以淡水鱼加工副产物制备鱼冻的工艺及配方研究

对淡水鱼加工中产生的头、皮、骨和鳞等副产物中的蛋白质进行提取,得到的提取液被用来制备鱼冻。结果表明,副产物中蛋白质的适宜提取条件为加入其重量1.5倍的1%食盐溶液的原料于90℃下恒温提取2h;甜味鱼冻加工的适宜配方为100g提取液、魔芋精粉与卡拉胶(3∶2)的复合胶0.8～1.0g、KCl0.7～1.0g、白砂糖9～10g和柠檬酸0.10～0.15g。     

Biogenic amine contents in fish and fish preserves

A method developed on the basis of highly efficient liquid chromatography of dansyl derivatives was used to study the content of biogenic amines (tyramine, histamine, cadaverine, putrescine, spermine and spermidine) in fish and canned fish. It was found that only 7 out of 149 samples contained histamine levels exceeding maximum permissible concentration (salted herring, smoked sardines, and salted Siberian salmon). No correlation was recorded between the increase of spermine content and spermidine.     

影响淡水鱼液化成鱼蛋白的因泰研究

采用胰蛋白酶和中性蛋白酶分别对草鱼鱼糜进行水解,水解产物为液化鱼蛋白.通过正交实验L9(34)法确定了实验的最终用酶和最佳的料水比、温度、pH、酶用量及时间.     

Fluoride content of fish protein concentrate and raw fish

The fluoride content of fish protein concentrate prepared by the Halifax isopropanol process and also of several possible raw materials was determined by distillation without fusion. The concentration of fluoride in this dry material ranged from 20 to 760 ppm and was dependent upon the raw materials. The major source of the fluoride was the bones which were incorporated in the product to a variable extent. The levels in fresh fillets ranged between 2·3 and 5·4 ppm while whole eviscerated fish contained 3·6-57 ppm fluoride.     

Production and quality of fish fingers from different fish species

Abstract Production of fish fingers was achieved by using fish species such as sardine (Sardina pilchardus, Walbaum, 1792), whiting (Merlangius merlangus, Linnaeus, 1758) and pike perch (Sander lucioperca, Linnaeus, 1758). Quality changes of battered fish patties during a period of 8 months at –18 °C were investigated. According to the results of microbiological and chemical analysis, fish fingers were found to be within acceptable limits during frozen storage for 8 months. However, sensory analysis showed that, at the end of the frozen storage, fish fingers made from sardine could not be consumed because of rancidity.     

鱼制品脱腥脱苦技术研究进展

概述了鱼制品腥味苦味产生的机理、脱除方法以及国内外的研究进展,简要介绍了物理法(包埋法、吸附法、盐溶法、掩盖法、有机溶剂萃取法和微胶囊法)、化学法(酸碱法、抗氧化剂法、酶法和类蛋白法)和微生物法三大类技术,并对各种技术方法的脱腥脱苦机理及优缺点进行了简要说明。     

Studies on fish protein concentrate and fish meal from river Nile bolti fish (Tilapia nilotica)

Fish protein concentrate (FPC) from river Nile bolti fish (Tilapia nilotica) was prepared and compared with commercial FPC and fresh bolti fish flesh. Fish meal (FM) from bolti fish offals was prepared and compared with commercial FM and also fresh bolti fish flesh. FPC from bolti fish showed a higher crude protein content but less fat, ash, calcium and sand than the commercial sample, while FM from bolti fish showed a higher content of ash and phosphorus than commercial FM but was nearly similar in crude protein, fat, calcium and sodium chloride. FPC from bolti fish had a higher content of lysine, arginine, aspartic acid, glycine and glutamic acid and a lower content of the other free amino acids. The bolti fish FM had a lower content of total amino acids and the contents of the free amino acids cysteine, glycine, aspartic acid, serine, alanine, valine, and methionine increased slightly. The yield was 12% for FPC and 19.5% for FM. Coliform bacteria were not present in both FPC and FM from bolti fish. Low moisture contents of FPC and FM were essential for preventing microbiol growth and to attain a good keeping quality. The FPC and FM from bolti fish reached moisture equilibrium and stopped increasing in weight within 144 to 192 h.     

DNA-based identification of fish species implicated in Puffer fish poisoning

A method for identification of fish species using three different mitochondrial DNA regions, 16S rRNA, cytochrome b and cytochrome c gene fragments, was investigated. The combined use of all three regions enabled reliable species identification in not only raw fish, but also dried, seasoned and boiled fish, products. Furthermore, the method was applicable even to vomitus from a patient involved in a puffer fish poisoning incident. However, further improvement is necessary to discriminate between closely related species such as Takifugu rubripes and T. chinensis, because they showed close similarity in the nucleotide sequences in the three gene fragments analyzed in this study.     

Biological value of protein from raw fish and canned fish

The authors evaluated the nutritive value of protein from 4 kinds of raw fish (herring, cod, mackerel, sprat) and its preserves. Experiments were made on rats fed the diets containing fish protein (8-10% of the total diet). Experiments included the determination of apparent and genuine digestibility, net protein utilization, and net dietary protein caloric value. Evidence was obtained that protein from fish and its preserves is characterized by high digestibility coefficient as compared with casein and egg powder. The highest net protein utilization was noted in animal groups fed the diet containing protein from raw fish. Protein assimilability from fish preserves was on the average 15% lower than that from raw fish.     

Physicochemical characterisation of raw fish and stickwater from fish meal production

Chemical and microbiological properties of raw fish (RF) and chemical properties of stickwater (SW) samples were studied as a function of the staleness level of the fish. As time elapsed from fish capture increased, the microbial count in RF, volatile nitrogen content in RF and SW, and dissolved solids and dissolved protein in SW, increased. The apparent viscosity of SW increased as the temperature decreased and as the dry solids or suspended matter content increased. The size distribution of suspended particles in SW depended on the sample preparation technique, method used to measure particle size and whether the size distribution was expressed in terms of the weight or population of fractions. The average size (by weight) of suspended solids in SW was 2.5 μm as estimated by electronic counting. The solubility of protein in SW decreased when acid or alkali were added or thermal treatment (1 h at 90°C) applied. A minimal solubility point occurred near pH 5. The molecular weight of most dissolved proteins in SF was 3 kD. SF also contained a small proportion of 67 kD proteins. The significance of this basic characterisation study for the selection of improved processes for stickwater recovery is discussed.     

应用DNA条形码技术鉴定烤鱼片、鱼干中河鲀鱼鱼种

应用DNA条形码技术对北京和厦门市市售烤鱼片、鱼干中河鲀鱼成分进行鉴定。方法 以烤鱼片、鱼干中提取基因组DNA为模板,利用针对河鲀鱼细胞色素氧化酶亚基Ⅰ(COⅠ)基因的特异性引物进行PCR扩增,将扩增产物克隆并测定线粒体COⅠ基因序列。将测序结果与GenBank中已有河鲀鱼的DNA序列进行BLAST比对,并且构建分子进化树。结果 本研究27份样品中有15份能扩增出特异性条带。通过BLAST比对和进化树分析,将15份样品归属到不同的河鲀鱼鱼种中。结论 北京和厦门市市售烤鱼片和鱼干中存在混入河鲀鱼的现象,应加强监管和规范产品的加工程序以避免中毒事件发生。     

Quantitative determination of trace metals in frozen fish, fish oil and fish meal (author's transl)]

As a contribution to the discussion on the "Verordnung uber Umweltkontaminanten" (draft) we examined 73 double samples of the frequent types of edible fish and 2 samples each of fish oil and fish meal for their content of arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg). Arsenic was determined photometrically, cadmium and lead by anodic stripping voltammetry and mercury by flameless atomic absorption spectrometry. We found the following average contents (ppm): 0.84 As, 0.003 Cd, 0.08 Pb, 0.06 Hg. The limits (ppm) set up in the draft for a German "H?chstmengenverordnung" (regulation specifying the maximum concentrations allowed) were by far not reached in the case of Cd, Pb, and Hg with all samples while they were fulfilled in the case of As by only 18% of the samples. It seems that the limit for As of 0.5 ppm has been set up too low. In the average, the following proportion applies for the trace contents found: Cd:Hg:Pb:As = 1:20:27:280. Correlations between the contents of trace metals on the one hand and fishing grounds or trawler or sample piece on the other could not be found.     

Consumer evaluation of fish quality as basis for fish market segmentation

This paper focuses on consumer evaluation of fish quality and its association with fish consumption, risk and benefit beliefs and information processing variables. Cross-sectional data were collected from a sample of 429 consumers in March 2003 in Belgium. Two dimensions shape fish quality evaluation: personal relevance attached to fish quality and self-confidence in fish quality evaluation, which allow segmenting the market in four fish consumer segments. The segments are typified as Uninvolved, Uncertain, Self-confident and Connoisseurs, and have distinctive behavioural, attitudinal and socio-demographic profiles. The Uninvolved are mainly young males, have the lowest fish consumption level, weakest belief in health benefits from eating fish, and lowest interest in both search and credence information cues. Uncertain fish consumers are mainly females, with a tendency of lower education and urban residence, who feel not confident to evaluate fish quality, although they find quality very important. They display a strong interest in a fish quality label. The most relevant findings about Self-confident consumers, whose socio-demographic profile matches best with the overall sample, are their high fish consumption level, and their relatively low interest in a fish quality label. Connoisseurs are mainly females in the age category 55+, who are strongly involved with food in general and most convinced of the association between food and health. They have the highest fish consumption and show a strong interest in both search and credence cues, as well as in a fish quality label. The segments do not differ with respect to risk perception about fish.     

Biogenic amines in fish,fish products and shellfish: a review

Fish, cephalopods and shellfish provide a healthy source of high-quality proteins, essential vitamins, minerals and polyunsaturated fatty acids. The beneficial effects of fish consumption on human health such as protection against coronary heart disease and certain cancer may be offset by fish decomposition and the formation of chemical contaminants such as biogenic amines. There are several toxicological effects of biogenic amines on humans, especially histamine. It is the causative agent of histamine or scombroid fish poisoning which is a significant public health problem. In individuals with diminished histamine detoxification, ingestion of even a low or moderate histamine- or tyramine-containing fish may lead to food intolerance. Biogenic amines such as putrescine, tyramine and cadaverine can potentiate histamine toxicity. Furthermore, dietary polyamine intake should be minimised in some cancer patients. Besides their potential toxicity, biogenic amines are used for the evaluation of hygienic quality of different marine and freshwater species. Spoilage pattern and biogenic amine formation are species specific. Histamine has been traditionally used as an indicator of the quality of histidine-rich fish (dark-muscle fish). On the other hand, putrescine and cadaverine are the most objective indicators of quality of histidine-poor fish (white-muscle fish), shellfish and fermented seafood products.     

鱼精蛋白对延长鱼糕制品有效保存期的作用

本文用鱼精蛋白、苯甲酸钠和山梨酸钾分别添加在鱼糕制品中，并于12℃和24℃条件下保存，观察其保存效果。结果表明：添加0．8％鱼精蛋白的鱼糕在12℃和24℃的有效保存期分别为7d和5d，达到添加0．3％苯甲酸钠和0．2％山梨酸钾的效果。