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1.
青鳞鱼蛋白风味酶控制水解动力学模型 总被引：1，自引：0，他引：1
在假设风味酶恒温控制水解动力学遵循内切酶限制水解动力学历程的前提下,通过实验方法求出了风味酶恒温控制水解动力学模型。结果表明,风味酶对青鳞鱼蛋白进行控制水解的动力学模型为:R= ( 54 .782e0 -0 .045s0 )exp( -0 .398DH),DH=2 .513ln[1+(21 .803e0 /s0 -0. 0179)t];其酶失活常数kd=22. 155 6min-1;水解反应能够顺利进行的条件是:e0 /s0 >c0,常数c0 =8 .214×10-4。验证实验证明,根据风味酶恒温控制水解动力学模型得到的理论水解度与实际水解基本吻合。 相似文献
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研究了木瓜蛋白酶的酶解温度、酶浓度、酶解时间、加水量、pH值对青鳞鱼可溶性蛋白得率的影响 ,探讨了α 氨态氮含量与青鳞鱼可溶性蛋白得率的关系。结果表明 :温度小于 5 0℃ ,随着酶解温度的提高、酶浓度的增加、酶解时间的延长青鳞鱼可溶性蛋白得率及α 氨态氮的含量均增加 ,α 氨态氮含量增加比可溶性蛋白得率的增加明显 ;加水量的增加 ,可溶性蛋白得率增加 ;pH值对水解效果及可溶性蛋白得率影响不大。综合考虑 ,最佳水解条件为 :温度 5 0℃ ,酶浓度为 1 5 0 0u/g ,酶解时间 80min ,m原料 :m水 =1∶2 ,pH 6 8。酶解所得可溶性蛋白经氨基酸分析仪检测 ,其氨基酸总量为 49 47mg/mL ,必需氨基酸占氨基酸总量的 41 0 % ,游离氨基酸含量为 6 3mg/mL ,肽含量为 87 2 %。 相似文献
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木瓜蛋白酶在制取青鳞鱼可溶性蛋白中的应用 总被引：6，自引：1，他引：5
研究了木瓜蛋白酶的酶解温度，酶浓度，酶解时间，加水量，pH值对青鳞鱼可溶性蛋白得率的影响，探讨了α－氨态氮含量与青鳞鱼与可溶性蛋白得率的关系。结果表明：温度小于50℃，随着酶解温度的提高，酶浓度的增加，酶解时间的延长青鳞鱼可溶性蛋白得率及α－氨态氮的含量均增加，α＝氨态氮含量增加比可溶性蛋白得率的增加明显；加水量的增加，可溶性蛋白得率增加；pH值对水解效果及可溶性蛋白得率影响不大。综合考虑，最佳水解条件为：温度50℃，酶浓度为1500u/g，酶解时间80min,m原料：m水＝1：2，pH6.8。酶解所得可溶性蛋白经氨基酸分析仪检测,其氨基酸总量为49.47mg/mL，必需氨基酸占氨基酸总量的41．0％，游离氨基酸含量为6.3mg/mL，肽含量为87．2％。 相似文献
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研究了青鳞鱼蛋白复合酶控制水解产物的功能特性。结果表明，复合酶控制水解能够显著地改善水解物的溶解性、乳化活力及起泡性能。水解物在pH2．0～10．0范围内其NSI为89．3％～98．5％，且在酸性范围NSI高于碱性范围；在酸性pH内水解物的乳化活力都高于112m^2／g，随着DH的增加，最大乳化活力出现的pH范围更宽广，但水解却降低了乳化稳定性。蛋白质质量分数为1％～5％时，FP随质量分数的增加而增加；泡沫形成后，未水解的蛋白质具有最高的稳定性，DH为8．4％的水解物具有最高的稳定性。 相似文献
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青鳞鱼蛋白复合酶控制水解物功能特性的研究 总被引：1，自引：0，他引：1
研究了青鳞鱼蛋白复合酶控制水解产物的功能特性。结果表明,复合酶控制水解能够显著地改善水解物的溶解性、乳化活力及起泡性能。水解物在pH 2.0~10.0范围内其NSI为89.3%~98.5%,且在酸性范围NSI高于碱性范围;在酸性pH内水解物的乳化活力都高于112 m2/g,随着DH的增加,最大乳化活力出现的pH范围更宽广,但水解却降低了乳化稳定性。蛋白质质量分数为1%~5%时,FP随质量分数的增加而增加;泡沫形成后,未水解的蛋白质具有最高的稳定性,DH为8.4%的水解物具有最高的稳定性。 相似文献
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【目的】优化太平洋牡蛎(Crassostreagigas)酶解工艺条件,并研究酶解产物及其超滤组分对体外培养的睾丸间质细胞增殖及睾酮分泌的影响。【方法】以多肽得率为参考标准,对木瓜蛋白酶酶解牡蛎的加酶量、初始pH、酶解时间、酶解温度进行单因素及正交实验优化;通过MTT法及酶联免疫吸附试验(ELISA)检测不同浓度牡蛎酶解产物及其超滤组分对TM3小鼠睾丸间质细胞增殖及睾酮分泌的影响。【结果】木瓜蛋白酶最佳酶解条件为加酶量3 000 U/g,初始pH 6. 5,酶解温度62.5℃,酶解时间4.5 h,在此条件下其多肽质量浓度为14.95 mg/mL;牡蛎酶解液及其超滤组分在0.25～1.00 mg/mL质量浓度范围内,与空白对照组相比,能够显著增加TM3细胞的增殖活性(P0.05),且具有浓度依赖性和时间依赖性。其中,5 ku和5～10 ku超滤组分细胞增殖活性及促进睾酮分泌活性均最强。【结论】牡蛎酶解产物及其超滤组分可有效增强小鼠睾丸间质细胞增殖活性并促进其分泌睾酮。 相似文献
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青鳞鱼蛋白复合酶控制水解动力学模型的研究 总被引：1，自引：0，他引：1
在假设复合酶恒温控制水解动力学遵循内切酶限制水解动力学历程的前提下 ,采用实验方法求出了复合酶恒温控制水解动力学模型。结果表明 ,复合酶对青鳞鱼蛋白进行控制水解的动力学模型为 :R =(0 .315 4e0 - 0 .0 186s0 )exp(- 0 .170DH) ,DH =5 .882ln[1+(0 .0 5 36 2e0 /s0 -0 .0 0 32 )t];其酶失活常数Kd=0 .0 5 36min- 1;水解反应能够顺利进行的条件是 :e0 /s0 >c0 ,常数c0 =5 .90× 10 - 2 。验证实验证明 ,根据复合酶恒温控制水解动力学模型得到的理论DH与实际DH基本吻合 ,该动力学模型具有很强的实用价值。 相似文献
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胰蛋白酶的固定化采用吸附-交联法.在单因素试验基础上,通过正交试验,获得了胰蛋白酶固定化的最佳条件酶与载体体积比为21,吸附时间为10 h,pH=4.5,缓冲液浓度为0.05 mol/L,戊二醛的质量分数为0.1%.此条件下制得的磁性酶活力回收在50%左右,相对酶活力达74%,该磁性酶对啤酒澄清防止冷浑浊有明显效果. 相似文献
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为探明雌雄细鳞斜颌鲴不同部位的蛋白质营养价值,测定雌雄细鳞斜颌鲴中脑、眼、性腺、鳔、肌肉及皮的水分、粗蛋白等基本营养成分,对各部位的氨基酸含量进行比较分析与评价。结果表明:1)鳔和皮中粗蛋白质量分数较高,肌肉次之,眼最低(♀/♂,8.48%/7.37%),雌雄鱼各部位粗蛋白质量分数,除雌性性腺极显著高于雄性(P<0.01)外,其他部位无显著差异(P>0.05)。2)6部位均测出18种氨基酸;3)6部位总氨基酸含量大小依次如下:雌性为鳔、皮、卵巢、肌肉、脑、眼,雄性为皮、鳔、肌肉、精巢、脑、眼;4)在性腺的氨基酸组成中,雌细鳞斜颌鲴氨基酸总量(20.70%)高于雄性(9.11%),差异极显著(P<0.01);5)雌雄的眼、鳔、肌肉、皮第一限制性氨基酸均为缬氨酸,雌鱼脑的第一限制性氨基酸为苏氨酸,雄鱼脑和雌雄性腺第一限制性氨基酸为(蛋氨酸+胱氨酸);6)雌雄脑的必需氨基酸指数(EAAI)在6部位中最高,分别为82.13和80.91,肌肉的EAAI分别为72.89和71.80,皮的EAAI最低,分别为39.07和38.29。雌雄细鳞斜颌鲴6部位均含有丰富的氨基酸,其中雌性营养价值较雄性高。 相似文献
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The new polyenzyme method for making gravy from Harengula zunasi offal involves protein enzymolysis with flavorase after proper alkaline and neutral protease levels were established by orthogonal trials to select the best hydrolytic conditions for processing offal with alkaline and neutral protease. The conditions for the polyenzyme method were pH of 7.0, temperature of 50℃ , alkaline and neutral protease concentration of 1.5% respectively, hydrolysis time of 120 min, andflavorase concentration of 2.0% , for 60 min. The new gravy-making technology yields a nutritious and delicious gravy containing 40.3 % of total essential amino acids, with delicious amino acids Glu, Asp, Gly, Ala, Pro and Ser comprising 49.5% , total and amino nitrogen being respectively1.9 and 1.1 g/100 g (amino acid nitrogen being 61.0% of total nitrogen), The polyenzyme method was used to make 14.8% protein gravy from Harengula zunasi offal. In addition, in inorganic elements, the phosphorus content is the highest. 相似文献
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Qiaowen Jiang Zhimin Cao Daoru Wang Yuanchao Li Zhongjie Wu Jianyu Ni 《中国海洋大学学报(英文版)》2017,16(6):1072-1080
Geochemical ratios in coral reef skeletons could be used as proxies to reconstruct past climatological and environmental records in data-poor regions. Using a 103-year data set(1902 to 2005), the annual variations in Ba/Ca and Mn/Ca ratios of Porites lutea skeletons at an eastern offshore area of Hainan Island(19?12'28.4'N, 110?37'38.8'E) were analyzed using inductively coupled plasma-optic emission spectrometry(ICP-OES). The analysis results showed that Ba/Ca ratios varied from a minimum of 3.120 μmol mol~(-1) in 1903 to a maximum of 10.064 μmol mol~(-1) in 1944, with an average of 5.256 μmol mol~(-1). Mn/Ca ratios varied from 0.206 to 5.708 μmol mol~(-1) with an annual average of 1.234 μmol mol~(-1), with peak values in 2001, 1964 and 1932, that correlated with strong rainfall events caused by typhoons. Variation in Ba/Ca and Mn/Ca ratios were compared with available river discharge and precipitation records, providing insight into past climatological events. Human activities and their indirect effects could impact the strength of the relationship between Ba/Ca and Mn/Ca ratios and observed precipitation and terrestrial input in the future. 相似文献
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The new polyenzyme method for making gravy fromHarengula zunasi offal involves protein enzymolysis with flavorase after proper alkaline and neutral protease levels were established by orthogonal
trials to select the best hydrolytic conditions for processing offal with alkaline and neutral protease. The conditions for
the polyenzyme method were pH of 7.0, temperature of 50°C, alkaline and neutral protease concentration of 1.5% respectively,
hydrolysis time of 120 min, and flavorase concentration of 2.0%, for 60 min. The new gravy-making technology yields a nutritious
and delicious gravy containing 40.3% of total essential amino acids, with delicious amino acids Glu, Asp, Gly, Ala, Pro and
Ser comprising 49.5%, total and amino nitrogen being respectively 1.9 and 1.1 g/100 g (amino acid nitrogen being 61.0% of
total nitrogen), The polyenzyme method was used to make 14.8% protein gravy fromHarengula zunasi offal. In addition, inorganic elements, the phosphorus content is the highest.
This project was aided financially by the Guangdong Science and Technology Office (No. 2KM06002S). 相似文献
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比较不同温度、光照及海水相对密度条件下无菌与自然带菌波吉卵囊藻(Oocystis borgei)生长的差异。结果表明:在20℃时,无菌藻的比增长率(μ)和叶绿素a(Chla)含量分别为0.398d-1和0.117mg/L,均显著高于带菌藻(P<0.05),在28和35℃时,无菌藻和带菌藻生长无显著性差异(P>0.05);在照度为16μmol·m-2·s-1时,无菌藻平均比增长率μ和Chla含量分别为0.345d-1和0.123mg/L,均显著高于带菌藻(P<0.05),在照度为39和88μmol·m-2·s-1条件下,无菌藻和带菌藻生长无显著性差异(P>0.05);在海水密度为1.007、1.020和1.030g/mL时,无菌藻和带菌藻的生长均无显著性差异(P>0.05),μ和Chla含量分别为0.325～0.374d-1和0.085～0.133mg/L。 相似文献
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以鲢鱼蛋白为原料,采用5种不同复合蛋白酶(P1,P2,P3,P4,P5)进行酶解,综合研究了复合生物酶酶量、酶解时间、pH、酶解温度等对鲢鱼蛋白酶解降血压肽ACE活性抑制效果的影响。结果表明,复合酶P1酶解降血压肽对ACE抑制率经体外检测为88.08%,具有最佳的酶解效果。对应最佳条件为:酶量25 IU/mL,酶解时间2 h,pH7.0,酶解温度60℃。 相似文献
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刘晓华 《大地测量与地球动力学》1993,(3)
本文利用WDM—89地球重力模型(完整到180阶)的位系数计算了南北构造带中段的30—50阶、50—100阶、100—150阶、150—180阶及2—180阶卫星重力异常,并探讨了该区的壳幔结构。结果表明,该区上地幔存在一个规模较大的低密度区。若尔盖和雅江一带有两个底部相连的高密度地幔块体。该区壳幔结构不但横向很不均匀,而且纵向也极为复杂。据此对区域岩石圈动力学特征进行了讨论。 相似文献
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In this study, we isolated a polysaccharide from Branchiostoma belcheri (PBB) by enzymatic protein hydrolysis and alcohol precipitation. We investigated the effects of PBB supplementation on DNA
oxidation and growth of the transplanted tumor cells Sarcoma (S180) in mice. Sixty healthy Kunming mice weighing between 18 and 25 g were randomly assigned to 6 groups, each consisting of
10 animals. All the mice, except for the blank control group, were inoculated with S180 sarcoma cells into the axilla of the
left foreleg. PBB was given to mice by gavage at doses of 0 (model control), 25, 50, or 100 mg/kg b.w. in 0.2 ml saline for
30 days. The fifth group of S180-mice was given cytoxan (50 mg/kg) by peritoneal injection as a positive control group. The animals had free access to food
and water. The mice were sacrificed after the final treatment and blood was quickly collected. Spontaneous and oxidized DNA
damage of peripheral lymphocytes induced by H2O2 were analyzed by SCGE. O6-methyl-guanine (O6-MeG) was measured by high-performance capillary zone electrophoresis. The average tumor weights (0.856–1.118 g) of the three
PBB groups were significantly lower than that of the model control group (1.836 g) (p<0.05). The tumor inhibition ratios of the PBB groups were 39.1%–53.4% and similar to the cytoxan positive group (57.5%).
There were no significant differences in spontaneous DNA damage in peripheral lymphocytes among the groups. The oxidative
DNA damage induced by 10 μmol/L H2O2 in the 50 and 100 mg/kg b.w. groups were 246.1 AU and 221.7 AU, respectively, both of which were significantly lower than
that in the model group (289.0 AU; p<0.05). The plasma concentrations of O6-MeG in the 25, 50, and 100 mg/kg supplemented groups were 2.09 μmol/L, 1.86 μmol/L, and 1.63 μmol/L, respectively, all of
which were significantly lower than that of the model group (2.67 μmol/L; p<0.05). These results indicated that PBB may have antioxidative activity and thus reduce oxidation-induced DNA damage. 相似文献