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1.
超声波法提取小麦胚芽蛋白的研究   总被引:11,自引:0,他引:11  
采用超声波法提取小麦胚芽蛋白(WGP)的方法,通过单因素和正交实验,得出最适提取条件:料水比为1:25,pH为9.0,超声处理时间为20min,功率为200W,此条件下小麦胚芽蛋白的提取率达到98.68%。与普通的碱溶酸沉法相比,提取率提高了29.66%。用SDS—PAGE电泳测定WGP分子量,分别为55.7kDa、44、41kDa、40.7kDa、23.7kDa、20、41kDa和很多18.14kDa~12.41kDa小分子量蛋白质,超声处理前后WGP分子量分布没有明显改变,超声处理没有改变蛋白质的一级结构。  相似文献   

2.
目的 研究低温等离子体(cold atmospheric plasma, CAP)对南美白对虾肌肉蛋白质性质和结构的影响。方法 采取不同等离子体条件(电压:20、40、60 kV;时间:1、2、3 min)对南美白对虾肌肉蛋白进行处理,通过分析肌浆蛋白、肌原纤维蛋白、表面疏水性、总巯基含量、Ca2+-ATPase活性、十二烷基硫酸钠-聚丙烯酰胺电泳(sodium dodecyl sulfate polyacrylamide gel electrophoresis, SDS-PAGE)指标,探讨了CAP对南美白对虾肌肉蛋白的影响。结果 与对照组相比,随着处理时间和电压的增加,虾体的肌浆蛋白、肌原纤维蛋白含量、总巯基含量、Ca2+-ATPase活性均显著下降(P<0.05),而表面疏水性显著升高(P<0.05)。处理条件为60 kV、3 min时,样品各指标变化最明显。SDS-PAGE电泳显示肌原纤维蛋白的肌球蛋白重链条带增强,副肌球蛋白条带逐渐消失,在分子量为25 kDa附近出现新的蛋白条带。结论 CAP处理能导致南美白对虾肌肉氧化,蛋白质变性。  相似文献   

3.
麦胚球蛋白的分离制备及理化性质研究   总被引:7,自引:0,他引:7  
采用Osborne分级分离的方法制备得到麦胚球蛋白,获得的球蛋白的蛋白质含量为87.3%(干基),得率为5.8g/100g脱脂麦胚粉,其在脱脂麦胚粉蛋白中的构成比例为15.6%。氨基酸分析表明,除蛋氨酸略低于FAO/WHO的推荐值外,其它七种必需氨基酸都高于或接近FAO/WHO的推荐值;另外,谷氨酸、精氨酸、天冬氨酸和丙氨酸的含量十分丰富,而胱氨酸和半胱氨酸的含量最低。还原的十二烷基硫酸钠-聚丙烯酰胺电泳(SDS—PAGE)表明,麦胚球蛋白主要有六备谱带,其分子量依次为57.8kDa、41.8kDa、38.7kDa、24.1kDa、16.5kDa和14.3kDa。差示扫描量热仪(DSC)分析表明麦胚球蛋白干粉和稀溶液的变性温度分别为98.2℃和83.8℃。  相似文献   

4.
以白木通籽为原料,采用碱提酸沉法,制备白木通籽分离蛋白(API),并对其理化性质与功能性质进行了分析。结果表明:白木通籽分离蛋白含17种氨基酸,其中谷氨酸和天门冬氨酸的含量相对较高,有贮藏蛋白的共性。苏氨酸为白木通籽分离蛋白的第一限制性氨基酸。通过SDS—PAGE分析,白木通籽分离蛋白的亚基分子量范围为25—35ku。圆二色性光谱分析表明,白木通籽分离蛋白的二级结构主要由β-折叠和无规则卷曲组成,含量分别为31.2%和36.6%。白木通籽分离蛋白的等电点在pH4~5之间.在此pH范围内.蛋白的溶解性和起泡能力均最低.  相似文献   

5.
本文通过SDS—PAGE电泳分析和氨基酸分析研究了两个大麦芽国产A和进口B酿造过程中的蛋白质及啤酒混浊蛋白,结果发现:影响啤酒非生物稳定性的蛋白质主要是分子量为37~43kDa和3~20kDa的混浊蛋白组分;啤酒混浊蛋白主要以谷氨酸和脯氨酸为主,A和B的谷氨酸含量分别为35.6%和36.9%,脯氨酸含量分别为20.2%和18.0%;认为谷氨酸和脯氨酸是啤酒混浊蛋白的最重要氨基酸成分。  相似文献   

6.
啤酒冷混浊蛋白的分析及硅胶、PVPP吸附效果比较   总被引:2,自引:0,他引:2  
利用SDS—PAGE电泳对3种不同品牌的啤酒中的冷混浊蛋白进行分析,结果表明,引起啤酒冷混浊的蛋白分为醇溶性蛋白和水溶性蛋白。其中醇溶性冷混浊蛋白占总含量的70%左右,分子量在43~50kDa之间。水溶性冷混浊蛋白的分子量在8~14kDa之间。另外,比较硅胶、PVPP的吸附效果,经二者处理后的样品浊度都有明显的下降,但经硅胶处理后的样品浊度更低一些。比较硅胶吸附前后样品的泡持时间没有很大的变化,而经PVPP处理后的样品泡持时间有一定的改变。因此,在啤酒生产过程中添加硅胶,能够有效地除去啤酒冷混浊蛋白,而且不会影响啤酒的泡持性。  相似文献   

7.
以采珠后的三角帆蚌肉和外套膜为原料,分别采用纯水和5%的NaCl溶液对其中的水溶性和盐溶性蛋白(合称为可溶性蛋白)进行提取,并对所获得蛋白质的一些性质进行比较研究。实验结果表明,运用1:10(m/V)纯水提lh(沉淀再重复提取1次1和1:10(m/V)5%NaCl提取24h所得的可溶性蛋白回收率均达到65%以上,SDS.PAGE电泳显示,三角帆蚌外套膜和蚌肉的水溶性蛋白较一致,而两者的盐溶性蛋白则不同,差异表现在:外套膜的盐溶性蛋白在82~97kD有4条带,而蚌肉的盐溶性蛋白质只在97kD处有一条带。氨基酸分析结果表明,所提取的可溶性蛋白必需氨基酸含量较高,均达46%以上,外套膜可溶性蛋白的呈味氨基酸(Glu和Asp)占氨基酸总量的28%以上,蚌肉的高达35%以上。  相似文献   

8.
开发了操作简便、电泳图谱清晰、分辨率高的啤酒大麦种子醇溶蛋白SDS—PAGE电泳方法,利用Gel—Pro软件对电泳图谱进行条带分析和比较,建立了每个品种的蛋白质“指纹”,组成加拿大啤酒大麦品种标准图谱库。利用Cross Checker2.8和MEGA3软件对供试啤麦品种进行遗传聚类分析,结果与传统分类相近。进行了人工混种试验,并成功将该技术应用于公司2004年进口加拿大啤麦的品种和纯度鉴定。  相似文献   

9.
刘岩林  佟恩杰 《啤酒科技》2011,(8):58-61,67
本文研究了11种地方品种大麦(普通大麦)和相对应的麦芽。根据相同的合约,11种大麦在相同气候和土壤条件下种植。为了确定相同种植条件下的大麦样品在糖化过程中的酶活变化,所有试样测定了α-淀粉酶和β-淀粉酶的活力。另外,通过SDS—PAGE测定了发芽过程中蛋白质类型的改变。每个大麦试样的蛋白质含量、淀粉酶数量和质量之间都有差别,尽管通过sDS—PAGE分析Betamy1提取液(含β-淀粉酶)得到两个务带41-42kDa和55—58kDa,但由于仅仅55—58kDa带有差别,因此考虑只用它来评估大麦是否适合于啤  相似文献   

10.
不同电解质溶液对AOT反胶束溶液萃取大豆蛋白的影响研究   总被引:1,自引:0,他引:1  
本文研究了不同电解质溶液对AOT反胶束溶液萃取大豆蛋白的影响,对蛋白质的提取率及通过SDS—PAGE电泳试验对蛋白质的亚基条带进行了比较。通过试验,可知阴离子与阳离子对反胶束溶液萃取大豆蛋白的前萃与后萃都有影响,电解质KCl和NaNO3溶液所提取的蛋白质得率较高,分别为56.71%和58.15%。  相似文献   

11.
The toxicity of the gastropod Nassarius glans was investigated. This gastropod was implicated in an incident of food paralytic poisoning on Tungsa Island, Taiwan, in April 2004. Six victims consumed both digestive glands and muscle. These tissues contained high concentrations of toxin; their highest toxicity scores were 2,048 and 2,992 MU/g, respectively, based on the tetrodotoxin (TTX) bioassay. The toxin was purified from these gastropods and analyzed by high-performance liquid chromatography, which revealed TTX and related compounds 4-epi TTX and anhydro-TTX; paralytic shellfish poisons were not found. The urine and blood samples from patients were cleansed using a C18 Sep-Pak cartridge column and 3,000 molecular weight cutoff Ultrafree microcentrifuge filters, and the eluate was filtered and analyzed by liquid chromatography and mass spectrometry. The detection limit for TTX was 1 ng/ml. The standard curves were linear in the range 30 to 600 ng/ml for urine and 1 to 30 ng/ml for blood. TTX was detected in all urine samples but in only three of four blood samples tested. Thus, the causative agent of gastropod food poisoning was identified as TTX.  相似文献   

12.
Consumption of nassariid gastropods often leads to poisoning incidents in some coastal provinces in China. To elucidate the pattern of toxicity dynamics and origin of toxins, samples of gastropod Nassarius spp. were collected from late May to early August 2007 from Lianyungang, Jiangsu province, where the poisoning incidents have been frequently reported. Toxicity was first screened with the mouse bioassay method, and tetrodotoxin and its analogues (TTXs) were analysed with high-performance liquid chromatography coupled with an ion-trap mass spectrometer (HPLC-MS(n)). The toxicity of nassariid N. semiplicatus showed an 'M'-shaped pattern of fluctuation during the sampling season. Two peaks of toxicity appeared in late May and late July. The maximum toxicity was recorded on 24 May, with the value of 846 mouse unit (MU) g(-1) of tissue (wet weight). TTX and its analogues trideoxyTTX, 4-epiTTX, anhydroTTX and oxoTTX were detected in the nassariid samples. TrideoxyTTX but not TTX was the major toxin in all the samples. No paralytic shellfish poison (PSP) was detected in the sample with the maximum toxicity by HPLC-FLD analysis. Variation of TTX content in the tissue of nassariid gastropods correlates well with the dynamics of toxicity. It is suggested that TTXs are the major toxins corresponding to the toxicity of the nassariids, and May and July are the high-risk seasons for consumption of nassariids, which is critical for the management of poisoning incidents.  相似文献   

13.
The efficiency of thin-layer capping in reducing sediment-to-water fluxes and bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans, hexachlorobenzene, and octachlorostyrene was investigated in a boxcosm experiment. The influence of cap thickness (0.5-5 cm) and different cap materials was tested using a three-factor experimental design. The cap materials consisted of a passive material (coarse or fine limestone or a marine clay) and an active material (activated carbon (AC) or kraft lignin) to sequester the contaminants. The cap thickness and the type of active material were significant factors, whereas no statistically significant effects of the type of passive material were observed. Sediment-to-water fluxes and bioaccumulation by the two test species, the surface-dwelling Nassarius nitidus and the deep-burrowing Nereis spp., decreased with increased cap thickness and with addition of active material. Activated carbon was more efficient than lignin, and a ~90% reduction of fluxes and bioaccumulation was achieved with 3 cm caps with 3.3% AC. Small increases in fluxes with increased survival of Nereis spp. indicated that bioturbation by Nereis spp. affected the fluxes.  相似文献   

14.
Consumption of nassariid gastropods often leads to poisoning incidents in some coastal provinces in China. To elucidate the pattern of toxicity dynamics and origin of toxins, samples of gastropod Nassarius spp. were collected from late May to early August 2007 from Lianyungang, Jiangsu province, where the poisoning incidents have been frequently reported. Toxicity was first screened with the mouse bioassay method, and tetrodotoxin and its analogues (TTXs) were analysed with high-performance liquid chromatography coupled with an ion-trap mass spectrometer (HPLC-MS n ). The toxicity of nassariid N. semiplicatus showed an ‘M’-shaped pattern of fluctuation during the sampling season. Two peaks of toxicity appeared in late May and late July. The maximum toxicity was recorded on 24 May, with the value of 846 mouse unit (MU) g?1 of tissue (wet weight). TTX and its analogues trideoxyTTX, 4-epiTTX, anhydroTTX and oxoTTX were detected in the nassariid samples. TrideoxyTTX but not TTX was the major toxin in all the samples. No paralytic shellfish poison (PSP) was detected in the sample with the maximum toxicity by HPLC-FLD analysis. Variation of TTX content in the tissue of nassariid gastropods correlates well with the dynamics of toxicity. It is suggested that TTXs are the major toxins corresponding to the toxicity of the nassariids, and May and July are the high-risk seasons for consumption of nassariids, which is critical for the management of poisoning incidents.  相似文献   

15.
织纹螺中河豚毒素限量研究   总被引:1,自引:0,他引:1       下载免费PDF全文
目的提出织纹螺中河豚毒素的限量建议值,为日常监控提供判定依据。方法对织纹螺中河豚毒素的来源、含量情况、毒性、检测标准以及国内外有关河豚毒素、麻痹性贝类毒素的规定等文献资料进行分析比较,探讨织纹螺中河豚毒素的限量要求。结果织纹螺可分为有毒织纹螺、无毒织纹螺、季节性有毒织纹螺,织纹螺中河豚毒素的浓度范围为0~177 mg/kg,而且河豚毒素毒性是麻痹性贝类毒素的30倍以上(以两者对小鼠的经口LD50比较)。对光织纹螺、正织纹螺等常年带毒且毒素含量高的有毒织纹螺应有效识别并禁止采捕、销售、食用,建议无毒织纹螺和季节性有毒织纹螺中河豚毒素的限量为0.05 mg/kg,测定方法采用GB/T 23217—2008《水产品中河豚毒素的测定》。结论提出织纹螺中河豚毒素的限量建议值应合理可行,有效地完善了织纹螺中河豚毒素的监控体系,保障广大公众的身体健康与生命安全。  相似文献   

16.
Isoelectric focusing (IEF) using 9.2M urea and 6.2% (v/v) ampholytes in a polyacrylamide gel was used to separate protein banding patterns for species identification of pink, white and rock shrimp. A 17-hr focusing time was used. IEF of water extracts of raw shrimp showed excellent banding patterns useful for distinguishing each shrimp species. For cooked shrimp, water and sodium dodecyl sulfate (SDS) were better protein extractants. Detection of shrimp species in a mixture was difficult due to similar banding patterns between closely related species.  相似文献   

17.
Isoelectric focusing (IEF) polyacrylamide gel containing an 80% pH 4–6.5 and 20% pH 3–10 ampholyte mixture greatly improved protein banding pattern for species identification of water extracts of raw pink, white and rock shrimp compared with the system using only the pH 3–10 range ampholyte. Identification of a specific species in mixture samples was achieved by the detection of water-extractable shrimp specific protein bands present in the gel. Sodium dodecyl sulfate (SDS) was a better protein extractant than water for cooked shrimp. Both water and SDS extracts of cooked shrimp showed specific protein banding patterns and improved resolution for species identification.  相似文献   

18.
大豆蛋白亚基组成对其功能特性的影响   总被引:3,自引:0,他引:3  
本文通过采用不连续的十二烷基磺酸钠-聚丙烯酰胺凝胶电泳技术,对不同所选大豆品种中蛋白质的亚基组成及其比值(75/11S)进行了测定,得出品种间差异对蛋白质亚基组成的变化影响较明显。并且采用流变仪测定不同品种分离蛋白的物理特性(凝胶硬度、表观弹性值及乳化值)。分别将这三个功能性指标与各亚基组成进行统计相关分析,得出不同基组成与其功能性之间相关显著性各不相同。其中7S/11S比值对其功能影响最重要。通过研究大豆蛋白的结构组成,对探索蛋白功能特性方面具有重要的作用。  相似文献   

19.
After washing the minced muscle tissue of 5 species of white-fleshed fish twice with water and a third time with 0.15% (26 mM) NaCl solution, a considerable, portion of the remaining protein was soluble when extracted with water at a 1:20 ratio. The amount of protein extracted was 20–36% of the protein extracted by buffered 1 M Lid solution, a good protein extractant. This amount of protein indicates that the extracted proteins were primarily myofibrillar. When soluble protein was plotted versus the logarithm of the NaCl concentration in the extracting solution, an inverse linear relationship was observed. The moisture content of the fish paste was related linearly to the log of the water-soluble protein with a correlation coefficient of 0.945. The solubility of the proteins of washed, minced Atlantic mackerel was much less than that of the five white-fleshed species tested.  相似文献   

20.
大宗淡水鱼类原料特性比较分析   总被引:2,自引:0,他引:2  
对7种大宗淡水鱼的原料特性进行比较分析,测定7种大宗淡水鱼鱼体各部分比例、采肉率、基本成分、pH值及蛋白质组成,并对鱼背肉进行质地多面剖析(TPA)测试。结果表明:7种大宗淡水鱼之间内脏和鱼头所占比例差异较明显;青鱼的采肉率最高为54.33%,鳙鱼的最低为32.80%;水分、灰分和粗蛋白含量差异较小;粗脂肪含量鳊鱼最高为4.08%;非蛋白氮、水溶性蛋白、盐溶性蛋白、碱溶性蛋白和碱不溶性蛋白在7种鱼肉中所占比例最高的分别为鲢鱼(1.67%)、鲤鱼(4.68%)、草鱼(9.91%)、鲤鱼(2.45%)和鳊鱼(0.83%);综合考虑TPA测试的相关参数,青鱼和鲤鱼肉的质构特性较好。  相似文献   

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