Some people who use front-loading washing machines wash their clothes only to find that their clothes are covered with black mould from the gasket in their washing machine. This is a common problem with front loading machines. The moisture and warmth from the machine promotes the growth of mould spores on the gasket. The same problem can occur on your refrigerator gasket. The solution is to remove the mould. You can do this with three different cleaning solutions: hydrogen peroxide, bleach or WD-40.
Fill a spray bottle with hydrogen peroxide, and spray it on the mouldy gasket. Leave the spray on for five minutes. Wipe off the mould with a dry cloth. Wipe the gasket with a damp cloth to remove the hydrogen peroxide.
Pour one part bleach and two parts water into a spray bottle. Spray the solution on the mouldy gasket, and allow it to set for five minutes. Wipe away the mould with a dry cloth. Wipe the gasket with a wet cloth to remove the bleach.
Spray WD-40 on the mould, and let it sit for five minutes. Wipe off the mould with a dry cloth. Clean off the WD-40 with a damp cloth and a mild cleaning solution like water and vinegar.