copy the content to a string variable and then use trim method to remove unwanted spaces from either side of the string.
Note that trim will not remove whitespace chars inside the string between words.
I hope it helps.
If you want to remove the spaces from the middle of the string too, you can use the replaceAll method of String class with a regex like \s to replace all the space characters with anything that you like. This method would be a little slow if you want to update all the records. You should try a bulk update query specific to your database to achieve that...