Mycotoxins- occurrence and effects in the foods in the Indian

context

Karthikeyan NanjappanErasmus mundus student

Outline of this presentation

• What are mycotoxins?• What are the major groups of mycotoxins?• Which produces mycotoxins?• How they are produced?• How it gets into the food chain of human and other

animals?• What are the health impacts of mycotoxins?• What are the economic impacts of mycotoxins?• How to get rid off them?

What are mycotoxins?

• Toxins of fungi• Secondary metabolites• Small molecular weight compounds• Produced during the disease formation on

plantsAlternarinFusarinsAspergillus toxins

The major groups of mycotoxins

• Aflatoxins• Ochratoxin• Patulin• Fusarium toxins

- fuminosins- trichothecenes- zearalenone

• Ergot alkaloids

Main mycotoxin-producing fungi In maize, the most important toxin producing fungi are • Aspergillus • Penicillium • Fusarium

 

AspergillusPenicillium

Fusarium

• World’s 3rd important food crop• Animal feed• Industrial raw material• Energy yielding (ethanol production)

Mycotoxins in maize

Aflatoxins(A- Aspergillus+ fla- flavus)

• Responsible for Turkey X disease in 1960

• Mainly produced byo Aspergillus flavuso Aspergillus parasiticus

Types of aflatoxinsB1,B2 ----- exhibit of blue fluorescence under UV-light G1,G2 -----exhibit yellow-green fluorescence under UV- light M1,M2 -----isolated from milk of lactating animals fed aflatoxin

Presence and effect of afloatoxins in foods and feeds

Present in• Milk• Corn products• Most of the cereal products• Peanut etc.,

Aflatoxins are• Hepatotoxic

o Synergistic effect with Hepatitis virus

• Teratogenico Cause birth defects

• Mutagenic• Carcinogenic

o Causes cancer

CerealsFusariumTrichothécènes(including DON ordéoxynivalénol)

CerealsFusarium graminearumFusarium culmorum 

Zéaralénone

Maize (Corn)Fusarium moniliformeFusarium proliferatum 

Fumonisines

FoodstuffsFungiField mycotoxins

 

Mycotoxins of Fusarium sp.

Fusarium graminearumFusarium liseola

ZearalenoneDeoxynivalenol(DON)

Trichothecenes

• Sequeterpene group of toxin• Vomitoxin(DON), T-2 toxin, nivalenol• Produced by

o Fusarium graminearumo F. sporotrichiodeso F. poae/ equiseti

• Main crop sources are maize and wheat• Can be present even in the finished foods• Due the poor management in the field

• Symptoms include vomiting, immuno suppression and reduced feed uptake

Zearalenone (ZEA)

• Non steroidal• Structure similar to estrogen• Produced by Fusarium spp

F. graminearum, F. culmorum• Highly heat stable• Associated with the ear and stalk rot of maize

Health effectsIt causes • Infertility• Abortion• Possibly carcinogenic• Other breeding problems in

swine

Fumonisins

• Produced by Fusarium verticilloides and F. proliferatum• Also produced by Alternaria sp• These are the maize pathogens• 15 related types of fumonisins found• Fumonisin B is the most important group• This toxin is water soluble due to the absence of the aromatic

structure

Health impact of fumonisins• Leucoencephalomalacia (fumonisin

B)• Nephrotoxicity• Hepatotoxicity• Affects immune system• Weakly carcinogenic

Factors influencing the toxin production by Fusarium

Pearl millet and ergot alkaloids in India

• India is the largest producer of pearlmillet • Both in terms of area (9.1m ha) and

production (7.3 m t)• Staple food for more than 80 million people

in India• Ergot disease is one of the important

disease of this crop• In 1975, poisoning of people due to ergot

infected grain

Pearl millet in India

Ergot of pearl millet

• Caused by Claviceps fusiformis and other species of Claviceps

• fungus infects the florets and develops in the ovaries

• long dark colored hard structures, sclerotia, develop from infected florets

• The sclerotia is the main source of all ergot alkaloids

• The ear head my be completely or partially infected

Ergot alkaloids

• contains alkaloids of the ergoline group• Three groups are found

➔derivativesof lysergic acid (eg. Ergotamine and ergocristine ) ➔ derivatives of isolysergic acid (eg. ergotaminine)➔ derivatives of dimethyl ergoline (eg. Clavines, agroclavines)

Uses of ergot alkaloids

• Used to induce child birth and to stop maternal bleeding after childbirth

• Used for certain kind of migranes• Used psychic disorders

Gangrenous ergotism was accompanied with fatigue, cold/tingling sensations, severe muscle pain, swollen inflamed limbs and burning pain, followed by chills. Limbs become numb, turn black and mummify

Convulsive ergotism involves the central nervous system and early symptoms are similar to those of gangrenous ergotism

Ergotism

Presence of mycotoxin in other crops and foods in India

• Aflatoxin M1 in milk 0.05-3.0μg/l • Aflatoxin B1 in groundnut cake,

chillies• Fumonisin in rainfed sorghum• Ochratoxin in coffee

Indian Council of Medical Research (ICMR) recommended tolerance limit for aflatoxin is 30μg/kg

Conditions that favour mycotoxin production in India

• Tropical conditions• Harvesting practices• Post harvest storage practices• High temperatures• Unseasonal rains• Sudden floods damaging standing

crop• Improperly stored grains

Prevention and control of mycotoxins

• Primary prevention• Secondary prevention• Tertiary prevention

Primary preventionby Good Agricultural Practices (GAPs)

• Development of fungal resistant varieties of growing plants

• Crop rotation with non host crops• Lowering moisture content of plant seeds after

post harvest and during storage• Storing at lower temperatures• Using fungicides and preservatives against

fungal growth• Control insect infection in stored bulk grains with

approved insecticides

Secondary prevention

• Stop growth of infested fungi by re-drying of the products

• Removal of contaminated seeds• Inactivation or detoxification of mycotoxins

contaminated• Protection of the stored products from

conditions which supports the fungal growth

Tertiary prevention

• Complete destruction o f the contaminated products

• Detoxification or destruction of mycotoxins to the minimal level

Physical method Ionizing radiations Chemical method

Conclusions

• Mycotoxins are inevitable compounds produced by different fungi in the foods and the feeds due to various factors

• These show lot of clinical symptoms due to their chemical properties

• These toxins affects the health of animals and humans causing economic losses

• By using Good Agricultural Practices (GAPs) and Good Manufacturing Practices (GMPs) we can prevent and control the mycotoxin menace in our life

Any questions?