食品生物技术研究进展

现代生物技术的飞速发展为解决人类的食品与营养、健康、安全等重大问题开辟了一条崭新途径。同时在食品安全方面可以为抗食品过敏原的治疗,益生菌作用的分子机理、病理-生物技术的运用和营养动力学提供支持和可能。     

粮食加工品和肉制品中克罗诺杆菌的污染状况及致病性阪崎克罗诺杆菌生物膜形成能力研究

目的 了解我国粮食加工品和肉制品中克罗诺杆菌(Cronobacter spp.)的污染情况及致病性。方法对我国8个省份的226份粮食加工品和肉制品的克罗诺杆菌污染情况进行检测,对分离菌株进行种间鉴定,并针对阪崎克罗诺杆菌进行脉冲场凝胶电泳(pulsed field gel electrophoresis, PFGE)分型及生物膜形成能力研究。结果 粮食加工品和肉制品中克罗诺杆菌的检出率分别为21.92%和12.50%。种间鉴定显示,115株分离菌株中有94株阪崎克罗诺杆菌。PFGE和结晶紫染色结果表明,94株阪崎克罗诺杆菌可被分为49个型别,均在36～60 h内达到最大菌膜生产量。结论 上述8个省份粮食加工品和肉制品中存在克罗诺杆菌污染,其中阪崎克罗诺杆菌有多种PFGE带型,且均具有生物膜形成能力,本研究可为食品安全风险评估及标准制定提供基础数据。     

曲霉菌酶学性质的研究

研究本实验室保存的2种曲霉my-1及my-2的特性,讨论了时间、温度、pH对曲霉菌产酶的影响,并对酶的适宜反应温度、pH及酶的热稳定性和pn稳定性进行了探讨。     

Factors affecting the presence of ochratoxin A in wines

Ochratoxin A (OTA) are synthesized mainly by different species of Aspergillus and Penicillium being its human toxicological effects reflected in different countries due to the consumption of different foods and beverages such as red, white, rose, and special wines. This review presents an overview of the direct (meteorological conditions, grape cultivation, and wine-making techniques) and indirect (latitude, year of production, use of pesticides, presence of spoilage microorganisms, conditions of storage of the harvested grapes, type of maceration, and conditions of fermentation), factors affecting the presence of OTA in wines.     

Aflatoxin M1 in Spanish infant formulae: occurrence and dietary intake regarding type,protein-base and physical state

The incidence of aflatoxin M₁ (AFM₁) in 69 different infant formulae marketed in Spain between 2007 and 2008 was studied and dietary intake estimated. Samples were analysed using an HPLC method coupled with fluorescence detection after immunoaffinity column clean-up. The toxin was detected in 26 formulae (37.7%) at levels below the permissible limit set by EC legislation, giving a range of 0.6–11.6 ng kg^?1 with a mean value of 3.1 ng kg^?1. Increasing occurrence was found in those formulae produced by the less complex manufacturing processes affecting casein/whey protein ratio: pre-term, 14.3%; starter, 35.3%; follow-up, 42.1%; toddler 87.6%; while hypoallergenic and lactose-free were totally exempt. Additionally, the influence of main protein source and physical state (powdered and ready-to-use formula) on AFM₁ occurrence was evaluated leading to similar conclusions. Dietary AFM₁ weekly intake was observed to be stable around 1 ng kg^?1 bw for standard formula and 0.1 ng kg^?1 bw for pre-term feeding.     

根霉菌在食品工业中应用的安全性

一些根霉菌种产生毒素使其在发酵食品中的应用安全性受到了质疑.该文从毒素的研究进展和现状出发提出根霉菌可能存在的食品安全问题,并介绍文献资料在毒素研究过程中采用的一些新方法,希望从食品安全角度研究根霉菌的科学应用问题,为我国合理利用根霉菌发酵生产安全的发酵食品奠定基础.     

International Risk Assessment Leading to Development of Food Safety Standards

The Sanitary and Phytosanitary (SPS) Agreement under the World Trade Organisation (WTO) provides the right to member countries trading in food commodities to take measures to protect plant, animal and human health. However, these measures cannot be arbitrary, but should be based on scientific risk assessments performed according to international standards. The agreement also requires countries to adopt international standards such as those developed by the Codex Alimentarius Commission for food safety and by the World Animal Health Organization (OIE) for animal health. Scientific risk assessments required for development of food safety standards are performed by FAO/WHO. Some examples of food safety standards set by the Codex Alimentarius Commission based on risk assessments are microbiological criteria for Listeria monocytogenes in ready to eat foods and Guidelines for control of pathogenic Vibrio spp in sea foods.     

PCR法快速检测三种食源性致病菌的研究

目的 探讨用PCR方法快速检测食品中沙门氏菌(Salmonella spp.)、金黄色葡萄球菌(Staphylococcus aureus)和志贺氏菌(Shigella spp.)的实用性。方法 采用能力验证实验和超市样品检测实验对PCR方法与传统检测方法进行比较。结果 与传统检测方法相比, PCR方法检测以上三种食源性致病菌的结果准确率达到99%以上, 假阳性率低于1%, 假阴性率为0。结论 PCR检测方法具有检测周期短等优点, 可以在当前的食品安全检测工作中应用推广。     

Aflatoxin levels and exposure assessment of Spanish infant cereals

Aflatoxins (AFB₁, AFB₂, AFG₁ and AFG₂) are immunosuppressant, mutagenic, teratogenic and carcinogenic agents with a widespread presence in foodstuffs. Since human exposure to aflatoxins occurs primarily by contaminated food intake, and given the greater susceptibility of infants to their adverse effects, the quantification of these mycotoxins in infant food based on cereals is of relevance. Aflatoxin levels were determined in 91 Spanish infant cereals classified in terms of non- and organically produced and several types from 10 different manufacturers, using a extraction procedure followed by inmunoaffinity column clean-up step and HPLC with fluorescence detection (FLD) and post-column derivatisation (Kobra Cell system). Daily aflatoxin intake was also assessed. Preliminary analysis showed a valuable incidence of detected infant cereal samples at an upper concentration level than the detection limit for total aflatoxin (66%), corresponding to a 46, 40, 34 and 11% for AFB₁, AFB₂, AFG₁ and AFG₂, respectively. Lower aflatoxin values (median, Q₁, Q₃) in conventional infant cereal (n?=?74, AFB₁: <LOD (n.d.; 0.02), AFB₂: n.d. (n.d.; 0.01), AFG₁: <LOD (n.d.; 0.004), and AFG₂: n.d. (n.d.; <LOD) and total AF (AFtotal): 0.01 (<LOD; 0.04 µg?kg^?1) in comparison with infant cereal ecologically produced (n?=?17, AFB₁: 0.02 (0.02; 0.21), AFB₂: n.d. (n.d.; 0.03), AFG₁: 0.02 (0.01; 0.05), and AFG₂: 0.007 (n.d.; 0.02) and AFtotal: 0.05 (0.03; 0.31 µg?kg^?1) were found. In addition, five organic formulations (3.11, 1.98, 0.94, 0.47 and 0.21 µg?kg^?1) exceeded European AFB₁ legislation (0.10?µg?kg^?1) versus two conventional cereals (0.35 and 0.12 µg?kg^?1). According to the type of infant cereal, those with cocoa had the highest aflatoxin levels. Gluten‐free and cereals with dehydrated fruits had an intermediate level and milk- or honey-based cereals and multi-cereals contained the lowest levels. With the exception of the non-compliant cocoa-based organic formulation, none of the infant cereals analyzed gave a higher intake of 1?ng?kg^?1 body weight per day, suggesting that infants fed on infant cereals are exposed to a low health hazard. Nevertheless, manufacturers are advised for continued efforts in routine monitoring and a more careful selection of raw material to minimize aflatoxin levels in these infant foods.     

食品新技术对食品安全的影响

食品新技术的产生,对食品安全产生了一定影响。现介绍现代生物技术、辐照技术、微波技术及其对食品安全的影响,并对如何消除其影响进行了探讨。     

In vitro effect of some fungicides on growth and aflatoxins production by Aspergillus flavus isolated from Capsicum powder

The aim of this study was to determine the effect of some pre-harvest fungicides on growth and aflatoxin (AF) production of three Aspergillus flavus strains found in Capsicum powder. Each isolate, previously isolated from paprika, chilli and smoked paprika, was inoculated on yeast extract sucrose agar and on a 3% paprika extract agar medium supplemented with different fungicides and incubated at 20 and 30°C during 7 days. Growth measurements were obtained on days 3, 5 and 7, and the AF production was determined on day 7. The significance of the effects of the factors (strain, medium, temperature, time and fungicides) and their interaction over colony diameter and AF production was determined. Temperature constrained the effectiveness of fungicides in reducing growth, the fungicides being most effective at 20°C. The efficacy of the fungicides over AF production depended on the medium used and temperature. The most effective fungicides in inhibiting growth and AF production, regardless of the strain tested or applied conditions, were tebuconazole 25% and mancozeb 80% applied at a concentration of 0.75 and 3.5?g?l^?1, respectively. Care should thus be taken in the choice of a suitable fungicide because their effectiveness may depend on intra-specific variation and temperature. Moreover, it is necessary to take into account that the most efficient fungicide in reducing growth is not always the best choice for pre-harvest treatments because it may promote AF production. Thus, the best fungicide is the one that can simultaneous prevent growth and AF production.     

沙门氏菌快速检测板在食品检测中的应用研究

目的研究沙门氏菌快速检测板在食品检测中的应用。方法以标准菌株为测试样本,参照GB4789.4-2010验证沙门氏菌快速检测板的灵敏度、特异性、假阳性率、假阴性率、准确度,同时利用卡方检验分析阳性率显著性差异。结果沙门氏菌快速检测板最低检测限能达到10~0 CFU/m L,灵敏度为100%,不存在假阴性,特异性为92%,假阳性率为8%,准确度为95%,显著性差异卡方值卡Χ~2为0.5,均达到定性方法验证的相关指标。结论沙门氏菌检测板技术方法具有快速准确、灵敏度高、操作简单的特点,可以作为一种快速筛查方法广泛运用在食品安全微生物检测领域。     

黄曲霉毒素脱除方法研究进展

黄曲霉毒素污染是影响花生、玉米、小麦等农作物安全性的重要原因之一。根据黄曲霉毒素的理化特性可用物理、化学或者生物方法进行脱除。本文对黄曲霉毒素的主要脱除方法进行了综述, 以期为保障农作物及其制品的安全性提供参考。