Look Before You Leap! Poison may be in the Can.



Right from time when bread was produced from wheat and wines from grapes planted around the Nile River in the ancient Egypt, food processing and packaging has continued to punctuate human development.

In our today's society, processed food has become a common denominator in every home, ranging from stock cube (popularly known as maggi) to noodles, tomatoes, soft drinks, beers, juice etc, such that no human in this 21st century can proudly attest to have not consumed processed food, rather the food Scientists, Technologists and Engineers have continued to excite our taste buds with foods of different flavours, aromas, colours, textures and other organoleptic properties as the day goes by.

What we now have as canned foods was invented by Nicholas Appert, a French confectioner and Food technologist in 1810 when he patented the preservation of food in bottles for soldiers and it became one of the most potent in extending the shelf life of foods for long distance distribution. As we speak, many solid and liquid foods have been bottled or canned for our consumption with so much thanks to Appert.

This canning process involve the cutting of the metal to shapes, inside and outside coating of the metal to prevent reaction with food, moulding of can, filling of the foods and seaming of the can to give an hematic closure (barrier against ingress of air and water vapour).

Finally, the can filled with food is then heat treated  and irradiated to inactivate all pathogenic and spoilage organisms to make the food attain commercial sterility.


Although, the aseptic production and distribution of processed foods are in the exclusive domain of food professionals, it is important for us to meticulously observe for the following when purchasing and consuming canned or bottled foods;

1. Do not buy bloated canned foods i.e canned foods with swelling sides or tops.  This shows that microbial spores or cells may have escaped heat treatment, causing the can to swell with C02-- a by-product of metabolism.

2. Do not buy deformed canned foods as deformation can remove the tin or chromium that is used in coating the inside of the can, making the food to react with the metal. This may cause food poisoning.

3. Do not buy over filled drinks i.e drinks filled to the brim .This is because the head space is for CO2 which create anaerobic condition in the packaging system and help in preserving the drink.

4. Do not buy under filled drinks as it result from machine error. The product constitute defective products.

5. When opening a bottled product, observe if there is evolution of C02 with great pressure. If absent, please do not drink as this is caused by wrong capping of the crown and can lead to food spoilage.

6. During the purchase of canned foods check for observable holes or cracks within the can. If found, do not buy as the wholesomeness of the food product has been truncated.

7. Finally, always check for the expiry date or 'best-before' date of food before purchase. The difference between these two dates will be discussed in a subsequent article.

Enjoy your day and when next you go shopping for food stuffs , never forget to thank Food  professionals the world over whose fingers and intellect have crafted the different processed foods all for your eating pleasure.


Samuel Adatang


Medicine and Surgery


Samuel Adatang