Cold Cooking !!!

Throughout my years cooking in Ireland I encountered quite a lot of customers who would send back marinated fish dishes such as the ”mackerel” recipe that I posted on my blog, complaining that it was raw.
I always ask myself why is this. I decided then to go to have a talk with such customers to try to find an answer to my questions. I realised then that for them cooked food meant that the ingredients have been exposed to heat. This is not a misconception of the word cooking but meat, vegetables or fish can also be cooked without heat.
First of all let’s define the action of cooking. The Oxford dictionary says : “prepare by mixing, combining and heating the ingredients” or “be heated so that the state required for heating is reached”. But for the cook, cooking has two objectives, make the food easier to digest and create new flavours. For the scientist/cook, cooking means breaking down of proteins and chemical reactions.
What are the effects of heat on ingredients like fish or meat in a recipe. Heat will tenderise tough molecules and start chemical reactions that will create new aromatic compounds.
The molecule that makes meat or fish tough is called collagen. Women would be quite familiar with this type of protein as it is widely used in cosmetics. This protein constitutes a third of all animal protein. Collagen can be broken down by heat therefore making meat or fish easier to chew and digest.
But protein can also be broken down with acid such as vinegar,lemon juice or acidic compounds in wine. This will happen without heating by just placing the ingredients in a marinade for some time. So a fillet of fish placed in a marinade will be cooked with the acid in the mixture.
I came to the conclusion that the customers were mainly worried about food safety. And there are right to be concerned about it. One of the most important things is the freshness of the produce.
But there is another way of ensuring food is safe without using heat and this is where food science kicks in. The acid in a marinade acts as a preservative and there are very few strains of bacteria that would live or survive in an acidic environment. Pickles are a good example of the preservative effect of acids. Another example is ascorbic acid, more commonly named Vitamin C, is naturally present in lemon juice. The food industry make good use of this preservative, you can find it very often on food packaging under the number E300.
So feel confident, try marinated fish or meat dishes.