Text Box: Welcome to the latest edition of our newsletter BioTalk for the food industry. This newsletter is produced four times a year with special editions for topical or current issues. There are regular items and general information on microbiological issues. Your feedback and suggestions are most welcome. Copies of this newsletter and previous issues are available from our web site. BioTalkBiotech LaboratoriesNEWSLETTERFood Industry

 Biological Testing  Reg No. 2787

Cert No. 7176 – 10

Editor: Glen Pinna
Text Box: Total Number of Salmonella Notifications. 1 Jan to 30 June 2004.

26

August 2004

 

Issue No.
Text Box: National Enteric Pathogens Surveillance Scheme The following data is reproduced from the National Enteric Pathogen Surveillance Scheme (NEPSS), Microbiological Diagnostic Unit, Public Health Laboratory, The University of Melbourne, Victoria. Text Box: Foods Standards Australia New Zealand - Media Release Text Box: Foods Standards Australia New Zealand (FSANZ) publicised the following on their website at http://www.foodstandards.gov.au/. New Advice on Listeria and Food: While Listeria infection is uncommon and causes few or no symptoms in most people, it can be very dangerous for unborn or newborn babies, the immuno-compromised and the elderly. The food industry, state and territory regulatory authority and FSANZ have extensive management processes in place to prevent Listeria contamination during food production. However, listeriosis is usually caused by at risk people eating food that has not been stored or handled properly once the food has been produced or cooked. The food industry, state and territory regulatory authority and FSANZ have extensive management processes in place to prevent Listeria contamination during food production. It is important you reduce your risk by taking a few simple precautions. If you or anyone in your household is in the higher risk group, you can take precautions to avoid Listeria by eating only freshly prepared and well-washed food, following good food hygiene such as washing and drying hands, by cooking foods thoroughly and by refrigerating leftovers immediately and keeping them no more than a day. A new brochure contains advice on safer alternatives for people at risk to eat in the meat, chicken, salads, seafood and dairy products food categories. It also lists some higher risk foods that people at risk should be wary of consuming especially if they are unsure about how the foods have been stored and handled. However, the higher risk foods become safe if you cook the food or reheat it to steaming hot throughout, and serve it hot. The brochure can be obtained from the FSANZ website at http://www.foodstandards.gov.au/_srcfiles/Listeria.pdf

Food Poisoning Outbreaks—Qld 2nd Quarter 2004 Source: Queensland Health Dept.

Foodborne disease is defined as any illness of an infectious or toxic nature caused by the consumption of food or water.  A foodborne illness outbreak is defined as the occurrence of two or more associated cases of foodborne illness.

Text Box: Food is considered spoiled when an undesirable change in the colour, flavour, odour or texture has occurred. Foreign substances in food products make foods undesirable. It is a gradual process and is a natural phenomenon; it occurs at varying rates depending on the storage temperature, kind of food involved, kind of microorganisms present, packaging materials used, food additives used and method of preservation. This discussion started in Biotalk 21 April 2003. Bread and Bread Rolls Breads can be produced in many shapes, sizes and from a variety of grains other than flour. They can be baked, cooked on hot plates or steamed. Although wheat is the predominant grain, other sources include rye, millet, spelt, triticale, barley, corn, sorghum and rice. The breads and rolls may contain a variety of fillings including vegetables, fruit, meat and dairy products and may be fully or partially cooked before sale. During cooking the centre of a loaf generally reaches 95 °C with a cooking temperature of about 230 °C. The final water activity of bread is greater than 0.90. The centre of the loaf is essentially commercially sterile after baking as the core temperature reached is enough to kill vegetative bacterial pathogens and commensal organisms. However the heat resistant spores of Bacillus species may survive the cooking process. If favourable growth conditions are provided after cooking then these spores may germinate and multiply. The crust of bread has a very low water activity (<0.50) and this will prevent all microbial growth. It is the post cooking contamination with microbes, especially moulds, that occurs before the packaging step that is the most prevalent source of spoilage. This is increased if the product is packaged in polyethelene while still warm due to moisture migration to the crust. The main moulds found are Penicillium (blue-green), Aspergillus (black), Mucor (white) and occasionally Neurospora (orange-pink colour). Fungal spores present in the baking, cooling, slicing or packaging environment are attached to dust and flour particles and are carried by air streams and fall onto the product. Yeasts appear as spoilage contaminants of bread less frequently than moulds. Their presence is generally due to poor hygiene practices of staff and cleaning procedures of surfaces, slicers and oiling brushes. A thick growth of wild yeast on the surface of sliced bread (known as chalky bread) is most evident on the darker rye breads as a confluent white growth with an accompanying fermented of fruity odour. Typical yeasts causing chalky bread are Endomycopsis and Trichosporon species. Osmophilic yeasts can contaminate sweet type bread products due to improper cleaning of icing containers. Zygosaccharomyces bailli and Zygosaccharomyces rouxii are the most commonly implicated yeasts. Rope spoilage of bread is caused by Bacillus endospores that infrequently occurs during storage. The spores must firstly survive the baking step of a highly contaminated product and secondly favourable conditions must be present such as the absence of preservatives, insufficient or slow cooling after baking, warm holding temperatures, moist and humid environments to allow germination. Control of microbial spoilage will include minimising air flows; cleaning coolers and cooling fans of dust build-ups; protection of stored product from aerial dust; maintaining a high level of hygiene in storage containers (including icing and decorative topping containers); sanitising slicing blades and keeping clean and dry; good hygiene practices by workers; and proper cooling practices being used before packaging. The discussion will continue in the next BioTalk Food Newsletter. Sources: Spoilage of Processed Foods: Causes and Diagnosis. AIFST Inc. NSW Branch, Food Microbiology Group. Food Text Box: Biotech Laboratories Pty Ltd Level 2, Administration Building, Greenslopes Private Hospital, Newdegate Street, Greenslopes Qld 4120 PO Box 505 Indooroopilly Qld 4068 Ph: (07) 3847 9488 Facsimile: (07) 3847 9890 E-mail: general@biotechlab.com.au Web site: http://www.biotechlab.com.au/ Text Box: Food Spoilage Microorganisms — Part 6

 

ACT

NSW

VIC

QLD

SA

WA

TAS

NT

TOTAL

Q1/04

28

818

323

1,106

150

193

47

123

2,788

Q2/04

48

554

334

674

140

130

25

97

2,002

Etiology

Month

No.

Exposed

Cases

Food

vehicle

Setting

Salmonella Singapore

Mar

Unknown

13

Sushi Rolls

Community

Bacillus cereus

Apr

190

16

Japanese Lunch Box

Restaurant

Salmonella Typhimurium PT 12a

Apr

Unknown

41

Unknown

National franchised fast food restaurant

Ciguatoxin

Apr

Unknown

5

Spanish mackerel / Golden Trevally

Private residence

Ciguatoxin

Jun

5

8

Trevally

Private residence

Ciguatoxin

Jun

4

3

Grey mackerel

Private residence

Unknown

Jun

35

25

Buffet meal with cold salad

Restaurant