Moulds: Spoilage aspects ❌ (3b)

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3) Products with low water activity (aw)
Spoilage aspects: products with low water activity (aw) - Osmophilic

4) Pasteurized products🔓


Products:


Canned fruit products • Bottled fruits, • Cartonned fruits products


Fungi:
Byssochlamys fulva and Neosartorya


 Heat-resistance of ascospores (sexual spores)
 Production of pectolytic enzymes by Neosartorya spp.
 Product recalls !!

2) Fresh fruits (High acidity, Pen. italicum) 🎊

5) Products containing chemical preservatives

1) Conditions for fungal growth


Moulds can grow in a broad range of environmental conditions.
They outcompete bacteria when:


pH ≤ 4.5
aw ≤ 0.90 (Ecological niche for moulds)

6) Mycotoxins

Moulds: Detection, enumeration and identification

Byssochlamys nivea


• Anamorph Paecilomyces niveus
• Soil inhabitant
• Produces heat resistant ascospores
• May require inactivation temperature above 90 °C
• Shows resistance to acids, chlorine and alcohol
• Spoils processed fruit products
• Produces mycotoxins: patulin

New techniques to combat spoilage fungi


Combination treatment:


• High pressure processing
• Ultrasound
• Heat (Alone can also improve the growth!!!)


Immune suppression - Tremorgenic activity Carcinogenic Gastro-intestinal disturbances - Nephrotoxic
Parasympathetic nerve system - Hepatic necrosis Oestrogenic - Haemorrhage of the lung and brain
Haemaorrhage of liver - Dermal toxicosis - Idiopathic pulmonary hemosiderosis

Two most important groups of mycotoxins


Aspergillus flavus toxins


•Aflatoxins • Special groups at risk (Infants – milk, veganists - nuts)


Fusarium toxins


• Fumonisins • Deoxynivalenol

Measures to control mycotoxin in the food chain

Prevention


 GAP = Good Agricultural Practice
 Controlled storage of agricultural product

“End-of-pipeline”


Decontamination:


● Chemical methods (Not very effective)
● Physical methods (Moderate effective, but huge impact on product quality)
● Biological – fermentation (Decreasing toxicity by metabolic conversion)

Enumeration - How many are there? ✏

Identification - Which species/strain? 👥

Detection - Fungus present yes/no ✅ ❌

Sample processing


Dlution in 0.1% peptone
Mild heat treatment (to activate possibile spores )

Plating


Antibiotics (Avoiding Bacterial Growth)
Osmotic value

Sampling


Uneven Distribution
Presence spores?!
Fragmentation mycelium

Immunological methods


• ELISA
• Latex agglutination tests


Principle of Latex-agglutination test


1) Mix the sample with (latex) beads that are covered with antibodies
2) If targets for AB are present, the latex beads clump (agglutinate)

DNA based methods


• RAPD (random amplified polymorphic DNA)
• Sequencing conserved regions 18SrRNA

Classical methods


• Selective plating
• Colony morphology
• Morphology - microscopy

Inspection and quality assurance

2) Public-private entities - Trade organizations


For example: organization of feed manufacturers:


• Internal monitoring among members
• Control of levels of aflatoxins in feed
• To prevent carry-over to milk

3) Private - Private enterprise


Internal Quality assurance:


• Quality management
• Implementation and use GMP (Good Manufacturing Practice)
• Implementation and use HACCP

1) Public body
Governmental Food inspection in the Netherlands

Tasks
• Inspection for mycotoxins
• Inspection for unlawful use of mouldy ingredients
• Risk assessments
• Informing enterprise and the general public

Approach
• Inspections of factories distribution centers, retail shops
• Analysis of samples
• Processing of complaints
• Research

Aim
• Inspection for adherence to the relevant legislation,
• e.g. Law on Public Health