DNA barcoding for the species identification of commercially important fishery products in Indonesian markets

The DNA barcoding approach was used for the species identification of 44 Indonesian commercial fishery products. Additionally, the intronless nuclear rhodopsin gene fragment (RH1) was added to the analysis to enable the identification of species not yet barcoded and possible hybrids. The 655‐bp cytochrome C oxidase subunit I (COI) gene fragment marker was successfully amplified and used to identify 86% of the total fish samples at the species level using the BOLD and BLAST public databases. Moreover, the RH1 marker was used to complete COI analysis. For a number of fish species, the COI sequences (six species) and RH1 sequences (eight species) were the first entries submitted to GenBank. This study demonstrated that COI barcoding is a promising tool for Indonesian fishery products and confirmed that it could be adopted in the future for regular seafood control as part of the Indonesian integrated food traceability system.     

生物传感器在水产品食用安全品质探制中的应用

主要就生物传感器在水产品质量监督及安全控制中的应用进行了综述,包括对于主要生化质量指标的评定,以及来自于环境的安全危害因子的监测,并就目前存在的问题及今后的发展趋势作了分析.     

Authentication of species in meat products by genetic techniques

In the present work, a method for the authentication of meat products was developed, using Polymerase Chain Reaction (PCR) followed by Forensically Informative Nucleotide Sequencing (FINS). This study describes the use of sequencing of the cytochrome b gene of the mtDNA in a wide variety of species to diagnose adulteration of meat through the substitution from one species to another that have less commercial value. The main importance of this work is to deal with a wide variety of species that have not previously been analyzed. This methodology strategy allows the authentication of meat species in all kind of products, fresh, or precooked products, the more usual format for marketing in that species. This method shows a specificity of 100%. The developed methodology was validated and finally applied to 20 commercial samples including some that had been subjected to intensive thermal treatment. In 15% of the products analyzed, the name of the species displayed in the label was not in agreement with the identified species. The main novelty of this work lies in the fact that it allows the identification of a large number of meat species not analyzed so far in previous works. In this work are included meat species, which can be easily found in our markets, and a wide variety of others whose consumption is common in other parts of the world. Therefore, this technique can be used as a routine method to avoid the mislabeling in the marketing of these products and to assess their correct traceability.     

A novel method for species identification in milk and milk-based products

This study describes a method for species-specific detection of animal DNA from different species (cattle, sheep, goat, water buffalo) in milk and dairy products. A primer set was designed in conserved region on the basis of the alignment of the sequence codifying the genomic kappa-casein gene in order to amplify all four species with a single primer pair. Polymorphisms were detected via minisequencing with extension primers designed in conserved sequences for haplotype determination that allow unambiguous assignment to each species. The method was successfully applied to the detection of raw and pasteurized milk from the four different species considered as well as to cheese products from the retail trade. Estimation of the limit of detection was carried out using a progression of dilutions of genomic DNA as well as DNA isolated from milk of a known number of somatic cells from different species in order to be able to achieve detection rates as low as 0.1% bovine milk mixed with buffalo milk.     

ELISA-test for cooked meat species identification on gelatine and gelatine products

The results of the ELISA-test with a commercial cooked meat species identification kit on gelatine and gelatine containing products can be influenced by different gelatine types and concentrations leading to false positive readings. The test cannot be applied especially to meat products containing relatively high amounts of soluble collagens because their extracts form solid gels in the test wells. In this case the different reagents added will penetrate the gels and react with each other. The kit may not speciate reliablely commercial gelatine in isolation or in products where gelatine is the sole animal protein source.     

Validation of a PCR-RFLP based method for the identification of salmon species in food products

The use of a PCR-RFLP based method for the identification of salmon species in food products was investigated. The reliability and practicality of the method was tested by a collaborative study in which five European laboratories participated. Two unknown samples (a commercial product of known species composition and a mix of two salmon species) required identification by comparison with authentic reference species. From a total of 50?cases, 100% of authentic species were correctly assigned, with all unknown samples also correctly identified. A larger scale analysis of UK commercial products was also performed spanning the whole range of salmon products available. In almost all cases the salmon species declared was confirmed, although, a trout species was detected in one product declaring only the presence of salmon. The investigation confirms the reproducibility of the method in different laboratories, and its applicability for commercial product analysis.     

Listeria in tropical fish and fishery products

Listeria monocytogenes is considered to be a ubiquitous organism occurring in both terrestrial and aquatic habitats. This organism has been isolated from fish and fishery products from different parts of the world and interestingly the incidence rate reported from tropical fish is rather low. Varying methodologies have been used by different investigators to study the incidence of L. monocytogenes in fish. Data on virulence of seafood-associated strains are lacking. For quality assurance in the fish processing industry, rapid and sensitive methods for the detection of L. monocytogenes are required.     

Determination of the heating temperature of fishery products

Summary The German Fish Directive prescribes that products must be heated to the core temperature of +70° C to kill existing larvae of nematodes. For subsequent determination of the heating temperature samples were extracted with water. The extracts were analysed for protein content, for protein patterns obtained by isoelectric focusing and by using the coagulation test. The suitability of these methods was investigated with heated extracts, heated minced fish flesh, and smoked herring and mackerel. Smoking was performed in the kiln of the institute at controlled temperatures. Analysis of commercial samples showed that the core temperature during smoking of herring and mackerel must have been clearly below 70° C in several cases.

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Bestimmung der Erhitzungstemperatur von Fischereiprodukten

Zusammenfassung Die deutsche Fischverordnung schreibt vor, daß zum Abtöten eventuell vorhandener Nematodenlarven eine Kerntemperatur des Produktes von mindestens +70 °C erreicht werden muß. Zur nachträglichen Bestimmung der Erhitzungstemperatur wurden wäßrige Extrakte erhitzter Proben folgenden Analysen unterzogen: 1. Bestimmung des Proteingehaltes; 2. Flockungstest; 3. Isoelektrische Focussierung. Die Eignung dieser Methoden wurde mit erhitzten Extrakten und Proben aus zerkleinertem Fischfleisch sowie mit Heringen und Makrelen, die bei definierten Temperaturen geräuchert wurden, geprüft. Die nachfolgende Analyse von Handelsware ergab, daß bei mehreren Proben die Kerntemperatur bei der Räucherung deutlich unterhalb von 70 °C gelegen haben mußte.

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Part of this work was presented at the 21^st Annual Meeting of the Western European Fish Technologists Association (WEFTA) in Copenhagen on 25 August 1991     

鱼类冷冻调理食品生产工艺

概述了鱼类冷冻调理食品的特点和现状,并以冷冻调理鲐鱼及冷冻调理鳗鱼的生产过程为例详细介绍了鱼类冷冻调理食品的生产技术工艺。     

天然水产滋味类产品概述

主要介绍了天然水产滋味类产品的原料、生产工艺、产品特性及其在食品工业中的应用。     

Determination of the formaldehyde content in fishery products

Summary The influence of external factors, such as storage temperature and time on the content of free formaldehyde (FA) in fishery products is described. On the basis of the examination of several methods for the determination of free and bound FA, the following procedures are recommended: (1) for measuring free FA, the samples are extracted using 6% perchloric acid at room temperature and the FA content of the extracts is measured by the formation of 3,5-diacetyl-1,4-dihydrolutidine; (2) bound, acid-labile FA is released by steam distillation using 1% sulphuric acid, giving a pH value of about 1. The FA content of the distillates may be determined either by chromotropic acid assay or by the method described for the extracts.

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Bestimmung des Formaldehydgehaltes in Fischprodukten

Zusammenfassung Es wird aufgezeigt, von welchen äußeren Einflüssen (z. B. Lagertemperatur und -zeit) der Gehalt an freiem Formaldehyd in einem Fischprodukt abhängt. Nach Überprüfung verschiedener Methoden zur Bestimmung des freien und gebundenen Formaldehyds werden folgende Verfahren vorgeschlagen: 1. Zur Messung des freien Formaldehyds wird die Probe mit 6%iger Perchlorsäure bei Raumtemperatur extrahiert; der Formaldehydgehalt des Extraktes wird über die Bildung von 3,5-Diacetyl-1,4-dihydrolutidin ermittelt. 2. Gebundener, säurelabiler Formaldehyd wird durch Wasserdampf-Destillation einer mit 1%iger Schwefelsäure versetzten Probe freigesetzt; der pH-Wert des Ansatzes beträgt etwa 1. Im Destillat kann Formaldehyd entweder über die Bildung des Lutidinfarbstoffes oder mit Chromotropsäure bestimmt werden.

     

Determination of the formaldehyde content in fishery products

The influence of external factors, such as storage temperature and time on the content of free formaldehyde (FA) in fishery products is described. On the basis of the examination of several methods for the determination of free and bound FA, the following procedures are recommended: (1) for measuring free FA, the samples are extracted using 6% perchloric acid at room temperature and the FA content of the extracts is measured by the formation of 3,5-diacetyl-1,4-dihydrolutidine; (2) bound, acid-labile FA is released by steam distillation using 1% sulphuric acid, giving a pH value of about 1. The FA content of the distillates may be determined either by chromotropic acid assay or by the method described for the extracts.     

Bio-based edible coatings for the preservation of fishery products: A Review

ABSTRACT

The popularity of preprocessed fresh fishery products such as fillets and peeled shrimps is growing in today s market due to their convenience for subsequent processing and cooking. However, fishery products are highly perishable because of the combined actions of biochemical reactions and microbial metabolism. Various methods have been proposed to address this problem. Among these methods, bio-based edible coating has been highlighted as a promising solution. This review updates and summarizes the recent literature on the application of coatings for the preservation of fishery products including the aspects of coating carriers, composite natural preservatives and coating methods, and a discussion of the protective effects based on microbial, physicochemical and sensorial evaluations. Moreover, some challenges and future research directions regarding optimization of formulas and exploration of mechanisms of coating are also discussed. Given consumer demand for fresh fishery products with long shelf life, edible coatings that are environmentally friendly and effective alternative will be used to extend the shelf life of fishery products.     

A quick and simple method for the identification of meat species and meat products by PCR assay

The polymerase chain reaction (PCR) was applied to identify six meats (cattle, pig, chicken, sheep, goat and horse) as raw materials for products. By mixing seven primers in appropriate ratios, species-specific DNA fragments could be identified by only one multiplex PCR. A forward primer was designed on a conserved DNA sequence in the mitochondrial cytochrome b gene, and reverse primers on species-specific DNA sequences for each species. PCR primers were designed to give different length fragments from the six meats. The products showed species-specific DNA fragments of 157, 227, 274, 331, 398 and 439 bp from goat, chicken, cattle, sheep, pig and horse meats, respectively. Identification is possible by electrophoresis of PCR products. Cattle, pig, chicken, sheep and goat fragments were amplified from cooked meat heated at 100 or 120°C for 30 min, but horse DNA fragments could not be detected from the 120°C sample. Detection limits of the DNA samples were 0.25 ng for all meats.     

水产品中甲醛的速测方法研究

试验采用水作提取剂（中性萃取）,超声波提取、离心分离样品,确定了快速检测水产品中甲醛含量的样品提取条件.本方法避免了化学试剂的毒性和污染,降低了成本,同时缩短了分析时间.实现了干、鲜水产品中甲醛的现场快速检测.     

水产品及水产制品中三聚氰胺检测方法的研究

采用气相色谱-质谱/质谱法（GC-MS/MS）对鲜、冷或冻水产品（养殖鱼、虾、蟹、贝等）及水产制品（干、熏、盐制水产）中三聚氰胺进行了检测。样品采用乙睛和甲醇提取,提取液离心净化,氮气吹干,利用衍生化试剂BSTFA-TMCS（体积比为99∶1）进行衍生化反应、优化仪器条件、考察基体干扰,利用三重四级杆气相色谱联用的多反应监测（MRM）技术,对三聚氰胺衍生物进行定性定量分析。以三聚氰胺衍生物离子对m/z 342〉171、m/z 342〉327离子对进行定性,以m/z 342〉327进行定量。方法的线性范围为0.005μg/L~0.1μg/L;回归方程为y=1 434 164.378 8x-704.012 5,相关系数R2=0.999 4;方法定量限0.03 mg/kg。回收率达90%以上,相对标准偏差RSD〈5.0%。该方法简便、快速、灵敏、准确,适合于水产品和水产制品中三聚氰胺含量的确证和定量测定。     

Characterization of yeast isolates originating from Hungarian dairy products using traditional and molecular identification techniques

Yeast isolates collected from various Hungarian dairy products were identified using simplified identification system (SIM) and restriction fragment analysis of PCR-amplified 18S rDNA with the neighbouring ITS1 region (ITS-PCR; ribotyping). The isolates were grouped into 26 species; Geotrichum candidum, Debaryomyces hansenii, Yarrowia lipolytica, Kluyveromyces lactis and Candida catenulata were found as the predominant species. SIM and ITS-PCR proved to be useful and convenient taxonomic tools for rapid identification at species level. Two most frequent species, G. candidum and D. hansenii, were further characterized by randomly amplified polymorphic DNA (RAPD-PCR) analysis. RAPD-PCR using M13 primer resulted in discrimination between most strains of the same species and allowed a certain degree of intraspecific typing.