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