Salt was already used as a preservative for food in the Neolithic Age. Meat is still salted today to keep for longer periods without refrigeration. But even in modern times, salt finds its practical application for preserving fresh food.

Milk only keeps fresh for a few days in the fridge once the carton has been opened. If you add a pinch of salt to the milk, it will keep fresh for almost twice as long. 

Cut apples, pears and potatoes quickly turn brown when exposed to the air. If you dip the freshly cut fruit slices briefly in lightly salted cold water, they will retain their beautiful fresh colouring for longer.

Fresh greens often contain soil. The leaves can be cleaned thoroughly by soaking the vegetables in cold salt water for a few minutes and then rinsing them thoroughly. This also keeps the green leaves fresh and crisp for longer.