Dry Peas, Lentils & Chickpeas as Functional Ingredients
In the U.S. and elsewhere, the rates of obesity, diabetes, and heart disease have reached what many healthcare professionals have referred to as epidemic levels. These unhealthy weight-related trends have prompted a surge in consumer demand and regulatory pressure for healthier food alternatives. In the face of these developments, commercial food manufacturers are finding it necessary to pursue new, more healthful products.
Many in the food industry are increasingly turning to the power of pulses as a solution. The dietary significance of pulses dates back almost 10,000 years when their rich nutritional characteristics were central to human health and the very viability of civilization itself. Today, legumes are actually listed twice on the USDA’s Food Guide Pyramid, once each in the protein and vegetable categories, and important features in the much-lauded Mediterranean Diet.
Food scientists are rediscovering the fact that natural legumes like dry peas, lentils, and chickpeas are highly functional ingredients, adding both flavor and robust nutritional bene fits to many dishes. Comprised of natural dietary fiber—both soluble and insoluble—as well as resistant starch and high-quality protein, they offer a health profile that is hard to match.
As a result, specialty and commercial bakers and pasta processors, among others, are looking to pulses and their derivatives as a means for meeting consumer demand while securing a portion of a functional food market that is expected to grow to $40 billion by 2011.
Nutritious and Delicious
Roasted (precooked) pea flour, or pease-meal, is perhaps the most commonly called upon legume in developing food formulations. Made from milled yellow peas, pea flour and its components contribute to healthier products without impacting traditional appeal. It is stabilized by roasting and/or steam precooking. Either process partially gelatinizes the starch, denatures the protein, and inactivates enzymes, thereby increasing product shelf life. Use of dry or wet milling produces different pea our purities, each with applications suitable to specific food functions.
The fiber alone of such products can be enough to capture consumer interest and loyalty. Though the USDA reports that only one in five Americans consumes the recommended daily amount of fiber, in a survey conducted by the 2008 International Food Information Council 77 percent of Americans claimed to be committed to improving their fiber intake. Offering more than 10 grams of natural dietary fiber per 1⁄4 cup, pulse flour can be an easy and effective way to achieve the daily recommended level.
Protein content marks another notable advantage to be gained when incorporating pulses into recipes and formulations. Pea protein concentrates and isolates are functional, bio-available, and loaded with lysine, making them an excellent alternative to soy flour. Such flours are also highly soluble with superb water-holding capacity. Pea protein’s promising potential as an egg replacer is also currently being explored.
Complementing pulse’s fiber and high-quality protein characteristics is the fact that roasted pea flour is an excellent flavor carrier and flavor improver. Its mild, toasty taste can enliven recipes and dishes, without adversely impacting the appearance or texture of the food. Together, this combination of attributes makes pulses uniquely well suited for inclusion in low-fat or fat-free food product applications, including:
- Special pastas
- Specialty foods
- Dry soups
- Dry food preparations
- Special dietetic food
- Snack bars
- Breading and batters
A recent creation by Canadian food scientists underscores what can be gained by adding pulses. By substituting 50 percent pea fiber, the Canadian team developed a lemon blueberry muffin with half the calories, a third the sugar, a fifth the sodium, and 8 grams of fiber, 2 grams more than a comparable raisin bran muffin. And it still earned high marks for taste.
An Array of Other Benefits
In addition to instantly enriching a product’s fiber and protein content, other benefits of incorporating pea and lentil flour include a pleasant light-golden appearance, a very fine ground, and positive blending and mixing attributes. Pulses also boast no additives or allergens, are GMO and cholesterol free, and offer a low glycemic index, extended shelf life, preserved flavor, and simple, clean labeling potential thanks to their natural ingredients. What is more, precooked flour supplies superb stability, comparable to that of wheat flour, and is microbially safe.
Starch is another consideration when adding pulses. At approximately 98 percent purity, pea starch isolates are distinctive for their excellent gel strength and bland taste. Such features, along with the ability to contribute to increased volume and expansion in extruded products and puffed snacks, make pea flour perfect for inclusion in cookie and cracker formulations as well as Asian-style noodles.
The use of pulses is also economical, especially when compared with fiber-fortifying gums or soy protein products. Pulses actually improve the soil by replenishing the soil’s natural nitrogen as they grow. Few other ingredients have a better environmental story to tell, with pulse crops requiring less water and minimal chemical fertilizers during production.
The Call for Gluten-Free Products
Consumers and food producers are increasingly taking note of another significant characteristic of pulses: They are gluten-free. In the U.S., one in 133 people is allergic to gluten, a natural protein found in wheat, rye, oat, and barley. The intolerance to this protein, called celiac disease, is diagnosed in more than 7,000 people every year and is predicted to increase. This is driving global food manufacturers to bolster their product offerings with gluten-free snacks, a market that the USDA expects to surpass $1.7 billion by 2010.
Pulses give food producers a ready solution in their pursuit of gluten-free foods. Legumes also serve as an effective way to add structure and enhance the nutrition of products made with other gluten-free ingredients such as rice, tapioca, or potato starches.
A Changing Market
The interest in eating healthy has never been higher. Evidence continues to mount linking serious health issues with the prevailing on-the-go eating habits evident in many countries. Such news comes at the same time as health care costs continue to escalate, motivating consumers to rethink how and what they eat.
But challenges remain. Many still contend that they do not have the time to prepare, buy, or eat more healthful foods. One of the difficulties can be credited to the ever lengthening commutes experienced by a growing number in U.S. and Europe. Marketing companies predict that time spent in the car or on a train traveling to and from work will only increase in years to come.
Many in the food industry see a significant opportunity ushered in by these trends. They are looking to respond by formulating foods that fit consumers’ hectic schedules and cater to their growing interest in exotic flavors, while also satisfying their desire to eat more healthfully.
The opportunity for such products appears to be sizable, with estimates for the international market for snack foods alone expected to increase in volume by more than 9.8 million U.S. tons by 2012 as consumers turn away from traditional salty and fatty-type foods. Add to this the high cost of cereal grains in recent years and it is little wonder manufacturers are working hard to develop value-added pulse-based foods.
U.S. food manufacturers are well-positioned to satisfy this growing need as local, U.S.-grown peas make excellent roasted pea flour. They are dried naturally in the sun, harvested only when completely mature, and contain low levels of foreign matter. The consequent pea our can then be stored at ambient temperature for three months with no resulting color loss, oxidation, or off flavors. Kept cool, under 80 degrees F (26 degrees C), and dry, the flour can achieve a one-year shelf life.
As explored below, examples of the new and novel pulse-based creations growing out of these developments are numerous and varied. They run the gamut from flatbreads to nutrition bars. Reinterpretations of traditional dishes are booming as well with new formulations being developed every day for everything from soup to pasta to baby food.
Among the more popular legume-based food applications are nutrition bars, an exploding category that offers busy consumers a convenient, functional food option. According to Packaged Facts, a leading publisher of market research in the food and beverage sectors, pulse-fortified nutrition bars were consumed by 13 percent of the population by 2008. The market is forecast to exceed $5 billion by 2010, evolving away from the “sweet” formulations offered by candy and cereal companies to more functional meal-replacement products.
The bars typically include a 30 percent to 40 percent combination of dehydrated lentil flour and yellow pea flours, with “legume powder” being identified as the primary ingredient on packaging. With more than 1 ounce of legumes, the bars also qualify as a “serving” of protein or vegetables in many school nutrition programs.
These healthier, all-natural bars are moist and deliver an appealing flavor profile that fits the demands for breakfast or snack food. Breakfast bars containing up to 30 percent pea flour deliver great taste in a nutritional template of high fiber, vegetable protein, oligosaccharides, isoflavones (i.e., one of a family of a naturally occurring plant compound called phytoestrogen that acts like estrogen in the body), zinc, selenium, and resistant starch.
The bars also provide a “whole food” combination of benefits, including serving as non-dairy and non-gluten ingredients. They also boast Omega 3 fatty acids as well as cholesterol-reducing properties. See pages 144–146 for sample nutrition bar formulations.
Soups are part of what is commonly referred to as the “fast casual” segment of the food service industry. As a category, it has doubled in revenue since 2001 to $11 billion, playing an important part as an accompaniment to sandwiches and salad. Legume-based soups provide welcome new varieties, while delivering added health benefits without sacrificing taste.
Often called a “power food,” legume soups provide a convenient way for consumers to meet their nutrition needs for vegetables, protein, and many micronutrients. By providing extensions or variations of popular, well-established recipes, pulse-based soups provide new variety and health appeal for a range of styles, including Italian, Hispanic, or Asian-inspired recipes seeking to incorporate emerging flavors.
Examples of this trend include filling out a traditional Italian vegetable and pasta stew with an “autumn blend” of lentils, chickpeas, and lentil-fortified pasta or thickening a cream of wild mushroom soup with legume powder. Such soups are eligible for a “good source of” claim for both protein and fiber. See pages 148–150 for sample soup formulations.
As healthy foods fortification grows in popularity and market share, commercial food producers are focusing more on “putting in” than “taking out” when it comes to their sauces. For many companies this has meant incorporating pulses into contemporary sauce flavors and recipes in an effort to attract health-conscious consumers.
As with other pulse-fortified products, the benefits of such a move include greater servings of protein and fiber, no gluten, essential amino acids, and other important nutrients.
This might take the form of an “authentic” Italian or Mediterranean recipe that now incorporates legumes, such as Sicilian lentil pasta sauce enhanced with a blend of “al dente-cooked” lentil varieties and classic Italian herbs and spices. Such a dish would qualify as high protein (6g), high fiber (6g), and fat-free (<0.5g) (based on a 1⁄2 cup serving). See pages 151-153 for sample sauce formulations.
Heat-and-Eat Rice/Starch Mixes
Food producers are also pursuing shelf-stable, value-added rice and pasta-based dry mixes for placement in both specialty (natural) and mainstream grocery channels. These products offer exotic “Mediterranean” flavor and ingredient variety that is both easy to prepare and still familiar.
Fortifying these mixes with lentils or peas is an easy and flavorful way to enhance the protein and fiber content of popular side dishes. Introducing Mediterranean lentils to a mix, for example, enables consumers to enjoy an exotic, more healthful dish that does not require any extra effort to prepare. The lentils hydrate quickly so that every component (lentils, rice, couscous, etc.) of the dish is thoroughly cooked.
Common legume-based side dish formulations contain 44 to 71 percent whole or crushed dehydrated lentils. See pages 154–156 for sample formulations.
Extrusion is a mechanical process in which certain materials are forced, under pressure, through a die opening to create products of a desired shape, size, and/or texture. In the case of food production, if the food is heated by external heaters during the process, it is referred to as extrusion cooking, a relatively new and advanced food processing technique. Due to its processing flexibility, extrusion cooking produces an incredibly broad range of food products, most notably in the cereal, dairy, bakery, and confection industries.
Legume flours are often used as the basis for formulations that are extruded in low-pressure systems. The flour is mixed with water and other ingredients like rice flour and spices to achieve a level of dough stickiness that is suitable for extruding and will produce a texture and taste that is acceptable to consumers.
The moisture content of the dough varies depending on manufacturer requirements. The extruded flour produced from chickpeas is approximately 11 percent moisture, 23 percent protein, 5 percent fat, and 59 percent carbohydrates. Pea flour is also commonly used as a base ingredient.
The nutritional, tasty, and convenient extruded pulse-based products offer a crunchy texture, usually in the form of snacks and breakfast cereal-type foods, are rich in protein and dietary fiber, very low in sodium and fat, and are cholesterol and gluten free.
The extrusion processing method is not currently being commercially used for pulse-based foods due to the perception that such foods do not expand well in extrusion. The rise in consumer demand for convenience foods with a more healthful nutritional profile has led researchers Dr. Jose De J. Berrios of ARS’ Western Regional Research Centre in Albany, Calif., and Dr. Juming Tang and Dr. Barry Swanson at Washington State University to pursue development of healthful, crunchy, great-tasting expanded snack-type foods from dry peas, lentils, chickpeas, and beans.
Though extrusion technology is not new, scientists are only now beginning to determine the processing speeds, heating temperatures, moisture levels, and formulations necessary to create consistent, desirable textures and tastes from every batch of pulse flour. Several breakfast-cereal-type foods and snacks in a variety of shapes have already been developed with other products sure to follow.
Dry peas offer twice the protein of cereal grains, delivering 8 grams of high quality, low-fat, all vegetable protein per 1⁄4 cup. Rich in lysine (i.e., a basic amino acid), dry peas and pea flour provide an amino acid balance that complements cereal grain proteins. Because of such benefits, pea flour and pea protein isolates and concentrates are ideal additions to protein-enriched baking applications.
Pea flour is also rich in slowly digestible starch and resistant starch, which contributes to its low glycemic index. In addition, this quality contributes to its strength as an ingredient in baked foods aimed at fighting obesity and meeting the needs of diabetics and those at risk for diabetes and heart disease.
Bakers are interested in pulse flours for another reason as well: as a natural, more economical and nutritious alternative to gums. Pea fiber fortifications not only enhance dough yield, they can also modify texture, create a full-bodied mouthfeel, improve uniformity and consistency, and reduce product breakage.
Its high water binding capacity, fat absorption, and dough conditioning properties also contribute to making pea fiber perfect for many baked products, especially low-fat or color-sensitive applications. By increasing wheat flour’s water absorption and easily substituting for up to 25 percent of wheat our in baked foods like cakes, cookies, and muffins, pea flour makes possible the development of products with up to 4 grams of fiber per serving.
Proprietary processes for producing insoluble pea fiber from the seed’s interior are also available. The resulting white powder, which is made up of 70 percent fiber, has emulsifying and gelling properties that make it especially useful when enriching white bakery products, without affecting color or flavor.
Also among the list of attractive benefits offered by pulses is the ingredient’s folate content. Typical of all legumes, pea flour can significantly reduce the need for additional folate fortification in baking formulations, with a single cup providing 37 percent of the recommended daily allowance. Because of its important role in preventing birth defects, folate enrichment is now a requirement for many U.S. baked products, including bread.
At just 2.5 percent fat—highly unsaturated fat—pea flour manages to be cholesterol free. This enables it to lend bakery products an enhanced nutritional value and structure, including improved crispness, loaf volume, and appearance. Finally, and of great importance to consumers, pre-cooked pulse flour can be an excellent way to improve the flavor in baked goods.
Given the myriad benefits, it should be no surprise that pulses and their derivatives are increasingly finding their way into a diverse array of baked goods, from cookies to crackers, naan (i.e., a leavened, often tear-shaped Indian flatbread) to noodles.
Tortillas are proving a suitable application for processed legumes. A growing category, from 1994 to 2004 sales of tortillas doubled to approximately $6 million, a level fresh bread did not reach until 2005. The growth has been driven in part by the desire among American consumers for fast, healthier foods. The market has also been tirelessly pursuing new and exotic foods and flavors. A concentration on ethnic foods and low-carb options has further galvanized interest.
To meet this demand, producers are constantly innovating, creating a market defined by novel, creative tortilla formulations. More and more, consumers are able to choose from flavored, colored, and healthier tortilla options. Some tortilla alternatives include spinach, tomatoes, jalapenos, basil, cilantro, chilies, wheat, and other unique ingredients. One producer, WrapOlé, boasts some 16 different varieties.
Processed lentil flour and dehydrated lentil granules are being used, as are yellow pea and chickpea flour. As with other baked goods, the nutrition data illustrates distinct calorie, carbohydrate, protein, and fiber advantages from such additions.
Each pulse brings a slightly different flavor and color influence. Lentils provide a distinct flavor and color enhancement, while those with yellow peas are notable for their slight yellow color and greater sweetness. Chickpea flour, meanwhile, does not noticeably alter the color or flavor.
Given their familiar, neutral nature, tortillas give producers the opportunity to more effectively showcase the flavor, color, and texture improvements brought about by the addition of pulses.
Pulses are able to deliver heightened nutritional value without compromising the appearance, texture, or taste. Legume-enriched tortillas are also stable, durable, shippable, and not prone to rapid degradation. See pages 164-167 for sample tortilla formulations.
The expanding popularity of tortillas has helped spawn consumer interest in flat-breads. In some Middle Eastern breads, pulses are actually already part of the traditional recipes. With other flatbreads, pulses can contribute to improvements in a range of varieties, from crispy to bubbly to bready. Styles include lavosh, pita, focaccia, naan, arepa, paratha, bammi, barbari, gorditas, horo, injera, chapati, and sopes.
Like tortillas, pulse-fortified flatbreads benefit from a more balanced macronutritional profile (e.g., carbohydrates, protein, fat, etc.) than equivalent products and provide superior fiber and protein content. Pulses also contribute additional flavor and a degree of ingredient authenticity when incorporated into the production of naan and cracker flatbread. See pages 168-169 for sample flatbread formulations.
Rolls and Biscuits
Incorporating pea flour is an effective way to bolster the fiber and protein content in quick breads, rolls, and buns. In one example, U.S. food technologists added 30 percent pea flour to a conventional commercial burger bun formula and then optimized for moisture. The result was a bun with 4 grams of fiber and 7 grams of protein. The product also achieved a delicious flavor while maintaining the product’s traditional texture and appearance. See pages 170–171 for sample formulations.
Other baking examples: Crackers
See a sample formulation on page 172.
See sample formulations on pages 173–174.
See pages 157–163 for other sample baking formulations.
Legume flours continue to be explored as a fortifying ingredient in pasta and noodle products, especially instant noodle formulations. Food producers and researchers have found that increasing pea flour in noodle products can increase elasticity, boost dough strength, and enhance the texture of noodles, while promoting the softness and chewiness found in traditional noodle formulations.
Pea flour has also been shown to impact the flavor profile and aroma of such products. Recent studies have suggested that an 80 percent pea flour, 20 percent wheat flour combination provides the optimal balance for taste, texture, and aroma.
The amount and type of pea our used directly impact the flour’s effects on the final product. For example, sensory qualities like flavor and texture tend to decrease with the use of cool season peas. See page 175 for a sample pasta formulation.
In recent years, pulse-based fortifications are being considered an innovative and potentially beneficial ingredient in baby foods for children aged 1 to 3 years old. Typically, a soup or porridge-like product, the formulations are naturally fortified with the vitamins A, D, E, iron, folic acid, and other important nutrients from pulses, while providing a balance of essential amino acids.
Such baby foods increase the daily intake of carbohydrates and protein, with product protein in some preliminary studies reaching 15 percent. Producers are similarly quick to point out the important role such products can play as an alternative for those children who are lactose intolerant or allergic to soy products.
The low cost of dry peas, in combination with rice, leads to overall lower product cost, making the foods an attractive option to manufacturers and consumers. This is especially true when the lower costs are considered alongside dry peas’ nutritional and microbiological benefits, and their long shelf life (up to 19 months with some products). See page 176 for a sample cereal formulation.
Fortified Beverages/UHT Ready-to-Drink
As market trends continue to point to a growing interest in more healthful food choices, commercial food processors, as well as private volunteer organizations (PVOs), are now attempting to bring pulses to beverage formulations as well.
Always looking for easy and effective ways to fill the gaps in their diets and daily nutrient requirements, health-conscious consumers are being introduced to a new generation of pulse-fortified beverages. The combination in these drinks of pulses and rice as the main raw materials results in a product with a balance of essential amino acids, as well as folic acid and other important nutrients.
In addition, the versatility and low cost of dry peas, lentils, and chickpeas allow the drink products to be used as an inexpensive extender or replacement for milk, soy, and other drinks that are already well-established in the market. These ready-to-drink products also provide a welcome convenience to today’s busy consumer by virtue of their easy portability. Sterile, UHT packaging, meanwhile, allows for simple, low-cost storage and a long shelf life.
See Appendix C for a collection of all sample formulations.