茶叶霉菌污染现状及微波防霉研究

介绍了25g茶叶经微波辐照6min,茶叶中污染霉菌的平均杀灭率达82．5％。12份市售茶叶样品经微波处理后,霉菌总数小于100个／g者占75％,大大超过实验前的8．3％。对30份市售茶叶水分含量及霉菌总数的测定表明,茶叶的霉菌污染相当严重,散装茶叶的水分含量和霉菌总数均明显高于包装茶叶。作者建议在茶叶的卫生指标中增加水分及霉菌总数的指标。     

茶叶霉菌污染现状及微波防霉研究所

介绍了２５ｇ茶叶经微波辐照６ｍｉｎ，茶叶中污染霉菌的平均杀灭率达８２．５％。１２份市售茶叶样品经微波处理后，霉菌总数小于１００个／ｇ者占７５％，大大超过实验前的８．３％。对３０份市售茶叶水分含量及霉菌总数的测定表明，茶叶的霉菌污染相当严重，散装茶叶的水分含量和霉菌总数均明显高于包装茶叶。作者建议在茶叶的卫生指标中增加水分及霉菌总数的指标。     

进口干酪中霉菌污染的调查

依据GB4 789.15- 94方法 ,对 133件进口干酪进行了霉菌总数的测定和菌相分析。86 .4 7%的样品无霉菌污染 ,但从 18件样品中检出了霉菌 (霉菌总数 >10CFU/ g) ,检出率为13.53%。不同种类干酪的检出率无差别。从 133件干酪中分离出 10 6株霉菌 ,青霉占被分离菌株的 6 8.87% ,其中大部分为娄地青霉。硬质干酪中优势菌群为娄地青霉和常现青霉 ,软质及半软质干酪中优势菌群为拟青霉和娄地青霉。由此可见 ,加强进口干酪的霉菌检测是十分必要的。     

不同生产流通环节花椒霉菌污染情况调查研究

对来源于不同生产流通环节花椒样品的霉菌污染情况和毒素残留情况进行了分析。结果表明:实验所采集的25个样品中,68%存在霉菌总数超标,粉末样霉菌污染程度明显高于颗粒样,菌落总数达3.4×103 cfu/g;塑料密闭包装条件下,4℃冷藏样品污染霉菌菌落总数较常温储藏的高2~10倍,达2.4~6.6×103 cfu/g;样品中黄曲霉素和赭曲霉素含量与霉菌污染程度存在一定的正相关性,辐照处理能够有效减少花椒中活菌数目,但对霉菌毒素含量影响较小。     

冲调谷物制品污染菌相的调查分析

目的 了解冲调谷物制品中的微生物污染情况及主要污染菌种类,探讨传统形态学鉴定法、分子生物学鉴定法和基质辅助激光解吸电离飞行时间质谱法（matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF-MS）鉴定微生物的适用效果。方法 以流通领域抽取的冲调谷物制品为研究对象,采用国家标准方法对其菌落总数和霉菌进行计数,分离纯化不合格产品中的污染菌,以基质辅助激光解吸电离飞行时间质谱（matrix assisted laser desorption ionization time of flight mass spectrometry, MALDI-TOF-MS）结合16S rRNA序列分析方法对污染细菌进行鉴定,以MALDI-TOF-MS方法结合传统形态学鉴定方法对污染霉菌进行鉴定。结果 110批次冲调谷物制品的菌落总数不合格率为3.6%,霉菌计数不合格率为4.5%;分离得到的159株细菌可归于28个种,芽孢杆菌属（Bacillus）细菌为优势菌群,分离频率达到71.7%;分离得到的98株霉菌可划分至25个属,青霉属（Penicillium）和曲霉属（Aspergillus）为优势菌群,分离频率分别为12.4%和7.1%。污染菌中含有克罗诺杆菌（Cronobacter）等条件致病细菌和多种常见产毒真菌,存在一定的食品安全风险。结论 冲调谷物制品的微生物污染情况较为严重,生产企业应重视生产加工过程中的微生物污染问题,相关部门应加强对冲调谷物制品的食品安全监管。MALDI-TOF-MS方法在鉴定细菌时具有较大优势;受限于真菌数据库的不足,其用于食品来源霉菌鉴定的准确率有待提高。     

我国部分地区饲料霉菌污染状况的研究

对从河南、湖北、山东、安徽四省采集的１０２份饲料及其原料样品进行了霉菌污染状况的分析。结果表明：曲霉属霉菌的检出频率最高，达９８％，颗粒饲料的含菌量明显低于粉状饲料；饲料中的霉菌污染状况与玉米、麸糠类等主要原料的带菌种类及含菌量有密切的关系。     

乳酸菌饮料中污染菌群的分析和控制

导致乳酸菌饮料变质的污染菌有酵母菌、霉菌和杂菌,其中主要污染菌为酵母菌。把这三种污染菌制成含菌量不同的带菌液,进行乳酸菌饮料的污染试验表明,只要有一个上述污染菌存在,就会导致乳酸菌饮料变质。将产品进行80℃、5min热处理,能有效的杀死这些污染菌;加入0.4％的山梨酸钾,能有效地抑制霉菌、酵母菌的生长。酵母菌生长的延迟期约4h,即产品生产后4h为最佳杀菌时机。     

瓶装天然矿泉水霉菌菌相分析

对瓶装天然矿泉水霉菌菌相进行了研究分析，３３５份样品霉菌检出率为６５．４％，检出２４属７１６６株霉菌中，产毒菌属占有较大比例，优势菌群为头孢霉属，曲霉属和枝孢霉属，它们是土壤，空气和植物体中的常见菌，也是通常造成瓶装矿泉水成品发生霉菌性沉淀的主要原因，结合菌相分析，讨论了优势菌属的自然分布及生态特性，导致污染的原因和预防对策。     

制做低糖果脯的关键技术

果脯是我国传统的糖渍食品,又名蜜饯。由于地域的不同,人们对它的风味爱好也不一样,并形成了五大产品系列：京式果脯、广式蜜饯、苏武蜜饯、闽式蜜饯、潮式蜜饯。果脯新技术产品少,绝大多数仍采用传统的煮制方法,不但含糖量高（一般为６５％～７５％）、含水量低（一般１８％～２３％）,而且营养成分损失多、表面发粘,吃后口中发腻,与当今人们追求低甜度、高品位、营养丰富的食品消费观念不相适应。 国内外对含糖量高低的划分,大多数是以产品总糖含量５５％为界限。产品总糖含量高于５５％的,为高糖果脯;低于５５％的,为低糖果…     

广州市场部分蜜饯中SO_2残留量调查

采用国标GB／T5009．34——2003第2种方法（蒸馏法）对广州市场上7类共43个蜜饯产品中的SO2残留量进行分析测定,同时测定样品中的糖度、总酸度和水分含量等指标。结果显示,SO2残留量超过国家GB2760——2007《食品添加剂使用卫生标准》规定标准（0．35g／kg）的有10个产品,占调查总数的23．26％,残留量为0．4704—3．8411g／kg;残留量超标严重的两个波萝果脯产品分别超出规定标准的9．08倍和10．97倍;合格产品的SO2残留量为0．0005～0．2530g／kg。调查结果表明,同类产品不同厂家之间的SO2残留量差异较大。     

Potential aflatoxin hazards to human health from direct mold growth on Teleme cheese

Ninety-four commercial Teleme cheese samples were examined for aflatoxins produced by direct mold growth. The mycoflora on the cheese and in the atmosphere of Teleme cheese plants also were monitored. Penicillium and Aspergillus genera were tested for aflatoxin production after growth on Teleme cheese at 25 degrees C. In all cases, over 78% of the molds were Penicillium species. Aspergillus made up 3.8 to 3.9% and 0 to 7.3% of the mold on cheese and in the plant atmosphere, respectively. None of the commercial samples contained aflatoxins and none of the 448 Penicillium isolates was an aflatoxin producer. Of 22 Aspergillus species, one was capable of producing aflatoxins after direct growth on cheese. Because the physicochemical characteristics of Teleme cheese (high moisture, low pH, and medium salt concentration) favor mold growth, care should be taken to avoid contamination of the cheese by aspergilli.     

Detection of aflatoxin-producing molds in Korean fermented foods and grains by multiplex PCR

An assay based on multiplex PCR was applied for the detection of potential aflatoxin-producing molds in Korean fermented foods and grains. Three genes, avfA, omtA, and ver-1, coding for key enzymes in aflatoxin biosynthesis, were used as aflatoxin-detecting target genes in multiplex PCR. DNA extracted from Aspergillus flavus, Aspergillus parasiticus, Aspergillus oryzae, Aspergillus niger, Aspergillus terreus, Penicillium expansum, and Fusarium verticillioides was used as PCR template to test specificity of the multiplex PCR assay. Positive results were achieved only with DNA that was extracted from the aflatoxigenic molds A. flavus and A. parasiticus in all three primer pairs. This result was supported by aflatoxin detection with direct competitive enzyme-linked immunosorbent assay (DC-ELISA). The PCR assay required just a few hours, enabling rapid and simultaneous detection of many samples at a low cost. A total of 22 Meju samples, 24 Doenjang samples, and 10 barley samples commercially obtained in Korea were analyzed. The DC-ELISA assay for aflatoxin detection gave negative results for all samples, whereas the PCR-based method gave positive results for 1 of 22 Meju samples and 2 of 10 barley samples. After incubation of the positive samples with malt extract agar, DC-ELISA also gave positive results for aflatoxin detection. All Doenjang samples were negative by multiplex PCR and DC-ELISA assay, suggesting that aflatoxin contamination and the presence of aflatoxin-producing molds in Doenjang are probably low.     

小麦粉污染霉菌的分离鉴定及产黄曲霉毒素 能力的研究

目的对污染小麦粉中所含霉菌进行分离和菌株鉴定,并对所分离菌株的产黄曲霉毒素能力进行评价。方法使用马铃薯-葡萄糖琼脂培养基和麦汁琼脂培养基对小麦粉污染的霉菌进行分离和纯化,根据菌落形态、显微形态观察和ITS序列分析结果对分离菌株进行鉴定,采用PCR技术检测黄曲毒霉合成路径的关键基因来判断菌株的潜在产毒能力,最后用高效液相色谱法确认菌株是否产毒。结果共分离出5株菌株,分别鉴定为链格孢霉(NHF1)、橘灰青霉(NHF2)、黑曲霉(NHF3)和米曲霉(NHF4、NHF5),其中2株米曲霉具有潜在的产黄曲霉素的能力,在一定条件下会产生黄曲霉毒素。结论需要加强小麦粉微生物检测,尤其是霉菌污染的检测、管理和控制,全面制定小麦粉中污染微生物的限量标准,尤其是霉菌的限量值。     

矿泉水中臭氧杀灭霉菌效果研究

采用从生产现场及矿泉水瓶和盖分离出的卵形孢霉 (Oosporasp .)、刀孢霉 (Clas terosporiumsp .)、青霉 (Penicilliumsp .)、结实串孢霉 (Hormisciumsp .)、峡筒串孢霉 (Pro phytromasp .)和南方常见污染霉菌中的黑曲霉 (Aspergillusniger)MIG3.2 7、米曲霉 (As pergillusoryzae)MIG3.2 9、桔青霉 (Penicilliumcitrinum )MIG3.1 0 0、绳状青霉 (Penicilliumfuniculosum)MIG3.1 0 4、拟康氏木霉 (Trichodermapseadokoningi)MIG3.1 42等标准菌株作为试验菌株 ,分别用PET瓶灌装臭氧质量浓度为 0 1、0 3和 0 6mg/L的矿泉水后 ,在矿泉水瓶和瓶盖中分别添加 0～ 30个霉菌孢子 ,当矿泉水中臭氧质量浓度达到 0 3mg/L以上时 ,对霉菌孢子有较好的杀灭效果 ,平均存活阳性率 <1 0 %。在 1年保质期内 ,霉菌存活阳性率在不同存放时间差异不大。     

应用DGGE技术研究玉米储藏过程中的霉菌群落时空分布特征

研究储粮过程中霉菌污染的发生规律,旨在减少霉菌及真菌毒素的污染,提高我国粮食安全。利用变性梯度凝胶电泳研究粮库中不同储藏时间和空间的玉米样品中霉菌群落的特点。结果表明,本研究中储藏玉米的霉菌污染以青霉、曲霉和毛霉为主,其霉菌群落的变化与储藏时间具有较强的相关性,而与其在粮库中的空间位置相关性较小。在储藏时间方面,储藏1a和3a的样品中霉菌群落具有较大的差异,而储藏2a样品的霉菌群落处于过渡期状态。本实验探究储藏玉米中霉菌群落的时空分布特征,可以为建立准确可靠的霉菌群落模型提供理论支持和数据支持。     

Identification of fungal contamination and determination of mycotoxigenic molds by micellar electrokinetic capillary chromatography in smoked paprika

The purpose of this work was to analyze the fungal contamination in smoked and unsmoked paprika processed from different cultivars of pepper and to investigate the ability of these and other mycotoxigenic molds to grow and synthesize mycotoxins in smoked paprika. Eighteen mycotoxins were evaluated using micellar electrokinetic capillary chromatography. No relevant differences were found in fungal contamination between smoked and unsmoked paprika. The number of yeasts obtained was low, ranging from 0.4 to 3.29 log CFU g(-1); most of the yeast strains were identified as Cryptococcus spp. followed by Candida spp. All mold counts were <4 log CFU g(-1). Aspergillus, Cladosporium, Penicillium, and Fusarium were the predominant hyphomycete genera. Six mycotoxins were identified in the extracts of several strains isolated from paprika and incubated on malt extract agar. Penicillium expansum followed by Penicillium citrinum and Penicillium raistrickii were the dominant mycotoxigenic fungi isolated. Most of themycotoxin-producing fungi produced detectable amounts of mycotoxins when grown on paprika agar.     

MOLD GROWTH AND PRESENCE OF AFLATOXIN IN SOME TURKISH CHEESES

Twenty-five random fresh market samples of Van herby cheese and pickled white cheese were examined for molds and aflatoxins. The mean total mold count in Van herby cheese was 2.50 × 10⁵/g; in pickled white cheese it was 4.95 × 10⁴/g. The mycoflora on the cheeses were determined. In all cheeses, over 65% of molds were Penicillium species . Aspergillus made up 0 to 1.6 % and 2.6 % to 4.0 % of the mold on pickled white cheese and Van herby cheese, respectively. Other isolated molds belonged to Mucor, Geotrichum and Trichoderma genera. None of the samples contained aflatoxins and none of the 6 Aspergillus isolates was an aflatoxin producer .     

泾渭茯砖茶发酵过程中霉菌的变化

茯砖茶发源于陕西泾阳,属于后发酵茶,霉菌是其发酵过程中起重要作用的菌,泾渭茯砖茶是茯砖茶的代表.本研究分析了泾渭茯砖茶发酵过程中的12个不同阶段(0、2、4、6、8、10、12、14、16、18、23、28 d)可培养霉菌的变化,结果表明,发酵过程中参与的霉菌有8种,分别为冠突曲霉(Aspergillus crista...     

Effect of fungi contamination in the chemical composition of Hungarian wines

The present study shows the effect of different types of mold, especially microorganisms isolated from the corks, on Tokaj white wines. The transformation in wine chemical composition induced by contamination with molds such as Penicillium chrysogenum, Penicillium expansum and Phanerochaete spp. was different in each type of mold. Molds can contaminate wine either by transferring from grapes contaminated or by non-hygienic conditions during wine technology. As a result of contamination, molds modify wine chemical composition in terms of total and volatile acidity, residual sugars, alcohol volume, total solids and ash.     

Nonspecific Enzyme-Linked lmmunosorbent Assay for Molds in Foods

A nonspecific enzyme-linked immunosorbent assay (ELISA) was developed to detect molds in foods by producing an antibody to a mixture of six common molds, Aspergillus versicolor, Cladosporium herbarum, Fusarium poae, Geotrichum candidum, Mucor circinelloides, and Penicillium chrysogenum. This antibody recognized these mold genera plus 10 others but not yeasts. Mold antigens added into Cheddar and cottage cheeses, fruit juices, nonfat dry milk, raisins, and yogurt could be detected. Molds (10² spores/g) inoculated into cottage cheese and yogurt and allowed to grow at 7 or 22°C were detected at 10³ CFU/g. A nonspecific ELISA could be developed to detect general mold contamination of foods.