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1.
以硫酸二乙酯(DES)诱变处理黄色短杆菌(Brevibacteriumflavum)XQ5122,得到突变株V3-36<Leu ̄1、α-AB ̄r、AHV ̄r),在10%葡萄糖培养基中可积累2.3%L-缬氨酸。以亚硝基胍(NTG)诱变V4-153,得到一株突变株(Leu ̄1、α-AB ̄r、AHV ̄r、2-TA ̄r),再进行单菌落分离,得到突变株ZQ-2,能在培养基中积累L-缬氨酸4.2%~4.5%,最高达5.57%.  相似文献   

2.
Valsol LTA在毛用活性染料低温染色中的应用性能研究   总被引:2,自引:0,他引:2  
殷来所 《纺织学报》1997,18(5):21-23
本文研究羊毛经低温染色助剂ValsoLTA处理后,毛用活性染料LanasoBlue3G的低温染色应用性能。  相似文献   

3.
L—异亮氨酸产生菌的选育   总被引:3,自引:0,他引:3  
以黄色短矸菌(Brevibacteriumflavum)ATCC14067为出发菌株,经硫酸二乙酯(DES),紫外线(UV)和亚硝基胍(NTG)逐级诱发处理,α-氨基-β-羟基戊酸(AHV),S-2-氨基乙基-L-半胱氨酸(AEC)磺胺胍(SG),乙硫氨酸(Eth)α-氨基丁酸(α-AB),异亮氨酸氧肟酸(IleHx)等氨基酸结构类似物及琥珀酸主碳源平板定向筛选,获得一株L-异亮氨酸高产菌ZQ-4  相似文献   

4.
为建立测定FTB的IC-ELISA方法,用复合抗原FTBS-BSA和FTBS-HSA作为免疫原免疫BALB/c小鼠,取免疫小鼠脾细胞与鼠SP2/O-Ag14骨髓瘤细胞融合,经反复筛选,获得2株稳定分泌抗FTB抗体的单克隆杂交瘤细胞株。免疫球蛋白亚型鉴定,1株为IgM,1株为IgG1。两株杂交瘤腹水的ELISA效价分别为1×10-6和1×10-8,用PEG沉淀法和辛酸-饱和硫酸铵法对抗体腹水进行了纯化,并分别测定了2种单抗与FTBS-IgG的亲和力常数以及与其它11种真菌毒素的相对交叉反应,建立了测定FTB的IC-ELISA法。  相似文献   

5.
以解淀粉芽孢杆菌(Bacillusamyloliqefaciens)A-4为出发菌株,经诱变处理,选育多重抗药性突变株。研究结果表明,抗药性突变株α-淀粉酶产量提高的正变率和正变幅度明显大于非抗药性突变株,负变率和负变幅度也较高。经NTG和NTG-UV诱变处理,获得一株林可霉素、D-环丝氨酸和万古霉素多重抗性突变株LCV_5(Lin ̄r,Cs ̄r,Vm ̄r),其α-淀粉酶活力比出发菌株A-4提高32.5%,发酵周期短,摇瓶为40h,酶活力达461u/ml.  相似文献   

6.
胆固醇合成抑制剂:———莫纳可林K关连物质的探索   总被引:1,自引:0,他引:1  
作为胆固醇合成抑制剂的ML-236B及莫纳可林K(monacolinK),是分别由笔者等人于1976、1979年发现的来自霉菌的东西,两者是化学构造很相似的物质,都能特异的抑制胆固醇合成途径上的速度决定酶———HMG-CoA还原酶(3-羟-3-甲基戊...  相似文献   

7.
由美国加利福尼亚州印刷工业协会(ThePrinting Industries Association of SouthernCalifornia)主办的 GUTENBERG FESTIVAL 2000将于4月 27-29日在美国举办。此展览会在美国涵盖面最广。展品范围包括:数字印前、印刷、出版发行和图形转换技术等领域。届时。所有制造商和供应商将展示其最新产品和技术,定将给与会者提供良好的商机。GUTENBERG FESTIVAL 2000展览会将举办  相似文献   

8.
盐蒿精油化学成分和杀虫活性初探   总被引:2,自引:0,他引:2  
生物活性筛选试验表明,菊科植物盐蒿(ArtemisiahalodendronTurcz,exBess)全草精油对赤拟谷盗的种群繁殖具明显的影响。采用GC-MS方法分析了盐蒿精油的化学成分,共检出了103个成分,鉴定了其中56个成分。其主成分为茵陈二炔。  相似文献   

9.
四川名茶矿质元素含量研究   总被引:3,自引:0,他引:3  
王云  马骥 《食品科学》1993,14(12):11-13
分析了四川名茶矿质元素含量及特点。在所分析的18种元素中,四川名茶K,P,S,Ca,Mg元素含量较高(>1500 10^-6),Ba,Cr,V,Co,Se含量较低(<10 10^-6);与普通绿茶相比,四川名茶含有较高的K,Zn,P,Na,Ni,Cu,S,Se,Co元素,其高幅为0.38%-115.65%,而Mg,Mn,Al,Ca,Ba,V,Rb,Fe,Cr元素则为7.32%-46.67%;红岩迎  相似文献   

10.
以特定方法筛得羟基脂肪酸聚酯(PHAS)产生株AMB-001,初步鉴定为产碱菌(Alcaligenes)属。经紫外线与亚硝基胍诱变,变异株AUN-39产聚羟丁酸(PHB)和聚羟丁戊酸共聚物(PHBV)的产率分别为细胞干重的35%和47.5%.透射电镜观察表明AUN-39胞内积累的PHB粒子可充满胞内空间。  相似文献   

11.
Abstract

The effect of replacing wheat flour with wheat bran (0–10%), coarse wheat flour (0–20%) or with rice flour (0–20%) on the quality of cookies was studied. The cookie dough was subjected to Instrumental Texture Profile Analysis in order to determine dough cohesiveness and adhesiveness. After baking spread factor, puncture force and fracture strength of the cookies was also determined. The control dough had cohesiveness and adhesiveness values of 0.279 and 13.6 N s whereas control cookies had puncture force and fracture strength of 90.84 N and 100.16 N. Wheat bran increased dough cohesiveness and adhesiveness whereas coarse wheat flour had the opposite effect. Increasing levels of rice flour decreased cohesiveness but increased adhesiveness. Wheat bran and rice flour lowered the spread factor where as coarse wheat flour increased spread factor. Coarse wheat flour and rice flour lowered the fracture strength where as wheat bran increased fracture strength. Sensory evaluation revealed that increasing levels of wheat bran lowered the overall acceptability whereas rice flour and coarse wheat flour improved sensory scores.  相似文献   

12.
通过在体外模拟构建消化和发酵体系,研究不同来源的三种麸皮(小麦麸皮、黑小麦麸皮和燕麦麸皮)配制成的粗粮粉对肠道菌群调节作用的影响。采用高通量测序技术16S rRNA对肠道菌群的多样性和组成进行分析,结果表明,粗粮粉发酵后微生物多样性降低,肠道菌群组成发生了较大变化,拟杆菌门比例下降,厚壁菌门比例升高,代谢产生的短链脂肪酸含量显著增多(p<0.05);其中,燕麦粗粮粉促进双歧杆菌体外增殖的效果优于其他两组粗粮粉,分别是小麦粗粮粉和黑小麦粗粮粉的1.45和2.14倍。本研究为调制加工性能好、保健价值高的粗粮粉配方提供了理论依据。  相似文献   

13.
The objective of this investigation was to compare total phenolic content and antioxidant activities of various types of cereal brans enriched snack as affected by storage conditions. Extruded snacks were prepared by the addition of cereal brans (wheat, oat and rice) singly and in combination (w:r:o::2:1.5:1.5) to rice flour at 10, 20 and 30 % bran supplementation. The content of total phenolics in the extracts (conventional and microwave assisted extraction) was determined spectrometrically according to the Folin–Ciocalteu procedure and calculated as gallic acid equivalents. Radical scavenging capacity measured by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) methods was studied. The effect of the storage on antioxidant content and capacity showed that total phenolic content and antioxidant activities of bran enriched snacks decreased during storage at ambient temperature. However, a little increase in moisture content, water activity and free fatty acid was observed in six of month’s storage period.  相似文献   

14.
Via substituting with wheat flour some high dietary fibre cookies were prepared (with 6, 12, 18 and 24%) from cereal industry by-products: corn bran (CB), rice bran (RB) and barley husk (BH). In vitro protein digestibility assay was used to examine the effect of substituting on protein digestibility. The applied nonlinear mathematical models indicated a higher determination coefficient between experimental and predicted data (R2 ≥ 0.999). A maximum in vitro protein digestibility (IVPD) of 88.4, 84.1, 85.2% was obtained when using optimum level substituting with wheat flour (7.9, 9.3 or 5.2%) in the CB, RB or BH respectively for producing cookies. The maximum improvement or minimum reducing IVPD by using fibre sources in producing cookies ranged from ?0.25% in RB to 4.9% in CB.  相似文献   

15.
The production of extracellular amylase by the thermophilic fungus Thermomyces lanuginosus was studied in solid state fermentation (SSF). Solid substrates such as wheat bran, molasses bran, rice bran, maize meal, millet cereal, wheat flakes, barley bran, crushed maize, corncobs and crushed wheat were studied for enzyme production. Growth on wheat bran gave the highest amylase activity. The maximum enzyme activity obtained was 534 U/g of wheat bran under optimum conditions of an incubation period of 120 h, an incubation temperature of 50 degrees C, an initial moisture content of 90%, a pH of 6.0, an inoculum level of 10% (v/w), a salt solution concentration of 1.5:10 (v/w) and a ratio of substrate weight to flask volume of 1:100 with soluble starch (1% w/w) and peptone (1% w/w) as supplements.  相似文献   

16.
The specific activity of 137Cs and 90Sr from the global fallout, as well as from the fallout after the reactor accident at Chernobyl, was determined in flour, bran and straw from wheat, rye, barley and oats as well in the corresponding soils (Cambisol). The results show that the activity of 137Cs, but not of 90Sr, in the plant material was considerably higher in 1986, and still to some extent in 1987, compared to 1982. For 137Cs an 90Sr, as well as for most cereal samples, the activity in the bran and straw was significantly higher than in the flour. Determination of stable potassium and calcium in all samples revealed that this enrichment is, to a large extent, the result of a comparable enrichment of these elements in brans and straw. The plant/soil concentration ratios, averaged over all cereals, were for 137Cs (1982 and 1987): flour 0.026 +/- 0.018; bran 0.079 +/- 0.042; straw 0.055 +/- 0.027. For 90Sr (1982, 1986, and 1987): flour 0.19 +/- 0.095; bran 0.70 +/- 0.23; straw 2.35 +/- 0.82.  相似文献   

17.
Alternaria species have been reported to infect a wide variety of vegetables, fruits, and cereal crops. Wheat is one of the most consumed cereal worldwide. A sensitive HPLC-DAD methodology was applied to quantify alternariol (AOH), alternariol methyl ether (AME) and tenuazonic acid (TeA) in 65 samples of whole wheat, bran, and flour. The extraction methodology allowed extracting the three toxins simultaneously. Limits of detection in wheat were 3.4, 4.5, and 0.5 µg kg?1 for AOH, AME and TeA, respectively. For bran, these data were 3.1, 4.5, and 12 µg kg?1 and for flour 50, 70, and 14 µg kg?1, respectively. The studied recoveries were higher than 70% and RSD was below 10%. Wheat and bran samples showed low AOH and AME contamination compared to TeA. The averages levels found for TeA in wheat, bran and flour were 19,190, 16,760, and 7360 µg kg?1, respectively.  相似文献   

18.
Cereal grains are a major source of human food and their production has steadily been increased during the last several decades to meet the demand of our increasing world population. The modernized society and the expansion of the cereal food industry created a need for highly efficient processing technologies, especially flour production. Earlier scientific research efforts have led to the invention of the modern steel roller mill, and the refined flour of wheat has become a basic component in most of cereal-based foods such as breads and pastries because of the unique functionality of wheat protein. On the other hand, epidemiological studies have found that consumption of whole cereal grains was health beneficial. The health benefit of whole cereal grain is attributed to the combined effects of micronutrients, phytochemicals, and dietary fibre, which are mainly located in the outer bran layer and the germ. However, the removal of bran and germ from cereal grains during polishing and milling results in refined flour and food products with lower bioactive compounds and dietary fibre contents than those from whole grain. Also, the level of bioactive compounds in cereal food is influenced by other food preparation procedures such as baking, cooking, extrusion, and puffing. Therefore, food scientists and nutritionists are searching for strategies and processing technologies to enhance the content and bioavailability of nutrients, bioactive compounds, and dietary fibre of cereal foods. The objective of this article was to review the research advances on technologies for the enhancement of bioactive compounds and dietary fibre contents of cereal and cereal-based foods. Bioactivities or biological effects of enhanced cereal and cereal-based foods are presented. Challenges facing the application of the proposed technologies in the food industry are also discussed.  相似文献   

19.
不同谷物麸皮对面团流变学特性及面筋蛋白结构的影响   总被引:1,自引:0,他引:1  
本实验选用小麦麸皮、黑小麦麸皮、燕麦麸皮为原材料,探究在高添加量(质量分数30%)情况下不同谷物麸皮对面团流变学特性、面筋蛋白组成及结构的影响。结果表明,谷物麸皮含有丰富的膳食纤维,麸皮的加入使面团的吸水率、黏度崩解值显著增加,回生值显著降低,面团的形成时间、稳定时间虽与麸皮种类有关,但整体均呈上升趋势;添加麸皮的面筋蛋白中麦谷蛋白与麦醇溶蛋白比例增加了24.7%~73.0%、二硫键含量显著下降了26.0%~35.5%;面筋蛋白中的二级结构以β-折叠为主,小麦麸皮和黑小麦麸皮的加入使得面筋蛋白中的β-转角结构向β-折叠结构转化;扫描电子显微镜图显示麸皮的加入破坏了面筋蛋白原本均匀致密的微观结构。综上所述,谷物麸皮的加入改变了面筋蛋白的组成及二级结构,这些变化可能是导致面团流变学特性及面制品品质下降的原因。  相似文献   

20.
Two non‐starch polysaccharides, guar gum and wheat bran, were used at 15% replacement level in a cereal base to produce an extruded breakfast cereal product from both wholemeal and high‐ratio wheat flour mixes. The inclusion of the non‐starch polysaccharides into the flour bases had no significant effect on the expansion ratio of the products. However, the product density and bulk density of the extruded products increased with guar gum and wheat bran addition. The pasting properties of the raw flour and polysaccharide base as well as the extruded products were altered with the incorporation of polysaccharides, with guar gum‐enriched products showing elevated peak and final viscosity readings. This appeared to be related to moisture manipulation and hence the regulation of gelatinisation. In vitro starch hydrolysis of the raw bases and the extruded samples illustrated that the extrusion process significantly increased the availability of carbohydrates for digestion. Additionally, the inclusion of non‐starch polysaccharides in the raw bases significantly reduced the rate and extent of carbohydrate hydrolysis. This potentially glycaemic reducing action was also evident in the extruded products where the incorporation of guar gum at 15% yielded a reduction of starch hydrolysis of 36% in the wholemeal base and 32% in the high‐ratio white wheat flour base.  相似文献   

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