Why is it Safe to eat Raw Beef?

July 24, 2015 / Food / 0 Comments /
why is it safe to eat raw beef

Nothing beats a medium rare steak – its soft, juicy and simply delicious (to me anyway). Perhaps medium rare isn’t your thing, but there is nothing wrong with eating steak medium rare – still raw on the inside. People eat barely cooked beef everyday, and no one bats an eyelid. Say you want a medium rare pork chop, or ‘pink’ chicken breast on the other hand, and people gasp, shake their head and say ‘you can’t do that!’ They are right of course, but why is it safe to eat raw beef (and raw lamb for that matter), and not raw pork or chicken?

 

Food poisoning

All food comes with a risk of food poisoning to some extent, even salads. Truth is raw beef is only safer than eating raw pork/ chicken, and there still is a risk of food poisoning, just to a lesser extent. So the real question should really be why is raw beef less likely to give food poisoning than raw pork or chicken?

 

Bacteria

Beef meat is very dense, more dense than chicken or pork. In fact, beef is so dense that bacteria cannot penetrate beyond the surface. This means that as long as the surface of the beef is cooked properly there is an incredibly small chance of food poisoning. However, the skin of raw beef often does contain common pathogenic bacteria such as E. coli, which if not killed by cooking, can cause illness.

There is evidence that certain strains of bacteria can break down muscle fibres of meat, and penetrate the meat after 36 hours of being at room temperature. This shows that although fresh or chilled beef might be ok to eat raw rare, any beef which has been left out for any length of time should be thoroughly cooked! Even if the meat is left out less than 36 hours, the meat will not have been instantly chilled in the butchers, and would have most likely already spent some time at room temperature, allowing the populations of these bacteria to grow. Play it safe, and keep your beef in the fridge until you want to eat it.

ParasitesPicture of a parasite in larval stage. This parasite is often found in pork, but not in beef.

Beef is rather low in parasites, whereas other meats (pork in particular) can contain some nasty parasites such as Trichinella spiralis (sometimes known as ‘pork-worm’), Taenia solium (tapeworm) and Toxoplasma gondii. Despite food hygiene getting better and better, these parasites will still likely be present in the meat, and so pork needs to be cooked right through to avoid infecting yourself with these parasites.

Beef doesn’t contain these parasites and this is because cows have a much more complex digestive system compared to chickens and pigs. The cows digestive system might be too hostile for these parasites to survive. Also, pigs are scavengers, and eat pretty much anything, whereas cow (and sheep) are more fussy, and just like eating grass. With pigs eating anything and everything, they have a much higher chance of picking up parasites.

 

Is raw beef ever not safe?

It is safest to eat a cut of rare beef, such as a steak, rather than a processed food product such as a burger or minced beef. The reason for this is that a steak will have come from one cow, and the chances of this cow having a disease is very low. However, processed beef products contain many many cows. If just one of these cows is contaminated, it will contaminate the entire batch of mince. The chances are still low that beef mince will cause food poisoning, but not as low as eating steak.

 

Summary – why is it safe to eat raw beef?

Raw beef and lamb are safe to eat because the meat is very dense, and bacteria struggle to penetrate the surface. If the surface is cooked, then the middle should be safe to eat raw as long as it hasn’t been sat out at room temperature for a long time. Beef and lamb are also unlikely to contain any parasites due to their complex stomach system and fussy eating habits, whereas pigs are almost guaranteed to contain parasites.


Can Babies Eat Strawberries?

March 27, 2015 / Humans / 0 Comments /

Babies can eat strawberries, but you must be careful because young babies may have an allergic reaction to them. The general recommendation is that you shouldn’t give strawberries to babies under the age of 6 months. Beyond 6 months, they can slowly be introduced, perhaps as strawberry purée or very small chopped up pieces.

 

Why are babies allergic to strawberries?

It seems odd that such a delicious and natural food is a common allergen in babies. However, strawberries contain a relatively large amount of a chemical called histamine. Histamine is a chemical which stimulates our immune system, particularly the inflammatory response, and babies are particularly sensitive to it.

You may have heard of histamine (or more likely anti-histamine) in the context of hay fever or pet allergies. This is because pollen/ pet hairs trigger the release of histamine in our body – causing puffy faces etc. An anti-histamine inhibits the action of histamine, which reduces the symptoms. It is not recommended to give babies anti-histamines though.

Typical signs of an allergic reaction to strawberries are itchy/ red skin (similar to hey fever), which are typical responses to inflammation.

When is best to introduce babies to strawberries?

can babies eat strawberries?The advice for preventing food allergy in infants is to delay introduction of potentially allergenic foods (e.g peanuts) until 3 years of age. However, this advice was based mainly on expert opinion and not evidence-based research.

In fact, delaying exposure to foods which commonly trigger an allergic reaction can actually increase the risk of developing an allergic reaction to that food later in life. Now, recent research suggests that early introduction of potentially allergenic foods at 4 to 6 months of age might actually provide a form of protection and help prevent an allergy, but scientists admit that more research is needed.

So, from the research there is still no clear answer, although it looks like the best time to introduce small amounts of strawberries is shortly after the 6 month mark. This way the introduction is within current guidelines to minimise risk of a reaction, but is still early in the babies life, which can help prevent the baby developing an allergy later in life.

When you do introduce strawberries be sure to keep an eye out for symptoms of a possible allergic reaction, such as puffy or itchy skin.

This Youtube video will give an overview of the information found on the article tab. If you want to know more about the topic, or want to see where the information came from, have a read of the article after you watch the video.

Yes, but strawberries are a common allergen to babies. Current guidelines for introduction are around 6 months.


How Long can Pizza Sit Out?

March 1, 2015 / Food / 0 Comments /
How long can pizza sit out for?

We have all been there – eyes bigger than your stomach when ordering pizza, resulting in a good few slices left over. You can try and cram it all in your stomach but sometimes it gets the better of you, and you have to face defeat until the morning. You put the pizza back in the box, and slump off to bed into a 12 hour pizza coma, and maybe before you drift of to sleep you wonder how long pizza can sit out for before it goes off…

 

What the experts say

According to the United States Department of Agriculture (USDA) you shouldn’t eat pizza which has been left out over 2 hours. This is because beyond this point the bacteria population can double every 20mins, meaning that the risk of getting food poisoning is greatly increased. Your left over pizza is ok to eat the next day however, if you have put it in the fridge once you have stopped eating it.

You would like to think that the USDA know a thing or two about food, and although they do get some things wrong, they shouldn’t get something as simple as rate of bacteria growth wrong, right?

Well they are right. Using E.coli as an example (because it is a pretty common food borne pathogen), it takes 15-20mins to double its population. So it looks like 2 hours is the limit in the eyes of the experts.

 

many people leave pizza sat out overnight and eat it the next day.Anecdotal evidence

Generally speaking, research will trump the anecdote every-time, but the experience of the population cannot be ignored. Doing so would be bad science!

Time and time again the lazy student, or forgetful pizza lover will leave a pizza in the box over night, and reheat what’s left for breakfast, or even lunch with no ill effects! I’ve been there a number of times myself (both as a student and pizza lover), so I know first hand that the pizza left over night can be fine to eat, and usually is.

So, despite the USDA’s recommendations, it look like pizza can sometimes sit out over night and still be fine.

 

So, how long CAN pizza sit out?

Truth is, there are a number of factors to consider aside from the length of time the pizza is sat out. You need to consider how much bacteria is on the pizza to being with, the temperature it has been left out for, and what toppings on the pizza (meat toppings are worse).

If you want to play it safe, then put your pizza in the fridge once you have finished, and you can eat it the next day. The recommendations say do this within 2 hours, but there will be some play in that really. Having said this, if you have gotten the pizza from a reputable pizza place (and so know it has been hygienically prepared/ cooked properly) then it will probably be fine for breakfast the next day if its left out, but any time after then and you are pushing your luck.

This Youtube video will give an overview of the information found on the article tab. If you want to know more about the topic, or want to see where the information came from, have a read of the article after you watch the video.

Officially, pizza shouldn’t be left out for more than 2 hours, but the risk of food poisoning from leaving it out overnight is very low, especially if you re-heat it properly.