食品中生物胺含量及生物胺氧化酶的研究进展

生物胺是一类具有潜在毒性的生物活性物质,在食品中广泛存在。生物胺氧化酶是广泛存在于动植物、微生物体内的,能够将已生成的生物胺分解成相应的醛、氨气和过氧化氢的一类酶,该类酶在降解食品中生物胺方面具有良好的应用前景。本文将从食品中生物胺含量以及生物胺氧化酶的分类、影响因素、产生菌株、降解特性等方面进行综述。     

食品中生物胺的研究进展

生物胺是一类具有生物活性、含氨基的低分子质量化合物。大多数食品中都含有生物胺,这些生物胺主要由微生物氨基酸脱羧酶作用于氨基酸脱羧而生成。适量生物胺可促进人体的正常生理活动,而过量摄入会产生不良反应。微生物在不同食品中的分布不尽相同,这导致在不同食品中生物胺种类和数量的差异。本文详细综述不同食品中生物胺的来源、产生机理、针对性的防治措施及其检测方法,为生产安全食品、降低食品中生物胺的含量提供解决方案。     

发酵肉制品中微生物对生物胺形成机理的影响研究

富含高蛋白质的食品中存在生物胺,发酵肉制品中蛋白质含量丰富可能存在高浓度的生物胺。微生物在不同发酵肉制品中的分布不尽相同,导致了在不同发酵肉制品中生物胺种类和数量上的差异。该文综述发酵肉制品中微生物对生物胺形成机理的研究进展,将发酵肉制品中的微生物群落构成与生物胺分析有机地结合起来,为利用发酵剂调控微生物菌群结构来降低生物胺潜在危害的应用提供科学依据。     

食品中与生物胺形成相关的微生物菌群及其控制技术研究进展

生物胺是一类具有生物活性的低分子含氮有机化合物,食品中的生物胺主要经微生物分泌的外源酶催化而 形成。适量的生物胺可促进生长、增强代谢,过量则导致人体产生过敏等不良反应。本文综述了生物胺的特点与危 害、食品中生物胺的形成、各类食品中与生物胺形成相关的主要微生物菌群及生物胺控制的关键要素,为控制食品 中的生物胺含量、生产安全食品提供解决方案。     

发酵肉制品中生物胺及其产生菌株研究进展

生物胺是一类具有生物活性的含氨基小分子有机化合物,其广泛存在于蛋白丰富的食品中。生物体内适量生物胺具有增强代谢、促进生长等功能,但当含量达到临界值时,会产生诸多不良影响。存在大量微生物的食品中,生物胺的含量较高,同类发酵肉制品中生物胺的种类和含量也有很大不同,如发酵时间、贮藏时间和包装材料等都会对此产生影响。本文主要介绍生物胺的常见种类、生理作用,发酵肉制品中产生物胺的微生物种类、形成途径、菌株筛选方法及检测方法,旨在为今后发酵肉制品中生物胺的进一步研究提供帮助,以期为发酵肉制品的质量保障提供参考。     

水产品中生物胺的检测技术研究进展

生物胺是一类具有生物活性的含氮、低分子质量有机化合物的总称,普遍存在于水产品等蛋白质和氨基酸含量较高的食品中,与腐败微生物密切相关,水产品在长时间的贮存和售卖过程中容易受到微生物的作用而腐败变质,产生超标的、对人体有害的组胺等生物胺,因此,生物胺的检测技术十分必要。本文详细综述国内外测定水产品中生物胺的前处理方法、检测方法及其优缺点,并展望了生物胺检测技术的发展前景,为水产品中生物胺的检测提供技术基础和方法学依据。     

胆固醇氧化酶的研究进展

胆固醇氧化酶在食品加工、医疗监测、生物抗虫等方面作用日益受到人们的重视,并且显示出巨大应用潜力,现已成为一大研究热点。笔者综述了产酶的微生物、酶活测定方法及发酵工艺等,并对胆固醇氧化酶的研究进行了展望。     

用于检测食品中生物胺荧光探针研究进展

生物胺(Biogenic amine,BA)等食源性污染物对人体健康有害,为保障食品安全,应严格控制食品中生物胺的含量。小分子荧光探针用于监测生物胺具有高灵敏度和选择性,操作简单,并且可以实现分析物的光信号可视化的特点。文章综述了选择性检测生物胺荧光探针的最新进展,讨论了近年来开发的用于检测生物胺的各种荧光探针的工作机理、传感性能,并对这些探针在食品中的应用进行了综述,讨论了分子荧光探针未来在食品中的研究方向、趋势和前景。     

咖啡中生物胺含量测定方法研究进展

生物胺是低分子量有机碱,存在于蛋白质丰富的食品尤其是发酵食品中。测定食品中的生物胺方法较多,每种方法都有自己优点和缺点。主要介绍了咖啡中生物胺测定的三种方法:反相高效液相色谱法、离子色谱法和薄层色谱法。重点介绍了三种方法的特点及其在咖啡中的生物胺测定中的应用,并总结了在各种类咖啡生豆、烘焙咖啡中的生物胺含量检测方法与技术,给出了咖啡中的生物胺含量检测结果。     

发酵蔬菜中生物胺控制技术研究进展

生物胺是发酵蔬菜中主要存在但易被忽视的一种有害代谢产物,过量的生物胺会引发产生一系列中毒反应,对人体健康造成不良影响。目前,由于产品的多样化等原因,规定发酵蔬菜中的生物胺残留量存在一定难度,在我国发酵蔬菜中的生物胺还没有相关的限量标准。研究发酵蔬菜生物胺控制技术,将有利于保证产品安全性,促进发酵蔬菜产业的长远发展。该文对食品中生物胺的危害、限量及控制发酵蔬菜生物胺的意义进行简述,综述发酵蔬菜生物胺控制技术,主要包括微生物酶解法、菌株筛选控制法及发酵工艺控制法。     

微生物葡萄糖氧化酶的研究进展

葡萄糖氧化酶（EC 1.1.3.4）作为一种高特异性氧化还原酶,能够催化β-D-葡萄糖转化为葡萄糖酸,并产生过氧化氢（H2O2）,在医疗检测、食品、生物燃料电池、畜牧养殖等领域发挥着极其重要的作用。该文从微生物来源、克隆表达、发酵优化、分离纯化及应用方面,阐述了葡萄糖氧化酶的研究进展,以期为葡萄糖氧化酶的开发和应用提供参考。     

Induction and characterization of a novel amine oxidase from the yeast Kluyveromyces marxianus

An amine oxidase from the yeast Kluyveromyces marxianus was induced, purified and completely characterized; it was shown to belong to the class of copper-containing amine oxidases (E.C. 1.4.3.6). The enzyme was induced by putrescine and, very strongly, by copper(II); structural-functional characterization of the enzyme was performed, including determination of molecular weight, glycosylation, copper and TPQ content, isoelectric point, K(M) and k(CAT) (with benzylamine as substrate), pH, temperature and ionic strength effect on catalysis, substrate and inhibitor specificity. A 700 bp clone was isolated containing the cDNA that encodes for the C-terminus of the enzyme; the amino acid sequence deduced (the first available for a benzylamine oxidase from yeast) was compared to that of other copper amine oxidases from microorganisms and higher organisms. From the results obtained, the putrescine/benzylamine oxidase from Kluyveromyces marxianus was found to have a good homology with other enzymes of this class from microorganisms, and particularly with AO I from Aspergillus niger. Nonetheless, some features resulted closer to those of animal amine oxidases and histaminases. Some potential biotechnological applications are proposed. The cDNA Accession No. is AJ320485.     

Control of biogenic amines in food--existing and emerging approaches

Biogenic amines have been reported in a variety of foods, such as fish, meat, cheese, vegetables, and wines. They are described as low molecular weight organic bases with aliphatic, aromatic, and heterocyclic structures. The most common biogenic amines found in foods are histamine, tyramine, cadaverine, 2-phenylethylamine, spermine, spermidine, putrescine, tryptamine, and agmatine. In addition octopamine and dopamine have been found in meat and meat products and fish. The formation of biogenic amines in food by the microbial decarboxylation of amino acids can result in consumers suffering allergic reactions, characterized by difficulty in breathing, itching, rash, vomiting, fever, and hypertension. Traditionally, biogenic amine formation in food has been prevented, primarily by limiting microbial growth through chilling and freezing. However, for many fishing based subsistence populations, such measures are not practical. Therefore, secondary control measures to prevent biogenic amine formation in foods or to reduce their levels once formed need to be considered as alternatives. Such approaches to limit microbial growth may include hydrostatic pressures, irradiation, controlled atmosphere packaging, or the use of food additives. Histamine may potentially be degraded by the use of bacterial amine oxidase or amine-negative bacteria. Only some will be cost-effective and practical for use in subsistence populations.     

A new type of methylamine oxidase: the sole oxidase produced during growth of Sporobolomyces albo-rubescens on primary alkylamines

Under conditions known to separate methylamine oxidase from benzylamine oxidase in other yeast strains, only a single oxidase could be detected in Sporobolomyces albo-rubescens. This occurred irrespective of whether methylamine or n-butylamine was the nitrogen source for growth. The oxidase did not attack benzylamine. It was concluded that this organism can only produce a methylamine oxidase. The enzyme was purified to 90% homogeneity and found to have properties significantly different from the methylamine oxidases previously characterised. It lost only 40% of its activity in 30 min at 45 degrees C, whereas methylamine oxidases previously described had half-lives of from 2 to 9 min at 45 degrees C. It showed also a lower activity with short chain 1-aminoalkanes and a higher activity with longer chain 1-aminoalkanes than other methylamine oxidases, and had a significantly smaller subunit molecular weight (57,000 compared with 80,000).     

Assembly of amine oxidase and D-amino acid oxidase in the cytosol of peroxisome-deficient mutants of the yeast Hansenula polymorpha during growth of cells on glucose in the presence of primary amines or D-alanine as the sole nitrogen source

We have studied growth of two peroxisome-deficient mutant strains of Hansenula polymorpha on glucose in the presence of different organic nitrogen sources (methylamine, ethylamine and D -alanine), the metabolism of which is mediated by peroxisome-borne oxidases in wild-type (WT) cells. Both strains grew well on each of these substrates with growth rates comparable to WT cells. Growth on both methylamine and ethylamine was associated with enhanced levels of catalase and amine oxidase in the cells; in D -alanine-grown cells D -amino acid oxidase activity and increased. In WT cells of H-polymorpha the activities of these enzymes were confined to the peroxisomal matrix; however, in both peroxisome-deficient strains their activities were localized in the cytosol. Electron microscopy indicated that, dependent on the stage of growth, the enzymes may form large protein aggregates. The molecular masses of both amine oxidase and D -amino acid oxidase in the mutant strains were identical to their respective counterparts in WT cells, indicating that both proteins were correctly assembled and active in the cytosol.     

Purification and characterization of an l-amino acid oxidase from Pseudomonas sp. AIU 813

An l-amino acid oxidase was found from a newly isolated strain, Pseudomonas sp. AIU 813. This enzyme was remarkably induced by incubation with l-lysine as a nitrogen source, and efficiently purified using an affinity chromatography with l-lysine as ligand. The enzyme oxidized l-lysine, l-ornithine and l-arginine, but not other l-amino acids and d-amino acids. The oxidase activity for l-lysine was detected in a wide pH range, and its optimal was pH 7.0. In contrast, the oxidase activity for l-ornithine and l-arginine was not shown in acidic region from pH 6.5, and optimal pH for both substrates was 9.0. The enzyme was a flavoprotein and composed of two identical subunits with molecular mass of 54.5?kDa. The N-terminal amino acid sequence was similar to that of putative flavin-containing amine oxidase and putative tryptophan 2-monooxygenase, but not to that of l-amino acid oxidases.     

Biogenic amines in traditional fermented sausages produced in selected European countries

Aminogenesis in traditional fermented sausages produced in Europe was studied during manufacturing process taking into account technological, physico-chemical and microbial factors. Tyramine was the major amine, followed by putrescine and cadaverine, although the occurrence of di-amines was much more variable. By principal component analysis, relationships between aminogenesis and the country of origin, physico-chemical parameters, processing conditions and microbial counts, were not found, probably due to the high dispersion observed in those variables. Therefore, biogenic amines occurred irrespectively of physico-chemical changes and technological conditions applied for sausage manufacture. By cluster analysis, five groups of fermented sausages were identified on the basis of their quantitative and qualitative profile of total biogenic amine content. Group A included products from very low to low total amine content (from not detected to 150 mg/kg); group B, products with moderate levels (from 150 to 350 mg/kg) tyramine being the major amine; group C, also with moderate amine contents but cadaverine being the major amine; and groups D and E, comprising products with high (from 350 to 550 mg/kg) and very high (higher than 550 mg/kg) amine content, respectively. Samples with moderate, high or very high levels of biogenic amines could be considered as products of less quality, and their consumption could be unhealthy for sensitive individuals or for those under classical monoamine oxidase inhibitor drug therapy.     

烟梗有机肥发酵过程中酶活性的变化

为了进一步揭示生物发酵机理,并为发酵有机肥腐熟标准体系的建立提供理论参考依据,以烟梗为原料进行了高温好氧堆肥试验,对发酵过程中物料的温度以及主要水解酶和氧化还原酶活性进行了测定。结果表明,烟梗有机肥发酵过程中,主要水解酶类和氧化还原酶类的活性均呈现出前期逐渐上升,后期趋于平稳或下降的变化趋势。添加发酵菌剂的烟梗堆料中水解酶类和氧化还原酶类的活性在发酵中期普遍较高,且出现峰值时间普遍较早,发酵结束时加菌剂处理和对照水解酶类酶活性相差不大,而氧化还原酶类活性相差较大。酶活性的提高促进了发酵代谢活性,提高了堆料发酵温度,加速了堆肥的腐熟。烟梗发酵有机肥后期果胶酶和碱性磷酸酶活性较为稳定,可作为烟梗有机肥腐熟的参考指标。     

微生物防腐剂及其在食品工业中的应用

微生物防腐剂是一类由微生物产生的能杀死或抑制微生物生长的天然、安全、高效的食品防腐剂。本文阐述了微生物防腐剂的来源、分类、结构特性、抑菌机制及其在食品工业中的应用和发展前景。     

酶法交联对食物蛋白的改性作用研究进展

食物蛋白通过分子间或分子内的交联作用,可有效地改善功能特性,有利于在食品加工中的应用。可用于蛋白交联的酶主要有转谷氨酰胺酶、多酚氧化酶、过氧化物酶等。主要阐述了转谷氨酰胺酶、多酚氧化酶、过氧化物酶交联蛋白的作用机理及最新研究进展。