Dried beans can be used as vegetables for both human and animal food. They are used in many traditional dishes throughout the world and can be cooked in various ways, including boiling, baking, and frying. Dried beans are low in fat but packed with fiber, protein, potassium, iron, and B vitamins. They are inexpensive, can be found in almost any grocery store, and are available year-round. When appropriately stored (kept in a sealed bag or an airtight plastic container in a cool and dark spot), this dried vegetable can last for more than a year. Also, there are many varieties of beans available already canned or cooked.
However, in order to preserve the nutritional properties of dried beans, they need to be handled gently and processed the right way before they hit the shelves.
Importance of the Common Dry Bean
The common dry bean is an agricultural legume crop which demonstrates phenotypic and genotypic diversity, global adaptability, and has multiple means of preparation and dietary use. The consumption patterns vary significantly among cultures and by geographic region. A broad spectrum of traditions and social interactions discriminate among means of preparation, bean types (size, shape, and color), and end product use.
Dry beans are the second most important legume class in the world, right after soybeans, and they are one of the basic foods in Latin America, India, and Africa. In countries where protein-energy malnutrition is prevalent, beans are especially important from a nutritional perspective.
More than 7,000 years ago, beans were first domesticated in the territory of Peru and Mexico, where indigenous tribes developed beans of different sizes, shapes, and colors. By wandering across North and South America, these tribes carried their beans with them, spreading them across both continents. And once the Spaniards discovered the New World, one of the things they took with them to Europe were different varieties of beans. Beans began to spread across the globe slowly, and by the mid-19th century, the bean industry began to boom in the U.S.
Bean Market in 2020 and Future Trends
According to GlobalTradeMag, global dry bean consumption indicates a relatively flat trend pattern. From common beans to kidney beans and faba beans, the demand for different types of bean products is on the rise. In 2018, the global dry bean market topped at $30.1 billion, which is a 2.4% reduction when compared to 2017. However, consumption is forecast to continue to rise over the current decade, in which market performance is expected to decelerate with a CAGR of +2.1% until 2030.
The coronavirus outbreak led many Americans to stock up with long-lasting pantries and essential goods. As a result, sales of medical supplies and non-perishable food increased significantly during March and April. After President Trump’s first conference on the COVID-19 issue and the first cases of suspected community transmission in the U.S. (late February), weekly sales of canned meat, dried beans, and powdered milk products jumped 32%, 37%, and 84% year-over-year, respectively.
The fact that lentils found in Egyptian tombs still managed to sprout even thousands of years after they’ve been harvested tells us that these are exceptionally shelf-stable foods. Goya Foods, a large U.S. food company specializing in the production of Latin culinary products (including canned beans), has seen a dramatic increase in sales of pinto beans, black beans, and other canned products (up to 400%), delivering as much as 24 million cans in just one week. During these uncertain and anxious times, people are turning to foods that are cheap and nutritious, and when properly stored, dried beans can sit in a pantry for more than a year.
Furthermore, food consumption patterns are rapidly changing due to the increasing trend of veganism in the U.S. and Europe (which is spreading across the world). Since 2018, the number of people following the animal-free diet has drastically increased and is one of the major drivers of the dried bean industry.
Distribution and Processing of Dried Beans
Dry beans possess biofunctional and techno-functional properties (which are postharvest changes that would affect bean nutritional quality, taste, texture, and quality) and are high in protein, fiber, non-digestible starches, and bioactive components. When it comes to distribution, the way beans are handled throughout the food production processing facility can also determine their quality. For example, seed coat damage is cumulative during each stage of physical distribution, and it must be minimized to prevent seed coat splitting. Also, moisture content control is essential for stability in bean storage systems.
A thorough assessment of procedures and strategies used for the distribution and processing of dry beans is necessary for improving the utilization of dried beans. By understanding the food chemical and physical components, diversified processing techniques, and inherent constraints that affect the development of innovative and economically-viable products, bean manufacturers will be able to implement required protocols and conveying and processing technology.
Handling and Storage Practices of Dried Beans
Dried beans are harvested when they are physiologically mature, and they may be subsequently air-dried to ensure storage stability. To remain stable during storage, beans require a moisture content of less than 18%. Beans with higher moisture content result in fungal spoilage and significant product loss.
During dry handling, bean seed coats are subject to physical damage, and careful handling is necessary to avoid excessive seed coat splits and cracks. Dry bean harvesting, storage, handling systems, and infrastructure vary significantly from rudimentary processes (in subsistent and rural environments) to sophisticated systems (common in urban settings and global markets). The resulting changes in quality may manifest in color and flavor defects, decreased digestibility, and seed hydration defects. Postharvest quality losses of dried beans increase energy and time requirements for preparation and decrease nutrient bioavailability and palatability.
To distribute fragile foods like dried beans, bean manufacturers cannot rely on just any type of conveyor system. For example, pneumatic, bucket, and belt conveyors will minimize bean breakage and keep them contaminant-free like tubular cable and disc conveyors. Cablevey Conveyors are designed to move fragile foods without battering, stress, bumping, or friction (both bean-to-bean and bean-to-conveyor), reducing bean breakage and enhancing cleanliness. They can also be installed in a configuration that fits the processing plant, thus saving space and removing the need for re-engineering processing plants.
Distribution and Processing of Dried Beans
Innovative technology has led to the development of different bean formulations and products, such as frozen, extruded, microwavable, and dehydrated bean products. Cablevey Conveyors conveying systems can help convey bean products, including:
- Packaged dry beans
These are whole, dried beans packaged in retail bags that are suitable for in-home preparation. The need for pre-soaking and cooking process requires pre-meal planning and cooking time in boiling water, which is why this form of beans is somewhat limited. There is also an increased prevalence of bean medley mixes, which are often used in homemade soups.
- Pre-cooked and dehydrated bean powders and flakes
Cablevey systems can move bean powders and fragile flakes in a clean and safe manner with virtually no product degradation or separation. Bean crumbles, flours, and flakes are formulated bean mixes that are processed and prepared in various foodservice systems.
- Frozen beans
Fully- or partially-cooked beans marketed as IQF (individually-quick-frozen) or as a frozen block are great for direct retail distribution or as institutional food ingredients. With the IQF freezing method, beans can be sent into a blast chiller (via tubular drag conveyor) that freezes the item quickly. The conveyor can move the frozen food gently from the chiller right into the packaging area.
Appropriate softening and hydration under low-temperature cooking conditions before freezing produces bean products that are ready to be used in recipe-based foods.
- Quick-cooking beans.
When it comes to bean utilization, preparation, and cooking, time is a major constraint, which is why many physical and chemical processing methods have been initiated or proposed to address the challenge. Compared to standard processing procedures, the addition of phosphates (salts) to bean soaking or cooking water results in increased hydration yield and a softer bean texture. When this method is used, we get quick-cooking beans with a cooking time of approximately 15 minutes.
- Pasta-type bean products
Food manufacturers have attempted to create pasta products from blends of protein concentrates or legume composite flours. Pasta-type products supplemented with about 10% legume flours have been deemed acceptable by taste panels, while pasta products with about 25% legume flours have been reported to have a “beany taste.”
Stages in dry bean processing (canned beans)
Typically, beans require gentle handling (to minimize mechanical damage), dry cleaning and sorting, and blanching or soaking prior to filling and thermal processing. Different varieties of bean products have appeared on the market thanks to the rising popularity of convenience foods, such as frozen, extruded, microwavable, and dehydrated bean products. Canned beans continue to be the major processed bean product, and we will describe the stages of the canning process in detail.
There are 8 unit operations during bean canning:
- Cleaning or grading
- Pack-style, sauce, or brine
- Filling and closing
- Thermal processing
- Labeling and casing
- Cleaning and grading
First, dried beans must go through a clipper cleaner or winnowing mill to remove small pieces of foreign material, dirt, and other extraneous matter. Cleaned beans are then inspected to remove defective and split beans, as well as other extraneous matter (e.g., insects or rocks), and it is done either manually or with the use of machine vision systems. If this step is performed before bulk storage, this step may be unnecessary at the canning facility.
- Blanching and soaking
Besides the quality of raw beans, the quality of processed beans is greatly influenced by the methods used in processing. Blanching and soaking procedures are performed to effect the hydration of the bean cotyledon so that the beans can sufficiently soften during cooking.
Before they are processed, the initial moisture content of raw beans needs to be between 12% and 16%. During the soaking stage, there is an initial rapid uptake of water due to the filling of capillaries on the bean seed coats’ surface. A wax-like, hydrophobic material covers the seed coat to impede water penetration, and as soaking continues, the rate of water uptake decreases because soluble materials get extracted. What is the goal of soaking and cooking? To provide beans with a final moisture level of about 53-57%. For soaking, soft water should be used because hard water can result in bean products that will require longer cooking time.
As for blanching, the purpose of this process is to provide a uniform product during filling and evacuate gases in the beans. Also, it may aid in bean water absorption and provide it with a more desirable texture. After blanching, beans are usually washed in cold water by shaker washers equipped with jets that spray water onto the beans as they rotate in the shakers or reels. During the washing step or through the use of a pneumatic separator, skins and splits can be removed from the blanched beans.
To remove small stones, soaked beans are often run over a water riffle, but there are also some advanced methods that combine cleaning, washing, and destoning steps into one operation. Light, floating waste gets removed in the initial floating section, while silt and stones are removed in the destoning stage. Ultimately, beans are dewatered, and fine stones are removed. Destoning can be performed after blanching or between the soak tanks and blancher.
- Canned bean pack styles
Commercial bean formulation, canning, and filling processes include different important factors that influence the product quality, organoleptic value, nutritional value, shelf-life, and market positioning to consumers. Beans are canned in a broad range of pack styles with different sauce consistency/viscosity and flavor profiles. These include chilled beans, refried beans, baked beans, bean soups, bean with frankfurters/wieners, and beans in sauce or brine.
The final characteristics of the product are determined by the ratio of beans to the cover sauce. Brines and sauces also help offer variety and product differentiation, as well as de-commoditized bean products. They often include certain functional salts that help in preservation. Sauce formulas range from brine-based to tomato-based and can include other ingredients, such as starches, flavors, seasoning, beef, and pork.
- Filling and closing
After soaking, blanching, and destoning, the beans are conveyed to the area where soaked/blanched beans are filled into cans (along with brine or sauce). It is an automated process where a specific amount of beans is placed in a can or jar, which is then filled with brine or sauce. To maintain a high closing temperature, the brine/sauce should be added as close to 100°C as possible. Properly filled cans will contain enough sauce to cover the beans after processing and a few weeks of storage. Atmospheric closure occurs when fill temperature is higher than 60°C, and after closure, cans are passed through a warm-water spray to remove any material adhering to the can.
- Thermal processing
Immediately following can closure, thermal processing is performed for sterilization of beans in sauce. Beans are low-acid foods and are subject to the FDA’s manufacturing practices regulations for low-acid canned foods. The thermal process required for sterilization is affected by the amount of sugar, starch, tomato pulp in the sauce formulation, and the degree of bean rehydration. In case beans aren’t fully rehydrated before canning, they might absorb the moisture from the sauce or brine, and that will result in little or no sauce or brine in the headspace.
To prevent thermophilic spoilage, it is critical that closed cans be water-cooled immediately after they are processed until the average temperature of the can content reaches about 38°C. Excessive cooling may lead to residual moisture and rusting of can surfaces.
Engineers at Cablevey Conveyors can design a custom configuration for your processing facility to save space and time, as well as the money you’d need to invest in re-engineering your plants and processes. Keep your products contaminant-free and minimize damage and breakage with the use of an enclosed tubular cable and disc system. It will reduce the need for maintenance and equipment downtime. Enclosed tubes keep your materials safe and clean during transportation, and they keep your plant clean while reducing wastage.
When it comes to cleaning, there are dry, wet, and in-line cleaning options available. Cablevey professionals are there to help you determine the best cleaning option for your needs, and they will train your staff on how to use the equipment. Damage and contamination of dry beans must be reduced to a minimum with proper handling practices and by following established standards for food handling and sanitation. Cablevey Conveyors is a company that provides a tubular drag solution to food manufacturers that need gentle and proper material handling. In most cases, product damage translates into profit loss, making the conveyor system a serious issue that needs to be addressed immediately.
We have engineered dry bean conveyor systems for processing and production facilities (large to small) in dozens of countries around the world. With almost 50 years of experience, we can provide you with a flexible and highly customizable conveying system for your plant configuration and dry beans production needs, while ensuring clean and safe environmental conditions, particularly during the cooking and sterilization processes.