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Post-harvest control strategies: Minimizing mycotoxins in the food chain.

By Naresh Magan and David Aldred

Abstract

Contamination of cereal commodities by moulds and mycotoxins results in dry matter, quality, and nutritional losses and represents a significant hazard to the food chain. Most grain is harvested, dried and then stored on farm or in silos for medium/long term storage. Cereal quality is influenced by a range of interacting abiotic and biotic factors. In the so-called stored grain ecosystem, factors include grain and contaminant mould respiration, insect pests, rodents and the key environmental factors of temperature, water availability and intergranular gas composition, and preservatives which are added to conserve moist grain for animal feed. Thus knowledge of the key critical control points during harvesting, drying and storage stages in the cereal production chain are essential in developing effective prevention strategies post-harvest. Studies show that very small amounts of dry matter loss due to mould activity can be tolerated. With < 0.5% dry matter loss visible moulding, mycotoxin contamination and downgrading of lots can occur. The key mycotoxigenic moulds in partially dried grain are Penicillium verrucosum (ochratoxin) in damp cool climates of Northern Europe, and Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxin) and some Fusarium species (fumonisins, trichothecenes) on temperate and tropical cereals. Studies on the ecology of these species has resulted in modelling of germination, growth and mycotoxin minima and prediction of fungal contamination levels which may lead to mycotoxin contamination above the tolerable legislative limits (e.g. for ochratoxin). The effect of modified atmospheres and fumigation with sulphur dioxide and ammonia have been attempted to try and control mould spoilage in storage. Elevated CO2 of > 75% are required to ensure that growth of mycotoxigenic moulds does not occur in partially dried grain. Sometimes, preservatives based on aliphatic acids have been used to prevent spoilage and mycotoxin contamination of stored commodities, especially feed. These are predominantly fungistats and attempts have been made to use alternatives such as essential oils and anti-oxidants to prevent growth and mycotoxin accumulation in partially dried grain. Interactions between spoilage and mycotoxigenic fungi and insect pests inevitably occurs in stored grain ecosystems and this can further influence contamination with mycotoxins. Effective post-harvest management of stored commodities requires clear monitoring criteria and effective implementation in relation to abiotic and biotic factors, hygiene and monitoring to ensure that mycotoxin contamination is minimised and that stored grain can proceed through the food chain for processing

Topics: Drying, Dry matter loss, Mycotoxins, Cereals, Preservation, Spoilage fungi
Publisher: Elsevier
Year: 2007
DOI identifier: 10.1016/j.ijfoodmicro.2007.07.034
OAI identifier: oai:dspace.lib.cranfield.ac.uk:1826/2390
Provided by: Cranfield CERES
Journal:

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Citations

  1. (2004). Prevention strategies for tricothecenes. doi
  2. (2004). HACCP and Mycotoxin control in the food chain. In: Mycotoxin in food: detection doi
  3. (1980). Gaseous and heavy metal pollutants. In: Experimental Microbial Ecology, doi
  4. (2005). Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain. doi
  5. (2006). Fusarium mycotoxins: Chemistry, genetics and biology. doi
  6. (1977). Aflatoxin formation in peanuts by Aspergillus flavus. Bulletin Agricultural Experimental Station, doi
  7. Sulphur dioxide –supplemented ambient air drying of high moisture corn. doi
  8. (1983). Microbial growth inhibition by SO2 plus NH3 trratments during slow drying of corn.
  9. (2002). Qualitative reasoning and integrated management of the quality of stored grain: a promising new approach. doi
  10. (1991). Filamentous fungi in food and feeds: ecology, spoilage and mycotoxin contamination.
  11. (1970). Handling and storage of food grains in tropical and sub-tropical areas.
  12. (1991). Use of an automatic electrolytic respirometer to study respiration of stored grain.
  13. (2003). Multi-target environmental approach for control of growth and toxin production by Fusarium culmorum using essential oils and antioxidants.
  14. (2005). Use of antioxidants and essential oils for controlling mycotoxins in grain.
  15. (2000). Study of the relationship between storage conditions and the growth of moulds and production of Ochratoxin A in grain-24 preliminary results.
  16. (1990). The use of sulphur dioxide as an aid in the storage of moist wheat.
  17. (1981). Factors affecting death of yeast by sulphur dioxide.
  18. (1972). Drying and storing grains, seeds and pulses in temperate climates. Institute for Storage and processing of Agricultural Products, Bulletin 205,
  19. (1997). Respiration of wheat grain in different environments.
  20. (2004). Predicting noncompliant levels of ochratoxin A in cereal grain from Penicillium verrusocum counts. doi
  21. (2003). Penicillium verrucosum in wheat and barley indicates presence of ochratoxin A. doi
  22. (1993). Early detection of fungi in stored grain. doi
  23. (1993). Use of sulphur dioxide to control fungi in stored grain.
  24. (2006). Mycotoxins in Europe: prevention and early detection strategies.
  25. (2007). Why do fungi produce mycotoxins? In “Food Mycology: a multifaceted approach to fungi and food”. doi
  26. (1984). Effects of gas composition and water activity on growth of field and storage fungi. doi
  27. (2003). Post-harvest fungal ecology: impact of fungal growth and mycotoxin accumulation in stored grain. doi
  28. (2004). Role of spoilage fungi in seed deterioration. Chapter 28, doi
  29. (1973). Control of mycoflora on moist grain. In: Preservation of wet harvested grains,
  30. (1989). The use of sulphur dioxide as an aid in the storage of wheat grains.
  31. (1998). Control of growth and fumonisin B1 production by F.moniliforme and F.proliferatum isolates in maize grain with propionate formulations.
  32. (2000). Selective effect of propionates on maize mycoflora and impact on fumonisin B1 accumulation. doi
  33. (1986). Control of T-2 toxin production using atmospheric gases.
  34. (2004). Fumonisin-producing strains of Fusarium: A review of their ecophysiology. doi
  35. (1991). Production of zearalenone in vitro and in corn grains stored under modified atmospheres. doi
  36. (1983). Ochratoxin production by Aspergillus flavus Wilhem grown under controlled atmospheres.
  37. (1988). Inhibition of T-2 toxin production on high moisture corn kernels by modified atmospheres.
  38. (2005). Ecology and control of ochratoxin in grapes and dried vine fruits. doi
  39. (2006). Efficacy of sulphur dioxide, controlled atmospheres and water availability on in vitro germination, growth and ochratoxin A production by strains of Aspergillus carbonarius from grapes and vine fruits. Postharvest Biology and Technology. doi
  40. (1969). Control of internal fungi in sorghum by fumigation. doi
  41. (1985). Post-harvest losses of paddy in the Krian/Sungei Manik areas.
  42. (2007). The influence of modified atmospheres and their intercation with water activity on the radial growth and fumonisin B1 production of Fusarium verticillioides and F.proliferatum on corn. Part 1.: The effect of initial headspace carbon dioxide concentration. doi
  43. (2004). Fate of ochratoxin A in the processing of whole wheat grain during extrusion.Food Additive and Contaminants doi
  44. (1991). The use of sulphur dioxide to preserve moist wheat for human consumption.
  45. (1995). The Stored Grain Ecosystems.
  46. (1970). Specificity of transport processes for sulphur, selenium and molybdenum anions by filamentous fungi.
  47. (1980). Handling of high moisture paddy during wet season-a practical approach to existing problems.
  48. (1982). Intergranular carbon dioxide as an indicator of biological activity associated with the spoilage of stored wheat.

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