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 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. April 2003 to March 2004. Text Box: 25

Text Box: May 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/.   Nitrofurans in imported Honey and Prawns: There have been incorrect reports that imported honey and imported prawns contain dangerous residues of an antibiotic known as nitrofuran. Food Standards Australia New Zealand (FSANZ) has conducted a safety assessment which has shown that imported honey and imported prawn products on supermarket shelves in Australia are safe. Nitrofurans are no longer registered for use as a veterinary chemical in food-producing animals in Australia. The longstanding interpretation of the Food Standards Code was that as nitrofurans have no residue limit in the Food Standards Code, even though they may be safe, they are not legal. Last year FSANZ advised the Australian Quarantine and Inspection Service (AQIS) to test imported honey and imported prawns for this antibiotic. Any food products found to contain detectable levels of nitrofurans will not be permitted for sale in Australia. To date 56 consignments of prawns have been tested of which 5 have been found to have levels of nitrofurans and these failed consignments have not been permitted into Australia.   New State Development Committee on Poultry Meat: In December 2003, the FSANZ Board appointed twenty members to a Standard Development Committee (SDC) to assist FSANZ develop a Primary Production and Processing Standard for Poultry Meat.   The SDC met for the first time in Sydney on 3-4 February 2004. The SDC is a cohesive group and fully supportive of FSANZ developing a Primary Production and Processing Standard for Poultry Meat. The SDC meeting also helped familiarise SDC members with issues connected with the safety of poultry meat; to plan the preparation of an Initial Assessment Report that will form the basis of public consultations; and to approve a communication plan for the project. Text Box: Food Poisoning Outbreaks—Qld 1st Quarter 2004 Source: Queensland Health Dept.

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.   Vegetables   Not only has there been an increase in the consumption over the last 10 years but also the way we prepare vegetables and the vegetables we  eat. For example, broccoli was traditionally cooked and served as a hot accompaniment to a main meal, but now it is also commonly served raw in salads and new types of edible plants are being consumed, including roots, leaves, flowers, seeds and sprouts.   Healthy raw vegetables harbour many microorganisms which can be on the surface or embedded within the plant tissue. These may originate from the air, soil or fertiliser. Bacteria are commonly the predominant microorganism present, but yeast and moulds may also be present in significant numbers. Studies of harvested plants have shown bacterial counts from less than102 to 108 CFU/gram and mould counts from less than102 to 108 CFU/gram. Coliform bacteria and other Gram negatives tend to dominate the bacterial population with coryneforms, lactic acid bacteria, sporeformers and micrococci. Yeasts found on vegetables include Candida, Kloechera, Rhodotorula, Cryptococcus and Sporobolomyces.   The harvesting process can be a source of additional microbial contamination. This can occur by physical injury to the plant which not only provides additional entry sites but also allows the plant to release nutrients that enhance the growth of microorganisms. This has been scientifically documented for Pseudomonas species on spinach leaves, cabbage leaves and celery. Also during the harvesting process additional microorganisms can be added to the plant via human contact and equipment used for harvesting and transportation. Temperature control during the time period from harvest to processing can also effect microbial growth and lead to food spoilage.   Water used for the washing of fruit and vegetables is required to meet drinking water standards. This is especially significant as many farmers wash the harvest on site. Frequently, the water used for this originated from environmental supplies such as bores, springs and waterways. These water sources rarely meet the necessary microbial standards and the problem is compounded by the water being stored in tanks that are not regularly cleaned and disinfected. This leads to a biofilm forming on the tank’s internal surfaces. This results in a situation where chlorination of the tank water will not penetrate this bacterial biofilm and the microbes will remain viable and shed into the water. Unless physical action is undertaken in the process of performing a complete tank disinfection the biofilm will continue to be a source of microorganisms. Vegetables washed in sanitised water have a lower microorganism load than the raw unwashed product. Researches have reported a 1 to 2 log CFU/gram decrease. Trimming and peeling and discarding outer leaves (cabbage and lettuce) will also decrease the total microbial load on a product as the outer leaves of these types of vegetables can have up to 4 log units higher in microbes as compared to inner leaves.   The cutting (slicing, dicing and shredding) of vegetables as well as the temperature abuse during storage all lead to increase the level of microorganisms of the product. The machinery used in this processing step will also lead to contamination if proper cleaning and disinfection is not maintained. This contamination can be up to 10 times higher than the raw product level of spoilage and/or pathogenic microorganisms.   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 5

 

ACT

NSW

VIC

QLD

SA

WA

TAS

NT

TOTAL

Q2/03

19

427

295

491

105

159

33

95

1,624

Q3/03

14

246

185

263

71

102

26

77

984

Q4/03

13

429

241

527

103

112

22

78

1,514

Totals

82

1,843

1,249

2,087

429

584

144

346

6,764

Q1/04

28

797

320

1,091

127

187

47

109

2,706
 

Etiology

Month

No.

Exposed

Cases

Food

vehicle

Setting

Norovirus

Jan

Unknown

4

Frozen Oysters

Restaurant

Ciguatoxin

Jan

2

2

Golden Spotted Trevalley Fish

Private residence

Ciguatoxin

Feb

Unknown

4

Coral Trout

Restaurant

Bacillus cereus

Feb

Unknown

6

Potato and Gravy

National Franchised Fast Food

Norovirus

Mar

Unknown

8

Unknown

Commercial Caterer

Ciguatoxin

Mar

Unknown

2

Unknown Fish spp.

Private residence

Salmonella Zanzibar Var 15+

Mar

Unknown

5

Unknown

Restaurant