蛋白酶及其作用方式对制取青鳞鱼肉水解蛋白的影响

研究了胰蛋白酶、风味酶单酶水解及与木瓜蛋白酶双酶水解对青鳞鱼鱼肉水解蛋白α 氨态氮含量和可溶性蛋白得率的影响 ,确定了最佳水解条件 ,分析了可溶性蛋白的氨基酸组成并对其进行了营养评价     

贻贝酶解物对羟自由基清除作用的试验研究

通过测定贻贝酶解物对离体实验系统（Fenton体系）产生的羟自由基的清除效果，从胰蛋白酶、木瓜蛋白酶、胃蛋白酶3种酶中筛选出木瓜蛋白酶和胰蛋白酶作为酶解贻贝制备具有较高清除羟自由基活性酶解物的理想水解酶；并通过正交实验L9（3^4）对2种酶的水解条件进行优化。结果表明木瓜蛋白酶在温度60℃、酶解时间15min、DH7．5、酶质量分数1．00％的水解条件下，酶解物对羟自由基的清除效果最佳；胰蛋白酶在温度45℃、酶解时间35min,pH8，5、酶质量分数0．75％的水解条件下，酶解物对羟自由基清除效果最佳。木瓜蛋白酶酶解物在最大洗脱峰时有最大羟基自由基清除率峰，清除率为76．15％，在最大峰处酶解物中活性肽的分子量为1．4kDa；胰蛋白酶酶解物在最大洗脱峰时也有最大羟基自由基清除率峰，其清除率为69．13％，该峰处活性肽的分子量也为1．4kDa。     

响应面法优化金带细鲹鱼肉蛋白质双酶酶解工艺

选用木瓜蛋白酶、中性蛋白酶、酸性蛋白酶、胰蛋白酶和菠萝蛋白酶对金带细鲹鱼蛋白质进行水解,以蛋白质的水解度为指标,筛选出酶解效果最好的酶类。通过响应面法对影响酶解效果的主要因素进行研究,并确定金带细鲹的最适酶解工艺。结果表明:对金带细鲹鱼酶解效果最好的方法是采用胰蛋白酶和木瓜蛋白酶进行双酶酶解,双酶最适酶解条件为:先加入胰蛋白酶,在45℃,p H8.0,加酶量2.0%(g/g),固液比1∶5(g/g)条件下酶解5h后,再加入木瓜蛋白酶,其加酶量1.6%(g/g)、温度60.76℃,p H 6.27,时间3.52h,在此条件下,实际测得蛋白质水解度可达43.23%。比胰蛋白酶单酶水解蛋白质水解度提高了12.72%。利用双酶法水解金带细鲹鱼蛋白质,能缩短生产周期,提高原料的利用率。     

双酶法提取牛蒡多糖的研究

本实验以牛蒡为原料,采用双酶法提取牛蒡多糖,并对其工艺条件进行探讨。结果表明：最佳提取条件为木瓜蛋白酶和植物水解蛋白酶各2％,酶解温度45℃,酶解时间4h,pH8．0,固液比1：15。采用双酶水解后,牛蒡多糖提取率为12．40％。     

金带细鲹鱼露制作过程中酶解工艺的研究

采用酶水解法对金带细鲹鱼的酶解工艺进行研究。以蛋白质的水解度为指标,采用木瓜蛋白酶、中性蛋白酶、酸性蛋白酶、胰蛋白酶和菠萝蛋白酶进行水解,筛选出适宜的酶种类。对影响胰蛋白酶和木瓜蛋白酶酶解效果的主要因素进行研究,并确定胰蛋白酶和木瓜蛋白酶对金带细鲹鱼中的最适酶解工艺。胰蛋白酶最适酶解条件为温度45℃,时间5h,pH 8.0,加酶量2.0%(g/g),固液比为1∶5(g/g),在此条件下,水解度达到30.51%;木瓜蛋白酶最适酶解条件为温度60℃,时间4h,pH 6.0,加酶量2.0%(g/g),固液比1∶4(g/g),在此条件下,水解度达到18.51%。利用酶法水解制取鱼露,能缩短生产周期,提高原料的利用率。     

多酶法在鱼露生产工艺中的应用

应用正交试验优选了碱性蛋白酶和中性蛋白酶对青鳞鱼下脚料 (鱼头、鱼骨、内脏、鱼皮等 )的水解条件 ,在此基础上 ,同时用碱性蛋白酶和中性蛋白酶 ,再用风味酶对青鳞鱼下脚料蛋白质进行水解 ,确定了以多酶法生产鱼露的新工艺。结果表明 ,青鳞鱼下脚料中蛋白质含量达 14 8% ,经多酶水解和适当调配可制得风味浓郁的鱼露。多酶法水解蛋白质的条件为 :同时用 1 5 %碱性蛋白酶和 1 5 %中性蛋白酶在 pH 7 0、5 0℃条件下水解 12 0min后再加入 2 %风味酶继续水解 60min ;新工艺生产鱼露中必需氨基酸含量达 40 3 % ,总氮达 19mg/L ,氨基氮达 11mg/g ,占总氮的 61 0 % ,呈味氨基酸含量达 49 5 %。因此新工艺鱼露营养丰富 ,味道鲜美。     

灵芝多糖酶解-Sevage法联合脱蛋白工艺研究

本文采用正交试验优化Sevage法对灵芝多糖脱蛋白的工艺参数,在最佳的工艺参数下,分别研究木瓜蛋白酶、胰蛋白酶和链霉蛋白酶在脱蛋自作用中的最适酶液浓度和酶解时间,然后进一步采用正交试验优化酶解-Sevage法联合脱蛋白工艺参数,实验结果表明：在酶解-Sevage法联合脱蛋白的工艺中,酶解时间及胰蛋白酶浓度对灵芝多糖脱蛋白率起主要作用,最佳工艺参数为木瓜蛋白酶浓度0．8％;胰蛋白酶浓度为0．8％;链霉蛋白酶浓度1．0％;各自酶解时间4h;脱蛋门次数3次,多糖蛋白脱除率为99．64％,与单一Sevage法脱蛋白比较,多糖中的蛋白基本可以脱除,且多糖损失率降低了20．64％,说明酶解和Sevage法联合使用对灵芝多糖具有很好的脱蛋白效果。     

苦荞麦蛋白质的酶法水解研究

以苦荞麦蛋白质作为底物,采用碱性蛋白酶(固体)、胰蛋白酶、碱性蛋白酶Alcalase 2.4L、高效水解蛋白酶、中性蛋白酶、木瓜蛋白酶对其进行酶法水解,并对酶解产物的氨基酸组成和相对分子质量进行研究.结果表明,碱性蛋白酶(固体)的酶解程度最高,在酶解2h时DH(水解度)接近20%,其酶解产物的疏水性氨基酸含量较高,大部分肽链的相对分子质量都低于1000Da.     

鸡肉多肽酶解条件的研究

探索鸡肉多肽酶解的最佳条件。以鸡肉、木瓜蛋白酶和胰蛋白酶为原料,酶解液中多肽浓度和最终多肽得率为指标,采用单因素和正交实验筛选鸡肉多肽酶解的最佳条件。结果：木瓜蛋白酶用量2．50％（[E]／[S],W/W）,底物浓度9％（[S]）,pH7．70,水解温度60℃,水解时N4h,多肽得率为58．22％。结论：木瓜蛋白酶能有效水解鸡肉获得鸡肉多肽,其酶解鸡肉多肽的得率比胰蛋白酶高。     

黄鲫(Setipinna taty)蛋白酶解液的抑菌活性及稳定性研究

以黄鲫为原料测定其氨基酸组成,比较风味蛋白酶、胰蛋白酶、胃蛋白酶、碱性蛋白酶和木瓜蛋白酶水解黄鲫蛋白所得酶解液对大肠杆菌的抑菌作用,并对抑菌效果最强的蛋白酶酶解液进行抑菌稳定性研究。结果表明：黄鲫蛋白必需氨基酸含量丰富,其中胃蛋白酶的水解液对大肠杆菌抑菌作用强,相对分子质量主要分布在3000～1000;黄鲫胃蛋白酶酶解液对热稳定,酸性低pH值可增强其抑菌效果,可耐受胰蛋白酶和β-内酰胺酶处理,该酶解液有作为天然抗菌剂应用的前景。     

Enzymatic hydrolysis of heated whey: iron-binding ability of peptides and antigenic protein fractions

This study evaluated the influence of various enzymes on the hydrolysis of whey protein concentrate (WPC) to reduce its antigenic fractions and to quantify the peptides having iron-binding ability in its hydrolysates. Heated (for 10 min at 100°C) WPC (2% protein solution) was incubated with 2% each of Alcalase, Flavourzyme, papain, and trypsin for 30, 60, 90, 120, 150, 180, and 240 min at 50°C. The highest hydrolysis of WPC was observed after 240 min of incubation with Alcalase (12.4%), followed by Flavourzyme (12.0%), trypsin (10.4%), and papain (8.53%). The nonprotein nitrogen contents of WPC hydrolysate followed the hydrolytic pattern of whey. The major antigenic fractions (β-lactoglobulin) in WPC were degraded within 60 min of its incubation with Alcalase, Flavourzyme, or papain. Chromatograms of enzymatic hydrolysates of heated WPC also indicated complete degradation of β-lactoglobulin, α-lactalbumin, and BSA. The highest iron solubility was noticed in hydrolysates derived with Alcalase (95%), followed by those produced with trypsin (90%), papain (87%), and Flavourzyme (81%). Eluted fraction 1 (F-1) and fraction 2 (F-2) were the respective peaks for the 0.25 and 0.5 M NaCl chromatographic step gradient for analysis of hydrolysates. Iron-binding ability was noticeably higher in F-1 than in F-2 of all hydrolysates of WPC. The highest iron contents in F-1 were observed in WPC hydrolysates derived with Alcalase (0.2 mg/kg), followed by hydrolysates derived with Flavourzyme (0.14 mg/kg), trypsin (0.14 mg/kg), and papain (0.08 mg/kg). Iron concentrations in the F-2 fraction of all enzymatic hydrolysates of WPC were low and ranged from 0.03 to 0.05 mg/kg. Fraction 1 may describe a new class of iron chelates based on the reaction of FeSO₄·7H₂O with a mixture of peptides obtained by the enzymatic hydrolysis of WPC. The chromatogram of Alcalase F-1 indicated numerous small peaks of shorter wavelengths, which probably indicated a variety of new peptides with greater ability to bind with iron. Alcalase F-1 had higher Ala (18.38%), Lys (17.97%), and Phe (16.58%) concentrations, whereas the presence of Pro, Gly, and Tyr was not detected. Alcalase was more effective than other enzymes at producing a hydrolysate for the separation of iron-binding peptides derived from WPC.     

不同蛋白酶酶解罗非鱼肉制备蛋白水解液的过程变化规律研究

本文选择五种蛋白酶(木瓜蛋白酶、Alcalase2.4 L、Protamex、Neutrase 1.5MG和Flavourzyme 500MG)对酶解罗非鱼肉制备蛋白水解液的过程变化规律研究.以Cn、Cp值和蛋白质利用率为指标对酶解过程进行分析,说明不同的酶解工艺参数对酶解过程及产物影响较大,其中Flavourzyme 500MG生成游离氨基酸态氮含量最高(12 h后达到4.25 mg/mL);木瓜蛋白酶生成短肽含量最高(5 h后达到39.82 mg/mL);Protamex的蛋白质利用率最高(12 h后达到44.74%).以高含量游离氨基酸的水解液为目的可选用Flavourzyme 500MG、Protamex;以高含量功能性短肽的水解液为目的可选用木瓜蛋白酶、Alcalase 2.4 L.     

双酶法水解猪皮工艺的优化

以猪皮为原料,以水解度(DH)为评价指标,在用Flavourzyme,Protamex,Neutrase,Alcalase,Papain进行单酶、双酶水解的基础上,筛选出了Flavourzyme和Protamex两种水解效果较好的酶,并采用Box-Benhnken响应面分析法,设计了3因素3水平实验,得到了双酶法水解猪皮的优化条件为:pH5.85,温度48.37℃,加酶量2.61%,底物浓度15%,时间6h,在此条件下,猪皮水解度最高,可达到19.25%。     

Physicochemical and bitterness properties of enzymatic pea protein hydrolysates

ABSTRACT:  The effects of different proteolytic treatments on the physiochemical and bitterness properties of pea protein hydrolysates were investigated. A commercial pea protein isolate was digested using each of 5 different proteases to produce protein hydrolysates with varying properties. After 4 h of enzyme digestion, samples were clarified by centrifugation followed by desalting of the supernatant with a 1000 Da membrane; the retentates were then freeze-dried. Alcalase and Flavourzyme™ produced protein hydrolysates with significantly higher ( P < 0.05) degree of hydrolysis when compared to the other proteases. Flavourzyme, papain, and alcalase produced hydrolysates that contained the highest levels of aromatic amino acids, while trypsin hydrolysate had the highest levels of lysine and arginine. Papain hydrolysate contained high molecular weight peptides (10 to 178 kDa) while hydrolysates from the other 4 proteases contained predominantly low molecular weight peptides (≤ 23 kDa). DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging activity of the Flavourzyme hydrolysate was significantly ( P < 0.05) the highest while alcalase and trypsin hydrolysates were the lowest. Inhibition of angiotensin converting enzyme (ACE) activity was significantly higher ( P < 0.05) for papain hydrolysate while Flavourzyme hydrolysate had the least inhibitory activity. Sensory analysis showed that the alcalase hydrolysate was the most bitter while papain and α-chymotrypsin hydrolysates were the least. Among the 5 enzymes used in this study, papain and α-chymotrypsin appear to be the most desirable for producing high quality pea protein hydrolysates because of the low bitterness scores combined with a high level of angiotensin converting enzyme inhibition and moderate free radical scavenging activity.     

Chemical and Biochemical Hydrolysis of Persian Sturgeon (Acipenser persicus) Visceral Protein

Chemical (pH 3.3, 70 °C, 85 °C; pH 12, 70 °C, 85 °C) and biochemical (Alcalase, Protamex, Neutrase, Flavourzyme, and Trypsin) hydrolysis of Persian sturgeon (Acipenser persicus) visceral protein was investigated. The results of this study revealed that there are significant differences between enzymes in terms of degree of hydrolysis (DH%; P < 0.05). Alcalase-hydrolyzed fish protein had the highest DH% (50.13%), and Trypsin-hydrolyzed fish protein had the minimum DH% (14.21%). The highest DH% in chemical hydrolysis was related to pH 3.3 at 85 °C (68.87%). The highest protein recovery (83.64%) and protein content (73.34) were related to enzymatic hydrolysis by Alcalase. The results of current study showed the significant effect of hydrolysis conditions on fish protein hydrolysate properties. Microbial enzymes could produce fish hydrolysates with higher degree of hydrolysis when compared to animal enzyme. Also, in chemical hydrolysis it is clear that hydrolysis at the lower pH and at higher temperature causes to more protein recovery and degree of hydrolysis.     

罗非鱼肉双酶分步酶解制备Maillard反应基液的研究

以罗非鱼下脚料为原料,对其进行双酶分步酶解来制备Maillard反应基液。以氨基酸态氮含量(Cn)、TCA可溶性蛋白(短肽)含量(Cp)的变化为指标对酶解过程进行分析,结合酶解液的感官评定,认为Flavourzyme和Protame、Flavourzyme和Alcalase2.4L两个组合的复合酶解效果较好。对其进行工艺改进以后,两者酶解液的Cn值分别达到0.4%和0.35%。     

采用控制酶解法从罗非鱼肉中制备血管紧张素转化酶抑制肽

实验以罗非鱼肉为材料,利用Trypsin、Alcalase2.4L、Protamex、木瓜蛋白酶、中性蛋白酶、Flavourzyme和Kojizyme酶解制备血管紧张素转化酶抑制肽(ACEIP)。以ACE抑制率(Ⅰ值)、氨基酸态氮含量(Cn值)和TCA可溶性蛋白(短肽)含量(Cp值)为指标对酶解过程进行分析,说明了酶法水解以及不同酶水解生成产物的特点,指出控制酶解的方法,其中Trypsin、Alcalase2.4L、Protamex对罗非肉控制酶解制备ACEIP的效果较好,酶解产物(稀释20倍)的最大Ⅰ值分别为酶解1hⅠ值91.2%、酶解3hⅠ值90.9%,酶解产物对ACE的抑制率比较高。     

Characterization of hydrolysates produced by mild-acid treatment and enzymatic hydrolysis of defatted soybean flour

Acid (0.05–0.2 N HCl) pre-treatments and subsequent enzymatic hydrolysis (Alcalase™ and Flavourzyme™) of defatted soybean flour (DSF) were performed under aseptic conditions. The acid pre-treatment facilitated enzymatic hydrolysis of the protein in DSF by increasing the nitrogen solubility index. Protein was hydrolyzed primarily during the first 5 h of enzymatic hydrolysis. The degree of hydrolysis and α-amino nitrogen contents of the hydrolysates increased after acid pretreatment. The average peptide chain lengths were estimated at 7∼8 amino acid units after 3 h hydrolyzation by Alcalase, and 3–5 amino acid units after 21 h by Flavourzyme/Alcalase mixture. Gel permeation chromatography provided molecular size distribution to determine the molecular weights of the corresponding hydrolysates. At the end of 24 h enzymatic hydrolysis, the amounts of free amino acid, dipeptide and tripeptide accounted for almost half of the proteins in the hydrolysate, while the oligopeptides constituted 40%.     

响应曲面法在鸡骨架蛋白酶解工艺中的应用

采用木瓜蛋白酶、碱性蛋白酶和复合蛋白酶水解鸡骨架蛋白制备富含氨基酸、生物寡肽的水解液,确定了酶解的前处理条件、理想用酶及适宜添加量。结果表明,理想用酶为复合蛋白酶,其适宜添加量为2400UP/g蛋白。采用响应面(RSM)法对复合蛋白酶酶水解条件进行了优化,最终确定复合酶的酶解条件为:[S]=2.8%(蛋白),T=54.0℃,起始pH=7.0,在优化条件下水解5h时的水解度(DH)=42.39%,较常规法水解度提高了约8%～10%,氨基酸分析表明,酶解液中富含各种必需氨基酸和生物寡肽。     

双酶法酶解猪瘦肉蛋白工艺优化研究

为制备腊味香精提供更丰富的前体物,以猪瘦肉为原料,水解度为指标,选用Alcalase和Flavourzyme为试验用酶,通正交试验优化双酶法水解猪瘦肉蛋白最佳工艺条件。结果表明:Alcalase和Flavourzyme水解瘦肉蛋白其最佳条件为,pH 9时,用1 000U/g Alcalase于60℃下水解6h,再用2 500U/g Flavourzyme于50℃、pH 4.5继续水解4h。此时,水解度达到34.82%,比Alcalase和Flavourzyme单酶水解度分别提高34.12%和27.48%,且酶解产物还含有丰富的制备腊味香精的前提物。