How many vitamins do frozen veggies lose by boiling?

I had my freezer full of frozen peas from back when my husband had broken foot and he used the bags to chill his swollen foot. I ran out of vegetable baby jars for my kid and I saw these bags in a freezer so I decided to boil them, then mash them and then use a hand mixer (I dont own a food processor) and try to puree it and put it in baby containers. My son ate it, he didnt mind it was chunky. I wonder how many vitamins is left in it after like 5 or 10 minutes of boiling or should I keep buying baby food (gerber, del monte, beach nut etc.) in the store?