Foodborne illness from citrus fruit: understanding the food safety risks

Transcription

1 Foodborne illness from citrus fruit: understanding the food safety risks S.P. Singh, PhD E: T: ; M:

2 Safety Quality, healthy & nutritious Environmental & ethical values Provenance

3 20 years ago.. In March 1999, Salmonella outbreak linked to the unpasteurised orange juice In August 2003, the Federal Court s judgement:...(growers).breached their contracts to supply fruit that was fit for sale...liability for the loss and damage found to rest with the.(growers).

4 Impact of a food safety failure Product recalls Consumer health Economic losses Reputation Consumer confidence Exports Market access Supplier contracts

5 Food Safety Risks Physical Chemical Microbial Food fraud physical objects chemical residues, heavy metals, toxins bacteria, viruses, parasites, moulds mislabelling, traceability

6 Citrus Industry s Food Safety Shield Microbial Risk Mitigation Food fraud and traceability National residue survey program Postharvest chemical residue Preharvest chemical residue control On-farm food safety certification

7 Microbial Risks Fungal Bacterial Viral Parasitic

8 Microbial contamination risks in the field

9 Microbial contamination risks in the field Contamination can occur anywhere along the supply chain, but the highest chances are in the orchard. Irrigation water Chemical spray water Animal manures Wildlife incursions Dust storms Field and harvest workers Farm machinery

10 Microbial hazards & their potential sources in the field Bacteria Salmonella species Listeria monocytogenes E. coli O157:H7 Viruses Noroviruses Hepatitis A Parasites Cyclospora Cryptosporidium

11 Postharvest sources of microbial contamination Entry of contaminated fruit in the packhouse Contaminated wash water Equipment Workers

12 Key Questions to the Citrus Industry? Q1. Can citrus fruit be a carrier of foodborne pathogens to consumers? Q2. Can foodborne pathogens survive on the citrus fruit during postharvest handling and supply chain? Q3. What is the current status of the industry practice to mitigate microbial risks?

13 Citrus as a carrier of foodborne pathogens Potential route for transfer of bacterial or viral pathogens and parasites from fruit to the consumer Rind Hand Edible part Consumer

14 Transfer of Salmonella from the Orange Peel to the Hands and Edible Flesh Orange fruit were immersed in the Salmonella culture for 30 sec Peel Flesh Gloves + Control Left to dry in a biosafety cabinet + Control: whole fruit in the broth Fruit inoculated with Salmonella were hand peeled Rind/Flesh/Gloves in the broth

15 Log10 CFU/mL Transfer of Salmonella from the Navel Orange Peel to the Hands and Edible Flesh 0 + CONTROL Peel Flesh Gloves

16 Log10 CFU/mL Transfer of Salmonella from the Afourer Mandarin Peel to the Hands and Edible Flesh CONTROL Peel Flesh Gloves

17 Transfer of Salmonella from the Hands to the Orange Peel and Flesh Sterile gloves were immersed in the Salmonella culture for 30 sec Peel Flesh Gloves + Control Inoculated gloves were allowed to dry in a biosafety cabinet + Control: inoculated gloves in the broth Sterile fruit were peeled using the inoculated gloves Peel/Flesh/Gloves in the broth

18 Log10 CFU/mL Transfer of Salmonella from the Hands to the Orange Peel and Flesh CONTROL Peel Flesh Gloves

19 Can foodborne pathogens survive through packhouse handling and supply chain?

20 Postharvest washing and sanitisation Postharvest washing and sanitisation does NOT completely remove the microbial pathogens. Contaminated wash water can introduce pathogens on to the fruit. Pathogens established on the fruit contact surfaces (e.g. conveyors and brushes) can be a continuous source of contamination.

21 Listeria monocytogenes - an environmental pathogen A Californian study on 5 citrus packhouses (2017) Total environmental samples collected = 355 Tested positive for Listeria monocytogenes = 62 (38%) Source: Sbodio & Suslow, UC Davis. CPS Symposium 2018

22 Log10 CFU/mL Survival of Salmonella on Navel oranges during storage at ~20 C Day Week 1 Week 2 Week 3 Week 4

23 Log10 CFU/mL Survival of Salmonella on Navel oranges during storage at ~4 C Day Week 1 Week 2 Week 3 Week 4

24 Final remarks Food safety risks can not be eliminated but can be minimised. Prevent contamination of the fruit in the orchards and packhouses Packhouse washing can not completely sanitise the fruit.

25 Final remarks Proactive approach Scientific evidence-based practice Preventative controls Good agricultural practices (Field) Good manufacturing practices (Packhouse) Good hygiene practices (Workers)

26 NSW DPI s Horticultural Food Safety Research Program Translational research & outreach Scientific evidence-based practice Proactive & preventative Industry-focused

27 Acknowledgements NSW DPI Horticultural Food Safety Research Team

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