Category Archives: Food Microbiology Research

Australia – Australian egg industry cracks down on Salmonella

Food Processing.com.au

The Australian egg industry has continued to work closely with authorities to respond to and eliminate the threat of Salmonella Enteritidis (SE) since its initial outbreak in September 2018.

Additional legislation was introduced in New South Wales in the form of a Biosecurity (Salmonella Enteritidis) Control Order to manage the risk of SE to consumers. It has been in effect since August 2019.

In its 2019–20 Annual Report, NSW Food Authority reported a reduction in compliance of the food safety program across the NSW egg industry as a result of increased regulatory controls placed on industry due to the introduction of the Biosecurity (Salmonella Enteritidis) Control Order.

USA – Sushi related outbreak stumps health officials; more than 150 sickened

Food Safety News

Public health officials in North Carolina have concluded their investigation of a foodborne illness outbreak linked to sushi, saying they were unable to determine the specific cause behind the illnesses of more than 150 people.

Only a handful of ill people who ate the suspect sushi sold at two Harris Teeter grocery stores agreed to provide samples for pathogen testing, according to the Cabarrus Health Alliance environmental health director. Officials also tested one sample of sushi.

All patient samples and the product specimen were tested for a broad range of pathogens in an attempt to identify the agent responsible for the illnesses. 

New Zealand – Campylobacter Action Plan 2020-2021

MPI

Campylobacter kswfoodworld

The 2020 –2021 Action Plan incorporates a risk-based, whole-of-food chain approach to identification, selection and implementation of new control measures that will significantly reduce the foodborne campylobacteriosis burden in New Zealand.

The Action Plan includes: prioritisation of selected actions for immediate evaluation/implementation; identification of a further list of potential control measures on the basis of current knowledge, and establishing a framework for their systematic evaluation, prioritisation and implementation; setting of a public health improvement goal for the reduction of foodborne campylobacteriosis; and a lead in to medium-term control measures that will likely be implemented in out-years 2022 –2023.

New Zealand Food Safety will be primarily responsible for agreed actions and reporting against the work schedule. Industry will have responsibility for implementing both legislated and non-legislated actions.

Norway – The rules for selling raw milk remain unchanged

Mattilsynet

The Ministry of Health and Care Services (HOD) has decided not to change the regulations for the sale of raw milk for human consumption. The background is to have a high level of protection of consumer health.

In the autumn of 2017, the Ministry of Health and Care Services commissioned the Norwegian Food Safety Authority to prepare a draft regulation that allows a limited sale of raw milk and raw cream for consumption.

The proposed change in the regulations was that the farm or farms can sell up to 5000 liters of raw milk or raw cream per year if certain conditions are met, such as satisfactory hygiene, unbroken cold chain, warning marking and that the turnover was from the farm or farm.

The draft regulation was out for consultation . The Norwegian Food Safety Authority carried out a compilation of the consultation statements which were submitted to the Ministry of Health and Care Services. In its decision not to change the regulations, the Ministry of Health and Care Services has, among other things, emphasized the warnings from the Norwegian Institute of Public Health, the Norwegian Veterinary Institute and the Norwegian University of Life Sciences. All three agencies opposed liberalization in the consultation statement, out of consideration for the risk of infection and the risk of serious illness.

-From a public health perspective, restrictive regulations will be the most important risk-reducing measure to avoid illness in connection with the consumption of raw milk. This is ensured, among other things, through heat treatment of all raw milk and a ban on turnover, says senior adviser Margrethe Hovda Røed in the Norwegian Food Safety Authority.

Research – Validation of simulated commercial manufacturing of flour tortillas to control Salmonella contamination

Wiley Online

Salm2

This study validated a typical batch commercial flour tortilla cooking process against Salmonella contamination. Tortilla dough prepared from flour inoculated with a 7‐serovar Salmonella cocktail was pressed in a dough press (preset at 200 °F [93.3°C]) for 3 s, then heated on a griddle (preheated to 221.1°C [430 °F]) for 30, 45 or 60 s on each side, followed by ~8 min of ambient air cooling. The maximum internal temperature of tortillas during cooking was >97°C for all cooking times. The Salmonella counts in tortillas decreased >6‐log at all cooking times; however, tortillas cooked for 30 and 45 s had an undercooked appearance. The water activity and pH of cooked tortillas after 60 s of heating on both sides followed by cooling were 0.934 and 6.62, respectively. The D‐values of the Salmonella cocktail in raw tortilla dough were 22.2, 13.4, and 4.6 min at 55, 58, and 61°C, respectively, and the z‐value was 8.9°C.

Research – Influence of Light and Water Activity on Growth and Mycotoxin Formation of Selected Isolates of Aspergillus flavus and Aspergillus parasiticus

MDPI

kswfoodworld

Image CDC

Aspergillus flavus and A. parasiticus are the main causes of aflatoxin contamination in various foods, particularly grains, as they can thrive in environments with lower water activity and higher temperatures. The growth of Aspergillus and the formation of the mycotoxins aflatoxin and cyclopiazonic acid are strongly influenced by environmental stimuli and can be reduced by modulating parameters such as water activity, pH, temperature and light during the storage. This study has two objectives—on the one hand, to assess how global warming and an increase in exposure to sunlight affect growth and mycotoxin formation, and on the other hand, how the findings from these experiments can be used to reduce fungal growth and mycotoxin formation in stored foods. Using growth substrates with two different water activities (aw 0.95, aw 0.98), together with a light incubation device consisting of different chambers equipped with diodes emitting visible light of five different wavelengths (455 nm, 470 nm, 530 nm, 590 nm, 627 nm) plus white light, we analyzed the growth and mycotoxin formation of selected Aspergillus flavus and A. parasiticus isolates. It was shown that light with a wavelength of 455/470 nm alone, but especially in combination with a lower water activity of aw 0.95, leads to a significant reduction in growth and mycotoxin formation, which was accompanied by reduced transcriptional activity of the responsible mycotoxin biosynthetic genes. Therefore, these results can be used to significantly reduce the growth and the mycotoxin formation of the analyzed fungi during storage and to estimate the trend of fungal infestation by Aspergillus flavus and A. parasiticus in water activity- and light exposure-equivalent climate change scenarios. Mycotoxin-producing aspergilli can be effective and sustainably inhibited using a combination of short-wave light and lowered water activity in the substrate. A higher annual mean temperature accompanying climate change may lead to an increased spread of aflatoxin-producing fungi in areas that were previously too cold for them. On the other hand, there will be regions in the world where contamination with aflatoxin-producing fungi will be reduced due to increased drought and sun exposure.

Research – The use of antifungal oat‐sourdough lactic acid bacteria to improve safety and technological functionalities of the supplemented wheat bread

Wiley Online

In the present study, predominant lactic acid bacteria (LAB) were isolated from oat sourdough. Then, the isolates were screened based on their in vitro antifungal activity. Subsequently, biotechnological capabilities of the selected LAB were evaluated in wheat bread supplemented with controlled fermented oat containing the isolate. Pediococcus pentosaceus was molecular identified as predominant antifungal isolate. Based on our results, fermented oat not only significantly (p < .05) reduced the mold expansion on the produced breads, but also improved the quality attributes of the product. Crumb porosity and antioxidant capacity of the supplemented bread revealed the positive effects of the isolate on textural and functional characteristics of the enriched bread. Wheat bread supplemented with controlled fermented oat had also the highest 2,2‐diphenyl‐1‐picrylhydrazyl radical scavenging activity compared to the other samples. Accordingly, the potential applications of Ppentosaceus isolate as profunctional starter culture in processing of mixed wheat‐oat sourdough bread were verified.

Research – Food safety against milk mycotoxins

All About Feed

According to the FAO and USDA, 25% of world agricultural crops are contaminated with some kind of mycotoxin and, as a consequence over, 532 million/ton of grains are contaminated. Considering that the base of animal feed is constituted by grains and cereals, most of this production may be contaminated with mycotoxins, which is very alarming. Economic consequences are significant and are not limited only to the added value of raw materials, but also to losses related to the loss of animal productivity, since the spread of mycotoxins occurs throughout the food chain, leading to contamination of final products, such as meat, milk and eggs.

Aflatoxins are secondary metabolites produced by Aspergillus parasiticus, Aspergillus flavus and the uncommon Aspergillus nomius. They appear in foods in the forms of aflatoxin B1 (AFB1), B2, G1 and G2 and in milk in the oxidative forms M1 and M2.

Research – Listeriosis Caused by Persistence of Listeria monocytogenes Serotype 4b Sequence Type 6 in Cheese Production Environment

CDC

Abstract

A nationwide outbreak of human listeriosis in Switzerland was traced to persisting environmental contamination of a cheese dairy with Listeria monocytogenes serotype 4b, sequence type 6, cluster type 7488. Whole-genome sequencing was used to match clinical isolates to a cheese sample and to samples from numerous sites within the production environment.

USA – Sources of Foodborne Illness Report Released – IFSAC

Click to access P19-2018-report-TriAgency-508.pdf