不同酶解条件对Ti鱼蛋白水解物苦味及氨基酸组成的影响

研究了不同酶解的Ti鱼可溶性产物苦味及呈味氨基酸组成的差异，以及其水解时间、水解率对苦味的影响。结果表明，随着酶解时间延长和水解率的提高，几种水解液的苦味值都有不同程度增强。胃蛋白酶和胰蛋白酶的复合水解液表现出随水解时间的延长，水解率提高明显，苦味强度上升平缓。当水解率从42％提高到78％时，苦味值只提高了2，水解液总的苦味分值为3．5；枯草杆菌蛋白酶水解2h后苦味分值急剧提高，水解4h后苦味分值达到6，水解液味道很苦，水解率从32％提高到62％时，苦味分值提高到了7，水解液总的苦味值为8．5。两种方法水解获得的可溶性产物氨基酸及必需氨基酸组成含量接近，但胃蛋白酶、胰蛋白酶复合水解的可溶性产物具有更高的氨基酸分值，主要鲜味氨基酸含量略高于枯草杆菌蛋白酶水解产物，苦味氨基酸则相反。     

低值鱼酶解蛋白的制取及其组成研究

研究了复合生物酶酶量，酶解时间，酶解温度等对低值鱼蛋白酶解效果的影响。研究结果表明，酶浓度提高，水解时间延长，均明显提高低值蛋白水解率，复合生物酶最适水解温度为50℃，温度高于50℃，水解率逐渐下降，苦味值随水解率提高而增加，综合考虑，该复合生物酶水解低值鱼的最佳条件为；酶量与底物之比：1.5:1000；温度：50℃，水解时间：4h，复合酶水解低值鱼蛋白经氨基酸分析仪检测，其氨基酸含量为73%，经高效液相色谱分析，其分子量组成范围在7400以下，其中3000以下占90%以上，1000以下的占54%。     

缢蛏肉的蛋白酶水解工艺研究

实验研究了用枯草杆菌中性蛋白酶水解缢蛏肉的工艺条件,通过单因素试验和正交实验,得出了最适水解工艺条件为加酶量2.4％,水解温度50℃.料水比1:3。pH值为中性,时间为6h.水解产物的水解率和总的氮收率分别为42.46％和83.04％。水解液经脱腥等处理后可用于复合调味料和营养口服液的生产。     

扇贝裙边氨基酸营养粉的制备工艺研究

为了对扇贝裙边进行综合利用,本文选择由中性蛋白酶、胰蛋白酶和复合蛋白酶3种酶组合成3对混合酶对扇贝裙边进行酶水解实验,以水解液中游离氨基酸态氮为考察指标,采用正交实验设计研究了加酶量、酶解时间、酶解温度及酶的种类对酶解效果的影响,从而优化了扇贝裙边的酶法水解工艺条件。以最佳水解工艺条件获得的酶解液经喷雾干燥制成的氨基酸营养粉,经检测,其粗蛋白含量为82.89%,粗脂肪含量为1.55%,总糖含量为6.82%。该氨基酸营养粉中氨基酸种类齐全,每100g粗蛋白中氨基酸总量达79.06%,其中游离氨基酸总量达51.53%。     

Ti鱼蛋白酶水解物的提取

用枯草杆菌中性蛋白酶（AS1398酶）提取Ti鱼蛋白酶水解物。酶水解条件由正交实验确定，即Ti鱼匀浆用AS1398酶350IU／ml在42℃下水解12h。水解液经活性炭吸附结合β－环糊精掩盖脱去苦味。生产性中试蛋白质回收率78．80％，喷雾干燥所得制品产率为14．91％。制品呈白色粉末，无苦味；蛋白质含量88．26％，必需氨基酸占总氨基酸43．61％，氨基酸间比例合理。Ti鱼蛋白酶水解物为优质蛋白质制品。     

沙蜇饮料基料酶解液酶解工艺的研究

以水解度为指标,选用胰蛋白酶、碱性蛋白酶、酸性蛋白酶、中性蛋白酶、风味蛋白酶和胃蛋白酶对沙蜇进行单酶水解,确定胰蛋白酶为水解用酶。通过正交实验确定胰蛋白酶的水解条件为：温度45℃、时间5．5小时、料液比1：4．5、加酶量255U／ml、pH7．5。实验表明,适宜条件下水解度为24．59％。水解液选用柠檬酸为除腥剂,处理后的水解液腥味和涩味都有大幅度降低。     

酶解罗非鱼鱼皮胶制备降血压肽的研究

为探讨罗非鱼鱼皮胶制备降血压肽的酶解工艺,研究选用Neutrase中性蛋白酶、Alcalase碱性内切蛋白酶、胰蛋白酶、木瓜蛋白酶和复合蛋白酶分别对罗非鱼鱼皮胶进行酶解,对其酶解液的水解度进行比较。结果表明复合蛋白酶的酶解效果最好。对复合蛋白酶的酶解工艺进行单因素优化,确定其最佳酶解工艺为:温度50℃、pH值7.0、料液比1∶5、酶量为底物量的1.5%。在此条件下水解6h时,水解度为60%,酶解产物对血管紧张素转化酶(ACE)的抑制率最高,达到78.96%。     

扇贝加工废弃物的酶解技术研究

由正交试验确定的两种酶酶解的最佳水解结果表明枯草杆菌中性蛋白酶最佳水解条件为:加酶量为3.0%,温度为60℃,pH为7.0,时间为4 h,蛋白质水解度为91.3%;木瓜蛋白酶酶解的最佳酶解条件为:加酶量为3.0%,温度为65℃,pH为7.0,时间为4 h,蛋白质水解度为85.3%。SephadexG-15葡聚糖凝胶柱层析对扇贝加工废弃物水解产物的分析结果表明两种酶酶解产物的分子量分布均集中在682 Da,这说明酶解产物是小分子蛋白肽和游离氨基酸,可深加工利用制备水解蛋白制品。     

鯷鱼蛋白酶水解物的提取

用枯草杆菌中性蛋白酶（ＡＳ１３９８酶）提取鱼蛋白酶水解物。酶水解条件由正交实验确定，即鱼匀浆用ＡＳ１３９８酶３５０ＩＵ／ｍｌ在４２℃下水解１２ｈ。水解液经活性炭吸附结合β－环糊精掩盖脱去苦味。生产性中试蛋白质回收率７８．８０％，喷雾干燥所得制品产率为１４．９１％。制品呈白色粉末，无苦味；蛋白质含量８８．２６％，必需氨基酸占总氨基酸４３．６１％，氨基酸间比例合理。鱼蛋白酶水解物为优质蛋白质制品。     

超声辅助酶解鲣加工副产物制备蛋白胨

为了提高水产加工副产物的利用率和附加值,以鲣加工副产物为原料,采用胰蛋白酶结合超声处理制备蛋白胨,并分析了鲣加工副产物超声辅助酶解过程中蛋白酶活性、水解度、氮回收率、TCA-可溶性氮回收率、酶解产物分子量分布等指标的变化,探究了超声辅助酶解的作用时间、温度以及超声功率等因素对鲣加工副产物酶解产物的影响,通过单因素实验优化确定了蛋白胨制备的最佳酶解工艺条件。结果显示,超声处理造成胰蛋白酶酶活发生显著变化,在功率为120 W的超声场下,胰蛋白酶酶活在30 min内呈上升趋势,但在超声场处理30 min后,胰蛋白酶的酶活呈明显下降趋势,至4 h后酶活变化趋势趋于平缓。超声功率和酶解温度都会影响胰蛋白酶对鲣加工副产物的酶解效率,在超声功率240 W和酶解温度50°C条件下,氮回收率比无超声处理组提高了18.66%,水解度提高了30.43%,TCA-可溶性氮回收率提高了33.20%,且超声处理有效提高了酶解液中小分子肽的含量。超声辅助酶解鲣加工副产物的最佳工艺条件为温度55°C,超声功率240 W,酶解时间4 h,此时氮回收率为81.40%,TCA-可溶性氮回收率为40.75%。     

Sensory Characteristics of Threadfin Bream (Nemipterus japonicus) Hydrolysate

ABSTRACT

Threadfin bream (Nemipterus japonicus) spray-dried hydro-lysate was prepared using Alcalase at predetermined optimum hydrolysis conditions consisting of pH 8.5, 60°C, 2% enzyme, and 2 h hydrolysis. The hydrolysate was evaluated for its preferred concentration in rice porridge. Its acceptability was compared with sauces and enzyme-treated rice and vegetable hydrolysate. The preferred concentration in rice porridge was found to be 3% (w/v) and bitterness increased with concentration of hydrolysate. Threadfin bream hydrolysate was preferred as much as soy sauce; however, it received a lower score for taste compared to fish sauce. In terms of color, threadfin bream hydrolysate received significantly (p < 0.05) lower score than Flavorzyme and Alcalase treated rice hydrolysate and Vegetable hydrolysate. Low preference to the hydrolysate could probably be due to its greenish yellow color in which the common color for flavorants are brownish. For overall acceptability, no significant difference was observed between threadfin bream hydrolysate and Alcalase-treated rice hydrolysate but was significantly lower than vegetable hydrolysate and Flavorzyme-treated rice hydrolysate.

The hydrolysis of threadfin bream with Alcalase produced hydrolysate having a combination of bitter, umami, salty, sweet and sour tastes with fishy flavor. Bitterness and umami were rated as having an intermediate intensity, salty as between weak and intermediate, and sour and sweet as weak. The three basic tastes for hydrolysate were bitter, umami and salty, with umami and bitterness being the determining tastes.     

酶解扇贝裙边制备复合氨基酸螯合钙的研究

扇贝裙边富含蛋白质、脂质等营养成分。为了高值化利用扇贝裙边,本研究选用中性蛋白酶、动物蛋白酶、风味蛋白酶、木瓜蛋白酶和酸性蛋白酶5种酶,以酶解液中游离氨基酸态氮为考察指标,对扇贝裙边进行酶解工艺条件探讨。首先,将5种酶制成复合蛋白酶进行正交实验,确定最佳酶解时间、温度、pH及加酶量,经检验,氨基酸转化率为77%;然后,通过实验确定CaCl2为最适钙源,以贝壳为原料,通过水飞法和酸法转化可制得贝壳源CaCl2。将扇贝裙边酶解液中复合氨基酸与来源于贝壳的钙螯合制备复合氨基酸螯合钙,以正交实验筛选出最佳螯合条件。经检验,该螯合反应螯合率达92%。     

仿刺参性腺酶解过程风味变化

生物酶解是提高水产品蛋白质利用率的有效手段，且酶解过程往往伴随肽类、氨基酸、小分子挥发性成分等的生成或反应，进而引起酶解液风味变化。仿刺参(Apostichopus japonicus)性腺富含蛋白质和多种功效成分，具有良好的开发利用前景。为探究仿刺参性腺酶解过程中蛋白质和风味的变化规律，采用中性蛋白酶对其进行酶解，对酶解过程中可溶性蛋白质、氨基酸态氮、游离氨基酸组成、挥发性成分的变化情况进行了检测分析。结果显示，仿刺参性腺匀浆液中可溶性蛋白质和氨基酸态氮的初始含量分别为1.14和0.15 g/100 g，可溶性蛋白质在酶解前30 min内迅速增加，之后基本保持不变，氨基酸态氮含量在前90 min内随时间延长而逐渐增加，90 min后略有下降，90 min时水解度最大，达43.66%。随着酶解时间的延长，酶解液的鲜味有所增强，腥味减弱，甜味和苦味也略有增强。酶解后游离氨基酸含量显著增加(P<0.05)，其中，呈鲜味的谷氨酸含量最高，其次为呈甜味的甘氨酸和丙氨酸。仿刺参性腺酶解过程气味发生明显变化，烃类种类和相对含量均明显增加，二甲基硫醚含量显著降低，这可能是酶解液腥味减弱的主要原因     

双酶法在鲨鱼肉水解液制备中的工艺改良研究

采用同时添加枯草杆菌中性蛋白酶与木瓜蛋白酶的改良酶解技术，对鲨鱼肉进行水解。正交试验结果表明，上述二酶同时水解的最适条件为：温度45℃，pH7．0，时间3h，酶浓度200U／ml（枯草杆菌中性蛋白酶及木瓜蛋白酶各100U／ml），原料：水＝1．5。蛋白质水解率达83．5％，所得水认的氨基酸含量为45．4mg/ml，其中必需氨基酸总量为19．8mg/ml。     

虾头内源酶酶解虾肉产物的ACE抑制活性及其降低原发性高血压老鼠血压的效果

虾头内源酶酶解虾肉产物的ACE抑制活性及其降低原发性高血压老鼠血压的效果=Angiotensin I converting enzyme inhibitory activity of shrimp meat hydrolysate by endogenous enzymes from shrimp head and its antihypertensive effects on spontaneously hypertensive rats［刊，中］/洪鹏志（广东海洋大学食品科技学院，湛江524088）,曹文红,郝更新,章超桦//水产学报，—2007，31(1).-76～83 在pH 7.35、温度57.2 ℃、水解时间4 h、虾肉/虾头为1∶1，底物浓度为20%（W/V）的条件下，利用虾头的内源酶酶解虾肉（南美白对虾），制备了具有血管紧张素转化酶（ACE）抑制活性的酶解产物，其对ACE的抑制率为41.9%（2 mg·mL-1）。通过凝胶过滤层析测定出酶解产物的分子量分布较广，在7.4×104至29.7之间。分子量在2.7×103以下的凝胶层析组分占酶解产物氨基酸总量的83.1%。收集的高活性组分分子量在959～338之间，其IC50为0.32 mg·mL-1苯丙氨酸、疏水氨基酸（亮氨酸、异亮氨酸和缬氨酸）和芳香族氨基酸（脯氨酸、酪氨酸和色氨酸）占氨基酸总量的42.33%。体内试验的结果显示，南美白对虾的虾肉虾头内源酶酶解产物经灌喂原发性高血压老鼠后显示较强的降血压活性。 图4表2参13 关键词：南美白对虾；内源酶；血管紧张素转化酶抑制活性；抗高血压作用 E-mail:zhangch@gdou.edu.cn     

牡蛎的营养成分及蛋白质的酶法水解

研究了牡蛎肉的营养成分和其蛋白质的酶法水解。结果表明,牡蛎肉中蛋白质和糖原含量分别为50.63%和22.41%,其氨基酸组成完善,8种必需氨基酸占氨基酸总量的40%;537酸性蛋白酶比较适合于牡蛎蛋白质的水解,其优化的作用条件为:加酶量为1700U·g-1蛋白质、pH4、50℃、2h,在此条件下,水解液中的蛋白质和糖原提取率分别为78.23%和50.58%,水解液中的游离氨基酸和牛磺酸分别占总氨基酸的39.27%和12.47%。     

Production of Interesting Peptide Fractions by Enzymatic Hydrolysis of Tuna Dark Muscle By-Product Using Alcalase

ABSTRACT

A protein hydrolysate was prepared from proteins of tuna dark muscle by-product. The hydrolysis conditions (time, temperature, pH, and enzyme concentration) using Alcalase was optimized by response surface methodology (RSM). The regression coefficient close to 1.0, observed during experimental and validation runs, indicated the validity of the model. The hydrolysate produced under the optimum conditions determined by RSM has a low rate of peptide fraction of molecular weight of 4–1 kDa. Meanwhile, the results obtained by hydrolysis under optimal conditions determined by a complementary study (temperature 55°C, time 60 min, 1% enzyme concentration, and pH 8.5) show that the hydrolysate produced has a height rate of the peptide fraction of molecular weight of 4–1 kDa. The amino acid composition of the protein hydrolysate prepared proved to have the potential for application as an ingredient in balanced fish diets and as a source of nitrogen in microbial growth media.     

Optimization of Protein Recovery During Hydrolysis of Yellowfin Tuna (Thunnus albacares) Visceral Proteins

Protein hydrolysates were prepared from yellowfin tuna viscera using Alcalase®. Response surface methodology (RSM) was applied to study the effect of independent variables, enzyme activity, temperature, and time on the protein recovery (PR) as the response. The coefficient of determination (r² = 98%) was satisfactory, and the lack of fit test showed a non-significant value for the PR model equation, indicating that the regression equation was adequate for predicting the PR under tested combinations of values. Enzyme activity at 79.9 AU/kg protein, temperature at 59.9°C, and the time of 105 min were found to be the optimum conditions to reach the highest PR (85%). Considerable soluble protein was released with increasing degree of hydrolysis (DH). The yellowfin tuna visceral hydrolysates' amino acids profiles showed high essential amino acids content, although lysine, methionine, and phenylalanine were limited. In addition, the results showed that with increasing hydrolysis time, the amino acids increased. Yellowfin tuna visceral hydrolysates were rich in flavor amino acids which can be used as a taste enhancer.