【作者】 翁丽萍；

【导师】 戴志远；

【作者基本信息】 浙江工商大学 ， 食品科学， 2012， 博士

【摘要】 大黄鱼(Pseudosciaena crocea)属鲈形目,石首鱼科,俗称黄花鱼,野生大黄鱼因肉质细嫩鲜美、金鳞朱唇、体形优美而深受消费者的青睐。目前市场上销售的多为养殖大黄鱼，是我国养殖规模最大的海水鱼类之一,因其脂肪肪含量高、腥味重、风味差,大大降低了人们对大黄鱼的认知度,给加工也带来一定的难度。本文旨在通过对养殖大黄鱼和野生大黄鱼风味物质的系统分析研究,比较两者之间主体香味物质和特征滋味物质的差异,为改善养殖大黄鱼及其加工制品的风味和口感提供理论依据,促进大黄鱼精深加工的进一步发展,满足人们对生活品质日益提高的需求。本文首先采用模糊数学方法对不同蒸煮条件下养殖大黄鱼的风味及其相关质量因素的感官评价结果进行分析,确定了其最佳蒸煮条件为：在100℃沸水中煮沸5min,为大黄鱼风味物质的提取确定了最佳原料预处理方法。为了更好的提取、分离和鉴定大黄鱼的挥发性风味物质,对萃取头、GC升温程序、固相微萃取等条件设计了单因素试验和二次回归正交试验进行分析,得出最佳条件为：样品量5g,NaCl添加量为5%即0.25g,气相程序升温速率为6℃/min,选用DVB/CAR/PDMS萃取头,萃取温度75℃,萃取时间35min,平衡时间20min,解析时间5min。并在最佳条件下同时提取、分离了养殖大黄鱼和野生大黄鱼中的挥发性风味物质,结合质谱和保留指数对实验结果进行定性分析,然后结合感觉阈值,利用相对气味活度值法(ROAV)确定了养殖大黄鱼的主体风味成分由辛醛、壬醛、己醛、庚醛、(z)-4-庚烯醛、1-辛烯-3-醉、乙酸乙酯、戊醛、(E,E)-2,4-庚二烯醛等化合物构成,野生大黄鱼的主体风味由(E)-2-辛烯醛、壬醛、三甲胺、辛醛、己醛、2-甲基丁醛、乙酸乙酯、3-甲基丁醛、癸醛、庚醛、(E,E)-2,4-庚二烯醛、1-辛烯-3-醇、苯乙醛、柠檬烯、2-甲基内醛等化合物构成。然后,比较热水法、冷水法、80%乙醇提取法、超声波-PCA法热水-乙醇法等五种方法对大黄鱼中水溶性呈味物质提取的效果,结果表明,热水抽提法的抽提效果最好,抽提率[(抽提物中总氮/原料中总氮)×100%]为22.90%。在此基础上系统分析了养殖大黄鱼和野生大黄鱼中非挥发性的滋味物质,包括游离氨基酸、水溶性小分子肽、ATP及其关联物、季胺碱、有机酸、无机离子等。通过对各呈味化合物的含量及呈味强度的分析,游离氨基酸对养殖大黄鱼滋味的贡献大小排序依次是：精氨酸(1.32)>组氨酸(0.77)>赖氨酸(0.73)>谷氨酸(0.55)>甘氨酸(0.21)>丙氨酸(0.18)；野生大黄鱼中各游离氨基酸对呈味贡献大小依次是：精氨酸(2.26)>谷氨酸(0.47)>组氨酸(0.31)>丙氨酸(0.28)甘氨酸(0.21)>氨酸(0.21)>蛋氨酸(0.18)>赖氨酸(0.15),其它氨基酸均小于0.15,起滋味协调作用。养殖大黄鱼中以水溶性肽形式存在的氨基酸总量仅为73.65mg/100g,野生大黄鱼中以水溶性肽形式存在的氨基酸总量为130.01mg/100g。IMP、AMP、GMP、TMAO、甘氨酸甜菜碱对养殖大黄鱼和野生大黄鱼的滋味有重要贡献。琥珀酸可能是形成大黄鱼整体滋味的主要物质之一,K-呈味强度大于1,是主要呈味离子,Na+、C1-也是重要的呈味影响离子。最后,对主要呈味物质氨基酸和核苷酸鲜味协同作用分析,发现养殖大黄鱼的味精当量(EUC)为13.43MSG/100g,呈味强度值达447.67,野生大黄鱼的味精当量为9.12MS G/100g,呈味强度值为304,这主要得益于高含量的IMP,解释了大黄鱼滋味鲜美的原因。最后,通过减缺实验和添加实验,利用一点法对养殖大黄鱼和野生大黄鱼的特征滋味进行了深入的比较和研究,确定了养殖大黄鱼的特征滋味物质为Glu、Ala、Lys、Arg、Cys、AMP、IMP、TMAO、 K+、Na+、Cl和甘氨酸甜菜碱,野生大黄鱼的特征滋味物质为Ser、Pro、Lys、Glu、Gly、Arg、Cys、AMP、IMP、TMAO、K+、Na+、C1-和甘氨酸甜菜碱。通过感官评价和电子舌数据分析表明,养殖大黄鱼和野生大黄鱼的主成分风味合成液都很好的再现了各自提取液的风味,为养殖大黄鱼及其加工品风味的改善提供理论依据。更多还原

【Abstract】 Pseudosciaena crocea, commonly known as large yellow croaker, are popular due to its delicious meat and charming apperance. It belongs to order Percifonnes and family Sciaenidae. Nowadays, large yellow croakers become one of the largest scale cultured marine fish in China. However, due to its high fat content, heavy fish smell and poor taste, people’s awareness of large yellow croaker is negatively influenced, which makes it difficult to be produced by industiy. This study aims to compare the cultured large yellow croaker with wild large yellow croaker through systematically analysis of the volatile substances. In order to provide a theoretical basis for improving its flavor and taste and relating products. Meanwhile, it will also promote the development of the deep processing of large yellow croaker to satisfy people’s increasing demand for the quality of life.Firstly, we analyzed the flavor of cultured large yellow croaker and related factors under different boiling condition by the fuzzy mathematics method. The optimum condition was boilling the fish5min in100℃water, which will extract the flavor substance well.The single factor experiment and the quadratic regression rotating combination test were designed to optimize the condition of extraction fiber, GC procedures, head of solid phase micro-extraction and other conditions. The optimum conditions were:5g sample,5%NaCl,6℃/min GC warming rate, DVB/CAR/PDMS fiber was selected, and the extract temperature was75℃, the extract time was35min, the incubation time was20min, and the desorb time was5min. Under this condition, the volatile flavor substances of cultured large yellow croaker and wild large yellow croaker were extracted and isolated. Meanwhile, the results were determined with combined mass spectrometry and retention indices. Combining with odor threshold, the relative odor activity value (ROAV) was applied to confirm the key odor compounds. The results indicated that the key odor compounds (ROAV>1) of cultured large yellow croaker were composed of Nonanal, Octanal, Hexanal, Heptanal,(Z)-4-Heptenal,1-Octen-3-ol, ethyl acetate, Pentanal,(E,E)-2, and so on., and the key odor compounds (ROAV>1) of wild large yellow croaker were composed of (E)-2-Octenal, Nonanal, Trimethylamine, Octanal, Hexanal,2-methyl butyl aldehyde, ethyl acetate,3-methyl butyl aldehyde, Decanal, Heptanal,(E,E)-2,4-Heptadienal,1-Octen-3-ol, Phenylglyoxylic, limonene,2-methyl propanal and so on. Secondly, effect of the five extracting solvents on water-soluble sapidity materials extraction were compared, including hot water, cold water,80%ethanol extraction, ultrasonic-PCA and hot-ethanol. The results showed that the method of hot water extraction was best, the extiaction rate [(total nitrogen in extraction/total nitrogen in raw material) X100%] was22.90%. Based on this, non-volatile flavor substances of the cultured large yellow croaker and wild large yellow croaker were analysed systematically, including free amino acids, water-soluble short peptide, ATP and the associated contents:TMAO, glycine betaine, organic acid, inorganic ions. Meanwhile, the order of the contribution of free amino acids on the taste of cultured large yellow croaker was concluded in this paper through analyzing the contents and the strength of the taste compounds, the order was:Arg (1.32)> His (0.77)> Lys (0.73)> Glu (0.55)> Gly (0.21)> Ala(0.18), and the order of the free amino acids contribution on the taste of wild large yellow croaker was: Arg(2.26)> Glu(0.47)>His (0.31)> Ala (0.28)> Gly(0.21)> Met(0.18)> Lys(0.15), the rest were less than0.15, behaving coordination function. The total amino acids content in the form of water-soluble peptide in cultured large yellow croaker were only73.65mg/100g, while that of wild large yellow croaker were130.01mg/100g. IMP、AMP、GMP、 TMAO and glycine betaine had important contribution on the taste of large yellow croaker. Succinic acid may be one of the important factors formed the main taste. The sapidity strength of K+was greater than1, which was the main sapidity ion, and the Na and Cl-ions were important also. Finally, the umami synergy analysis of the main sapidity free amino acids and nucleotide materials showed that the cultured Large Yellow Croaker’s monosodium glutamate equivalent (EUC) was as high as13.43MSG/100g, and the sapidity strength value was447.67? while the wild large yellow croaker’s EUC was as high as9.12MSG/100g, and the sapidity strength value was304, all of these were benefit from the high content of IMP, which also explained the well taste of large yellow-croaker.Finally, the representative flavor substances of cultured large yellow croaker and wild large yellow croaker were compared and researched deeply by the method of three points in the reduction of experiment and add tests. And then the characteristic flavor substances of the cultured large yellow croaker were conformed, which were Glu, Ala, Lys, Arg, Cys, AMP, IMP, TMAO, K+Na+, Cl’and glycine betame, while the wild large yellow croaker’s were Ser, Pro, Lys, Glu, Gly Arg, Cys, AMP, and IMP, TMAO, K+, Na+, Cl-and glycine betaine. Sensory evaluation and electronic tongue data showed that the characteristic flavor compounds confirmed the former data as well. It provided a theoretical basis to improve the flavor of cultured large yellow croaker and its products.更多还原