SEROLOGIC IDENTIFICATION OF SPECIES OF ORIGIN OF SAUSAGE MEATS

SUMMARY: A partially purified immunoglobulin G (lgG) solution prepared from the serum of species to be tested was heated to the specifications for sausages. The resulting supernatant fluid was decanted and the precipitate washed with saline and used to immunize rabbits. The supernatant fluid was used to sensitize tanned sheep red blood cells. The immune serum was rendered monospecific by absorptions with heterologous, heated lgG precipitates. A sample of monospecific immune serum was absorbed with a washed homogenate of sausage. Aliquots of the monospecific immune serum, both untreated and sausage absorbed, were tested with cells sensitized with the homologous heated lgG supematant fluid. A significant reduction of titer by sausage absorption indicated that the sausages contained the meat homologous to the immune serum.     

SIMPLIFIED IDENTIFICATION OF YEASTS BY A SEROLOGICAL TECHNIQUE

A scheme is described for comparison of yeast colonies isolated on normal or selective media or by membrane filtration. By streak culture of each colony, or of a selection of each type of colony, on Oxoid WL medium followed by serological and morphological testing of the cultures, the different species present are detected with minimal effort. Colonies of the same species are identical in appearance, and in serological and morphological properties of the cells; therefore if a complete identification is desired, only one colony need be tested of each type. This saves the effort of fermentation and other tests on a large number of colonies, but results of morphological and serological tests alone normally provide sufficient information for identification of taxonomic groups of yeasts, if not of individual species. Three examples of the use of the method are described: identification of the various yeast species of the sherry flor complex, and identification of yeasts in samples of clean and polluted water.     

线性聚合技术制备氨基硅油

制备氨烷基分布均匀的硅油。分子量分布很窄的线状端羟基二甲基聚硅氧烷ＷＳ－６２Ｍ代替Ｄ４与氨烷基硅烷酯交换反应、聚合反应,制得氨烷基分布均匀、且无杂质的氨基硅油。解决了Ｄ４开环、聚合反应中,Ｄ３～Ｄ１２杂质、反应副产物和反应过程不合理而导致氨烷基分布不均匀、影响整理织物柔软效果的问题。该合成方法简单,收率高,工艺合理,整理织物柔软效果好。     

IDENTIFICATION OF BARLEY VARIETIES USING THE POLYMERASE CHAIN REACTION

The polymerase chain reaction (PCR) with oligonucleotide primer sequences from alpha-amylase genes was used to distinguish between morphologically similar malting and feed barley varieties. The varieties “Chebec” (feed) and “Schooner” (malting) could be separated and the varieties “Skiff” (feed) and “Franklin” (malting) were identified by using two sets of primers. Primer BSW3 (5-CAGCTTGGCCTCCGGGCAAGTC-3) and BAS2 (5-CACCTTGCCGTCGATCTC-3) gave a 215 bp product that distinguished “Chebec” from “Schooner” and a 1230 bp fragment that distinguished “Skiff” from “Franklin”. Primer BSW5 (5-GGAGCTGGAATTGATGTTG-3) with primer BAS2 gave markers at 735 bp and 730 bp respectively to allow unique identification in comparisons of these pairs of varieties. DNA extracted from grain could be used for these analyses, but DNA from leaves gave clearer results.     

基因芯片技术鉴定食源性金黄色葡萄球菌

为了建立快速鉴定食派陛金黄色葡萄球菌的基因芯片技术，采用PCR方法扩增金黄色葡萄球菌16SrRNA基因的DNA片段．序列进行BLAST比较并通过软件设计其特异性探针，采用基因芯片杂交技术鉴定食源性金黄色葡萄球菌样品。结果：对所有样品进行基因芯片杂交技术处理并扫描观察，金黄色葡萄球菌的杂交结果呈阳性，其检测结果与传统方法鉴定结果一致。结论：应用基因芯片鉴定技术可快速、准确地鉴定食源性金黄色葡萄球菌，值得推广应用。     

利用生物素链霉亲和素放大酶联免疫方法检测猪肉中莱克多巴胺残留

以酶联免疫方法为基础.结合生物素-链霉亲和素系统的放大作用,建立直接竞争生物素链霉亲和素放大酶联免疫(BA-ELISA)检测方法,并将其用于猪肉肌肉组织中莱克多巴胺残留的检测,方法灵敏度(IC50)为(0.3±0.05)ng/mL,样品检出限为(0.3+0.1)ng/kg,平均加标回收率在84%以上.     

涤纶超细纤维的生产技术──（一）设备

本文主要介绍了德国ＨＥＵＭＡＧ公司采用ＰＯＹ－ＤＴＹ工艺路线生产涤纶超细旦预取向丝（ＰＯＹ）的生产设备状况。     

C60的重要技术价值及其潜在应用前景

1985年C60的发现是对碳认识的新阶段，是科学上的重要发现，使我们了解到一个全新的碳化学世界。短短的10多年来，C60已经广泛地影响物理学、化学、材料学、生命学及医药科学等领域，极大丰富和提高了科学理论，同时也显示出巨大的潜在应用前景。     

I. DETERMINATION OF BARLEY AND MALT NITROGEN CONTENT USING AN AUTOANALYSER TECHNIQUE

A rapid semi-micro method of Kjeldahl digestion and the use of an Autoanalyser for the estimation of digest ammonia content are described. Adoption of these methods has achieved throughput rates of 40 to 50 samples per hr. with resultant savings in labour and materials.     

Identification of Aloe species by random amplified polymorphic DNA (RAPD) analysis

Juice and integument of leaves of 3 Aloe species, Aloe vera, A. ferox and A. africana, are not allowed to be used as food according to the Pharmaceutical Affairs Law in Japan. On the other hand, whole leaves of A. arborescens can be used as food. The present study was designed to distinguish Aloe species by random amplified polymorphic DNA (RAPD) analysis. DNA was isolated from fresh and dried leaves of the 4 Aloe species. Five out of 32 different 10-mer primers examined were useful for analysis. By comparison of the characteristic bands of PCR products on agarose gel, it was possible to distinguish the 4 species. Thus, the botanical species of Aloe in commercial food products can be identified by RAPD analysis.     

THE DETECTION AND IDENTIFICATION OF PEDIOCOCCUS AND MICROCOCCUS IN BREWERIES,USING A SEROLOGICAL METHOD

A commercially-available antiserum for the identification of group D strains of Streptococcus contains antibodies which react with Pediococcus and Micrococcus, and provides a convenient method to detect these genera in yeast, wort and beer. After suitable adsorption it can be used to distinguish between Pediococcus and Micrococcus and, within each genus, to differentiate between groups normally found in a brewery environment and those from other sources.     

PROBABILISTIC SIMULATION OF BATCH TRAY DRYING USING MARKOV CHAINS AND THE MONTE CARLO TECHNIQUE

The objective in food dehydration is to dry the product to a specified uniform moisture content. In practice, a distribution in final moisture content is unavoidable, arising from the intrinsic variability of food properties and the probabilistic nature of the food drying process. A methodology is outlined whereby the inherent stochastic dynamics of batch tray dehydration in cabinet or tunnel dryers can be modeled efficiently using Markov chains. By simulating the drying process with the model, the progressive transformation of the moisture distribution of the trays throughout the drying cycle can be quantified. Output from the model is validated with experimental drying results to test its accuracy. In addition the output of the Markov approach is compared with that of an equivalent Monte Carlo simulation model to provide inter-model comparisons. Markov analysis can predict the variation in final moisture content and thus has the potential to help maximize the value of the dried product.     

IDENTIFICATION OF POULTRY MEAT FROM PORK AND BEEF ON THE BASIS OF THE TITIN PEVK REGION USING PCR

The possibility of distinguishing three kinds of meat species (chicken, porcine and bovine) alone or in two-component meat mixtures was investigated using the polymerase chain reaction. The contribution of each component in the meat mixtures ranged from 1 to 100%. The identification of meat was performed on the basis of the sequence coding the PEVK region of titin and by employing polymerase chain reaction. DNA was isolated from raw, fresh and chilled meat. The data presented in this study suggest that it is possible to detect chicken meat, pork and beef in meat mixtures on the basis of PEVK region by using PCR.

PRACTICAL APPLICATIONS

The polymerase chain reaction (PCR) is a precise and quick technique that has many practical applications. Using PCR with primer sets designed on the basis of the PEVK region present in titin can be a convenient tool for species identification, especially for chicken meat mixed with pork and beef meat in two-component meat mixtures. Reliable and sensitive methods for species differentiation can give consumers confidence about authentic meat product composition.     

COLORIMETRIC DETERMINATION OF IRON IN BEER BY FLOW INJECTION ANALYSIS USING THE MERGING ZONES TECHNIQUE

A flow injection analysis system with colorimetric detection for the iron determination in beer is described. The methodology is based on the formation of a complex produced by the reaction of iron (II) with 1,10-phenanthroline, after reduction of iron (III) to iron (II) by ascorbic acid. The asymmetric merging zones technique was used to allow the sequential blank and sample absorbance readings. The results obtained with the developed system were in good agreement with those provided by the reference method (relative deviations lower than 4%) and exhibited a precision (relative standard deviation) better than 7%. A sampling-rate of 60 determinations per hour can be achieved.     

Random amplified polymorphic DNA (RAPD) fingerprints for identification of red meat animal species

The random amplified polymorphic DNA (RAPD) method was used to generate fingerprint patterns for 10 meat species: wild boar, pig, horse, buffalo, beef, venison, dog, cat, rabbit and kangaroo. A total of 29 10-nucleotide primers, with GC contents ranging from 50–80%, were evaluated for their specificity and efficiency. The fingerprint patterns that were generated were found in some cases to be species-specific, i.e. one species could be differentiated from another. The advantages and disadvantages of using RAPD-PCR for the identification of red meat species are also discussed.