Soybeans are a versatile and nutritious legume, central to many diets, particularly vegetarian and vegan. Their nutritional profile changes depending on how they are prepared, making it important to distinguish between raw, boiled, and roasted forms when considering caloric and protein intake. A 100g serving is a common benchmark for dietary comparison, and the differences in preparation can dramatically affect the nutritional density of your meal.
Nutritional Breakdown of Boiled Soybeans
For those consuming soybeans in their most common form, boiled and often seasoned, the nutrition is as follows. A 100-gram serving of boiled soybeans (without salt) contains approximately:
- Calories: 172-173 kcal
- Protein: 16.6-18.2 grams
- Fat: 9 grams
- Carbohydrates: 8.4-9.9 grams
- Fiber: 6 grams
This breakdown shows that boiled soybeans offer a balanced macronutrient profile, with a significant amount of high-quality plant protein and dietary fiber. They are also a good source of various vitamins and minerals, including iron, calcium, and potassium.
Raw vs. Cooked Soybeans: The Significant Difference
The most crucial factor influencing the caloric and protein content of soybeans is their water content, which changes drastically with cooking. Raw, mature soybeans have not absorbed the water that boiling adds, concentrating their nutrients and calories by dry weight.
Raw Soybeans
Based on USDA data, 100 grams of raw, mature soybeans contains a much higher concentration of nutrients:
- Calories: ~446 kcal
- Protein: ~36.5 grams
- Fat: ~19.9 grams
- Carbohydrates: ~30.2 grams
- Fiber: ~9.3 grams
Dry-Roasted Soybeans
Similarly, dry-roasted soybeans also have a high concentration of nutrients due to moisture removal. A 100-gram serving of dry-roasted soybeans contains:
- Calories: ~451 kcal
- Protein: ~40 grams
- Fat: ~22 grams
- Carbohydrates: ~33 grams
- Fiber: ~8 grams
Comparison of Soybean Nutrition per 100g
The following table illustrates the dramatic nutritional differences based on preparation method. It is clear that boiled soybeans offer a lower-calorie, more hydrated option, while raw and dry-roasted versions are significantly more calorie-dense and protein-packed due to the absence of water.
| Nutrient | Boiled (100g) | Raw (100g) | Dry-Roasted (100g) |
|---|---|---|---|
| Calories | 172-173 kcal | 446 kcal | 451 kcal |
| Protein | 16.6-18.2 g | 36.5 g | 40 g |
| Fat | 9 g | 19.9 g | 22 g |
| Carbohydrates | 8.4-9.9 g | 30.2 g | 33 g |
| Fiber | 6 g | 9.3 g | 8 g |
Protein Quality and Health Benefits
Soybeans are notable not only for their quantity of protein but also their quality. They are a complete protein, meaning they contain all nine essential amino acids necessary for the body. This makes them an excellent protein source for vegetarians and vegans.
Additional health benefits of soybeans include:
- Heart Health: Consumption has been linked with a modest decrease in cholesterol levels.
- Bone Health: Isoflavones in soy may help reduce the risk of osteoporosis, especially in postmenopausal women.
- Menopause Symptom Alleviation: Isoflavones may help reduce symptoms like hot flashes in some women.
- Gut Health: The fiber content promotes healthy gut bacteria.
Beyond the Whole Bean: Other Soy Products
The nutritional content of soy varies across different products. For instance, tofu and edamame (immature soybeans) offer different profiles.
Common soy products and their protein content per 100g:
- Tofu (firm): Approximately 16 grams of protein.
- Edamame (shelled, prepared): Approximately 11-12 grams of protein.
- Soy Milk: Around 3-4 grams of protein per 100ml.
This shows that while whole soybeans are highly nutritious, a wide range of soy products can help you meet your nutritional goals. For a deeper dive into the health effects of soy, you can read more from reliable sources like Healthline.
Conclusion
For 100 grams of boiled soybeans, you can expect a modest 172-173 calories and a substantial 17-18 grams of protein. However, the caloric and protein density increases significantly in raw or dry-roasted versions due to lower water content. Regardless of the preparation, soybeans remain an excellent source of complete plant-based protein, fiber, and other vital nutrients, making them a valuable addition to many diets.
