Good Bacteria in Food

Written by Dr. T. M. Wassenaar Tuesday, 08 March 2005

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Most people would think bacteria in or on food can only be harmful. True, food poisoning caused by bacteria and their products is a serious problem, and how to ensure food safety is treated in a different exhibit. However, certain bacteria are safe in food, and are required for the desired taste and texture. This exhibit describes some of the applications of bacteria and their products in the food industry.

Bacteria are commonly used in dairy products. Sour cream and Creme fresh (make your own! Creme fresh are both the products of cream after bacteria were allowed to grow in it. The difference in flavour, texture, and behavior (sour cream will curdle when heated, creme fresh will not) all result from the differences in bacteria required to produce the two products. Buttermilk is low in fat and cheese comes many variations. Yogurt is probably one of the oldest forms of fermented milk.
Is it dangerous to eat food containing bacteria? Certainly not, as long as they are the right kind of bugs. It may even be benificial to eat diary products with living cultures, although the evidence is still controversial. True or not, fermented milk products are often suitable for people with a lactose intolerance though the product should not be heated after fermentation.
Fermented milk products are not completely fluid because casein, the major protein in milk, is insoluble in acid. Casein is also the protein that makes cheese solid. Fermented diary products taste different due to the bacteria used to make them. So what kind of bacteria are used for the many different diary products that exist? Most manufacturers will not release their magical strain of bacteria, producing just the right flavour, but here are their general characteristics:

Vegetables can be fermented too. Read about an ancient tradition. For instance, bacteria are the working lot to produce sauerkraut. The word 'sauerkraut' is German and means sour cabbage. And that is what it is: finely cut white cabbage leaves, left fermenting by lactic acid bacteria. Believe it or not: kraut only contains cabbage and salt. It doesn't taste salt because of the acid produced by the lactic acid bacteria, and the salt prevents fouling bacteria to grow. The bacteria used for sauerkraut is Leuconostoc mesenteroides. The same principle is used with  pickling other foods, such as onions, olives, or meat. Almost always do lactic acid bacteria their little jobs to 'pickle to perfection'.

Have you ever thought that bacteria were used to produce chocolate and coffee? Although bacteria are not present in the final products containing chocolate (providing a bit of history on the black stuff),  bacteria help fermeinting choclolate beans and so helps create its taste. Chocolate may not even be bad for you but just don't overdo it.

Another example of bacteria helping to produce food products is vinegar. Whether good or bad depends on what the product should be. Wine makers will do their best to inhibit Acetobacter ferminting their grape juice: in order to produce wine, yeast should grow but not bacteria. However, if the desired product is vinegar, bacteria have their chance. Read more about wine and vinegar making in our special feature file.

Fermenting bacteria are used in the production of sausage. This time, lactic acid bacteria and Pediococci do the job. Fermentation of sausage. Don't worry, you can still enjoy your meat snacks since bacteria used in sausages are not at all related to E. coli or Salmonella, the enemies of every butcher. In fact, lactic acid bacteria are able to kill Listeria, a newly discovered ability that supports the safety of cured meats.

And, finally, if you want to be active yourself, get started!


Last Updated on Sunday, 01 March 2009