The freezing process causes ice crystals from water in the cells to break through cell walls. Although much of the flavor will be retained, the consistency will be mushier. Same thing for any fruit like strawberries, etc. A neat trick if you want peeled tomatoes for a sauce is to freeze them solid as a rock the day before. The next day take them out of the freezer and run a little hot water over them. Bang! The skins pop right off. Since it's for a sauce anyway the change in consistency usually isn't an issue.