豆新品种选育及栽培技术。     

枯草芽孢杆菌Natto3的筛选及其降解黄曲霉毒素B_1的初步研究

从可食用的纳豆中筛选出一株能够高效降解黄曲霉毒素B1(aflatoxin B1,简称AFB1)的细菌,该细菌的发酵上清液经浓缩后制成的粗酶液对AFB1降解率达到91.4%。对该菌进行了分类地位鉴定并初步研究了粗酶液的酶学性质。结果表明,该菌经生理生化和16S r DNA序列比对鉴定为枯草芽孢杆菌,并命名为Natto3。Natto3的粗酶液降解AFB1的最适培养时间为72h,最适反应温度为37℃,最适p H值是8.5,Zn2+、Mn2+、Mg2+、Cu2+、Li+五种金属离子均会不同程度地抑制降解活性。此外,将该粗酶液添加在被黄曲霉毒素高度污染的花生样品中进行脱毒实验,可使花生中AFB1的浓度从192μg/kg降至43μg/kg。     

豆渣固体发酵产纳豆激酶的工艺优化及其部分酶学性质研究

研究纳豆菌固体发酵产纳豆激酶的工艺及其部分酶学性质.采用单因素和正交试验,对以豆渣为原料纳豆菌固体发酵生产纳豆激酶的工艺条件进行优化,并利用最佳发酵工艺制备纳豆激酶粗品,对纳豆激酶的部分性质进行研究.结果表明固体发酵培养基最佳配比:豆渣:麸皮=5:2,初始含水量65%,接种量为10%,初始pH为8.0,培养温度30℃.采用最适培养基和优化工艺,在250 m1三角瓶中进行验证实验,纳豆激酶的酶的产率可达到1577U·g-1.酶学性质研究表明,最适反应温度为60℃,37℃以下稳定,最适反应pH为8.0,在pH7-9溶液中基本稳定.体外溶栓作用表明,纳豆激酶溶解纤维蛋白的方式是直接溶解,而不是通过激活纤溶酶原.     

Anti-hypertensive substances in fermented soybean,natto

Natto is a traditional Japenese fermented food made by fermenting boiled soy beans withBacillus natto. Its contents of inhibitors against the angiotensin converting enzyme (ACE, EC3.4.15.1) were investigated. Relatively strong inhibitory activity (IC₅₀:0.4 mg/ml, 11.8 inhibition units/g natto) was detected in natto extracts and the inhibitory activity observed in the viscous fraction was more potent than in the bean extract. Two groups of inhibitors in the viscous material, high and low molecular weight inhibitors, were resolved by dialysis test. The inhibitor of high molecular weight was a protein with low IC₅₀ value (0.12 mg/ml). The two types of low molecular weight inhibitors were detected in ethanol extracts (IC₅₀: 0.53 mg/ml and 0.95 mg/ml) and they were found to be stable over a wide range of pH and temperature up to 100°C. They were different in the mode of ACE inhibition. One is competitive, and the other noncompetitive against the hydrolysis of Bz-Gly-His-Leu by ACE.     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.