I know winter purslane, as we usually put it in salads, especially with fresh vegs, due to its bitter taste it was good combine it with sweet chopped apples. It is really strange taste people can love it or hate it. But once you learn the taste in children's age then it is always that memory that comes immediately with taste. I have never tried it as part in my juices. May be worth to try but then do you use fresh young leaves for that.