Hazelnuts as Possible Substrate for Aflatoxin Production1

1988 ◽  
Vol 51 (4) ◽  
pp. 289-292 ◽  
Author(s):  
V. SANCHIS ◽  
Mª L. QUILEZ ◽  
R. VILADRICH ◽  
I. VIÑAS ◽  
R. CANELA
Keyword(s):  
Water Activity ◽  
Aspergillus Parasiticus ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Potassium Sorbate ◽  
Fungal Contamination ◽  
Activity Temperature ◽  
High Production

A study was carried out on the fungal contamination of commercially available hazelnuts, and the effect of different factors (water activity, temperature and presence of potassium sorbate) on fungal growth and aflatoxin production in hazelnuts. All samples (100%) of raw hazelnuts showed fungal contamination. None of the samples showed aflatoxin contamination, but when hazelnuts were inoculated with Aspergillus parasiticus, and water activity and temperature were optimal formold growth, high production of aflatoxin was found. Potassium sorbate at subinhibitory levels seemed to inhibit fungal growth, but enhanced aflatoxin production.

Aflatoxin production by Aspergillus flavus and Aspergillus parasiticus on deoiled ground nyjer seeds

2021 ◽  
Vol 14 (2) ◽  
pp. 213-220
Author(s):  
D. Gizachew ◽  
C.-H. Chang ◽  
B. Szonyi ◽  
W.E. Ting
Keyword(s):  
Water Activity ◽  
Aspergillus Flavus ◽  
Aspergillus Parasiticus ◽  
Animal Feed ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Growth Conditions ◽  
Growth Patterns ◽  
Aflatoxin B ◽  
Similar Growth

Nyjer seeds are oil rich (35-40% oil content) seeds of the plant Guizotia abyssinica, which is closely related to sunflower. They are pressed mechanically for cooking oil in Ethiopia and elsewhere. The remaining deoiled cake, which contains approximately 10% oil is commonly used as animal feed. This study investigated the effect of water activity and temperature on the growth and aflatoxin production of the four main forms of aflatoxin (B1, B2, G1 and G2) by Aspergillus flavus and Aspergillus parasiticus on ground nyjer seed with 10% oil. The ground nyjer seeds were adjusted to different water activity aw levels (0.82, 0.86, 0.90, 0.94 and 0.98 aw) and incubated at 20, 27 and 35 °C, up to 30 days. Our results show that A. flavus and A. parasiticus had similar growth patterns in which the slowest fungal growth occurred on ground seeds with 0.86 aw at 20 °C. There was no fungal growth for either A. flavus or A. parasiticus at 0.82 aw. The most rapid growth conditions for A. flavus and A. parasiticus were 0.94 aw at 35 °C, and 0.94 aw at 20 °C, respectively. Aspergillus flavus produced aflatoxins (13 μg/kg aflatoxin B1) only on seeds with 0.94 aw at 27 °C, while A. parasiticus produced high levels of aflatoxins under several conditions; the highest concentrations of aflatoxin B1 (175 μg/kg) and AFG1 (153 μg/kg) were produced on deoiled ground seeds with 0.94 aw at 27 °C. It is likely that storing ground deoiled nyjer seeds with a water activity up to 0.82 aw at 20 °C will reduce fungal growth aflatoxin production.

Production of Aflatoxin in Cocoa Beans

1979 ◽  
Vol 62 (5) ◽  
pp. 1076-1079 ◽  
Author(s):  
Lawrence M Lenovich ◽  
W Jeffrey Hurst
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Ivory Coast ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Growth Conditions ◽  
Aflatoxin Contamination ◽  
Cocoa Beans ◽  
Total Aflatoxin ◽  
Substrate Variation

Abstract Aflatoxin was produced in both non-autoclaved and autoclaved Ivory Coast cocoa beans inoculated with Aspergillus parasiticus NRRL 2999 under optimum laboratory growth conditions. Total aflatoxin levels ranged from 213 to 5597 ng/g substrate. Aflatoxin was quantitated by using high pressure liquid chromatography (HPLC). Raw, non-autoclaved cocoa beans, also inoculated with aspergilli, produced 6359 ng aflatoxin/g substrate. Variation in aflatoxin production between bean varieties was observed. Total aflatoxin levels of 10,446 and 23,076 ng/g substrate were obtained on Ivory Coast beans inoculated with A. parasiticus NRRL 2999 and NRRL 3240, respectively. Aflatoxin production on Trinidad and Malaysian beans was 28 and 65 ng aflatoxin/g substrate. These data support previously reported low level natural aflatoxin contamination in cocoa.

Extracts of Agave americana inhibit aflatoxin production in Aspergillus parasiticus

2011 ◽  
Vol 4 (1) ◽  
pp. 37-42 ◽  
Author(s):  
A. Rosas-Taraco ◽  
E. Sanchez ◽  
S. García ◽  
N. Heredia ◽  
D. Bhatnagar
Keyword(s):  
Aspergillus Parasiticus ◽  
Public Awareness ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Aqueous Extracts ◽  
Total Aflatoxin ◽  
Toxigenic Fungi ◽  
Agave Americana ◽  
Acid Accumulation ◽  
Norsolorinic Acid

Toxigenic fungi invade crops prior to harvest as well as during storage and produce harmful, even carcinogenic toxins such as aflatoxins. Since consumers demand safe commodities, and due to enhanced public awareness of the dangers of many synthetic fungicides, the importance of investigating alternative, natural products to control these toxigenic fungi is clear. This study investigated the effect of aqueous extracts of Agave americana on growth, conidia and aflatoxin production. Aspergillus parasiticus strains SRRC 148, SRRC 143 (Su-1), and A. parasiticus SRRC 162, a mutant (nor-) that accumulates norsolorinic acid (NOR, an orange-coloured intermediate of the aflatoxin pathway), were first inoculated into Adye and Mateles liquid medium, then plant extracts were added, and incubated at 28 °C for 7 days. Aflatoxin and norsolorinic acid were assayed by HPLC and spectrophotometry, respectively. While the extract of A. americana stimulated growth of the studied fungi, conidiogenesis, norsolorinic acid accumulation (in the nor- mutant), and aflatoxin production were significantly affected. The reduction was produced by the extracts at concentrations higher than 5-10 mg/ml, where all types of total aflatoxin analysed (aflatoxins B1, B2, G1 and G2) were reduced from 64% to >99% in the whole culture, and a reduction of 75% of norsolorinic acid. The results of the present work indicate that extracts of A. americana may be promising safe alternatives to harmful fungicides for controlling aflatoxin contamination.

No Effect of Soybean Lipoxygenase on Aflatoxin Production in Aspergillus flavus–Inoculated Seeds

2002 ◽  
Vol 65 (12) ◽  
pp. 1984-1987 ◽  
Author(s):  
J. E. MELLON ◽  
P. J. COTTY
Keyword(s):  
Aspergillus Flavus ◽  
Fungal Pathogens ◽  
Seed Viability ◽  
Soybean Seed ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Soybean Seeds ◽  
Heat Treated ◽  
Significant Difference

Soybean lines lacking lipoxygenase (LOX) activity were compared with soybean lines having LOX activity for the ability to support growth and aflatoxin B1 production by the fungal seed pathogen Aspergillus flavus. Whole seeds, broken seeds, and heat-treated (autoclaved) whole seeds were compared. Broken seeds, irrespective of LOX presence, supported excellent fungal growth and the highest aflatoxin levels. Autoclaved whole seeds, with or without LOX, produced good fungal growth and aflatoxin levels approaching those of broken seeds. Whole soybean seeds supported sparse fungal growth and relatively low aflatoxin levels. There was no significant difference in aflatoxin production between whole soybean seeds either with or without LOX, although there did seem to be differences among the cultivars tested. The heat treatment eliminated LOX activity (in LOX+ lines), yet aflatoxin levels did not change substantially from the broken seed treatment. Broken soybean seeds possessed LOX activity (in LOX+ lines) and yet yielded the highest aflatoxin levels. The presence of active LOX did not seem to play the determinant role in the susceptibility of soybean seeds to fungal pathogens. Seed coat integrity and seed viability seem to be more important characteristics in soybean seed resistance to aflatoxin contamination. Soybean seeds lacking LOX seem safe from the threat of increased seed pathogen susceptibility.

Effects of Potassium Sorbate on Growth and Aflatoxin Production by Aspergillus parasiticus and Aspergillus flavus1

1983 ◽  
Vol 46 (11) ◽  
pp. 940-942 ◽  
Author(s):  
LLOYD B. BULLERMAN
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Spore Germination ◽  
Mycelial Growth ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mycelial Mass ◽  
Yeast Extract Sucrose

Growth and aflatoxin production by selected strains of Aspergillus parasiticus and Aspergillus flavus in the presence of potassium sorbate at 12°C were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and slowed growth of these organisms in yeast-extract sucrose broth at 12°C. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of aflatoxin B1 by A. parasiticus and A. flavus for up to 70 d at 12°C. At 0.10 and 0.15% of sorbate, aflatoxin production was essentially eliminated. A 0.05% sorbate, aflatoxin production was greatly decreased in A. flavus over the control, but only slightly decreased in A. parasiticus.

Enhanced Aflatoxin Production by Aspergillus flavus and Aspergillus parasiticus after Gamma Irradiation of the Spore Inoculum

1980 ◽  
Vol 43 (1) ◽  
pp. 7-9 ◽  
Author(s):  
A. F. SCHINDLER ◽  
A. N. ABADIE ◽  
R. E. SIMPSON
Keyword(s):  
Radiation Dose ◽  
Aspergillus Flavus ◽  
Gamma Rays ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Distilled Water ◽  
Mycotoxin Production ◽  
High Production ◽  
Dose Levels ◽  
Medium Dose

Distilled water plus 0.1% surfactant suspensions of spores of Aspergillus flavus and Aspergillus parasiticus were exposed to several radiation levels of cobalt-60 gamma rays. Spores of A. flavus isolate M-141 were exposed to radiation levels of approximately 16, 90 and 475 Krads and inoculated onto a sterile rice substrate which was then monitored for aflatoxin production. In this initial trial with A. flavus M-141, aflatoxins B1 and M production on rice increased as radiation dose increased. At the highest dose, this increase was more than 50 times higher than the non-irradiated controls. Spores of an aflatoxin G1-producing A. parasiticus isolate, M-1094, were exposed to 90, 215 and 430 Krads and resulted in increased production of aflatoxins G1, B1, and M. Aflatoxin production by M-1094 was highest at the low and medium dose levels. Irradiation of spores of this isolate with 430 Krads produced no observable spore germination or growth on rice and no detectable aflatoxin after 1 week of incubation at 27 C. A typical colonies from irradiated spores were selected and their mycotoxin production was determined. Increase in aflatoxin production by these strains, as compared to non-irradiated controls, was 67:1 for aflatoxin B1, 136:1 for B2, and 138:1 for M. This potential for greatly increased mycotoxin production must be considered when food is irradiated or when a high production of aflatoxins is desired.

scholarly journals Chestnut Drying Is Critical in Determining Aspergillus flavus Growth and Aflatoxin Contamination

Toxins ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 530 ◽  
Author(s):  
Simona Prencipe ◽  
Ilenia Siciliano ◽  
Carlotta Gatti ◽  
Maria Gullino ◽  
Angelo Garibaldi ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Total Phenol ◽  
Fungal Colonization ◽  
Total Phenol Content ◽  
Phenol Content ◽  
Drying Treatment ◽  
Drying Conditions

Chestnut drying is used to prevent postharvest losses and microorganism contamination during storage. Several studies reported the contamination by aflatoxins (AFs) produced by Aspergillus spp. in chestnuts. The effect of drying temperatures (from 30 to 50 °C) was evaluated on the growth of A. flavus and the production of aflatoxins in chestnuts. The influence of the treatment on the proximate composition, the total phenol content and antioxidant activity of chestnuts was considered. Fungal colonization was observed on the nuts dried at 30, 35, and 40 °C; the incidence was lower at 40 °C. The highest concentrations of AFB1 and AFB2 were produced at 40 °C. No aflatoxins were detected at 45 or 50 °C. At 40 °C A. flavus was under suboptimal conditions for growth (aw 0.78), but the fungus was able to synthesize aflatoxins. As the temperatures applied increased, the total phenol content increased, while the antioxidant activity decreased. A drying treatment at 45 °C for seven days (aw 0.64) could be a promising method to effectively control both the growth of aflatoxigenic fungi and the production of aflatoxins. This study provides preliminary data useful to improve the current drying conditions used in chestnut mills, to reduce both fungal growth and aflatoxin production.

Growth and Aflatoxin Production by Aspergillus parasiticus in a Medium Containing Plant Hormones, Herbicides or Insecticides

1987 ◽  
Vol 50 (12) ◽  
pp. 1044-1047 ◽  
Author(s):  
R. S. FARAG ◽  
M. A. EL-LEITHY ◽  
A. E. BASYONY ◽  
Z. Y. DAW
Keyword(s):  
Acetic Acid ◽  
Gibberellic Acid ◽  
Plant Hormones ◽  
Aspergillus Parasiticus ◽  
Synthetic Medium ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Inhibitory Effect ◽  
Indol Acetic Acid ◽  
Acid Herbicides

The effect of some widely used plant hormones (indol-3-acetic acid and gibberellic acid), herbicides (gramoxone, stomp and treflan) and insecticides (malathion, actellic and guthion) on Aspergillus parasiticus growth and aflatoxin production in a synthetic medium was studied. Addition of indol acetic acid to the medium increased aflatoxin production more than gibberellic acid. Treflan at 5, 10 and 20 ppm levels caused a highly significant stimulatory effect on A. parasiticus growth and aflatoxin production. In contrast, stomp at 10 and 20 ppm produced the reverse effect. Guthion, an insecticide, caused a marked decrease in fungal growth and aflatoxin production. The inhibitory effect of insecticides under study on both fungal growth and aflatoxin production in effectiveness followed the sequence: guthion>actellic>malathion. At the recommended application rate (10 ppm), with the exception of indol acetic acid and treflan, all compounds suppressed mold growth and aflatoxin production.

Growth and Synthesis of Aflatoxin by Aspergillus parasiticus in the Presence of Sorbic Acid

1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH
Keyword(s):  
Incubation Period ◽  
Aspergillus Parasiticus ◽  
Sorbic Acid ◽  
Aflatoxin Production ◽  
Potassium Sorbate ◽  
Mold Growth ◽  
Early Stages ◽  
Cumulative Data ◽  
The Media ◽  
Growth Ph

Two media [basal (M1) and enriched (M2)] containing potassium sorbate (0–300 ppm as sorbic acid) were inoculated with spores (104 – 106/flask) of Aspergillus parasiticus and incubated for 5 days at 28 C. The greater the amount of sorbate added, the higher was the pH of the media after incubation and the smaller was the yield of mold mycelium. Intermediate amounts of sorbate sometimes resulted in greater accumulation of aflatoxin than when media were free of sorbate. Sorbate more effectively inhibited mold growth and aflatoxin production in medium M2 than M1 and when the small rather than the large inoculum was used. A second trial was done with 106 or 105 spores/flask of M2 (ca. 27 ml) and 105 spores/flask of M2 (ca. 27 ml) containing sorbate (200 ppm of sorbic acid). Cumulative data for mold growth. pH and content of aflatoxin in the medium showed that relative effects of different treatments changed during the incubation period. An index to measure the capacity of molds to synthesize aflatoxins was developed. Application of the index indicates that sorbate delayed mold growth but did not inhibit biosynthesis of aflatoxin. The ability to synthesize aflatoxin was greatest in the early stages of mold growth and then decreased linearly as mold growth progressed.

Evaluation of Post-harvest Aflatoxin Production in Peanut Germplasm with Resistance to Seed Colonization and Pre-harvest Aflatoxin Contamination

2004 ◽  
Vol 31 (2) ◽  
pp. 124-134 ◽  
Author(s):  
H. Q. Xue ◽  
T. G. Isleib ◽  
G. A. Payne ◽  
G. OBrian
Keyword(s):  
Genotypic Variation ◽  
Fungal Growth ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Block Designs ◽  
Plastic Bags ◽  
Arachis Hypogaea L ◽  
Seed Colonization ◽  
Highly Correlated

Abstract Contamination of peanut (Arachis hypogaea L.) with aflatoxin produced by species of Aspergillus remains a problem for the U.S. peanut industry. Several peanut genotypes were reported to be resistant to in vitro seed colonization by Aspergillus flavus Link ex Fries (IVSCAF), to field seed colonization by A. flavus (FSCAF), or to preharvest aflatoxin contamination (PAC), but few to production of aflatoxin per se. Cotyledons of 39 peanut genotypes reportedly resistant to IVSCAF, FSCAF, or PAC, and eight susceptible to PAC were evaluated in four tests for their ability to support aflatoxin production after inoculation with A. flavus. Cultivars Perry and Gregory were used as checks in each test. Seed cotyledons were separated, manually blanched, inoculated with conidia of A. flavus, placed on moistened filter paper in petri dishes, and incubated for 8 d at 28 C. Dishes were arranged on plastic trays enclosed in plastic bags and stacked with PVC spacers between trays. Incomplete block designs were used for all tests. In each test, none of the genotypes examined was completely resistant to aflatoxin production, but significant genotypic variation was observed in the amount of total aflatoxin accumulated in seeds. Genotypes previously reported to be resistant to IVSCAF, FSCAF, or PAC exhibited differential abilities to support aflatoxin production. PI 590325, PI 590299, PI 290626, and PI 337409 supported reduced levels of aflatoxin, and their degree of resistance was consistent across tests. Fungal growth was highly correlated with aflatoxin production in three tests. The results from this study suggested that there were no absolute relationships of aflatoxin production resistance with IVSCAF, FSCAF, or PAC resistance, but that it should be possible to identify a genotype with high IVSCAF, FSCAF, or PAC resistance and reduced capacity for aflatoxin production by A. flavus.

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