Effect of Water Activity and Temperature on Aflatoxin Production by Aspergillus parasiticus

Northolt, M. D.; Verhülsdonk, C. A. H.; Soentoro, P.S.S.; Paulsch, W. E.

doi:10.4315/0022-2747-39.3.170

Cited by 76 publications

(23 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A. flavus populations are influenced by agricultural and processing practices but, in many cases, the mechanism and reason are unclear. Several environmental factors are known to influence aflatoxin production, but temperature and relative humidity (RH) are critical (Northolt et al 1976;Chiou et al 1984;Denizel et al 1976b). The hard shell of nuts is a good barrier against bacterial and fungal contamination (Bayman et al 2002;Campbell et al 2003); nevertheless, the rate and degree of contamination are dependent on temperature, humidity, soil and storage conditions.…”

Section: Introductionmentioning

confidence: 99%

“…The optimum water activity for growth of A. flavus is 0.98-0.99 (ICMSF 1996;Pitt and Miscamble 1995) and the range for growth of A. flavus and A. parasiticus is between 0.99 and 0.80 (Bresler 1998;Holmquist 1983;Nesci 2003). Studies on hazelnuts and pistachios suggest that optimum temperature and RH for aflatoxin production is 25-30 C and 97-99%, respectively (Diener and Davis 1967;Schindler et al 1967;Northolt et al 1976;Simsek et al 2002). Although the recorded water activities of the samples fits the optimum conditions for aflatoxin formation, in this study aflatoxin was not Table IV for the three regions listed in Table I.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Factors influencing fungal and aflatoxin levels in Turkish hazelnuts (Corylus avellanaL.) during growth, harvest, drying and storage: A 3-year study

Özay

Seyhan

Pembeci

et al. 2008

Food Additives & Contaminants: Part A

View full text Add to dashboard Cite

The levels aflatoxins in Turkish hazelnuts have been monitored over a 3-years period (2002)(2003)(2004). Periodical sampling was made in 72 different orchards at different locations representative of the hazelnut-growing areas and post-harvest applications. Various parameters (aflatoxins, water activity, moulds) were analysed and environmental conditions (temperature and relative humidity) recorded during growing and at different stages of harvest and post-harvest processing, involving three different harvesting methods (collection in nets, from the ground, etc.) and four drying techniques (traditional sun-drying, mechanical drying, etc.). Fungal and aflatoxin analyses (HPLC) showed no significant difference except between samples which had been in contact with the ground and those which had not (at 95% confidence level). Aflatoxins levels from the orchard recorded a maximum of 0.77 AE 0.08 ng g À1 from a total of 1624 samples. Regarding harvesting and post-harvest processes, the only application where aflatoxins were detected was in samples which had been in direct contact with the ground (max. 3.18 AE 0.03 ng g À1 ). Aflatoxin formation was low during storage (max. 0.34 AE 0.003 ng g À1 ). As a result of mycological studies, a total of 5546 Aspergillus flavus (89%) and A. parasiticus (11%) species were isolated and identified from samples. The results indicated that harvesting hazelnuts into a canvas by shaking the trees, manual harvesting of mature hazelnuts where possible, use of jute instead of nylon sacks and mechanical drying technique would minimize aflatoxin levels in hazelnuts. These recommendations have been implemented and about 4000 people in the hazelnut industry have been trained in these practices.

show abstract

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Factors influencing fungal and aflatoxin levels in Turkish hazelnuts (Corylus avellanaL.) during growth, harvest, drying and storage: A 3-year study

Özay

Seyhan

Pembeci

et al. 2008

Food Additives & Contaminants: Part A

View full text Add to dashboard Cite

show abstract

“…Oxygen also influences production of mycotoxins. The production of patulin and penicillic acid decrease sharply at low oxygen concentrations, while fungal growth is not noticeably influenced (Northolt, 1979). Aspergillus growth is restricted at an oxygen concentration of less than 1% (Pitt and Hocking, 1997) (Tables 1 and 2).…”

Section: Oxygenmentioning

confidence: 94%

Mycotoxins in animals: Occurrence, effects, prevention and management

Zaki¹

2012

J. Toxicol. Environ. Health Sci.

View full text Add to dashboard Cite

Globalization of the trade in agricultural commodities has contributed significantly to the discussion about potential hazards involved and has increased in particular the awareness of mycotoxins. Safety awareness in food and feed production has also risen due to the simple fact that methods for testing residues and undesirable substances have become noticeably more sophisticated and more available at all points of the supply chain. Mycotoxins comprise of a family of fungal toxins, many of which have been implicated as chemical progenitors of toxicity in man and animals. There are four classes of mycotoxins of major concern namely aflatoxins, zearalenone, ochratoxins, and fumonisins. Formation of mycotoxins varied between species as well as within a given species. A variety of physical, chemical, and biological methods to counteract the mycotoxin problem have been reported, but large-scale, practical, and cost-effective methods for detoxifying mycotoxin-containing feedstuffs are currently not available. Detoxification strategies for the contaminated foods and feeds should be done to reduce or eliminate the adverse actions of mycotoxin to improve food safety and prevent economic losses. The most recent approach to the problem has been the addition to the animal's diet of nonnutritive sorbents that sequester mycotoxins, reduce their gastrointestinal absorption and avoiding their toxic effects on livestock and toxin carryover into animal products. This review comments on the potential hazards of several mycotoxins together with prevention strategy for fungal and mycotoxin contamination.

show abstract

“…An example for Pénicillium chrysogenum is giv en in figure 3. While isopleth curves have been generated previously for a limited number of fungi growing on food stuffs [31][32][33], to the authors' knowledge no similar curve fitting exercise has been attempted previously and the isopleths shown are unique for the built environment.…”

Section: Prediction Of Mould Growth In Buildingsmentioning

confidence: 99%

Development of a Computer Programme for the Prediction and Control of Mould Growth in Buildings Using the ESP-r Modelling System

Rowan¹,

Anderson²,

Smith³

et al. 1997

Indoor Built Environ

View full text Add to dashboard Cite

Based on an analysis of the best published data, critical limits for the growth of six commonly occurring indoor moulds (defined in terms of relative humidity and temperature) have been formulated into a mould prediction computer programme. The fungi were selected as representative of moulds which differ in their relative humidity and temperature requirements to sustain surface growth, and because several were known mycotoxin producing species and of potential health significance. Each growth limit curve was generated from a series of data points on a temperature-relative humidity (RH) plot and fitted using the third-order polynomial equation RH = a-)T3 + a2T2 + ajT + ao. The model was incorporated within the Environmental Systems Performance research programme for transient simulation of the energy and environmental performance of buildings, thereby enabling the system to predict the likely occurrence of mould development for fungi which exhibit similar temperature/ RH requirements to the reference moulds. The model predicts the interactive parameters which give rise to local environmental conditions that encourage mould growth. The system’s predictive capability was tested via laboratory experiments and by comparison with monitored data from a mouldy building.

show abstract

Effect of Water Activity and Temperature on Aflatoxin Production by Aspergillus parasiticus

Cited by 76 publications

References 0 publications

Factors influencing fungal and aflatoxin levels in Turkish hazelnuts (Corylus avellanaL.) during growth, harvest, drying and storage: A 3-year study

Factors influencing fungal and aflatoxin levels in Turkish hazelnuts (Corylus avellanaL.) during growth, harvest, drying and storage: A 3-year study

Mycotoxins in animals: Occurrence, effects, prevention and management

Development of a Computer Programme for the Prediction and Control of Mould Growth in Buildings Using the ESP-r Modelling System

Contact Info

Product

Resources

About