Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the ...Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction(SPME) method and simultaneous distillation extraction(SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry(GC-MS) along with Kovats indices(KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols(i.e.,(E)-2-penten-1-ol and 2-octanol), esters(i.e., ethyl butyrate and methyl geranate), aldehydes(i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones(i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.展开更多
目的:建立高效液相色谱快速测定血管紧张素转换酶I抑制剂活性的方法。方法:以马尿酰-组胺酰-亮氨酸为底物,血管紧张素转换酶Ⅰ为催化剂,酶促反应产物马尿酸为检测指标,卡托普利为抑制剂的代表进行方法学研究。采用Phenomenex Luna C18...目的:建立高效液相色谱快速测定血管紧张素转换酶I抑制剂活性的方法。方法:以马尿酰-组胺酰-亮氨酸为底物,血管紧张素转换酶Ⅰ为催化剂,酶促反应产物马尿酸为检测指标,卡托普利为抑制剂的代表进行方法学研究。采用Phenomenex Luna C18色谱柱,流动相为甲醇和乙酸溶液,等度洗脱,检测波长为228 nm。根据保留时间定性,外标峰面积法定量。结果:马尿酸最低检测限为0.01μmol/L,加标回收率为93.8%～103%。应用该方法测得实验室制备的鳕鱼寡肽浓度与其ACE抑制率呈自然对数关系,计算得鳕鱼寡肽对ACE的IC50为4.56 mg/ml。结论:该方法可作为体外测定血管紧张素转换酶抑制剂活性的方法,具有操作简便快捷、精密度和准确性高的特点。展开更多
本文利用DA201-C大孔树脂对鳕鱼肉碱性蛋白酶酶解液进行脱盐后,用SP Sephadex C-25阳离子交换层析和反相高效液相色谱等方法对鳕鱼肉酶解液进行分离纯化,最终得到了浓度较高的两种苦味肽。将得到的苦味肽采用液相色谱-飞行时间串联质谱(...本文利用DA201-C大孔树脂对鳕鱼肉碱性蛋白酶酶解液进行脱盐后,用SP Sephadex C-25阳离子交换层析和反相高效液相色谱等方法对鳕鱼肉酶解液进行分离纯化,最终得到了浓度较高的两种苦味肽。将得到的苦味肽采用液相色谱-飞行时间串联质谱(LC-TOF-MS/MS)技术对多肽结构进行鉴定,确定其氨基酸序列分别为:HWPWMK(His-Trp-Pro-Trp-Met-Lys)和AVVLII(Ala-ValVal-Leu-Ile-Ile)。同时本文采用感官评定与多肽Q值相结合的方法对苦味进行评价,通过氨基酸分析仪对苦味样品进行氨基酸组成的测定,得出具有苦味的C7和S9组分的Q值分别为6.03 k J/mol和6.79 k J/mol,通过感官评定得出其苦味强度为:9±0.8和8.2±1.6。鉴定得到的苦味肽S9purity和S10purity的Q值分别为:8.85 k J/mol和8.53 k J/mol,苦味强度为:9.4±0.8和8.9±0.9。本文从鳕鱼肉酶解液中分离纯化得到的苦味肽为苦味肽家族增添了新成员,为下一步的研究提供了原料和实验基础。展开更多
基金supported by the National Natural Science Foundation of China (Nos. 31401476, 31471606)National High-Tech Research and Development Program of China, 863 Program (2014AA093508)Shandong Province Regional Innovation and Development of Marine Economy Demonstration Project
文摘Codfish is a kind of abyssal fish species with a great value in food industry. However, the flavor of codfish, especially the unpleasant odor, has caused serious problems in its processing. To accurately identify the volatile compounds in codfish, a combination of solid phase micro-extraction(SPME) method and simultaneous distillation extraction(SDE) method was used to extract the volatiles. Gas chromatography-mass spectrometry(GC-MS) along with Kovats indices(KI) and authentic standard compounds were used to identify the volatiles. The results showed that a total of 86 volatile compounds were identified in codfish, of them 24 were extracted by SDE, 69 compounds by SPME, and 10 compounds by both SDE and SPME. Seventy volatile compounds were found to have specific odors, of them 7 typical compounds contributed significantly to the flavor of codfish. Alcohols(i.e.,(E)-2-penten-1-ol and 2-octanol), esters(i.e., ethyl butyrate and methyl geranate), aldehydes(i.e., 2-dodecenal and pentadecanal) contributed the most to fresh flavor while nitrogen compounds, sulphur compounds, furans, as well as some ketones(i.e., 2-hydroxy-3-pentanone) brought unpleasant odor, such as fishy and earthy odor. It was indicated that the combination of multiple extraction methods and GC-MS analysis can enhance the accuracy of identification, and provide a reference for the further study on flavor of aquatic products.
文摘目的:建立高效液相色谱快速测定血管紧张素转换酶I抑制剂活性的方法。方法:以马尿酰-组胺酰-亮氨酸为底物,血管紧张素转换酶Ⅰ为催化剂,酶促反应产物马尿酸为检测指标,卡托普利为抑制剂的代表进行方法学研究。采用Phenomenex Luna C18色谱柱,流动相为甲醇和乙酸溶液,等度洗脱,检测波长为228 nm。根据保留时间定性,外标峰面积法定量。结果:马尿酸最低检测限为0.01μmol/L,加标回收率为93.8%～103%。应用该方法测得实验室制备的鳕鱼寡肽浓度与其ACE抑制率呈自然对数关系,计算得鳕鱼寡肽对ACE的IC50为4.56 mg/ml。结论:该方法可作为体外测定血管紧张素转换酶抑制剂活性的方法,具有操作简便快捷、精密度和准确性高的特点。
文摘本文利用DA201-C大孔树脂对鳕鱼肉碱性蛋白酶酶解液进行脱盐后,用SP Sephadex C-25阳离子交换层析和反相高效液相色谱等方法对鳕鱼肉酶解液进行分离纯化,最终得到了浓度较高的两种苦味肽。将得到的苦味肽采用液相色谱-飞行时间串联质谱(LC-TOF-MS/MS)技术对多肽结构进行鉴定,确定其氨基酸序列分别为:HWPWMK(His-Trp-Pro-Trp-Met-Lys)和AVVLII(Ala-ValVal-Leu-Ile-Ile)。同时本文采用感官评定与多肽Q值相结合的方法对苦味进行评价,通过氨基酸分析仪对苦味样品进行氨基酸组成的测定,得出具有苦味的C7和S9组分的Q值分别为6.03 k J/mol和6.79 k J/mol,通过感官评定得出其苦味强度为:9±0.8和8.2±1.6。鉴定得到的苦味肽S9purity和S10purity的Q值分别为:8.85 k J/mol和8.53 k J/mol,苦味强度为:9.4±0.8和8.9±0.9。本文从鳕鱼肉酶解液中分离纯化得到的苦味肽为苦味肽家族增添了新成员,为下一步的研究提供了原料和实验基础。
