Mycoflora and aflatoxin contamination in shelled pistachio nuts

A total of 143 pistachio nut samples collected during harvest, storage and processing were examined for mould growth and aflatoxin production. The mould count was in the range of 10³?10⁴ cfu g^?1 and 10⁵?10⁶ cfu g^?1 for the harvest and storage samples, respectively. The growth of Aspergillus flavus was 38-5-39-5% on the surface of the shells and 6–16% on the kernels without aflatoxin production. The contamination level of A flavus varied among samples collected from different regions. Peeling off the soft shell of pistachio nuts by hand reduced the contamination risk of A flavus to kernels. The predominant flora on stored pistachio nuts were Aspergillus, Penicillium, Cladosporium, Rhizopus, while the genera of Ulocladium, Trichothecium, Aureobasidium and Eurotium were less frequent. Thirty-five percent of the A flavus isolates produced aflatoxins on synthetic media.     

一株防治花生采后黄曲霉污染的拮抗菌的筛选及其防控效果

为预防花生储藏过程中的黄曲霉污染,从农田土中分离出2株拮抗芽孢杆菌,通过平板对峙法优选出1株作为研究对象,研究其对黄曲霉的抑制效果及对花生采后黄曲霉污染的防控效果。采用平板对峙法检测拮抗菌的抑菌广谱性并绘制生长曲线,并通过生理生化实验、形态特征观察及16S rDNA序列分析对该菌株进行鉴定。结果表明：优选出拮抗菌B419作为研究对象,其可有效抑制黄曲霉的生长,在拮抗菌浓度为1.0×10⁶ CFU/mL,黄曲霉孢子浓度为1.0×10³ CFU/mL时,黄曲霉孢子萌发抑制率达到98%;相比拮抗菌无菌发酵滤液和拮抗菌细胞悬浮液,拮抗菌发酵液防治花生黄曲霉污染效果最好;该菌株对互隔交链孢霉、枝孢霉、青霉、拟盘多毛孢等多种霉菌都有抑制作用,对大肠杆菌、酵母菌也有抑制作用;该菌株在培养4 h后进入对数期,14 h达到最大,26 h后进入衰亡期;该菌株被鉴定为贝莱斯芽孢杆菌(Bacillus velezensis)。综上,分离的拮抗菌B419对多种微生物都有抑制作用,不仅可以用来预防花生储藏过程中的真菌污染,在防治植物微生物病害方面也具有良好的应用潜力。     

曲霉羧肽酶的分离纯化研究

采用 (NH4) 2 SO4、酒精、DE52 和SephadexG1 0 0对AspergillusspCP 1发酵液进行分离纯化 ,并检测在分离纯化过程中酶的回收率和比活力 ,最后用SDS PAGE电泳检验酶的纯度。确定 (NH4) 2 SO4饱和浓度在 60 %～ 90 %之间 ,酒精浓度为 3 5 %～ 70 %之间用于粗酶液的提纯 ;电泳得到一个清晰的条带。它们的分子质量约为 15 942u。     

Aspergillus species from section Flavi isolated from soil at planting and harvest time in peanut‐growing regions of Argentina

Aspergillus species from section Flavi were isolated from soil samples in three peanut‐growing regions of Córdoba Province, Argentina. The samples were collected during the planting and harvest periods. Both total fungal population and Aspergillus species from section Flavi showed no significant differences between planting and harvest time in two of the regions evaluated. Only in one region were there significant differences in cfu g^?1 of total fungal population and Aspergillus species from section Flavi. A flavus was the dominant species isolated in all three localities during the planting and harvest periods. There were significant differences (p < 0.05) in the ratio of toxigenic and atoxigenic strains dependent on the period and the region evaluated. In one region, higher frequencies of toxigenic A flavus and A parasiticus in soil were found and a high contamination level of aflatoxins was detected in peanut seeds. Copyright © 2003 Society of Chemical Industry     

农产品冷链物流中供应链透明管理的概述

与常温物流相比,农产品冷链物流属于一个典型的系统工程项目,投资水平更大、建设要求更高、涉及环节更复杂。由于冷藏农产品、生鲜农产品等具有较强的时效性,农产品冷链物流企业需要通过供应链透明管理增强各环节的协调性。农产品冷链物流系统的反馈信息和需求信息均通过网络传递,以此实现信息共享,这使农产品冷链物流供应链上的全部企业均能够对供应链的整体运行情况和市场供需信息进行实时掌握。本文总结了农产品冷链物流的特点,并分析了基于供应链透明管理的农产品冷链物流模式,从而进一步探讨电子商务在农产品冷链物流的供应链透明管理中的应用,以期为实现农产品冷链物流可持续性发展作出贡献。     

Natural co-occurrence of aflatoxin and cyclopiazonic acid in peanuts grown in Argentina

Natural occurrence of aflatoxins and cyclopiazonic acid (CPA) contamination in peanuts was investigated. Co-occurrence of CPA and aflatoxins was detected in two of 50 samples analysed. The levels of these toxins found in positive samples were 4300 and 493 μg kg -1 for CPA, 625 and 435 μg kg -1 for aflatoxin B (AFB 1 ), and 625 and 83 μg kg -1 for aflatoxin G (AFG 1 ), respectively. Levels of CPA contamination in the positive samples were similar to those registered in other substrates. This is the first report of natural co-occurrence of CPA and aflatoxins in Argentina.     

23株曲霉属菌种的形态学复核鉴定研究

对中国工业微生物菌种保藏管理中心(CICC)保藏的23株19种曲霉属菌种进行了形态学复核鉴定研究。根据《The Genus Aspergillus》、《中国真菌志——曲霉属及其相关有性型》和《Identification of commonAs-pergillusspecies》,采用曲霉属菌种形态观察的标准培养条件,以菌种培养特征和显微形态为依据进行复核鉴定。22株19种菌种的复核结果与原鉴定结果一致,其中5种5株菌种根据分类命名规则的最新进展重新命名;另1株CICC 2106,原定种为溜曲霉(Aspergillus tamarii),复核鉴定结果为黑曲霉(Aspergillus niger),ITS1-5.8S-ITS2序列分析和Biolog微生物快速分析实验支持复核结果。通过形态学复核鉴定,CICC保藏的23株曲霉属菌种原鉴定结果的准确性达到95.6%。     

Impact of volatile compounds generated by essential oils on Aspergillus section Flavi growth parameters and aflatoxin accumulation

BACKGROUND: The advantage of essential oils is their bioactivity in the vapour phase, a characteristic that makes them attractive as possible fumigants for stored grain protection. In this study the antifungal and antiaflatoxigenic effects of the volatile fractions of five essential oils (EOs) were evaluated by vapour contact on Aspergillus section Flavi isolates. RESULTS: In maize meal extract agar the volatile fractions of Pimpinella anisum L. (anise), Pëumus boldus Mol. (boldus), Hedeoma multiflora Benth. (mountain thyme), Lippia turbinata var. integrifolia (Griseb.) (poleo) and Syzygium aromaticum L. (clove) were able to decrease the growth rate and lag phase of aflatoxigenic isolates. Boldus EO showed the best antifungal effect on Aspergillus section Flavi growth rate. In sterilised maize grains, boldus and poleo EOs showed antifungal effects on growth rate and aflatoxin accumulation. The volatile fraction of boldus EO completely inhibited the growth of isolates at water activity (a_w) levels of 0.955, 0.930 and 0.900, while poleo EO showed this effect only at the lower a_w levels (0.930 and 0.900). All aflatoxigenic isolates showed reduced total aflatoxin accumulation in the presence of boldus EO under all a_w conditions. CONCLUSION: These findings clearly indicate that the volatile fraction of boldus EO could be used to control aflatoxigenic fungi in stored maize. Copyright © 2009 Society of Chemical Industry     

花生中黄曲霉毒素的防控及去除方法

黄曲霉毒素（Aflatoxin）s是一类有毒致癌物,广泛地分布在发霉粮食及其制品中,特别是花生及其制品。对人体及生物危害较大。该毒素的解毒与去毒一直是研究的热点。     

海洋巨大芽孢杆菌在培养基和花生中对黄曲霉产毒的抑制

目的 研究海洋巨大芽孢杆菌在PDA、MM培养基和花生中对黄曲霉产毒的抑制。方法 采用酶联免疫吸附法和高压液相色谱荧光检测法测定培养基和花生中黄曲霉毒素B1含量。结果 PDA、MM培养基培养的黄曲霉通过酶联免疫吸附法检测后, 实验组黄曲霉毒素B1含量分别在5.5158.1 pg/mL和2.210.3 pg/mL, 对照组毒素B1含量分别在2407.22986.3 pg/mL和4.42755.6 pg/mL。通过高压液相色谱检测28 ℃和37 ℃培养的被黄曲霉侵染的花生, 实验组黄曲霉毒素B1含量均未检出, 对照组28 ℃下, 黄曲霉毒素B1含量为(8.588?0.322)μg/kg, 37 ℃下黄曲霉毒素未检出。结论 不同培养基中, 海洋巨大芽孢杆菌对黄曲霉产黄曲霉毒素均有抑制作用。黄曲霉在28 ℃比37 ℃更容易在花生上产毒, 海洋巨大芽孢杆菌对花生上黄曲霉产毒素有显著抑制作用。     

Potential use of phenolic antioxidants on peanut to control growth and aflatoxin B1 accumulation by Aspergillus flavus and Aspergillus parasiticus

Food‐grade antioxidants: butylated hydroxyanisole (BHA), propyl paraben (PP) and butylated hydroxytoluene (BHT) (10 and 20 mmol g^?1) and all the mixtures of these chemicals were tested for inhibitory activity on the growth of and aflatoxin B₁ (AFB₁) accumulation by Aspergillus parasiticus and A. flavus on irradiated (7 kGy) peanut grains. Also, the influence of these treatments was evaluated in different water conditions (0.982, 0.955, 0.937a_w) at 11 and 35 days of incubation at 28 °C. Water activity (a_w) affected the fungal growth, no fungal development was observed at the highest stress water condition (0.937a_w). Butylated hydroxyanisole at 10 mmol g^?1 level and all the mixtures with PP and/or BHT were significantly effective (P = 0.05) in increasing lag phase and reducing growth rate and colony forming units per gram of peanut of both Aspergillus section Flavi strains and AFB₁ accumulation. The application of BHA at concentrations of 20 mmol g^?1 alone or with PP and/or BHT totally inhibited fungal growth at 11 and 35 days of incubation. The results suggest that the addition of these chemical mixtures on peanut grains at low levels has potential to impact synergically on the control of Aspergillus section Flavi. Copyright © 2007 Society of Chemical Industry     

Analysis of industry-generated data. Part 2: Risk-based sampling plan for efficient self-control of aflatoxin M1 contamination in raw milk

Aflatoxin M₁ (AFM1) contamination in 21 969 milk samples taken in Italy during 2005–08 and 2010 provided the basis for designing an early warning self-control plan. Additionally, 4148 AFM1 data points from the mycotoxin crisis (2003–04) represented the worst case. No parametric function provided a good fit for the skewed and scattered AFM1 concentrations. The acceptable reference values, reflecting the combined uncertainty of AFM1 measured in consignments consisting of milk from one to six farms, ranged from 40 to 16.7 ng kg^?1, respectively. Asymmetric control charts with these reference values, 40 and 50 ng kg^?1 warning and action limits are recommended to assess immediately the distribution of AFM1 concentration in incoming consignments. The moving window method, presented as a worked example including 5 days with five samples/day, enabled verification of compliance of production with the legal limit in 98% of the consignments at a 94% probability level. The sampling plan developed assumes consecutive analyses of samples taken from individual farms, which makes early detection of contamination possible and also immediate corrective actions if the AFM1 concentration in a consignment exceeds the reference value. In the latter case different control plans with increased sampling frequency should be applied depending on the level and frequency of contamination. As aflatoxin B₁ increases in feed at about the same time, therefore a coordinated sampling programme performed by the milk processing plants operating in a confined geographic area is more effective and economical then the individual ones. The applicability of the sample size calculation based on binomial theorem and the fast response rate resulting from the recommended sampling plan were verified by taking 1000–10 000 random samples with replacement from the experimental databases representing the normal, moderately and highly contaminated periods. The efficiency of the control plan could be substantially enhanced if the dairy farms used feed with a tolerable level of AFB1.     

Assessment of azole fungicides as a tool to control growth of Aspergillus flavus and aflatoxin B1 and B2 production in maize

ABSTRACT

Aspergillus flavus is a highly aflatoxin (AF)-producing species infecting maize and other crops. It is dominant in tropical regions, but it is also considered an emerging problem associated with climate change in Europe. The aim of this study was to assess the efficacy of azole fungicides (prochloraz, tebuconazole and a 2:1 (w/w) mixture of prochloraz plus tebuconazole) to control the growth of A. flavus and AF production in yeast-extract–sucrose (YES) agar and in maize kernels under different water activities (a_w) and temperatures. Aflatoxins B₁ and B₂ were determined by LC with fluorescence detection and post-column derivatisation of AFB₁. In YES medium and maize grains inoculated with conidia of A. flavus, the growth rate (GR) of the fungus and AFB₁ and AFB₂ production were significantly influenced by temperature and treatment. In YES medium and maize kernels, optimal temperatures for GR and AF production were 37 and 25°C, respectively. In maize kernels, spore germination was not detected at the combination 37ºC/0.95 a_w; however, under these conditions germination was found in YES medium. All fungicides were more effective at 0.99 than 0.95 a_w, and at 37 than 25ºC. Fungicides effectiveness was prochloraz > prochloraz plus tebuconazole (2:1) > tebuconazole. AFs were not detected in cultures containing the highest fungicide doses, and only very low AF levels were found in cultures containing 0.1 mg l^–1 prochloraz or 5.0 mg l^–1 tebuconazole. Azoles proved to be highly efficient in reducing A. flavus growth and AF production, although stimulation of AF production was found under particular conditions and low-dosage treatments. Maize kernels were a more favourable substrate for AF biosynthesis than YES medium. This paper is the first comparative study on the effects of different azole formulations against A. flavus and AF production in a semi-synthetic medium and in maize grain under different environmental conditions.     

Plackett-Burman设计在曲霉Aspergillus sp.GX-0010果糖基转移酶发酵条件主要因子筛选中的应用

试验采用Plackett-Burman试验设计,选取蔗糖、蛋白胨、硫酸亚铁、pH值、温度、培养时间、装液量,接种量共8个相关因素进行设计,统计分析表明,pH(p=0.019)、温度(p=0.003)、装液量(p=0.131)为对曲霉(Aspergillus sp.)菌株GX-0010产果糖基转移酶具有显著影响的因素。     

Modified atmosphere influences aflatoxin B1 contamination and quality of peanut (Arachis hypogaea L.) kernels cv. Khon Kaen 84-8

Storage of ‘Khon Kaen 84-8’ peanut kernels in laminated bags (Low density polyethylene (LDPE)/Nylon) (20×30 cm; 120 μm thickness) under different packaging atmospheres had effect on quality, fungal occurrence and aflatoxin B₁ (AFB₁) contamination. During fifteen week storage, peanuts (6.4% moisture content) were kept under different packaging atmospheres with some inoculated (Inoc.) and without (Non-Inoc.) aflatoxin producing fungus Aspergillus flavus. The treatments include; 100% CO₂+Inoc., 100% N₂+Inoc., vacuum + Inoc., Air + Inoc., and Air + Non-Inoc. packed with only ambient air. The storage room conditions were a temperature of 29±2 °C and 70 ± 5% r. h. Mycobiota occurrence, AFB₁ level, moisture content, lipase activity, free fatty acids and rancidity (Thiobarbituric acid; TBA value) were investigated. A total of five major fungi were identified with four storage fungi and one field fungus; Rhizopus stolonifer, Aspergillus niger, A. flavus, Penicillium spp., and Fusarium spp., respectively. Packaging in 100% CO₂+Inoc. significantly repressed the fungal occurrence especially A. niger while all other packaging atmospheres suppressed proliferation of both R. stolonifer and Penicillium spp. The peanuts kept in vacuum + Inoc. package revealed AFB₁ level below detection limit (0.4 μg/kg). Peanut kernels in 100% CO₂+Inoc. packaging atmosphere maintained an acceptable color indicated by L* and a* values, as well as the color change (ΔE) compared to other treatments. Different packaging atmospheres showed variable results in relation to the free fatty acids level with packaging under 100% N₂ revealing the lowest. Subsequently, 100% N₂ packaging atmosphere relatively inhibited rancidity occurrence in peanut kernels during storage. The results of this study portray that 100% CO₂, 100% N₂ and vacuum packaging atmosphere could have a potential to suppress occurrence of mycobiota, maintain peanut kernel quality in relation to color and lipid oxidation, and as well curtail AFB₁ contamination respectively, for fifteen weeks or more given the quality of kernels at the end of storage.     

Changes in enzyme activities and aflatoxin elaboration in sorghum genotypes following Aspergillus parasiticus infestation

Sorghum is a relatively poor substrate for aflatoxin production compared with high‐risk agricultural commodities like maize and groundnut, even though it is susceptible to fungal attack. Fungal infestation of sorghum results in a varied biochemical composition of the deteriorated grain. In this study, six sorghum genotypes (red—AON 486, IS 620; yellow—LPJ, IS 17 779; white—SPV 86, SPV 462) were inoculated with a toxigenic strain of Aspergillus parasiticus (NRRL 2999) in order to evaluate the changes in the activities of various hydrolytic enzymes (α‐ and β‐amylases, protease and lipase) in comparison with those in uninfected grains. Enzyme activities were measured at different times after fungal infestation, and the enzymatic activities were correlated with the aflatoxin production. Alpha‐amylase activity was observed to be greater than β‐amylase activity in all six genotypes under both healthy and infected conditions. The increase in α‐amylase activity during the period of infection was higher in white genotypes than in red sorghum genotypes. Alpha‐amylase activity in all the genotypes increased up to day 6 after fungal infection, but was significantly lower in infected grains than in healthy grains. The variability in the basal enzyme activities among the six sorghum genotypes was quite high compared with the amount of induction of each specific enzyme due to infection and germination. Higher protease activity was observed in the infected grains than in healthy grains. The enzyme activities in high tannin red genotypes were less than those in yellow and white genotypes. The α‐ and β‐amylase activities were positively correlated (r = 0.406 and 0.436; P < 0.05) to aflatoxin production. Inherent lipase activity was highest (on day 0) in AON 486, SPV 462 and SPV 86, as compared with the activity in infected grains. The total aflatoxins produced (quantified by TLC‐fluorodensitometry) were lower in red genotypes than in yellow and white genotypes, suggesting that red genotypes were least susceptible to aflatoxin elaboration among the various genotypes tested. All four aflatoxins, (B₁, B₂, G₁ and G₂) were present in five genotypes (IS 620, LPJ, IS 17 779, SPV 86 and SPV 462) at all the stages of infection, but, aflatoxin could not be detected in the red genotype AON 486 on day 3 after infection. White genotypes SPV 86 and SPV 462) showed maximal aflatoxin (total) production on day 6 after infection. © 2000 Society of Chemical Industry     

电子商务在食品供应链及食品安全中的应用

作为一种商务模式,电子商务在很多领域中得到了广泛应用。利用电子商务能够充分发挥食品供应链的优势,通过食品供应链和电子商务的有机结合,食品企业能够更好地保障食品安全,有效应对行业内日益激烈的市场竞争,全面提升企业自身的市场竞争力。本文对电子商务在食品供应链及食品安全中的作用和优势进行了论述和分析,介绍了基于电子商务的食品供应链和食品安全管理的理念,并立足于信息共享机制的建立和协同整合对其前景进行了介绍和分析。     

提升造纸企业在供应链上的影响力

造纸企业在供应链上处于相对上游的位置，对下游企业和整个供应链的影响力比较弱小。本文试图提供一种思路：造纸企业可以通过积极主动的供应链建设来提高自身在供应链上的影响力。     

Surveys of aflatoxin B1 contamination of retail Turkish foods and of products intended for export between 2007 and 2009

Surveys were carried out between 2007 and 2009 to determine the aflatoxin B₁ content of 3345 commercial Turkish foodstuffs supplied by producers for testing for their own purposes or for export certification. To simplify the reporting of data, foods were categorized as: 1, high sugar products with nuts; 2, nuts and seeds; 3, spices; 4, grain; 5, cocoa products; 6, dried fruit and vegetables; 7, processed cereal products; 8, tea; and 9, baby food and infant formula. Aflatoxin analysis was carried out by high-performance liquid chromatography with fluorescence detection after immunoaffinity column clean-up, with a recoveries ranging from 91% to 99%, depending on the matrix. Of the 3345 samples analysed, 94% contained aflatoxin B₁ below the European Union limit of 2 µg kg^?1, which applies to nuts, dried fruit, and cereals products. The 6% of the 206 contaminated samples were mainly nuts and spices. For pistachios, 24%, 38%, and 42% of the totals of 207, 182, and 24 samples tested for 2007, 2008 and 2009, respectively, were above 2 µg kg^?1, with 50 samples containing aflatoxin B₁ at levels ranging from 10 to 477 µg kg^?1.