What Beans Are Legumes?
Beans are categorically legumes, meaning they belong to the plant family Fabaceae. However, not all legumes are beans in the way the term is commonly used; a bean is typically understood to be a large, edible seed from a specific subset of legume plants.
Legumes: The Broader Plant Family
The term “legume” refers to a member of the Fabaceae plant family, one of the largest plant families in the world. This family includes a vast diversity of plants, from towering trees to delicate herbs. What unites them is their fruit: a pod that splits open along two seams, containing seeds inside. These seeds, in many cases, are what we commonly know as beans.
Understanding the Bean Subgroup
While all beans are legumes, the term “bean” is often used more restrictively to refer to a specific group of legumes known for their relatively large size and edible seeds. This includes familiar varieties like kidney beans, pinto beans, black beans, and soybeans. Other legumes, such as peanuts, lentils, and chickpeas, are not typically referred to as beans, even though they technically belong to the same family. This is largely due to differences in seed size, shape, and culinary use.
Defining Characteristics of Legumes
Legumes possess several defining characteristics beyond their pod-like fruit:
- Nitrogen Fixation: Legumes have a symbiotic relationship with nitrogen-fixing bacteria in their root nodules. These bacteria convert atmospheric nitrogen into ammonia, a form of nitrogen that plants can use. This ability reduces the need for nitrogen fertilizers, making legumes valuable in sustainable agriculture.
- High Protein Content: Legumes are renowned for their high protein content, making them an essential food source, especially in vegetarian and vegan diets.
- Versatility: Legumes are incredibly versatile in the kitchen and can be used in a wide range of dishes, from soups and stews to salads and dips.
- Edible Seeds and Pods: While the seeds are the most commonly consumed part, some legumes, like green beans and snow peas, are eaten whole with their pods.
Nutritional Benefits of Legumes (and Beans)
Legumes offer a multitude of health benefits:
- Excellent Source of Protein: Essential for building and repairing tissues.
- Rich in Fiber: Promotes digestive health and helps regulate blood sugar levels.
- Good Source of Complex Carbohydrates: Provides sustained energy.
- Low in Fat: Makes them a heart-healthy food choice.
- Contain Essential Vitamins and Minerals: Such as iron, folate, potassium, and magnesium.
- May Reduce the Risk of Chronic Diseases: Studies suggest that regular legume consumption may lower the risk of heart disease, type 2 diabetes, and certain cancers.
Common Legumes (and Bean) Varieties
Here is a table showcasing common legumes, differentiating between those commonly called “beans” and other types:
| Category | Examples |
|---|---|
| Commonly Called “Beans” | Kidney beans, black beans, pinto beans, navy beans, great northern beans, cannellini beans, lima beans, soybeans |
| Other Legumes | Lentils, chickpeas, peanuts, peas (garden peas, split peas), alfalfa, clover |
Preparing Legumes (and Beans)
- Soaking: Most dried beans benefit from soaking before cooking to reduce cooking time and improve digestibility. Overnight soaking is the traditional method, but a quick-soak method (boiling beans for a few minutes, then letting them sit for an hour) can also be used. Lentils and split peas generally don’t require soaking.
- Cooking: Beans should be cooked until tender. This can be done on the stovetop, in a slow cooker, or in a pressure cooker. Adequate cooking is crucial to neutralize certain compounds that can cause digestive discomfort.
- Seasoning: Legumes readily absorb flavors, so don’t be afraid to experiment with different herbs, spices, and seasonings.
Common Mistakes When Cooking Legumes
- Not Soaking: Skipping the soaking step can result in longer cooking times and potentially tougher beans.
- Undercooking: Undercooked beans can be difficult to digest and may contain compounds that can cause digestive issues.
- Over-Salting Early: Adding salt too early in the cooking process can toughen the bean skins. It’s best to add salt towards the end of cooking.
- Using Old Beans: Older beans may take longer to cook and may not soften properly.
Frequently Asked Questions (FAQs)
Are peanuts considered beans?
Peanuts, despite their common association with nuts, are botanically legumes. They share the characteristic pod and nitrogen-fixing abilities of other legumes, even though they are often consumed in ways similar to nuts.
Why are legumes so good for the environment?
Legumes are environmentally friendly because of their nitrogen-fixing abilities. This process reduces the need for synthetic nitrogen fertilizers, which can pollute waterways and contribute to greenhouse gas emissions.
Do all beans cause gas?
Beans are known to cause gas in some individuals due to the presence of oligosaccharides, complex sugars that are difficult for the human body to digest. Soaking and thorough cooking can help reduce this effect. Beano and similar products can also assist with digestion.
Are green beans considered beans in the same way as kidney beans?
Green beans are, in fact, legumes, but they are consumed differently from dried beans like kidney beans. We eat the entire pod, not just the mature seeds inside. They are picked and eaten before the seeds fully mature.
Can I sprout beans?
Yes, many beans can be sprouted. Sprouting increases the nutritional value and can make them easier to digest. Common sprouting beans include mung beans, lentils, and adzuki beans.
Are soybeans considered beans?
Yes, soybeans are absolutely considered beans. They are large, edible seeds from a legume plant and are used to make a variety of products, including tofu, soy milk, and edamame.
Are lentils considered beans?
While lentils are definitely legumes, they are not typically referred to as “beans” in common usage. They have a distinct shape and size, and they cook much faster than most beans.
What is the difference between a pulse and a legume?
The terms pulse and legume are often used interchangeably, but “pulse” specifically refers to the dried, edible seeds of legume plants. Thus, all pulses are legumes, but not all legumes are pulses (e.g., green beans).
How can I make beans easier to digest?
To make beans more digestible, soak them for at least 8 hours or overnight, drain the soaking water, and rinse them thoroughly before cooking. Cook them until they are very soft, and consider adding a small piece of kombu seaweed to the cooking water.
Are there any beans that don’t need to be soaked?
Lentils and split peas generally do not need to be soaked before cooking. They cook relatively quickly and are typically easier to digest than other types of beans.
What are some good sources of protein besides beans for vegetarians and vegans?
Besides beans, vegetarians and vegans can obtain protein from other sources, including tofu, tempeh, lentils, nuts, seeds, and whole grains like quinoa. A varied diet is essential for obtaining all necessary amino acids.
Can eating too many beans be harmful?
While beans are incredibly healthy, overconsumption can lead to digestive discomfort such as bloating and gas. Consuming a balanced diet with a variety of foods is always recommended.