Studies on the Production and Improvement of Flavors of Fishes and Shells in Microalgae

微藻鱼贝类风味的生产及改良研究

基本信息

批准号：
63860027
负责人：
ISHIDA Yuzaburo
金额：
$ 4.93万
依托单位：
Kyoto University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Developmental Scientific Research (B).
财政年份：
1988
资助国家：
日本
起止时间：
1988 至 1990
项目状态：
已结题

项目摘要

In this study, we concentrated to make clear the biosynthesis and role of volatile sulphur compound, especially dimethylsulphide, in microalgae and macroalgae. The major source of dimethylsulphide in the aquatic environment appears to be the enzymatic cleavage or alkaline degradation of dimethyl-beta-propio thetin into dimethylsulphide and acrylate. The dimethylsulphide producers are chlorophyta (such as Ulva and Enteromorpha), rhodophyta (such as Polysiphonia), haptopyta (such as Emiliania and hymenomonas) and dinophyta (such as Gymnodinium, Gyrodinium, and Crypthecodinium). This dimethylsulphide fills the role originally assigned to H2S ; that of transferring sulphur from the seas through the air to land surface, and is very likely the compound most responsible for the characteristic "odor of the sea" or "flavour of sea weeds".We established the growth condition of Crypthecodinium cohnii (dinoflagellate) to get high cell yield (12g wet weight/L).From the relationship between the stru … More ctures of methionine, dimethyl-beta-propiothetin and dimethyl-sulphide, our recent study make clear that, in C. Cohnii, the methyl group and the sulphur of dimethyl-beta-propiothetine are derived from the methyl group and the sulphur of methionine and that the carboxyl group of methionine is not incorporated. We showed the crude extracts of C. Cohnii had methionine decarboxylase activity and did not have methionine deaminase activity. The observation are consistent with the hypothesis that methionine is converted to 3-methylthiopropylamine by decarboxylation and that 3-methylthiopropylamine is converted to dimethyl-beta-propiothetin by deamination, oxidation and methylation, and that the carboxyl group of dimethyl-beta-propiothetine may arise from the 2-carbon of methionine.We also found that the precursor of dimethylsulphide, dimethyl-beta-propiothetin, greatly accelerates the biting behaviors of goldfish, carp, crucian carp and tilapia. Dimethyl-beta-propiothetin proved not only to be an effective stimulant for the striking behavior of fishes but also to be able to promote fish growth. A crude extract of Crypthecodinium cohnii and its main component, dimethyl-beta-propiothetin, significantly and dose dependently protected the gastric mucosa against HCI-ethanolーinduced lesions in rats. Since indomethacin pretraetment reduced the protective effect to some extent, endogenous prostaglandins might be partly involved in the mechanism of action. Both the crude extract and dimethyl-beta-propiothetin significantly increased gastric secretion.The volatile components of Crypthecodinium cohnii were investigated to find its pleasant flavour compounds that could be associated with some edible seashore products. Heating the fresh wet alga with glass beads gave 66 volatile components. The first intact distillate greatly contained dimethylsulphide nearly 99%. Other components included some strong sweet-odorus compounds ; 2ーhydroxy-3-methy1-2-cyclopenten-l-one (cyclotene), 2, 5-dimethyl-4-hydroxy-3 (2H) -furanone (furaneol), and 3-hydroxy-2-methyl-4H-pyran-4-one (maltol). Less

在这项研究中，我们集中研究了微藻和大型藻类中挥发性硫化合物（尤其是二甲硫醚）的生物合成和作用。水生环境中二甲硫醚的主要来源似乎是二甲基-β-丙酸的酶裂解或碱降解。二甲硫醚的生产者是绿藻（如石莼和丙烯酸酯）。浒苔属 (polysiphonia)、红藻属 (Polysiphonia)、弓形藻属 (Emiliania) 和膜单胞菌属 (hymenomonas) 以及甲藻门 (Gymnodinium、Gyrodinium 和 Crypthecodinium)。空气到陆地表面，并且很可能是对特征“气味”最有影响的化合物。海”或“海藻味”。我们建立了隐甲藻（甲藻）的生长条件，以获得高细胞产量（12g湿重/L）。从蛋氨酸、二甲基-β-的结构之间的关系来看Proiothetin 和二甲硫醚，我们最近的研究表明，在 C. Cohnii 中，甲基和硫二甲基-β-丙硫氨酸衍生自甲硫氨酸的甲基和硫，并且未掺入甲硫氨酸的羧基，我们表明C. Cohnii的粗提物具有甲硫氨酸脱羧酶活性，并且不具有甲硫氨酸脱氨酶活性。假设甲硫氨酸通过脱羧转化为 3-甲硫基丙胺，并且3-甲硫基丙胺通过脱氨、氧化和甲基化转化为二甲基-β-丙硫氨酸，二甲基-β-丙硫氨酸的羧基可能来自蛋氨酸的2-碳。我们还发现二甲硫醚的前体二甲基- beta-propiothetin，大大加速金鱼、鲤鱼、鲫鱼等的咬食行为罗非鱼二甲基-β-丙肽不仅能有效刺激鱼类的行为，而且能够显着促进鱼类的生长。剂量依赖性地保护大鼠胃粘膜免受盐酸乙醇引起的损伤，因为吲哚美辛预处理在一定程度上降低了内源性的保护作用。前列腺素可能在一定程度上参与了作用机制。粗提物和二甲基-β-丙碘塞汀均显着增加胃液分泌。对隐甲藻的挥发性成分进行了研究，以发现其令人愉悦的风味化合物，这些化合物可能与一些可食用的海滨产品有关。用玻璃珠加热新鲜的湿藻类，第一完整馏出物含有近99%的二甲基硫醚。其他成分包括一些强烈的甜味化合物。；2-羟基-3-甲基1-2-环戊烯-1-酮（环烯）、2, 5-二甲基-4-羟基-3(2H)-呋喃酮（呋喃醇）和3-羟基-2-甲基-4H -吡喃-4-一（麦芽酚）较少。