Probably applies to other countries from the global South and North respectively
My grandmother says: Food that has been warmed twice should not be warmed again.
And her son, my dad, used to store even canned food in the fridge.
Especially milk and milk products are moved directly from the shopping basket into the fridge, and I remember that my dad sometimes used to go even with a cooler box to do the groceries, in order to keep the stuff cool on the way home from the supermarket.
I got to know that in order to keep food fresh, you need to keep it cold.
But in Kenya I learned that the opposite way works just as well. My in-laws have cows which they milk once or twice a day. Whenever my mother-in-law gets a cup of freshly drawn milk, she uses two thirds of it for tea. She boils it with water and adds tea leaves and lemon grass. The rest goes just as it is into a five litres container that used to carry cooking oil. Now it is her storage for milk. She doesn’t have a fridge. She sometimes even puts the container in the sun. Then she thoroughly shakes it. This way she makes the milk ferment.
She uses that kind of sour milk for the preparation of indigenous vegetables. They are leafy greens that are fried with onions and tomatoes and then the milk is added.
When I make spinach in Germany, I take the leaves and the cream from the fridge. In Kenya, it is actually the same concept, only that the leaves and the thick sour milk are boiled for several days. That makes them very soft and creamy.
When I have some left-overs of food here in Nairobi, I don’t put them in the fridge (simply because I don’t own one).
I will boil it over and over again. This doesn’t only make it last, but mostly also enhances the flavours.