双酶同加法制备花生粕多肽的工艺研究

选用AS1.398中性蛋白酶和木瓜蛋白酶作为水解酶,采用双酶同加法制备了花生粕功能性小肽.对各水解工艺参数进行了优选,发现各因素对蛋白水解度影响的顺序依次为:反应温度＞pH值＞底物浓度＞酶用量＞反应时间,确定最佳工艺参数如下:底物浓度为3.5%、反应温度为45℃、酶用量为12 500 U·g-1、pH值为7.5、反应时间为3.0 h.     

花生粕制备活性肽复合工艺研究

利用木瓜蛋白酶和中性蛋白酶水解花生粕提取花生蛋白。研究了温度、粕水比、提取时间对多糖提取率的影响,确定最佳提糖条件为温度80℃、粕水比1：25、提取时间1h。通过正交实验研究了加酶量、液固比、水解时间对蛋白质提取率的影响。确定最佳工艺参数为加酶量3％、粕水比1：25、水解时间2h,在此条件下,蛋白质转化率为80％。最终先去糖再酶解复合工艺蛋白收率为60％,相对分子量1000Da以下的活性肽占87％。     

酶解大豆粕蛋白制备大豆低分子肽的研究

以小分子肽得率为考察指标,研究了由枯草杆菌AS1.398中性蛋白酶制备大豆低分子肽的工艺条件。通过单因素实验和正交实验确定AS1.398中性蛋白酶酶解大豆粕蛋白制备大豆低分子肽的最佳条件为:底物浓度6%、温度45℃、加酶量17 000 U.g-1、pH值7.5。检测了在最佳条件下水解不同时间所得酶解液的活性,发现水解2.5 h的大豆肽液的抗氧化活性最强。     

可控酶解蚕蛹蛋白制备抗氧化活性多肽的研究

以脱脂、脱色后的蚕蛹蛋白粉为原料,选取碱性蛋白酶、胰蛋白酶、中性蛋白酶、木瓜蛋白酶和胃蛋白酶对超声处理后的蚕蛹蛋白溶液进行单酶以及复合酶水解实验,以蛋白水解度、多肽得率和水解产物的抗氧化活性为指标筛选出最适单酶和最适复合酶,采用响应面法确定可控酶解蚕蛹蛋白制备抗氧化活性多肽的最佳工艺条件为:选用碱性蛋白酶+中性蛋白酶(碱性蛋白酶∶中性蛋白酶=1.3∶1)作为最适水解酶,超声处理(10min,工作3s,间歇2s)蚕蛹蛋白溶液,pH值7.47、固液比1∶10(g∶mL)、加酶量2.1%、水解时间2.7h、温度59.2℃。在此工艺条件下,蛋白水解度为41.73%,多肽得率为33.29%,水解产物的羟基自由基清除率为59.48%、超氧阴离子自由基清除率为40.57%。     

脱脂豆粕酶法制备大豆肽

采用单因素实验研究了超声处理对脱脂豆粕蛋白质浸提率的影响,结果表明,容器式超声仪(300 W)浸提蛋白的最佳工艺为:频率30 kHz、料液比(质量体积比)为5%、在pH值8.5下处理20 min,此时上清液中蛋白质浓度增加58.68%.比较了五种蛋白酶对脱脂豆粕的水解效果,筛选出水解能力最强的碱性蛋白酶, 用正交实验法确定了其水解脱脂豆粕的最佳条件为:底物质量分数5%、酶用量10 000 U/g底物、温度55℃、pH值8.5、反应时间4 h,此时大豆肽溶出率为59.34%.     

复合酶法制备紫花芸豆抗氧化肽

目的 采用复合酶法制备紫花芸豆蛋白抗氧化肽.方法 以水解度为指标选定碱性蛋白酶和中性蛋白酶为复合酶组合,在单因素试验基础上,进行复合酶水解紫花芸豆蛋白的响应面优化.结果 最适水解条件为:温度55℃,pH 10,酶添加比例为1∶2(碱性蛋白酶:中性蛋白酶),酶添加量5 000 u/mL,在此条件下,紫花芸豆蛋白的水解度为...     

虾肉的蛋白酶酶解过程研究

以蛋白水解度为主要目标，通过实验研究了虾肉的酶解过程。比较了不同蛋白酶制剂对虾肉的酶解效果，确定了一种适宜于酶解虾肉的碱性蛋白酶，并通过实验优化了相应的工艺控制条件。得到的最佳工艺条件为：水肉比1：1-2：1，碱性蛋白酶质量分数0．3％（酶活力4．75×10^4U／mg），pH8-9，温度55-60℃，酶解时间4h。在此条件下，虾肉蛋白的水解度可达28％以上。此外，实验结果还表明加热预处理不能提高虾肉蛋白的水解度。     

竹黄两种预水解制备糠醛的工艺比较研究

为使竹屑资源得到充分利用,对两种预水解制备糠醛的工艺进行了比较探究。首先采用亚硫酸氢钠预处理和稀酸预处理对半纤维素进行提取,然后研究了反应温度、反应时间、硫酸浓度、戊糖初始浓度和NaCl用量对糠醛收率的影响,最后对水解底物的酶解效果进行了初步探究。在相同的酶解条件下,亚硫酸氢钠预水解底物酶解率高于稀酸水解底物酶解率。     

木瓜蛋白酶水解明胶制备多肽的工艺研究

以明胶为原料,用木瓜蛋白酶降解制备多肽。试验中用甲醛滴定法和三氯醋酸法(TCA)测定明胶水解度,并将两种方法进行比较。得出甲醛滴定法简单易行便于过程控制,适合于工业生产需要。并系统的研究了pH、温度、酶量、底物浓度、以及反应时间等因素对明胶降解的影响,确定了制备护发调理剂最佳的水解工艺条件:底物浓度5%(w/v)明胶溶液,pH=7.0,木瓜蛋白酶量0.20%～0.30%,反应温度60℃,反应时间60 min。     

三相泡沫灭火剂的改良

三相泡沫灭火剂是近年来应用于煤矿的新型灭火剂,可快速有效地解决大范围采空区、高冒区、高温点等普通防灭火措施难以解决的难题。但其施用量巨大,必须考虑其对环境的潜在危害。以特定酶解后的南瓜籽粕蛋白浓缩液为发泡基料,期望获得一种高生物降解性的三相泡沫灭火剂。结果表明:采用碱性蛋白酶为工具酶,在底物浓度100 g/L、温度50℃、加酶量为12 500μ/g,pH值为10. 0的条件下,水解3. 5 h的蛋白水解液是最佳发泡基料;其使用28 d后的生物降解率为93%,易于降解。     

Optimization of Enzymatic Production of Oligopeptides from Apricot Almonds Meal with Neutrase and N120P

Neutrase 0.8L and N120P proteases were used for oligopeptide production from apricot almonds meal, and response surface design was carried out to optimize the effect of hydrolysis conditions on hydrolysis degree (DH) and oligopeptide yield rate. Four independent variables were used to optimize the hydrolysis process: hydrolysis temperature (X(1)), enzyme-to substrate ratio (E/S) (X(2)), substrate concentration (X(3)) and reaction time (X(4)). Statistical analysis indicated that the four variables, quadratic terms of X(1), X(3), and X(4), and the interaction terms with X(1) had a significant (p < 0.05) effect on DH. The yield rate was also significantly affected by the four variables and quadratic terms of X(1), X(2) and X(4). Two mathematical models with high determination coefficient were obtained and could be employed to optimize protein hydrolysis. The optimal hydrolysis conditions were determined as follows: hydrolysis temperature 52.5 °C; enzyme-to-substrate ratio (E/S) 7200 U/g; substrate concentration 2%; reaction time 173 min. The initial pH 6.5 and Neutrase-to-N120P dosage ratio 2:1 were fixed in this study according to the preliminary research. Under these conditions, the experimental DH and yield rate were 34.10 ± 5.25% and 72.42 ± 2.27%, respectively.     

青霉素菌丝中蛋白质酶法水解工艺

采用碱热法溶解青霉素菌丝,研究酶法催化水解菌丝溶解液中蛋白质转化为氨基酸的过程.考察酶种类、溶解液pH值、酶与蛋白质质量比、反应温度和时间等因素对蛋白质水解度的影响,建立最佳水解工艺.结果 表明,酶种类、酶与蛋白质之比、pH、温度和时间均对蛋白质水解过程产生影响.以单酶为催化剂,碱性蛋白酶催化水解效果最好,蛋白质水解度...     

不同预处理方法对玉米蛋白水解的影响

在没有外加碱的pH值渐变条件下,考察了添加乙醇、添加亚硫酸盐、特殊热处理三种方法对玉米蛋白水解度的影响。并在此基础上通过正交试验进一步优化出水解玉米蛋白的最佳条件：水解温度为60℃,酸性蛋白酶加入量为10%（g/g）,底物浓度为80 g/L,水解时间为8 h。在上述最佳条件下,玉米蛋白的降解率可达36.70%,蛋白质的水解度可达19.85%,水解产物的平均分子量达到1918。结果表明,采用特殊的热处理方法能够显著提高玉米蛋白降解率以及蛋白质水解度。     

Enzymatic modification of proteins of commercial sesame meals (Sesamum indicum, L.)

Sesame (Sesamum indicum, L.) is one of the most important oilseed crops in Venezuela. However, the low solubility of the flour made of commercial meals does not allow its use in the preparation of fluid foods. To solve this situation, the alternative of solubilizing the sesame proteins by an enzymatic method, using commercial proteases, was studied. Hydrolysis was carried out with two types of bacterial proteases: neutrasa 0.5L, and alcalase 0.6L. Basically, the process consisted of milling and sieving the sesame cake (60 mesh), concentrating the proteins by solubilizing them at a pH of 9.5, and then precipitating at a pH of 4.5. Proteins were hydrolyzed by an enzymatic method, and the hydrolysates freeze-dried and spray-dried. Optimal conditions of hydrolysis using neutrase 0.5L at a pH of 7 were: 6% substrate concentration, 3% enzyme:substrate ratio, temperature 50 degrees +/- 1 degree C, and hydrolysis degree of 8%. When alcalase 0.6L was used at a pH of 8, optimal conditions were: 8% substrate concentration, 2.3% enzyme:substrate ratio, temperature 58 degrees +/- 1 degree C, and hydrolysis degree of 10%. The enzyme affinity (Km) was best at temperatures near the optimal temperature for the hydrolysates. Dried hydrolysates had protein values which ranged between 66.3% and 66.9% and a nitrogen solubility in water, of approximately 85%. Hydrolysis yields referred to the concentrate dried mass were 42% for the atomized hydrolysate, and 56% for the freeze-dried one. In conclusion, the enzymatic hydrolysis process improved the nitrogen solubility in water of the sesame proteins.     

交联柚苷酶聚集体水解柚皮苷制备普鲁宁

为了提高普鲁宁的收率、简化分离提纯的工艺、得到较高纯度的普鲁宁,本实验采用交联柚苷酶聚集体水解柚皮苷制备普鲁宁,以普鲁宁浓度为优化指标,研究了底物浓度、p H、温度、加酶量、反应时间对制备普鲁宁的影响。利用正交设计对水解过程进行优化,确定最佳工艺条件为:柚皮苷浓度13.79 mmol/L、p H=8.0、温度65℃、加酶量18.0 mg/m L、反应时间12.0 h,优化后制备得到的普鲁宁浓度为13.36 mmol/L、收率达到96.87%。连续使用3个批次后,普鲁宁的收率可以达到91.29%,交联酶聚集体的稳定性较好。采用聚酰胺树脂对水解产物进行吸附,体积分数为40%~60%的异丙醇线性梯度洗脱,从0.36 g柚皮苷反应液中可以分离得到0.22 g普鲁宁。     

植物纤维原料纤维素酶水解的研究

以麦草为原料,探讨纤维素酶水解植物纤维的适宜条件。麦草含大量的纤维素和聚戊糖,其中的纤维素在纤维素酶的作用下分解生成葡萄糖和纤维二糖。对温度,pH值,酶解时间,酶用量分别进行单因素实验,通过测定葡萄糖含量和总还原糖含量,找出酶水解麦草的适宜条件为:pH4.6,温度47℃,酶解时间48h,酶用量7.5IU(每克绝干原料)。对不同底物浓度的实验表明,在尽可能高的底物浓度下连续水解,产物浓度高,得率也高。     

响应面法优化鹿血肽的制备工艺

采用碱性蛋白酶水解鹿血蛋白制备鹿血肽.应用响应面分析法选取温度、时间、pH值、酶量4个主要因素,以水解率为响应值,对其工艺进行了优化.得出了鹿血蛋白水解的最佳工艺条件为:温度(53％)、时间(5.5h)、pH(9.5)、酶量(1272U·g-1),在此条件下鹿血的实际水解率为22.13％.实验证明响应面法对鹿血肽的制备...     

Optimization of antioxidant hydrolysate production from flying squid muscle protein using response surface methodology

The squid muscle protein, extracted from by-products of flying squid (Ommastrephes bartrami) was hydrolyzed by five proteases (pepsin, trypsin, papain, alcalase and flavourzyme). DPPH radical scavenging power was used to evaluate antioxidative activity of hydrolysates. The hydrolysate obtained by papain exhibited the most excellent potential of antioxidative activity. Furthermore, response surface methodology (RSM) was employed to optimize hydrolysis conditions, including enzyme to substrate (E/S) ratio, reaction temperature, and hydrolysis time. The optimum conditions obtained were as follows: E/S ratio of 1.74%, temperature of 51 °C and time of 46 min, under which, DPPH radical scavenging activity of 74.25% was obtained. Moreover, it was found that the optimum hydrolysate of 8 mg/mL displayed relatively stronger inhibitory effect on lipid peroxidation compared with α-Tocopherol of 0.1 mg/mL.     

油酸甲酯烯烃复分解合成1-癸烯的工艺优化

以油酸甲酯(MO)为植物油脂模型物,通过烯烃复分解反应制备1-癸烯,以油酸甲酯转化率和1-癸烯得率为评价指标,探究了反应底物、催化剂类型、反应温度、反应时间、催化剂用量和MO与反应底物物质的量之比对烯烃复分解反应制备1-癸烯的影响,最后通过正交试验设计优化得到最佳工艺条件.结果 表明:反应底物丁香酚和Grubbs第二代...