Q: "I often cook up a big batch of soup, freeze the leftovers and heat it up in the microwave when I’m ready to use it. Are nutrients lost in this process?"
Marie Caires-Forlano, via email
A: Dietitian Vered Moses replies:
“In a word, yes. Vitamin C is very sensitive to heat and light, so is most likely to be destroyed by cooking, freezing and reheating. Some B vitamins, such as thiamin and riboflavin, may also be lost. But don’t throw it out yet – not all nutrients are lost, and your reheated, homemade soup is still likely to be much more nutritious than takeaway from your local fast food joint! And a note on the microwave – they get a bad rep, but it’s thought that the ‘dry’ heat and short cooking time required might be more beneficial for retaining nutrients than some more traditional, slower methods of cooking. So you’ve made a great reheating choice!”