Tag Archives: microbial contamination

Research – Low Moisture Foods – Microbial Contamination Control

Food Safety News

University of Maine researcher has received a $4.9-million grant from the U.S. Department of Agriculture and the National Institute of Food and Agriculture to develop ways of using non-thermal technologies to control microbial contamination of low-moisture foods.

Dr. Vivian Wu, a professor of food science, will be lead researcher on a five-year project to explore new technologies to better control microbial contamination of low-moisture foods, such as cereals, nuts and spices, without using heat.

“Heat is a very effective way to control microbial contamination, but there are food products that heat just doesn’t work that well,” she said, mentioning such foods as produce and grains. “We want to develop nonthermal processing techniques to eliminate, to maintain the safety of produce and low-moisture food.”

Research – Revolutionary Compressed Air Microbial Test Unit

I have not used this item but it may interest some of you

Parker Balston

How to Reduce the Risks of Microbial Contamination in Compressed Air
Compressed air is often in direct contact or indirect contact with food product. The impurities in the compressed air may contaminate the food product which can result in:
  • change of color and taste
  • reduced shelf life
  • product recalls
Compressed air is warm, dark, and contains moisture which makes it the ideal environment to promote the production of microbes. These microbes migrate through the entire compressed air system and are released at exit points – critical places where the air contacts food, packaging, or surface areas.

Research – Levels of microbial contamination of domestic refrigerators in Italy

Science Direct iStock_000012710183Small


According to the EFSA Report 2013, 32.7% of outbreaks of foodborne illness registered in Europe occurs within the home, due to inadequate hygienic behaviour of consumers when preparing foods in the kitchen. The efficacy of proper cleaning of cutting boards, dishes and cutlery in limiting microbial cross-contaminations in the kitchen has been documented many times, whereas few researches have been performed to determine the microbial load of the internal walls of domestic refrigerators, in Italy. The aim of this investigation is to ascertain the role played by internal surfaces of home refrigerators as possible sources of microbial contamination of foods.

Material and methods

We analyzed 293 domestic refrigerators of students or workers at the university campus of Agripolis (Legnaro, Italy). For each refrigerator, 2 internal surfaces were sampled using sponge-bags. The amounts of total viable count (TVC), Gram-negative spoiling bacteria, moulds and yeasts and the main pathogenic bacterial species were determined.


TVCs greater than 1 log CFU cm−2 are in a little over 50% of the samples analyzed and are found mainly on the bottom of the refrigerator (61%) compared to the walls (39%) (P < 0.001). Even for other microbial counts the risk ratio of finding them on the bottom of the refrigerator is significantly higher than on the walls; the possibility of there being a finding on the bottom with respect to the walls varies from 2.5 to 8.5 times respectively for moulds and Aeromonas spp. Salmonella spp. was found in 1.7% of the samples, Bacillus cereus in 5.6%, Coagulase-positive staphylococci (CPS) in 4%, the prevalence of which is always higher on the bottom of the refrigerator. Listeria monocytogenes and Yersinia enterocolitica were never found.


It is necessary to better educate consumers to clean their appliances more frequently.

Australia – Yoghurt Recall – E.coli


Shaw River Buffalo Cheese has recalled Shaw River Buffalo Yoghurt from some small gourmet retailers and health food stores in NSW, QLD and VIC due to microbial (E. coli) contamination. Foods contaminated with E. coli may cause illness if consumed. Customers should return these products to the place of purchase for a full refund.

Date notified to FSANZ

8 March 2013

Food type


Product name

Shaw River Buffalo Yoghurt (natural yoghurt)

Package description & size

500g and 1.2kg white plastic tamper-proof tub

Date marking

Best before 14 APR 13

Country of origin


Reason for recall

Microbial contamination (E. coli)

Australia – Recall Mixed Spice Rack – Salmonella


Ontrack Pty Ltd and Big W have recalled Truly Gifted Spice Rack 12 Bottle Spice Set 375g from Big W stores in ACT, NSW, TAS and VIC only, due to microbial contamination (Salmonella) in the peppercorn portion of the product. Consumers should not eat this product and should return it to the place of purchase for a full refund.

Date notified to FSANZ


Food type


Product name

Truly Gifted Spice Rack

Package description and size

12 Bottle Spice Set 375g – 2 tier

Date marking

Best Before 30/11/2013

Country of origin

China (raw ingredient from India)

Reason for recall

Microbial contamination (Salmonella) in the peppercorn portion of the product

Australia- Recall Favor Swallow Bean Sauce – Bacillus cereus


Delin (Australia) Trading Pty Ltd has recalled Favor Swallow Bean Sauce from some Asian supermarkets in Victoria due to microbial contamination (Bacillus cereus). Food products contaminated with Bacillus cereus  may cause illness if consumed. Consumers should not eat this product and should return it to the place of purchase for a full refund.

Microbial safety and quality of various types of cooked chilled foods

Science Direct

Refrigerated Processed Foods of Extended Durability (REPFEDs) are a diverse group of food products. Their production process consists of a variable sequence of different processing steps leading to various types of REPFEDs being introduced to the market. To assure microbial safety, the food industry relies on a combination of mild heat treatment (i.e. pasteurization), appropriate product formulation (i.e. pH, water activity, modified atmosphere packaging, preservatives), cold storage and shelf life limitation. In this paper a classification of REPFED food types is presented and their microbiological safety is evaluated. REPFEDs were classified according (i) to the production process and (ii) to the expected consumer’s reheating practices. To evaluate the microbiological safety, historical data on the microbial contamination of REPFEDS were collected from five companies, 706 analyses on the day of production (T0) and 2912 analyses at the end of shelf life (TEoS). Results demonstrated that the microbial safety of the products is overall satisfactory. The number of samples exceeding the acceptable levels for Bacillus cereus/sulfite reducing Clostridia (T0: 103 CFU/g, TEoS: 105 CFU/g) was 4.07%/1.94% at T0 and 2.04%/0.69% at TEoS. None of the samples exceeded the acceptable levels for Listeria monocytogenes (T0: Absent in 25 g, TEoS: max 102 CFU/g). In addition the temperature of 38 products was monitored during reheating according to instructions of the manufacturer. The pasteurization values obtained during reheating are very heterogeneous, and only 7 products obtained a P70 of 2 min throughout the entire product. To assess the effect of reheating on L. monocytogenes a challenge test (including reheating) of paella with L. monocytogenes was performed. This demonstrated that L. monocytogenes can grow up to 0.63 log CFU/g in 6 days at 4 °C and that reheating the paella according to the instructions on the label does not guarantee absence of L. monocytogenes. These findings demonstrate the microbial food safety of the tested REPFEDs is satisfactory, and that producers should not rely on the reheating at consumer level to eliminate L. monocytogenes.