Text Box: Welcome to the latest edition of our newsletter BioTalk for the food industry. This newsletter is produced up to 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 IndustryText Box:  Biological Testing  Reg No. 2787

Text Box: Cert No. 7176 – 10

Text Box: Editor: Glen Pinna

Text Box: Total Number of Salmonella Notifications. 2003 and 2004. Text Box: 27

Text Box: March 2005   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/.   Sudan red food dyes in Australia: The United Kingdom Food Standards Agency (UKFSA) has recently advised consumers not to eat a wide range of foods that have been inadvertently contaminated with an illegal dye, Sudan I. This dye was in a batch of chilli powder used to manufacture a Worcester sauce, which was then used as an ingredient in a wide range of UK products.   Most of these UK products are fresh or chilled so it appears unlikely that any of the affected batches are present in Australia. However, this is being further investigated through industry and the states and territories. Sudan red food dyes, including Sudan I, are not approved for use in Australia. tested. Text Box: Food Poisoning Outbreaks—Qld 4th Quarter 2004 Source: Queensland Health Dept.

Text Box: 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.   Dried Foods   Dried foods characteristically have a low water activity (aw) and are therefore subject to spoilage by xerophilic fungi yeast and moulds. The term xerophilic means the ability of an organism to survive under dry conditions. The dried foods considered here are solid foods, low in moisture and soluble carbohydrates, and include cereals, nuts, dried meat (biltong and jerky) and spices. The xerophilic fungi that cause spoilage of these foods grow rapidly above about 0.77 aw and slowly at 0.75 aw and below to about 0.68 aw.   Eurotium species are probably the most common fungi causing spoilage of dried foods as this group appears to have no preference for nutrient type. Wallemia sebi is common in cereals and spices, Aspergillus penicillioids is important in grains and spices. Nuts are very susceptible to a wide range of Aspergillus species, whereas grains are more likely to become contaminated by Penicillium species, especially when stored in cooler climates.   Control of these xerophilic fungi normally relies on keeping the aw low to prevent growth. For long term storage (one year or more) foods should be held at or below 0.70 aw; for 6 months shelf-life 0.75 aw is adequate; and aw levels above 0.77 are unsafe except for short term storage.  Remember that the moisture content of a food is not the water activity (aw) and the moisture content to achieve these water activity levels vary widely and is dependent on the humidity isotherms for particular products. Also, it is important to remember that the aw stated relate to normal ambient temperatures of 20 - 30 °C and that refrigerated storage will prolong shelf-life of dried products so long as the air is effectively dehumidified.   In cereals, Penicillium is the most common cause of spoilage in wheat, barley and oats. In rice and other small grains Penicillia is a common spoilage fungi in tropical regions however Eurotium and Aspergillus are far more significant.   Because maize cobs and kernels are relatively large, the moist conditions during harvest often result is slow drying. A consequence of this is that pre-harvest and post-harvest fungi may become well established. Various species of Eurotium, Penicillium, Aspergillus and Fusarium may persist in high numbers.   In soybeans and mung beans Eurotium, Penicillium, Aspergillus, Alternaria and Cladosporium dominate the mycoflora and are responsible for spoilage. In chickpeas Aspergillus, Emericella nidulans and Penicillium species are the commonly found  spoilage fungi.   Nuts such as macadamias, where they are well protected by a heavy shell during development, are rarely colonised by fungi. Others that are formed underground, such as peanuts, may be invaded pre-harvest by a very wide range of fungi. Dried nuts are very susceptible to spoilage because their soluble carbohydrate content is low. So any increase in moisture content causes an appreciable increase in aw. Because of their relatively high oil content, even a slight increase in aw will result in spoilage from growth of Eurotium species and other xerophilic fungi.   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 Lobby l Lobby level, 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 7 Text Box: There is questionable evidence that Sudan I dye may be associated with cancer formation in laboratory animals, but there is no evidence that they can cause harm in humans, particular at the low levels found in these foods.  Based on the currently available data, the potential risk to human health from low levels of Sudan I is extremely low. A national survey coordinated by Food Standards Australia New Zealand, and carried out by the states and territories in March 2004, tested chilli and paprika powders and found that there were no detections of Sudan dyes in the products tested.

 

ACT

NSW

VIC

QLD

SA

WA

TAS

NT

TOTAL

2003

82

1,838

1,259

2,093

431

591

142

345

6,781

2004

108

2,154

1,147

2,754

528

608

120

374

7,793
 

Etiology

Month

No.

Exposed

Cases

Food

vehicle

Setting

Unknown

Oct

94

8

Unknown

Commercial caterer

Norovirus

Oct

17

13

Unknown

Private residence

Salmonella Litchfield

Oct

32

2

Pool water from nearby Dam

Scout camp

Cryptosporidium species

Dec

Unknown

5

Pool water

Public swimming pool

Cryptosporidium species

Dec

Unknown

24

Pool water

Public Water park