摘要:

Aflatoxin research in the Philippines started at the FNRI in 1967 with a survey on the aflatoxin content of various foods. Local researchers from government institutions and academe also conducted studies on the aflatoxin contamination of agricultural crops and their products/by‐products. The data indicated that corn and peanuts are the two commodities that contain toxic levels of aflatoxin. Past and current research in the country is documented. Problems and research needs for the surveillance and/or control of aflatoxin contamination are discussed.

ISSN:0265-203X    

DOI:10.1080/02652039509374306

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Contamination of maize with aflatoxins was detected in Tamaulipas in 1989 and the Mexican government organized a Supervising Programme to check the maize crop of Tamaulipas from 1989 to 1992. The monoclonal immunoaffinity column method quantified by fluorometry was chosen as the official one. After detecting, in 1989, the first lots of contaminated maize, in 1990 87% of the crop was quarantined and the Supervising Programme was implemented. Laboratories were constructed in each warehouse that received the maize; one chemical analysis for aflatoxins was performed for every 100 tons of maize received and there were around 60000 analyses in the whole Programme (1989–1993). A random sampling method was applied, taking 2 kg from each truck. In 1991, the contaminated maize was dyed and separated as feed. Decontaminating methods with aluminosilicates and with ammonia were tested, but the cost was high and these practices were abandoned. A Technological Package for the fanners was organized by different institutions: the Ministry of Health, the Ministry of Agriculture, Conasupo, and the government of the State of Tamaulipas. This specified sowing time, insecticides, fungicides, fertilizers, irrigation periods, maize cultivars, etc. and had successful results in the field, in 1992, when lower quantities of total aflatoxins in maize were detected. On the other hand, the aflatoxin combination of maize persisted in storage areas, especially in the last week of July and the first week of August. The aflatoxin maize problem will be solved only when both field and storage contaminations are controlled.

ISSN:0265-203X    

DOI:10.1080/02652039509374307

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The mycoflora of 130 samples of postharvest and stored corn was analysed throughout one year. The sample originated from Riberirão Preto, State of São Paulo, Brazil. The influences of abiotic factors (moisture content, relative humidity, temperature, rainfall) and mycotoxin occurrence were also verified. The isolation of the fungi was performed with Potato Dextrose Agar. Fungi were identified by using standard techniques. The determination of mycotoxins (aflatoxins, ochratoxin A, sterigmatocystin, zearalenone, deoxynivalenol and fumonisin B1) was carried out by thin‐layer chromatography. TheFusariumspp. was the most dominant fungi (83.8%) followed byPenicilliumspp. (55.3%),Aspergillusspp. (40.7%) and 11 other filamentous fungi. All of these were isolated from grains with moisture contents of 12.3–17.8%, an average temperature of 18.4–24.l°C, a relative humidity between 640 and 97.5% and rainfall of up to 337 mm. With regard to the number of colony forming units (cfu),Fusariumspp. was the main contaminant, varying from 545 × 103to 1.5 × 103. The Simple linear correlation analysis showed significant positive correlation of theFusariumgenus with moisture content of grains, and a significant negative correlation in relation to the minimum and medium temperatures, rainfall and relative humidity. The linear correlation of thePenicilliumandAspergillusgenera with the abiotic factors was not significant. In the samples analysed only one contained aflatoxin B1.

ISSN:0265-203X    

DOI:10.1080/02652039509374308

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Some 60 countries have currently enacted or proposed regulations for control of mycotoxins (primarily the aflatoxins) in food and animal feed. Various factors influence the establishment of limits for certain mycotoxins, but there is no consistent rationale for setting limits or for enforcement control. The enforcement of the regulations requires monitoring of suspected commodities. Many laboratories perform large numbers of determinations of mycotoxins, in particular aflatoxins, and consider their results to be reliable. Nevertheless, it often happens that laboratories find quite different analytical results on samples that have been especially homogenized for interlaboratory studies. The application of Quality Assurance principles contributes to the reliability of mycotoxin measurements. Quality Assurance is focused on the organizational process and the conditions under which laboratory studies are planned, performed, monitored, recorded, reported and archived. This is, in itself, an important contribution to the scientific value of a study. A Quality Assurance programme should include various elements, including (certified) reference materials, if available. Certified reference materials are stable, homogeneous products with certified values of the analyte(s) of interest. Various certified reference materials for mycotoxins have been prepared by the European Commission's Community Bureau of Reference, in co‐operation with several European laboratories (aflatoxin M1in milk powder, aflatoxins B1B2G1, and G2in peanut butter, aflatoxin B1in peanut meal and compound feed, deoxynivalenol in wheat and maize flour). Other reference materials are in a well‐advanced development stage (ochratoxin A in wheat flour and pig kidney, fumonisins B1and B2in maize).

ISSN:0265-203X    

DOI:10.1080/02652039509374309

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Patulin is immunosuppressive and there is limited evidence of its carcinogenicity in experimental animals. The International Agency for Research on Cancer (IARC) initiated a programme for the development of degradation techniques for the commonly investigated mycotoxins. As a part of this programme, the following techniques were tested for the degradation of patulin: treatment with ammonia, treatment with ascorbic acid, and treatment with potassium permanganate in acidic or in alkaline conditions. Patulin analysis was performed by using HPLC with UV detection. Mutagenic activity of degradation residues was tested by inSalmonella typhimuriumstrains TA 97a, TA 98, TA 100, and TA 102. Complete disappearance of patulin was not achieved after 92 h of treatment with ascorbic acid. All the other methods tested led to complete removal of the molecule. However, the technique using potassium permanganate in acidic conditions produced residues which were mutagenic without activation toSalmonella typhimuriumstrains TA 100 and TA 102, which was attributed later to Mn2+. The two other techniques gave satisfactory results and were selected for further validation studies.

ISSN:0265-203X    

DOI:10.1080/02652039509374310

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In the present work the influence of bag materials on the moisture loss and final aflatoxin content of stored moist in‐shell peanuts (MIP) was studied in the rainy season of 1990, in Marília, São Paulo, and in the rainy season of 1991, in Jaboticabal, São Paulo. In each season, MIP were ventilated, as they arrived from the field, to get rid of extraneous materials and then put into 120 bags of jute and into 120 bags of polypropylene, and stored in stacks (12 bags base × 10 bags high). In the rainy season of 1990 (February‐April) moisture and aflatoxin were determined at the beginning (average moisture = 14.31%; aflatoxin not detected). Subsequently, moisture was determined twice a week in samples taken from the external part of the stacks for 80 days, when the stacks were dismantled and moisture and aflatoxin were determined in six samples of each stack. In the rainy season of 1991 (February-March), because of operational difficulties, closed mesh jute bags were used (green coffee type) and the experiment lasted only 30 days. Moisture and aflatoxin were determined only at the beginning (average moisture = 15%; aflatoxin not detected). At the end of the storage period three samples were taken from each lot, for moisture and aflatoxin analyses. The results showed, in both experiments, that in jute bags, even with closed mesh, moisture loss was slightly faster with an average final moisture = 9.68% in jute bags and 10.38% in polypropylene in 1990, and 9.50% in jute and 10.36% in polypropylene in 1991 and that the final aflatoxin content was considerably lower in jute bags, with average figure of 51μg/kg (1990) and 361μg/kg (1991) for jute against 1380μg/kg (1990) and 3703μg/kg (1991) for polypropylene. From the results it was concluded that the use of jute bags for storage of moist in‐shell peanuts allowed a slightly better moisture loss when compared with polypropylene bags and that the use of jute bags showed that this may be better than polypropylene and can be considered for preventing aflatoxin build‐up during storage of in‐shell peanuts, especially when threshed and bagged moist. However, further studies are needed.

ISSN:0265-203X    

DOI:10.1080/02652039509374311

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In the present work, the effect of propionic acid (ammonium salt) at 3000 mg/kg of unshelled peanuts (PA1) and at 5000 mg/kg (PA2), grapefruit seed extract at 5000 mg/kg (GF1) and 10000 mg/kg (GF2), sodium orthophenylphenate at 2500mg/kg (SOP1) and at 5000mg/kg (SOP2) and thiabendazole at 1000 mg/kg (TBZ1) and at 5000 mg/kg (TBZ2) was studied for controlling total and potentially aflatoxigenic fungi in unshelled peanuts (UP). Samples of sound mature UP were moistened by adding water and kept refrigerated till they reachedca16% moisture. The samples were then sprayed with the chemical solutions and incubated at 30 ± 2°C for 28 days. Control samples were sprayed with water. An evaluation of total and aflatoxigenic fungi was made, in pods of UP and in kernels obtained aseptically, before and at 7, 14, 21 and 28 days of incubation, by serial dilution in culture media Dichloran Rose Bengal Chloramphenicol (total fungi count) and inAspergillus flavus parasiticusAgar (potentially aflatoxigenic count). In relation to the period and conditions of this experiment the overall best treatment was PA2, when the lowest average value of total and aflatoxigenic fungi were obtained in UP and were maintained in its kernels. Although SOP2 treatment could control fungal contamination in pods, it was not effective in controlling contamination through the kernels. The other treatments were ineffective.

ISSN:0265-203X    

DOI:10.1080/02652039509374312

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Propionic acid (ammonium salt) at 3000 mg/kg (PA1) and 5000 mg/kg (PA2) of unshelled peanuts (UP); grapefruit seed extract at 5000 mg/kg (GF1) and 10000 mg/kg (GF2); sodium orthophenylphenate at 2500mg/kg (SOP1) and 5000mg/kg (SOP2); thiabendazole 1000 mg/kg (TBZ1) and 5000 mg/kg (TBZ2) were studied in the laboratory, to verify their efficiency in controlling fungal growth and aflatoxin (AF) production on moist UP (16–18% moisture content). Moist UP were put into polyethylene bags with cotton plugs and incubated at 30 ± 2°C for 28 days. Treatments were considered efficient when the AF content (B1+ G1) remained under 30μg/kg. PA1 treatment was efficient till 14 days of incubation and PA2 during the whole incubation period (28 days). All other treatments were not efficient, showing AF contents from 150 to 108 333μg/kg during the incubation periods. Propionic acid, used as ammonium propionate, at 5000 mg/kg shows promise in controlling aflatoxin production when applied to moist unshelled peanuts.

ISSN:0265-203X    

DOI:10.1080/02652039509374313

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In order to estimate the incidence of ochratoxin A (OA) in biological fluids, a study was carried out to determine the concentration of OA in breast milk of donor mothers in Italy. Out of 111 samples, 22 were contaminated in the range 0.1–12μg/kg.

ISSN:0265-203X    

DOI:10.1080/02652039509374314

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

A review of mycetisms reported in Mexico and a description of two interesting cases are given. Worldwide mycetisms are rarely studied. To identify the causal agents, clinical notes were analysed and field research with some of the persons involved in the poisonings were carried out. Symptoms and field data confirm a mortal hepatotoxic poisoning and a gastrointestinal mycetism produced byAmanitaandRamariarespectively. In addition, mycetisms produced in Mexico byBoletus, Chlorophyllum, Conocybe, Hypomyces, Panaeolus, Psilocybe, SclerodermaandStrophariaare discussed.

ISSN:0265-203X    

DOI:10.1080/02652039509374315

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor