How foods are produced, processed, fermented, cured and manufactured, and what those processes change.
Raw yellowfin tuna provides about 109 calories, 24.4 g protein, 0.5 g fat and 45 mg sodium per 100 g. A USDA canned-light-in-water reference has 86 calories, 19.4 g protein, 1 g fat and 247 mg sodium. Canned light tuna in oil can approach 198 calories and 8.2 g fat even after draining.
Canned sardines with bones are calcium-rich because you eat the fish's skeleton. A USDA-derived reference contains about 382 mg calcium per 100 g; an 85 g serving is roughly 325 mg. Pressure and heat soften the small bones enough to chew, but they do not create new calcium.
Cottage cheese and ricotta look similar in a bowl but are structured differently. A 2% cottage product can provide much more protein for the same calories, while whole-milk ricotta brings more fat, richness and a smoother filling texture.
Hard Parmesan contains roughly 35–36 g protein per 100 g, more than ten times the concentration in milk. Aging does not create new protein: curd formation, pressing and months of moisture loss concentrate the casein and other milk solids that remain in the cheese.
Plain skyr can pack a large amount of protein into a small cup. Icelandic Provisions Plain Skyr currently provides 17 g protein, 120 calories, 2.5 g fat and 3 g sugar per 150 g—about 11.3 g protein and 80 calories per 100 g.
Cottage cheese can deliver close to 20 g protein in one small cup. Good Culture 2% provides 19 g protein, 130 calories and 3 g fat per 150 g; its 4% whole-milk single serve also provides 19 g protein but 140 calories and 6 g fat. Sodium is often the number worth checking alongside protein.
Calcium in many plant milks is added during manufacturing rather than coming mainly from the diluted almond, oat or soy itself. Current Silk examples range from 300 mg calcium per cup in unsweet soy to 470 mg in unsweet almond. Fortification can make calcium substantial, but it does not make every other nutrient equivalent to dairy milk.
Textured vegetable protein is usually defatted soy flour turned into dry porous pieces. A plain current product provides 12 g protein and 4 g fiber per 23 g dry serving; hydration changes weight, not total protein.
Sourdough and whole grain describe different things. Sourdough refers to a fermentation method; whole grain means the grain kernel retains the bran, germ and endosperm. A loaf can be white sourdough, whole-grain yeast bread or whole-grain sourdough. For fiber and grain nutrients, flour composition comes first; sourdough adds fermentation-related changes such as acidification and possible reductions in phytate and fructans.
Nutritional yeast is yeast that has been grown, inactivated and dried for use as food, usually as flakes or powder with a savory, umami flavor. It is not active baker’s yeast and will not make dough rise. A USDA survey reference provides about 40.4 g protein and 26.9 g fiber per 100 g, but a 10 g sprinkle is only about 4.0 g protein and 2.7 g fiber. Vitamin content varies dramatically depending on fortification.
Most olives picked from the tree are too bitter to enjoy because of oleuropein and other phenolic compounds. Curing is not simply a way to add salt: brine, fermentation, water or alkaline treatments remove or transform much of the bitterness and create a stable table olive. Depending on the style, processing can take from days to many months.
During sourdough fermentation, lactic acid bacteria and yeasts transform sugars and produce acids, gases and aroma compounds. The pH falls, flavor and dough structure change, and phytate and some fermentable carbohydrates such as fructans may decrease. The size of those changes is not fixed: flour, microorganisms, temperature, fermentation time and acidity all matter, so not every bread labeled sourdough undergoes the same process.