Answer to Question #24428 in Molecular Biology for Mordy Grubin

Question

when milk spoils whats the most active chemical and its chemical name ?

Answer 1

Unrefrigerated milk spoils quickly. For example, for every 5°C rise in temperature over the ideal 4°C, the shelf-life is shortened by 50%. When serving milk during a meal, keep the container out just long enough to pour and serve, and return the unused container to the refrigerator immediately. Leaving the carton or bag of milk on your table for the duration of a meal is not recommended.
The signs of chemical change when milk turns sour are formation of a solid precipitate which is when it becomes hard. Gas bubbles are released as it spoils which is the odor as well.As for sour milk, bacterial action on milk produces lactic acid, which ruins the taste of fresh milk. This indeed is a chemical reaction.Lactic acid bacteria ferments the lactose in the milk turning it to lactic acid.