According to this site (worth reading)

http://www.glycoscience.org/glycoscience/start_frames.wm?FILENAME=C012

"Overall, fruits retain more nutrients if they are frozen rapidly,
stored in airtight packaging, and thawed rapidly.(1)  Damage during
storage is more common than damage during actual freezing or thawing."(2)

"Even though blanching (brief boiling) causes some losses of vitamins,
minerals, and saccharides, overall nutrient retention is higher
(sometimes twice as high) if vegetables are first blanched before they
are frozen." (2)

" Up to 45% of vitamin C is lost when vegetables are blanched;
unblanched frozen green beans lose more than 75% of their original
vitamin C after one year of freezing."(2)

"Fruits and meats are less vulnerable to vitamin C losses." (3)

"Minerals are generally stable to blanching"

refs:

(1) Skrede G;. Fruits. Jeremiah LE;. Freezing Effects on Food Quality.
New York, NY, Marcel Dekker, Inc.; 1996: 183-246

(2) Cano MP;. Vegetables. Jeremiah LE;. Freezing Effects on Food
Quality. New York, NY, Marcel Dekker, Inc.; 1996: 247-298

(3) Bauernfeind JC;Lachance PA;. Concepts and practices in nutrifying
foods. Bauernfeind JC;Lachance PA;. Nutrient Additions to Food.
Trumball, CT, Food and Nutrition Press, Inc.; 1991: 19-86

The cell walls of anything frozen become exploded when the liquids expand.

There are some studies done about this. I remember that some
phytochemicals in some berries are almost unaffected when frozen,
whereas some phytochemicals of other berries are partly distroyed
(about half of them). I think that this applies also to fruits; some
fruits might stand freezing better than others. Still I think that
freezing is the best method of conserving foods.

Jan