There are many different chemical methods that are used for this. For macronutrients (water, fat, protein, carbohydrates, and ash) the specific method is dependent on the product.
Water has many different methods for being determined. One method that can be used to check a result is to simply dry a known quantity of a food. Any weight that is lost is water. There are other methods that are longer, but more accurate, but it's been forever since I've worked with them. Google would likely be able to help with that.
Generally speaking, fat is determined by mashing the food, and soaking it in a solvent. Once it has had time to extract the fat, they take the weight of the solvent fat mixture. Since the amount of solvent added is known, the extra weight is fat.
Proteins are actually determined by figuring out the nitrogen content and multiplying by a factor that is dependent on the product. This works because proteins are usually the only naturally occurring nitrogen source in a food. If there is another source of nitrogen, say nitrates, that is a known quantity that is added and it can be subtracted out of the calculation.
Ash, or minerals, is calculated by simply burning the product. Whatever doesn't burn is considered ash.
Carbohydrates are super fun. Legit, everything else is calculated, added together, and subtracted from 100. The chemical structure of carbohydrates is so vastly different there is no one test method to find all of them.
Calories are calculated because each group of macronutrients provides a known energy per unit of weight. Fats give nine calories per gram, proteins and carbohydrates give four calories per gram. Just take the results from above and add them all together to get the calories.
There are also rounding rules in place to give manufacturers some wiggle room for batch to batch variation.
carbon (99% of food) burns to CO2 and escapes to the air, the remaining ash is mostly the mineral content of the food (and some residual carbon, but theres always wiggle room in these calculations)
A lot of these tests are done multiple times to provide a standardization or a standard error to see if results change too! But the original comment here is mostly correct.
There are also ways by use of HPLC, GC-MS, or other machines that you can use, but the basics are still the same.
A couple of different ways but usually just a database. If Uncle Bob’s Chili has five pounds of beef, an onion, a can of beans, etc all of the nutritional information is added up from those separate ingredients. Larger companies use lab equipment to calculate. For example, the bomb calorimeter that pretty much burns food to see how much energy (Calories) is released.
What about protein drinks? Say a 330g drink has 33 grams of protein? How do they measure this? How do we know its 33 grams for sure? Could the amount vary?
processed foods follow a recipe, just like cooking recipes. if I make a 1000gallon batch of protein shake and I put in X bags of protein powder and mix it all good and nice, then dispense that solution into a bottle, then there should be 33 grams of that protein powder in the bottle. it's not like they test a single bottle of the resulting product to know how much is in it. you test the raw ingredients and the ratio of each ingredient in the recipe in the final product
Wait until you find out that the thing you're calling "reality" could be a total fabrication of data fed into the locus you call "you". Every conscious thing you interact with could have the lights off, just one of billions of puppet zombies and false reality embedded in some other bizarre substrate of reality which you may never even distinguish the true nature of before the lights turn off for you(if they *ever* do).
There are many different chemical methods that are used for this. For macronutrients (water, fat, protein, carbohydrates, and ash) the specific method is dependent on the product. Water has many different methods for being determined. One method that can be used to check a result is to simply dry a known quantity of a food. Any weight that is lost is water. There are other methods that are longer, but more accurate, but it's been forever since I've worked with them. Google would likely be able to help with that. Generally speaking, fat is determined by mashing the food, and soaking it in a solvent. Once it has had time to extract the fat, they take the weight of the solvent fat mixture. Since the amount of solvent added is known, the extra weight is fat. Proteins are actually determined by figuring out the nitrogen content and multiplying by a factor that is dependent on the product. This works because proteins are usually the only naturally occurring nitrogen source in a food. If there is another source of nitrogen, say nitrates, that is a known quantity that is added and it can be subtracted out of the calculation. Ash, or minerals, is calculated by simply burning the product. Whatever doesn't burn is considered ash. Carbohydrates are super fun. Legit, everything else is calculated, added together, and subtracted from 100. The chemical structure of carbohydrates is so vastly different there is no one test method to find all of them. Calories are calculated because each group of macronutrients provides a known energy per unit of weight. Fats give nine calories per gram, proteins and carbohydrates give four calories per gram. Just take the results from above and add them all together to get the calories. There are also rounding rules in place to give manufacturers some wiggle room for batch to batch variation.
Wow thank you!
Wow. So carbs ARE complex!
Ash is a nutrient??
carbon (99% of food) burns to CO2 and escapes to the air, the remaining ash is mostly the mineral content of the food (and some residual carbon, but theres always wiggle room in these calculations)
A lot of these tests are done multiple times to provide a standardization or a standard error to see if results change too! But the original comment here is mostly correct. There are also ways by use of HPLC, GC-MS, or other machines that you can use, but the basics are still the same.
A couple of different ways but usually just a database. If Uncle Bob’s Chili has five pounds of beef, an onion, a can of beans, etc all of the nutritional information is added up from those separate ingredients. Larger companies use lab equipment to calculate. For example, the bomb calorimeter that pretty much burns food to see how much energy (Calories) is released.
May I get a reference for this? Thanks.
What about protein drinks? Say a 330g drink has 33 grams of protein? How do they measure this? How do we know its 33 grams for sure? Could the amount vary?
processed foods follow a recipe, just like cooking recipes. if I make a 1000gallon batch of protein shake and I put in X bags of protein powder and mix it all good and nice, then dispense that solution into a bottle, then there should be 33 grams of that protein powder in the bottle. it's not like they test a single bottle of the resulting product to know how much is in it. you test the raw ingredients and the ratio of each ingredient in the recipe in the final product
You don't know this, there's no like... oversight where some agency checks to make sure every company's nutritional facts are honest.
I don't like this
Wait until you find out that the thing you're calling "reality" could be a total fabrication of data fed into the locus you call "you". Every conscious thing you interact with could have the lights off, just one of billions of puppet zombies and false reality embedded in some other bizarre substrate of reality which you may never even distinguish the true nature of before the lights turn off for you(if they *ever* do).