Main content
pH and bacteria growth
The presenter and an expert discuss the pH scale and why some foods go off while others stay fresh. They look at a range of foods and demonstrate how bacteria, which cause the food to go bad, prefer a pH close to 7 or neutral. A substance with a pH of 3.5 or lower is acidic and kills the bacteria, keeping the food fresh. Manufacturers of food stuff use this knowledge to stop food going off.
Duration:
This clip is from
More clips from Materials and Their Properties
-
![]()
Neutralising acids and alkalis
Duration: 00:32
-
![]()
How neutralisation is used in diving apparatus
Duration: 03:22
-
![]()
Formation of an oxide
Duration: 03:01
-
![]()
Acidic, alkaline or neutral
Duration: 03:03
More clips from Science in Action
-
![]()
Neutralising acids and alkalis—Materials and Their Properties
Duration: 00:32
-
![]()
Why do you feel lighter in water?—Physical Processes
Duration: 00:46
