Not software, but you can use several on-line databases where you enter the ingredients, either separately or as a "meal" or "recipe" and it gives you the basic (or extended) nutrient breakdown.
From the breakdown, you can then convert to blocks.
SparkRecipes.com (SparkPeople) - http://recipes.sparkpeople.com/recipe-box.asp
SparkPeople - enter food recipe as a meal, and you get full nutrient breakdown.
Zone calculator - http://www.formulazone.com/Help.asp...D=MDSearch
USDA Food Composition - http://www.nal.usda.gov/fnic/foodcomp/search/
Nutrition data - http://nutritiondata.self.com/
With most, you have to subtract the Fiber from the Carbs to get net Carbs.
All that require registration are free.
Spark People & related Spark Recipes appears to be the most comprehensive!
I can not find some "alternate" ingredients in most of the other websites,
like "Ground Flax Meal" & "Coconut Flour".