Bacteria are one-celled organisms. They produce one or more kinds of acid as by-products of their metabolism.
Some bacteria are used in making fermented foods; most of these bacteria produce lactic acid. It is the lactic acid which gives most fermented foods its taste. One example of a fermented food is yoghurt. If lactic acid producing bacteria are added to milk, they use the sugar in milk for food and make lactic acid as a by-product of their metabolism.
The lactic acid grows in the milk, making it taste sour and causes it to become thicker. It gets thicker because the proteins in milk denature and coagulate, giving a custardy texture to the milk. When this occurs, the product is called yoghurt.
We will look up and discuss these key words on Monday:
bacteria, texture, denature, coagulate, custardy, metabolism, fermented, lactic acid, by-product, one-celled organism, acidic, yoghurt
You might like to discuss the last two postings with family and friends over the weekend. Maybe you could have a look at the ingredients in a pottle of yoghurt and the nutritional value of yoghurt. Be prepared to discuss your findings on Monday!
No comments:
Post a Comment