Young Brunette Girl Undresses Her Yellow Top And Short Jeans On The Floor With Many Fruit And Vegetables

The red/blue coloring of some fruits and vegetables (e.g., blackberries and red cabbage) are due to anthocyanins, which are sensitive to changes in pH. When the pH is neutral, the pigments are purple, when acidic, red, and when alkaline, blue. These pigments are quite water-soluble. This property can be used in rudimentary testing of pH.
Safety
For food safety, the CDC recommends proper fruit handling and preparation to reduce the risk of food contamination and foodborne illness. Fresh fruits and vegetables should be carefully selected. At the store, they should not be damaged or bruised and pre-cut pieces should be refrigerated or surrounded by ice. All fruits and vegetables should be rinsed before eating. This recommendation also applies to produce with rinds or skins that are not eaten. It should be done just before preparing or eating to avoid premature spoilage. Fruits and vegetables should be kept separate from raw foods like meat, poultry, and seafood, as well as any cooking utensils or surfaces that may have come into contact with them (e.g. cutting boards). Fruits and vegetables, if they are not going to be cooked, should be thrown away if they have touched raw meat, poultry, seafood or eggs. All cut, peeled, or cooked fruits and vegetables should be refrigerated within 2 hours. After a certain time, harmful bacteria may grow on them and increase the risk of foodborne illness.