Dried shrimp is a popular aquatic food worldwide due to its unique flavor.However,its flavor qualities on the market remain uneven.This study aimed to compare flavor substances in dried shrimp processed by Litopenaeus...Dried shrimp is a popular aquatic food worldwide due to its unique flavor.However,its flavor qualities on the market remain uneven.This study aimed to compare flavor substances in dried shrimp processed by Litopenaeus vannamei from two aquaculture patterns(earthen pond and greenhouse)using amino acid automatic analyzer,high-performance liquid chromatography(HPLC),gas chromatography(GC)-ion mobility spectrometry(IMS),and GC-mass spectrometry(GC-MS).The results revealed that dried shrimp from earthen pond had significantly higher free amino acids and 5’-nucleotides than those from greenhouse(P<0.05),and their corresponding equivalent umami concentrations(EUCs)were 23.45 g MSG(100 g)^(−1)and 14.86 g MSG(100 g)^(−1),respectively.For volatile compounds,GC-IMS analysis indicated significant differences in volatile compounds between dried shrimp from different aquaculture patterns.According to the quantitative analysis of GC-MS,11 volatile compounds were identified as aroma-active compounds(AACs),of which six AACs(1-octen-3-ol,3-methylbutanal,nonanal,trimethylamine,2,5-dimethylpyrazine,and 2,3,5-trimethylpyrazine)were found in all dried shrimp samples.Although dried shrimp from greenhouse possesses higher OAVs,OAVs of(E,E)-2,4-nonadienal(fishy smell),and 3,5-diethyl-2-methylpyrazine(burnt smell)reached 171.2 and 333 respectively,imparting negative effects on flavor.In general,dried shrimp from earthen pond had a better flavor profile than those from greenhouse.展开更多
该研究采用高效液相色谱、电感耦合等离子发射光谱法等技术对宫保鸡丁中有机酸、呈味核苷酸及游离氨基酸等进行定性定量分析,并结合滋味活性值(taste active value,TAV)探究宫保鸡丁的特征滋味物质。结果显示,5种宫保鸡丁(A1~A5)中均检...该研究采用高效液相色谱、电感耦合等离子发射光谱法等技术对宫保鸡丁中有机酸、呈味核苷酸及游离氨基酸等进行定性定量分析,并结合滋味活性值(taste active value,TAV)探究宫保鸡丁的特征滋味物质。结果显示,5种宫保鸡丁(A1~A5)中均检出6种有机酸、3种呈味核苷酸、6种无机离子、17种游离氨基酸及辣椒素,且均未检出二氢辣椒素。其中,A4样含有较高的有机酸和无机离子,其呈味核苷酸及游离氨基酸含量均高于其他4种样品,含量分别为1392.65 mg/kg和10567.80 mg/kg,滋味更浓厚。另外,富马酸、苹果酸、琥珀酸、乙酸、5′-肌苷酸、辣椒素、钠离子、钾离子、氯离子、磷酸根离子、谷氨酸及组氨酸12种呈味组分的TAV均大于1,表明其为宫保鸡丁的特征滋味物质,对产品整体滋味呈现至关重要。展开更多
Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3...Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.展开更多
Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic a...Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic acids（HCAs）. The stabilities were studied in buffers at p H 1.3, p H 5.0, and p H 7.4 including the human plasma. All the compounds were found highly stable at acidic p H, but underwent hydrolysis at neutral p H. Furthermore, the hydrolysis proceeded much faster in plasma in the following order as indicated by half-life values（t1/2）, 2c（1.21 h）〈2e（1.52 h）〈2d（1.85 h）〈2b（3.38 h）〈2a（3.88 h）, correlating with the number of electron-donating groups. It has been proven by UV spectrum that 2c, 2d, and 2e displayed red shift of more than 50 nm as compared to 2a and 2b, because of the presence of OH and OCH3 groups. In addition, the compounds（2b–e） showed no cytotoxicity on normal HUVEC cells as DA, although 2a displayed a 16% inhibition of proliferation at 40 μM following 48 h incubation. Their free radical-scavenging activities were evaluated using ABTS^＊＋ and superoxide anion assays and the mechanisms were proposed. It was found that they all exhibited higher activities than trolox, a recognized antioxidant. Amazingly, in the case of the hybrids（2a–e）, their activity was higher than that of HCAs while lower or comparable to that of DA, suggesting that there may be a ＂saturation effect＂ with the hybrid molecules in the antioxidant activities.展开更多
基金supported by the National Key R&D Program of China (No.2018YFD0901004)the Central Public-Interest Scientific Institution Basal Research Fund,YSFRI,CAFS (No.20603022020013).
文摘Dried shrimp is a popular aquatic food worldwide due to its unique flavor.However,its flavor qualities on the market remain uneven.This study aimed to compare flavor substances in dried shrimp processed by Litopenaeus vannamei from two aquaculture patterns(earthen pond and greenhouse)using amino acid automatic analyzer,high-performance liquid chromatography(HPLC),gas chromatography(GC)-ion mobility spectrometry(IMS),and GC-mass spectrometry(GC-MS).The results revealed that dried shrimp from earthen pond had significantly higher free amino acids and 5’-nucleotides than those from greenhouse(P<0.05),and their corresponding equivalent umami concentrations(EUCs)were 23.45 g MSG(100 g)^(−1)and 14.86 g MSG(100 g)^(−1),respectively.For volatile compounds,GC-IMS analysis indicated significant differences in volatile compounds between dried shrimp from different aquaculture patterns.According to the quantitative analysis of GC-MS,11 volatile compounds were identified as aroma-active compounds(AACs),of which six AACs(1-octen-3-ol,3-methylbutanal,nonanal,trimethylamine,2,5-dimethylpyrazine,and 2,3,5-trimethylpyrazine)were found in all dried shrimp samples.Although dried shrimp from greenhouse possesses higher OAVs,OAVs of(E,E)-2,4-nonadienal(fishy smell),and 3,5-diethyl-2-methylpyrazine(burnt smell)reached 171.2 and 333 respectively,imparting negative effects on flavor.In general,dried shrimp from earthen pond had a better flavor profile than those from greenhouse.
文摘该研究采用高效液相色谱、电感耦合等离子发射光谱法等技术对宫保鸡丁中有机酸、呈味核苷酸及游离氨基酸等进行定性定量分析,并结合滋味活性值(taste active value,TAV)探究宫保鸡丁的特征滋味物质。结果显示,5种宫保鸡丁(A1~A5)中均检出6种有机酸、3种呈味核苷酸、6种无机离子、17种游离氨基酸及辣椒素,且均未检出二氢辣椒素。其中,A4样含有较高的有机酸和无机离子,其呈味核苷酸及游离氨基酸含量均高于其他4种样品,含量分别为1392.65 mg/kg和10567.80 mg/kg,滋味更浓厚。另外,富马酸、苹果酸、琥珀酸、乙酸、5′-肌苷酸、辣椒素、钠离子、钾离子、氯离子、磷酸根离子、谷氨酸及组氨酸12种呈味组分的TAV均大于1,表明其为宫保鸡丁的特征滋味物质,对产品整体滋味呈现至关重要。
基金supported by the High Technology Research and Development Program of China (No. 2006AA09Z438)the National Natural Science Foundation of China (No. 30871943).
文摘Fish skin collagen hydrolysates （FSCH） were prepared from walleye pollock （Theragra chalcogramrna） using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of 〈1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical （DPPH）, superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione （GSH）. FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore FSCH may have potential applications in the medicine and food industries.
基金The National Natural Science Foundation of China(Grant No.21302079)the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2014-151)
文摘Hybrid antioxidants cinnamoyldopamine（2a）, p-coumaroyldopamine（2b）, caffeoyldopamine（2c）, feruloyldopamine（2d） and sinapoyldopamine（2e） were synthesized by conjugation of dopamine（DA） and hydroxycinnamic acids（HCAs）. The stabilities were studied in buffers at p H 1.3, p H 5.0, and p H 7.4 including the human plasma. All the compounds were found highly stable at acidic p H, but underwent hydrolysis at neutral p H. Furthermore, the hydrolysis proceeded much faster in plasma in the following order as indicated by half-life values（t1/2）, 2c（1.21 h）〈2e（1.52 h）〈2d（1.85 h）〈2b（3.38 h）〈2a（3.88 h）, correlating with the number of electron-donating groups. It has been proven by UV spectrum that 2c, 2d, and 2e displayed red shift of more than 50 nm as compared to 2a and 2b, because of the presence of OH and OCH3 groups. In addition, the compounds（2b–e） showed no cytotoxicity on normal HUVEC cells as DA, although 2a displayed a 16% inhibition of proliferation at 40 μM following 48 h incubation. Their free radical-scavenging activities were evaluated using ABTS^＊＋ and superoxide anion assays and the mechanisms were proposed. It was found that they all exhibited higher activities than trolox, a recognized antioxidant. Amazingly, in the case of the hybrids（2a–e）, their activity was higher than that of HCAs while lower or comparable to that of DA, suggesting that there may be a ＂saturation effect＂ with the hybrid molecules in the antioxidant activities.
