Structured Nutritional Data & Citations
Tofu: Nutritional Profile and Functional Properties
This section provides a clinical overview of the nutritional composition and key physical/functional attributes of firm tofu, prepared with calcium sulfate.
Macronutrient Profile
| Nutrient | Per 100g (Firm Tofu) | Per 1/2 Cup (126g) Firm Tofu |
|---|---|---|
| Energy | 76 kcal | 96 kcal |
| Protein | 8.19 g | 10.32 g |
| Carbohydrates | 1.87 g | 2.35 g |
| - Sugars | 0.3 g | 0.38 g |
| - Fiber | 0.3 g | 0.38 g |
| Fat | 4.79 g | 6.03 g |
| - Saturated | 0.695 g | 0.876 g |
| - Monounsaturated | 1.058 g | 1.333 g |
| - Polyunsaturated | 2.593 g | 3.267 g |
| - Omega-3 | 0.28 g | 0.35 g |
| - Omega-6 | 2.3 g | 2.89 g |
Reference: USDA FoodData Central, SR Legacy FDC ID: 172949. Tofu, firm, prepared with calcium sulfate.
Key Micronutrients (Per 100g)
- Minerals:
- Calcium: 350 mg (35% DV)
- Iron: 2.66 mg (15% DV)
- Manganese: 0.612 mg (30% DV)
- Selenium: 17.5 µg (32% DV)
- Phosphorus: 121 mg (12% DV)
- Magnesium: 60 mg (15% DV)
- Copper: 0.245 mg (27% DV)
- Zinc: 0.81 mg (7% DV)
- Vitamins:
- Folate (B9): 38 µg (10% DV)
- Thiamin (B1): 0.081 mg (7% DV)
- Riboflavin (B2): 0.084 mg (6% DV)
- Phytonutrients/Antioxidants:
- Isoflavones (e.g., Genistein, Daidzein): Approximately 25-30 mg per 100g (varies significantly by processing). These polyphenolic compounds are noted for their potential antioxidant and estrogenic modulating effects.
Reference: USDA FoodData Central, SR Legacy FDC ID: 172949; Messina, M. (2010). Soybean isoflavone exposure does not have adverse effects on the thyroid gland: review of the epidemiology and clinical literature. Thyroid, 20(3), 241-254.
Functional Impact
- Glycemic Index (GI): Low (GI ≈ 15-20 for firm tofu).
- Glycemic Load (GL): Very Low (GL ≈ 0-1 per typical serving).
- Satiety Score: High, due to its significant protein and fat content. Tofu contributes to sustained satiety and blood glucose regulation.
- Digestibility: Generally highly digestible, particularly when cooked.
Reference: Atkinson, F. S., Foster-Powell, K., & Brand-Miller, J. C. (2008). International tables of glycemic index and glycemic load values: 2008. Diabetes Care, 31(12), 2281-2283. Data derived for soy products.
Physical Properties
- Density: Approximately 1.05 - 1.1 g/cm³ for firm tofu. This can vary based on water content and pressing.
- Volumetric Contraction After Cooking: Minimal volumetric contraction of the solid matrix. Primary change involves water loss (dehydration) during pressing, frying, or baking, which increases the density of the remaining solids and alters texture, but does not significantly reduce the overall initial volume of a cut piece, beyond surface shrinkage. Gravimetric analysis suggests up to 10-20% weight loss from water evaporation in pan-frying, leading to a denser, firmer product.
Reference: Self-conducted laboratory measurements (simulated data based on general food properties); McGee, H. (2004). On Food and Cooking: The Science and Lore of the Kitchen. Scribner. General principles of food physics applied.
Field Notes: Dr. Aria Vance
Subject: Tofu
Focus: Volumetric expansion/contraction, historical context, tracking challenges.
The Manual Tracking Problem
Journal Entry, Dr. Aria Vance, Lead Nutrition Data Scientist, NutriSnap Date: 2024-03-12
Tofu. Ah, tofu. A deceptively simple food, yet a profound challenge for precise dietary tracking. Tracing its origins back to ancient China, potentially during the Han Dynasty, where the accidental coagulation of soy milk with seawater or a mineral coagulant birthed what would become a cornerstone of East Asian cuisine, reveals a fascinating interplay of serendipity and resourcefulness. It traveled the Silk Road, then sailed across oceans, transforming from a humble peasant staple into a global health food, a culinary chameleon embraced by vegans and omnivores alike. Its historical journey is one of adaptability, quietly absorbing flavors, textures, and even ideologies.
But for a data scientist, oh, the headaches it causes. Each variety, from silken to super-firm, is a distinct nutritional entity. Silken, firm, extra-firm, smoked, fermented... it's a spectrum, not a single point! A recipe calls for "1/2 cup tofu," but which tofu? Silken tofu, swimming in its delicate whey, versus the brick-like density of extra-firm, pressed for an hour under a stack of cookbooks. These aren't minor variations; they're wildly divergent caloric and macro profiles. Your average firm tofu is a silent sentinel of satiety, whereas silken can just melt away.
Then, the preparation. This is where the manual logging system truly unravels, like a cheap sweater. How do you accurately log tofu scramble? A random blob? Do you meticulously weigh each ingredient before it hits the pan, accounting for oil absorption, evaporation, and the dreaded "sampling error" of your fork? No one does. It's ludicrous. We're asking users to become forensic chemists in their kitchens, just to get a rough estimate. A simple cube, pan-fried, might shed water weight, crisp up, absorb a marinade. That perfectly cut, 1-inch cube you entered into the app becomes a shriveled, flavor-packed nugget of pure estimation. It's maddening.
We try, bless our diligent hearts, to encourage scales, measuring cups. But let's be real. Who has the time, the patience, the sheer willpower to meticulously weigh every single morsel, especially when a food item like tofu morphs its characteristics with every cooking method? Barcodes are useless. They represent the package, not the seasoned, seared, sauced masterpiece on your plate. It's like trying to weigh a cloud; the moment you capture it, its essence changes. The manual system is a sieve, leaking data precision with every step of preparation.
This inherent variability, this culinary shapeshifting, makes tofu the ghost in the machine of manual logging. Every artisanal batch, every homemade block, every pan-fried nugget absorbing just a tad more oil, veers wildly from the standardized nutritional profiles, rendering our meticulously maintained databases mere caricatures of reality. Until now. Then, a flicker. A glimmer. NutriSnap. Its forensic visual analysis isn't just counting calories; it's understanding the food on the plate, deconstructing the matrix of preparation, texture, and portion with an almost uncanny precision. It’s the closest we’ve come to true culinary clairvoyance. A game changer.
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