While gourmet canned legumes or prepared dishes are typically sterilized to ensure the complete elimination of microorganisms and their spores, you’ll also find refrigerated legume preserves or ready-made dishes on the market, where pasteurization has been chosen instead.

In this article, we’ll walk you through the key aspects to consider when pasteurizing or sterilizing your gourmet legume preserves or prepared dishes made with legumes. First, we’ll cover the benefits of this food and its different varieties.

Legumes: An essential food in our diet

A legume is the dry seed produced by a plant in the legume family, separated from its pod.

Nutritionists recommend eating legumes as they are an excellent source of plant-based protein, even greater than that found in whole grains like wheat.

Additionally, legumes are characterized by:

Low glycemic index

They are also low in fat and high in fiber, making them suitable for people with diabetes and beneficial for reducing the risk of coronary heart disease.

Rich in B vitamins

They provide vitamins such as folate and are also high in potassium and iron.

Low in sodium

They help prevent hypertension and are gluten-free.

Consumption of legumes

Thanks to all their benefits, legumes should always have a place in our diet. Nutrition experts recommend consuming 2 to 4 servings of legumes per week, with each serving around 60–80 grams.

As for their production, the FAO has long emphasized the importance of legumes in achieving global food security and supporting sustainable agrifood production systems.

Legume crops require significantly less water than other protein sources, are resilient, and can adapt to arid environments, making them ideal for vulnerable populations with limited or no access to advanced technology.

Additionally, these seeds have a long shelf life, which helps reduce food waste.

Many of our clients produce legume-based preserves. Discover some examples in our success stories section.

Fun fact:

Did you know that the United Nations General Assembly designated February 10 as World Pulses Day?

Types of legumes

Legumes are classified based on their lipid content and are divided into the following categories:

Oilseeds or Oil-Bearing Legumes

These contain high levels of fat, ranging between 20% and 50%.

Dry or Non-Oil-Bearing Legumes

These have a much lower fat content, typically between 1% and 7%.

Legume-based preserves and prepared dishes

The most common legume-based preserves and prepared dishes on the market include:

Boiled legumes with water and salt
Hummus
Legume pâtés
Ready-made dishes, either in cans or glass jars, such as lentils with quinoa and chia, chickpeas with kale, chickpeas with spinach, etc.

All these products must undergo a preservation process before they can be sold. This ensures compliance with current health and hygiene regulations and allows them to be stored for extended periods with full quality assurance.

How to make legume preserves

Regardless of the type of preserve or prepared dish you’re making, the first step is to ensure you have the necessary containers and that they’re in good condition—that is, not cracked or deformed. You should do the same with the lids, if applicable.

If your preserve is simply legumes with water and salt, start by rinsing the legumes in water and then soaking them for the required time based on the type of legume.

Next, place the raw legumes in the container and cover them with a solution of water and salt.

Then, put the container in the autoclave, where they will cook and be sterilized at the same time.

If your product is more complex—such as hummus, a pâté, or a prepared dish—remember to soak the legumes for a while, then prepare them as needed by blending, mixing with other ingredients, or cooking them into a stew.

In this case, we recommend that you don’t fully cook the dish on the stove; instead, leave it slightly underdone so it finishes cooking in the autoclave, resulting in a better texture.

Sterilization of canned legumes

As we’ve mentioned, there are two types of legume preserves depending on how they are prepared:

Raw-Pack Preserves: The legumes are washed and then cooked inside the container. This cooking can be done directly in the autoclave during the sterilization process.
Prepared Dishes with Legumes: Different ingredients are pre-cooked or sautéed, depending on the type of dish. We recommend not fully cooking the product on the stove, allowing it to finish cooking in the autoclave.

When choosing a thermal treatment for your product, consider both the characteristics of the food and the desired outcome.

Sterilization uses higher temperatures, provides a longer shelf life, fully eliminates microbial load, and doesn’t require refrigeration during transport and storage.

In contrast, pasteurization doesn’t completely eliminate microbial load or inactivate bacterial spores, so products generally need refrigeration and have a shorter best-by date.

Sterilization removes nearly all microorganisms, while pasteurization does so partially. Both processes are safe, proven, and do not pose any health risks to the consumer.

Most gourmet legume preserves and prepared legume-based dishes are sterilized, but they must be pre-cooked before sterilization to ensure even cooking.

Keep in mind that to sell your preserves to third parties, it is essential to comply with legislation on safety, quality, and food hygiene for canned preserves and prepared dishes. This requires applying thermal treatment with professional equipment and recording the treatment results for each batch, as our autoclaves do.

pH of canned legumes

The pH of your gourmet legume preserve or prepared dish will vary depending on the ingredients used.

Main pH values of canned legumes and prepared dishes

The pH of a food determines the temperature and duration of thermal treatment, as this value indicates which types of microorganisms can grow in it and how easily. A lower pH means higher acidity, allowing for gentler thermal treatments, while a higher pH indicates lower acidity and requires more intense thermal treatments.

pH 4.5 – 5.5	pH 5.5 – 7
Natural white beans	Fabada (Asturian bean stew)
Chickpeas in brine	Chickpeas
Lentils in brine	Lentils

F₀-P₀ values for legume sterilization

Since cooking and sterilization are usually combined in the same autoclave for legume preserves and legume-based prepared dishes, an F₀ value of 8 to 10 is typically applied. This is because spore-forming bacteria that may be present have much higher resistance. The peak temperature generally ranges from 114 to 118ºC, depending on whether other ingredients are included.

For smaller legumes, an F₀ of 8 is usually applied, while for larger legumes, an F₀ of 10 is recommended.

It’s important to note that these values are approximate, as F₀ and P₀ thermal values depend on the type of product, its ingredients, and how it was prepared beforehand. We recommend evaluating each product individually by accurately measuring its pH and performing subsequent checks to assess the entire process. This allows for selecting the most appropriate F₀-P₀ target values for each recipe.

Common issues in legume sterilization

One important factor when preparing legumes is the necessary pre-treatment they require. To ensure the best texture, it’s advisable to soak dried legumes before cooking. This allows water to penetrate the bean, softening it both inside and out and making it easier to cook.

The soaking time varies depending on the type of legume. Recent recommendations suggest soaking them for 8 to 12 hours and changing the water at least three times. This process helps break down the skin membranes and releases oligosaccharides, which are responsible for intestinal gas, as well as any pesticide residues that might be present.

This is why it’s essential to change the water and avoid boiling the legumes in it. Some argue that nutrients are lost with this process, but there is no research to support this claim.

It’s also important to use soft or demineralized water for both soaking and cooking. This helps prevent the legume skins from becoming tough.

We can find highly heat-resistant spores, such as those of Clostridium botulinum, which is the primary microorganism of concern in the sterilization of low-acid foods.

Molds commonly appear on legumes during storage, known as storage molds. These molds invade the product at low moisture levels and sometimes produce aflatoxins, which are also harmful to humans. Properly applied sterilization can eliminate these toxins as well. This group includes molds from the Aspergillus and Penicillium genera.

Recommended containers for the sterilization of legumes

If you take a look at most supermarket shelves, you’ll generally find legume preserves packaged in glass jars and cans. You may also see some prepared dishes in the refrigerated section, packaged in plastic trays.

When the contents are simply boiled legumes, the container is almost always glass. Cans, on the other hand, are more commonly used for legume-based prepared dishes, such as fabada.

It’s worth noting that this trend is shifting, with more producers of legume-based prepared dishes opting for glass.

As for containers for pâtés and hummus, these tend to be in glass or clear plastic.

If you choose to pack your preserves in a glass container, there’s only one important consideration. When filling the container, leave some headspace between the legumes and the lid. If you’re wondering why, we explain it here.

That said, at TERRA Food-Tech^®, we cannot specifically recommend one type of container over another, as it will depend on the type of preserve, your preferences, budget, product distribution, and other factors.

What we can assure you is that our autoclave is suitable for any type of container, so feel free to choose whichever container best suits your needs.

Sterilizing legumes with TERRA Food-Tech^® autoclaves

TERRA Food-Tech^® autoclaves provide the option to cook products before subjecting them to thermal treatments like pasteurization or sterilization. Thanks to the counterpressure they generate, they prevent container deformation. To avoid unwanted overcooking, these autoclaves are equipped with a rapid cooling system after the thermal treatment, ensuring the product retains its ideal texture.

If you seek reliability, safety, and efficiency in producing gourmet preserves, a food autoclave is the ideal choice.

With TERRA Food-Tech^® autoclaves, you can not only sterilize but also cook and pasteurize—three functions in one device.

Using our food autoclaves ensures compliance with legislation on safety, quality, and hygiene for canned preserves and prepared dishes. They allow you to record the process applied to each batch, making them essential for those looking to market these products.

TERRA Food-Tech^® autoclaves were created to meet the needs of micro-entrepreneurs, chefs, cooks, farmers, livestock producers, and social enterprises who have made gourmet preserves their life’s work.

Success stories of legume-based preserves and prepared dishes

Gourmet legume preserves are an excellent choice for people who are short on time but still want to eat well and maintain a healthy diet.

Some of our clients are well aware of the benefits of these products, which is why they produce them in a variety of ways and formats. In our success stories section, you can learn about their experiences.

Ibsa Bierzo

Production of vegetable preserves and sauces

Mixblik

Elaboration of artisan preserves

Tarro Verde

Preparation of canned vegetables, ready meals and vegetable spreads

Looking to learn more about TERRA Food-Tech^® autoclaves for sterilizing gourmet legume preserves? Contact our experts today

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