How can someone tell the difference between usable and non-usable protein? Is there a chart anywhere saying what is and isn't?

It's more a measure of the amino acid constituents.
Animal proteins are made of an amino acid composition that is similar to what we need...being animals.
Vegetable proteins are not balanced well for humans but they can be combined to complement the weaknesses of one vegetable with the strengths of another.
For example neither rice nor bean protein is particularly "useable" but rice and beans TOGETHER will easily support life with a much more nearly balanced and "useable" composition of amino acids.

Same with wheat and legumes.

Probably the most useable proteins are those in egg and milk, because both are geared to provide a perfect balance to totally support growth with no other protein source.

THe usual standard is to measure the NPU (net protein utilization which pretty much runs from near 100(%) for completely useable to the low 30's for some grains and down near 0% fpr some one ot two amino acid proteins like gelatin.

Of course, any protein in excess of what the body needs is either burned or converted to fat no matter HOW "useable" it is.

Some new research is showing that this "balancing" is not as important as previously thought.

Proteiun supplements on the market today have a very high NPU whether soy or whey or casein based. Soy is the most balanced and useable protein in the vegetable world.

I looked for a good list online but there is too much clutter from health food stores sellingg stuff. Maybe you can be more persistent than I.

For example neither rice nor bean protein is particularly "useable" but rice and beans TOGETHER will easily support life with a much more nearly balanced and "useable" composition of amino acids.

do they have to be eaten together, or in the same meal, or how much time between, or do the proteins linger in the body until they can be used with the others?

Proteiun supplements on the market today have a very high NPU whether soy or whey or casein based. Soy is the most balanced and useable protein in the vegetable world.

is there an NPU count on the nutrition facts labels of foods or products?

and thank you for looking for a list. i too looked and couldn't find any.

At the same meal is the best idea so that the component amino acids are absorbed near the same time. It's easy to do because there are so many dishes built around the idea. Even a cracker with peanut butter is a good example. But rice and beans is the world's standard.

Nope, no NPU required for the protein on a nutrition label.
If you think
Animal: high NPU (except gelatin)
Soy good NPU
Other vegetable proteins: Low NPU
You won't go far wrong.

Here's something from Franco Columbu (former Mr. Olympia) that might be of limited use:
Food NPU
Eggs 88%
Fish 78%
Dairy products 76%
Meat 68%
Soybeans 48%
Natural brown rice 40%
Red beans 39%
Coconut 38%
Nuts 35%
White beans 33%
Maize 25%
Whole wheat bread 21%
White bread 20%

sweet, yeah, right now i'm big on

eggs
fish
beans
soy
health bread
milk
nuts
granola
pasta
noodles

i read somewhere that i should be getting near 100 g of protein per day if i work out pertaining to my weight. is this correct?

Smith,

SInce you didn't tell me your weight, your age or your sex, there's no way for me to tell.:D:D:D

But 100 grams is certainly safe with a good safety margin for anyone but Franco Coumbu in training...YEARS ago!:D:D Don't go much over that because you don't want to be using too much protein as fuel.

21
male
130 pounds

highly active.
and why is too much protein as fuel bad?

Amino acids that make up protein contains nitrogen. WHen protein is burned the nitrogen forms poisons that must be excreted as ammonia and urea compounds. The body can handle small amounts but too much is extremely hard on the kidneys and other organs.
Protein is well designed to reconstitue lean body mass but poorly designes as fuel. The ideal fuel is carbohydrate which "burns clean." Fats can be completely burned UNLESS there's an absence of carbs and then fat leaves acidic wastes of aldehydes and ketones.
But protein can never be completely burned.

A hundred grams of protein will get you some good muscle mass with good workouts.

where do you learn all this stuff?

and i think i have a hard time getting that much protein in a day while staying low in fat. the thermic effect of food always holds me back from eating meats.

you know those protein shake powders that they sell at health food / workout stores? what percent usable protein are those drinks that they make? someone told me it's low.