Category Archives: Food Microbiology

Research – Antimicrobial Treatment of Escherichia coli and Staphylococcus aureus in Herbal Tea Using Low-Temperature Plasma

Journal of Food Protection

A low-pressure capacitively coupled discharge was used to study antimicrobial treatment in herbal tea. Ambient air with a relative humidity of 40% was used as a precursor gas and fed into the chamber via a perforated power electrode. An electrical discharge plasma was produced at a radio frequency of 10 kHz and power of 80 W. The operating pressure during treatment was kept constant at 260 Pa. The target microorganisms, Escherichia coli and Staphylococcus aureus, isolated from the herbal tea were inoculated on nutrient agar petri dishes and exposed to the plasma for 0.5, 1.0, 1.5, and 2.0 min. All treatments were carried out in triplicate for different exposure times to calculate the D-value by the enumeration method. D-values of 0.73 and 0.67 min were obtained corresponding to E. coli and S. aureus reduction, respectively.

Research -Effect of Succinic Acid on Elimination of Salmonella in Chicken Meat

Journal of Food Protection

The aim of this study was to determine the effect of selected concentrations of succinic acid on the survival of Salmonella on microbiological media and on the surfaces of chicken carcasses. Samples were inoculated with Salmonella serovars Enteritidis, Typhimurium, Hadar, Infantis, and Virchow. Each strain from each dilution was plated on nutrient agar without chemical substances (pH 6.75, control) or with 0.02% (pH 5.73), 0.05% (pH 4.77), 0.1% (pH 4.42), or 0.25% (pH 3.90) succinic acid. The addition of 0.25% succinic acid in agar medium completely inhibited the growth of all Salmonella strains tested. The 150 samples of broiler chicken breasts were immersed for 2 min in 80 mL of a 107 CFU/mL Salmonella cocktail. The samples were then transferred to sterile beakers with 250 mL of 2 and 5% succinic acid for 5 min. With 2% succinic acid, Salmonella reductions (compared with the control) were 1.27 to 1.47 log CFU/g. With 5% succinic acid, reductions were 2.00 to 3.20 log CFU/g. The results indicate that it is possible to reduce the level of Salmonella on broiler chicken carcasses by immersing them in a 2% succinic acid solution.

Rsearch – Navel Orange Peel Essential Oil To Control Food Spoilage Moulds in Potato Slices

Journal of Food Protection

The aim of this study was to investigate the efficacy of navel orange, Citrus sinensis (L.) Osbeck, peel essential oil (NOPEO) for inhibiting spoilage fungi in potato slices. Sixteen different components accounting for 99.79% of the headspace components of NOPEO were identified by gas chromatography–mass spectrometry. d-Limonene was the major component of NOPEO. Antifungal activity of NOPEO was tested in vitro and in vivo against four foodborne fungi. A MIC of NOPEO against the four fungal species was 9.40 μL/mLair. NOPEO provided about 74, 74, 73, and 69% protection against Aspergillus niger, Mucor wutungkiao, Penicillium funiculosum, and Rhizopus oryzae at 2.00 μL/mLair concentration, respectively. NOPEO has been demonstrated to significantly improve the microbiological quality of potato slices.

New Zealand – Shellfish biotoxin alert (extended) – North Island West Coast region

MPI

The Ministry for Primary Industries (MPI) today extended the public health warning against collecting shellfish on the west coast of the North Island in the Taranaki, Waikato, Wanganui, Manawatu, and Horowhenua regions. The warning now extends from the mouth of Port Waikato southward to Te Horo Beach in the Wellington region.

Routine tests on shellfish samples taken from this region have shown levels of Paralytic Shellfish Poisoning (PSP) toxins above the safe limit of 0.8 mg/kg set by MPI. Anyone eating shellfish from this area is potentially at risk of illness.

MPI today also removed the public health warning against collecting shellfish in Nydia Bay Pelorus Sounds

Warnings remain in place for the Bay of Islands and Akaroa Harbour.

Mussels, oysters, tuatua, pipi, toheroa, cockles, scallops, catseyes, kina (sea urchin) and all other bivalve shellfish should not be eaten.

Note: cooking shellfish does not remove the toxin.

Pāua, crab and crayfish may still be eaten if the gut has been completely removed prior to cooking, as toxins accumulate in the gut. If the gut is not removed its contents could contaminate the meat during the cooking process.

North Island West coast

Research – Evaluation of food safety knowledge and microbial status of food contact surfaces in schools

Wiley Online Library 

Staph

Abstract

The purpose of this study was to evaluate the hygiene of food contact surfaces in 37 high school kitchens in order to identify the factors involved in the deficiencies found. The microbial status of kitchen surfaces (mesophilic aerobic bacterial count) and the hygienic sanitary knowledge (assessed by a questionnaire) of 158 food handlers were evaluated. The microbial count was determined by conventional plating methods and by a redox potential‐based testing method. Large differences regarding microbial count on food contact surfaces were found among the kitchens. In connection with the unfavorable results, the food hygiene knowledge level of kitchen workers was unsatisfactory. The microbial profile assessment of a catering unit largely depends on the efficiency of the food safety management system used, therefore the level of microbial contamination can be used as an indicator. The results showed that the hygienic‐sanitary knowledge of food handlers highly affects food safety standards in public kitchens.

Practical applications

The microbial profile of food contact surfaces is a suitable indicator of a food safety management system with objective results that are easily interpreted. Recurrent unsatisfactory results can indicate failures in some or all areas of the food safety management systems. This study shows that in most cases these failures are related to the food handler’s knowledge. The improvement of food handler’s professional knowledge is an effective way to improve food safety levels in catering units.

RASFF Alerts – Salmonella – Chicken Kebab Meat – Lettuce – B-Eggs – Chicken Fillet – Chilled Beef – Sesame Seeds -Water Spinach -Pandan Leaf

kswfoodworld food safety poisoning

RASFF-Salmonella (presence /25g) in frozen chicken kebab meat from Poland in Poland

RASFF -Salmonella in lettuce from the Netherlands in the Netherlands

RASFF-Salmonella (presence) in organic B-eggs from Germany in Germany

RASFF-Salmonella enterica ser. Enteritidis (presence /25g) in frozen chicken fillet from Poland in France

RASFF-Salmonella (presence in /10g) in chilled beef from Belgium in Belgium

RASFF-Salmonella (presence /25g) in sesame seeds from Sudan in Greece

RASFF-Salmonella (presence /25g) in sesame seeds from Sudan in Greece

RASFF-Salmonella group D (present /25g) in water spinach from Thailand in Finland

RASFF-Salmonella enterica subsp. salamae (II) (presence /25g) in pandan leaf (Pandanus amaryllifolius) from Thailand in Finland

RASFF Alert – Campylobacter – Chilled Chicken Breast

kswfoodworld food safety poisoning

RASFF– Campylobacter coli (100 <–> 8000 CFU/g) and Campylobacter jejuni (100 <–> 8000 CFU/g) in chilled chicken breasts from France in Denmark