Mould, the consumer and the retailer

Many searchers of this blog have asked "Will spoiled food make you sick?"  I have commented on this before.

Over the last few weeks, I have purchased two blocks of cheddar cheese from a large supermarket chain in New Zealand.  When they were opened, both blocks were found to have a few mould colonies growing along the edges and at the corners.  This became apparent when the plastic film was peeled back.

Do these mould colonies represent a health hazard?  According to Dr. John Pitt, Aspergillus flavus is unable to produce aflatoxin at refrigerator conditions, so it is unlikely that there is a health hazard if the cheese is eaten.  I just cut the mould off, together with a bit extra to avoid eating cheese with changed flavour resulting from the mould growth. 

My wife, who is obsessed with "food going out of it's date stamp" suggested that the cheese might be old,  ("Well, that's why you buy mature cheese, dear"), but the best-before date stamp was mid-2013.

I wrote, complaining to the supermarket chain and pointing out that there were probably only two reasons  that these blocks of cheese could have had mould growth inside the pack - the cheese was packed under poor hygiene conditions in which mould spores were able to contaminate the block, and maybe the film had been pulled too tightly at the edges and corners, increasing the gas permeability and allowing air to penetrate the pack to allow the strictly aerobic moulds to grow.

No harm, no foul you might say.  But the consumer is entitled to buy safe, wholesome food and to have mouldy cheese only when mould is part of the normally accepted description of the cheese, such as Brie, Camembert and Roquefort.  Cheddar is not mould-ripened.

What I found interesting about this, besides the technical issue, was that the supermarket chain completely ignored my complaint, not even sending some sort of "We are looking into it" brush-off.  Do they not care about consumer perceptions of their stores, or does this happen so often that they feel it is 'normal'?

Eat at your own risk?

I just spent a week in Miami attending the 6th American Society for Microbiology Biofilms Conference.  Over 400 biofilm microbiologists met to discuss all aspects of biofilm research.

Of course, nobody can sit in a darkened room and listen to heavy duty research papers all day for a week, and food microbiologists always have to investigate the local food and beverage outlets!

A couple of menus caught my eye.  One was on the waterfront in Downtown, where raw food seemed to be the major offering.  Another was in one of the glorious sidewalk restaurants on Ocean Drive.  Both had almost identical wording:
"Consuming raw or undercooked hamburgers, meats, poultry, seafood, shellfish or eggs may increase your risk of foodborne illness, especially if you have certain medical conditions".

All good, and if you want to eat such delicacies, you need to be informed of the risks.  Consumption of any of these foods can potentially lead to illness.  Consumers are totally dependent on the purity of the raw materials and the water from which they are sourced, as well as the hygiene of preparation; a range of bacteria and viruses can be found in raw foods.

I wonder what Bill Marler would have to say about such a disclaimer - is the restaurant owner absolved of responsibility, assuming they take reasonable care in preparation, if a customer can show that they became ill as a result of eating the raw or rare-cooked food?

Odd Spot - cause of my heartburn?

Sometimes the life of a food safety researcher can be fun.  (Well, actually it's nearly always fun).

Today I saw this interesting ingredient listed on a meat pie:

Look at the fourth line down.  Perhaps this is why I get heartburn when I eat meat pies.

Thank you!

I note that over the weekend, the cumulative number of page views topped 100,000.

It's very gratifying to see that Safe Food is read around the world and that there is such interest in food safety.

Thank you all for reading my blog; I'll try to keep it interesting and to provide comment on current food safety issues.  I guess the next target is the quarter million views mark.

J

Economic downturn no excuse for sloppy hygiene

Reporter Katie Chapman writes in the Dominion Post this week that some restaurants in Wellington are blaming their lapses in hygiene on the economic downturn.  The number of restaurants temporarily closed has more than doubled in the last six months compared with the average over the last five years.  In addition, one in five restaurants managed to achieve only the minimum standard.

Rodent and cleaning failures were the reasons given for temporary closures of all eight restaurants between February and July this year.  In most cases, the restaurants reopened within a day.  This suggests that the effort required to keep them clean and hygienic would not be very great if cleaning and self inspection were done on a daily basis.

Hard times are no excuse for sloppy hygiene, even if staff numbers have been reduced.  It's essentially the same argument sometimes presented against a requirement for food companies to have risk based food safety plans - "We can't be expected to have a food safety plan, we are only a small operation and we can't afford it".

My suggestion is "If you can't afford to keep your premises clean and rodent free, you can't afford to be in business;  if you cause a food poisoning outbreak, you'll pretty soon be out of business and looking for work somewhere else".

Listeria strikes in Hawke's Bay, NZ

The news service Stuff has reported that Listeria has caused one death and contributed to another between May and June this year in Hawke's Bay, New Zealand .  At this stage, two other people have been infected, but have recovered.  It is not clear where the infection came from, though there is circumstantial evidence that pre-packaged ready-to-eat meat may have been involved.

Investigation of this type of food poisoning is very difficult.  The great majority of the population will not become ill from exposure to Listera.  In the two deaths, the women were 60+ and 80+ respectively and both were apparently immunocompromised, putting them in a more susceptible group.  The infection can take up to a few weeks for symptoms to show, making it unlikely that patients can remember what they ate and even more unlikely that samples remain for testing.

Listeria is capable of growing at refrigeration temperatures, so cooked and ready-to-eat foods should be stored for only one or two days.  Of course, this poses a problem with salad vegetables, which are not going to be cooked before consumption.

The only real way to combat food borne listeriosis is to be very careful in handling foods, prevent cross contamination between raw and cooked foods, wash fruits and vegetables thoroughly and keep utensils, chopping boards and hands clean.

If you are at risk - pregnant, already unwell, immunocompromised, elderly etc. it is better to eat freshly cooked foods, pasteurised dairy products, canned foods, bread and baked goods without cream, cereals and beverages such as tea, coffee or beer, which have all been heated during production.

You can find more articles on Listeria in this blog by typing "Listeria" in the search box at the top left of this page.

Don't be an Alice

In Lewis Caroll's Alice in Wonderland, Alice found that taking a bite out of a mushroom would make her grow very tall; the other side made her shrink.  At one level, this is a childrens' tale, or at another it could be argued to be about taking hallucinogenic drugs.

Unfortunately, if you don't know what you are doing when it comes to eating mushrooms, you can wind up taking a different kind of trip - to the hospital or the mortuary.

There are many mushrooms (fruiting bodies of fungi) that can be eaten.  At this time of year in New Zealand, the mornings are often damp and we see mushrooms and toadstools popping up all over the place.  In my opinion, field mushrooms, Agaricus campestris, have a much better, stronger flavour than cultivated mushrooms bought from the supermarket.  They are a delight to collect and eat and I have spent many hours walking around our small farm searching for these delicacies.

But how can you tell if a mushroom is safe to eat?  My grandfather told me that you should cook them in cream and eat them on toast for supper.  If you woke up in the morning, they were edible!  This is NOT the way.  Neither is peeling and cooking a way of making mushrooms safe - the toxins of many poisonous fungi, such as the Amanitas are not destroyed by heating. 

The only safe way to know if a mushroom is edible is to have a good knowledge of their appearance and where they are found.  There are guides to help you identify mushrooms and toadstools, but to the untrained eye, many different species look the same.  If you aren't sure, don't eat!

Even the terminology is open to interpretation.  Strictly, the word ‘mushroom’ refers only to the genus Agaricus.  The cultivated mushrooms sold in the supermarkets are usually the white buttons of Agaricus bisporus, though we do see other varieties, such as the large browns. The word 'toadstool' is then used to describe any other fruiting body with a cap and stem that appears different from Agaricus, often implying that it is poisonous.

I took the following from an ABC report that followed the death this week of a Chinese visitor to Australia who appears to have eaten Death Cap (Amanita phalloides) toadstools:

History:

• Death cap mushrooms are considered the most poisonous in the world and one is enough to kill an adult human.
• At least six people have died and at least 12 made sick from eating death cap mushrooms in Australia in the past decade.
• Death caps have been involved in the majority of deaths around the world from mushroom poisoning, including that of Roman emperor Claudius.

Appearance:

• Death cap mushrooms are similar in appearance to several species of edible mushrooms commonly used in cooking, such as paddy straw mushrooms and Caesar's mushroom.
• Death caps may be white but are usually pale green to yellow in colour, with white gills and a white or pale green stalk up to 15cm long. (See image below from Wikipedia)
• The entire mushroom is poisonous and cooking or peeling the mushroom does not remove toxicity.

Symptoms:

• Death caps are said to taste pleasant and symptoms can occur six to 24 hours after consumption.
• Initial symptoms can include abdominal pain, diarrhoea, vomiting, hypotension and jaundice, followed by seizures, coma, renal failure and cardiac arrest.

Habitat:

• Death cap mushrooms can be found in parts of south eastern Australia, particularly ACT and parts of Victoria.
• They are commonly found near established oak trees and some other hardwood trees and are most common during later summer to early winter after heavy rain or irrigation.
• It is thought death caps were introduced to Australia with the importation of different hardwoods.

Treatment:

• Death caps are extremely poisonous and if consumed it is a medical emergency.
• Anyone who suspects they have eaten a death cap should seek immediate medical attention and where possible take a mushroom sample for identification.  

There are approximately eight toxins in A. phalloides, the major ones being α-amanitin and β-amanitin, which inhibit RNA polymerase.  This prevents protein synthesis, resulting in the death of cells.  The liver is usually the first organ to be damaged, often irreparably, and later the kidneys.

Picture of Amanita phalloides from Wikipedia:  http://en.wikipedia.org/wiki/Amanita_phalloides


Have a look at Peter Valda's comments on mushrooms and toadstools:

http://www.burkesbackyard.com.au/1997/archives/27/in_the_garden/gardening_tips,_books,_techniques_and_tools/mushrooms_and_toadstools