Specialty ingredients from grains
By Suanne J. Klahorst
Contributing Editor, Food Product Design
Table of Contents
Corny ingredients
Soy in the mainstream
Really rice
Barley parley
Oat and rye guys
Wheat just like mummy's
Quinoa is keen
Food ingredients made from the starchy endosperm, the protein- and lipid-rich germ, or the fiber-laden pericarp of a grain are as much of a staple to food product designers today as they were to the diet of the common man in ancient history. The contemporary place occupied by grains in defining a healthy diet ensures that they will continue to maintain their place in the modern history of the human diet.
In the language approved by the FDA for health claims for grain-enriched products, "diets rich in whole grain foods and other plants foods and low in total fat, saturated fat and cholesterol, may help reduce the risk of heart disease and certain cancers."
Science plays a part in the modern granary, but so does history. Just as quickly as biotechnology adopts a new trait that promises to increase yield and reduce the use of agrochemicals, old grains are rediscovered, revived and embellished with science and folklore that transform something old into something new and appealing to the adventurous 21st century browser.
Indians in the Western hemisphere had grown corn for thousands of years prior to Columbus' arrival in the New World. The Indian name for corn was ma-hiz; the early settlers called it maize. It was so valuable that it was used as money and traded for meat and furs.
Corn flour, corn masa, cornmeal and corn grits are just a few of the many specialty ingredients that can be obtained from two varieties, yellow and white dent corn. The yellow dent corn is slightly higher in vitamin A than its white counterpart. Flaking grits are the basis of corn flakes for breakfast cereals, while cornmeal and corn flour are used for puffs and shaped cereals. Cornmeal is a popular ingredient in batter, baking and stuffing mixes.
Corn masa, the traditional ingredient of Mexican tortillas, has now been usurped up to 50% by the more popular industrial corn flour, due to the ease of use, lower water requirement and improved consistency in continuous processing. Corn flour can be made from white or yellow dent corn. Organic flours are also available from blue, white and yellow corn hybrids. Corn masa continues to play a dominant role in the manufacturing of corn and tortilla chips.
Corn kernels contain an average of 75% starch. As a result, cornstarch is one of the most abundant forms of starch produced domestically, and is converted into sweeteners and other nutritive sources of energy with the use of hydrolytic enzymes and chemical processes. The hydrolysis of cornstarch to food ingredients is a vast science that has produced thousands of different products with unique functionalities.
Maltodextrins, made from partial hydrolysis of cornstarch, are well-established nutritive carriers for many products, including tabletted nutraceutical supplements. Research has shown interesting applications that go beyond acting as mere fillers for other nutritional ingredients, though. In the health beverage market, they are valuable as a source of low osmole, a readily-absorbed carbohydrate for sports drinks.
Osmolality refers to the number of molecules in a solution and the tendency of a high concentration of molecules to pull water through permeable membranes such as human cell walls. A high concentration of sugar molecules in the gut will pull water out of the cells during physical exertion, contrary to the goal of maintaining hydration.
Maltodextrins provide a readily-available source of glucose with a lower contribution to osmolality, since the number of molecules is less than for an equivalent quantity of glucose. According to Celeste Sullivan, senior applications chemist, Grain Processing Corporation, Muscatine, IA, "Clinical studies show that there is no significant differences between blood glucose response curves whether the maltodextrin consumed is 5 DE or 20 DE This makes maltodextrin an excellent source of readily available energy."
Sullivan recommends the agglomerated version for instant powdered drinks since it is highly dispersible. "By the time it reaches the bottom of the glass it is already dissolved," she says. To provide palatability, crystalline fructose is used to provide sweetness along with flavors, mineral salts and vitamins. Maltodextrin is an excellent way to add nutrition to a beverage without it becoming overly sweet or masking flavors. Maltodextrins can also be used in infant formulas, as binders in cereals and snacks, as carriers for artificial sweeteners and spice blends, as dispersing agents in coffee whiteners, as film formers in glazes and coatings and as cryoprotectants to control ice growth in frozen foods.
Soybeans were utilized for centuries in Asia; however, now worldwide consumption of soybeans has increased to its present level of four to five pounds per capita. Today, as Frances Moore Lappe's classic book "Diet for A Small Planet" forecasted, people are seeing the benefits of eating soybeans directly rather than processing it into muscle protein through the digestive system of swine and cattle. Although soybeans are classified as a legumes, their utilization is similar to grain. Human consumption of the whole bean remains low, but components of soybeans show great promise in the coming decade, particularly those derived from soy protein.
Soy protein has been favored by vegetarians and the health-food industry alike as a low-fat protein source. Combining textured soy protein with textured wheat protein and other wheat-gluten-based binders provides a well-balanced amino acid profile. Additionally, persuasive disclosures to the consumer that its phytochemicals appear to be useful for prevention of diseases such as cancer and heart disease has increased demand.
Soy contains a class of phytochemicals that are referred to as isoflavones which mimic the female sex hormone estrogen (hence the term phytoestrogen) and has sent a whole generation of female peri- and post-menopausal baby boomers in search of the perfect soy latte on which to launch the day. The isoflavones that are getting the majority of press are genistin and diadzein, as well as some of their associated chemical cousins.
Defatted soy flour, generally by a hexane extraction, is one of the richest isoflavone sources, with levels as high as 2.0 mm per gram of soy protein. Soy concentrate that is aqueous-washed rather than alcohol-washed is another good source at 1.5 mm per gram. In comparison, soymilk can contain as little as 0.1 mm per gram.
Still, soy milk is increasing its market share. Alan Routh, president and CEO, SunRich Inc., Hope, MN is enthusiastic about the improvements in soy milk and their current popularity in new beverages such as smoothies and blended teas. "It is exciting to see new good-tasting, high-quality soy products coming on the market to be enjoyed by people who previously didn't enjoy soy," he says.
Soy milk is typically made from a soy milk base, a whole-bean extraction by soaking, grinding, and straining. This base is available as a liquid or a spray-dried powder, but like powdered milk, it develops a cooked flavor during evaporation. Therefore, the liquid base has a more desirable flavor, while the less perishable, powdered version is useful for reconstituting into soy cheese, adding to frozen desserts, or as an alternative to dairy solids in baking mixes and dry formulations. Soy milk is an excellent source of high-quality protein and B vitamins, and makes an excellent milk substitute for lactose-intolerant individuals.
Soy proteins are available in three major forms that are all derived from defatted soybean flakes: soy flours and grits; soy protein concentrate; and soy protein isolates. Defatted flours and grits range from 40% to 54% protein, 30% to 32% carbohydrate, 2.5% to 3.5% fiber and up to 1% fat. Functionality of soy flours and grits is related to their capacity to bind water and absorb fat. These characteristics vary according to the particle size and the degree of heat treatment that the flour and grits undergo, resulting in protein denaturation. In general, lower heat treatment and smaller particle size means more functionality. As a general rule, up to 3% of wheat flour can be replaced by soy flour without any adjustments other than water addition, approximately a 1:1 to 1:1.5 ratio based on weight of soy flour.
New processes for micromilling soybeans are capable of converting whole soybeans into soy flour. This dry grinding process results in flour with a particle size of less than 20 microns. The flour is completely water-soluble and forms a suspension in water, making it suitable as a basis for soy-based beverages, frozen desserts, non-dairy yogurts and puddings.
The oil in the soybean becomes an advantage in the micromilling process, because it reduces the heat created by friction. The natural tocopherols in the oil make it resistant to fat oxidation, and therefore it is shelf-stable for up to two years. Since the flour is subjected to very little heat during milling, pasteurization or other types of thermal processing are recommended to inactivate natural enzymes, trypsin inhibitors, and to remove beany flavor.
Soy protein concentrates have a protein content of at least 65%. The protein is concentrated by one of three processes, acid leaching, alcohol extraction, or denaturing protein with heat and extracting with water, called aqueous extraction. Soy protein concentrates have improved flavor characteristics when compared to soy flours. They are capable of forming fat emulsions in food systems that stabilize fat micelles. The emulsifying properties of soy protein concentrate are affected by pH and temperature. The polysaccharides in concentrates bind a significant amount of water, some of which can be tightly bound in the finished product.
Textured soy proteins (TSP) undergo additional processing to impart a structure similar to that of a meat product, such as fibers or chunks. These products have enabled the veggie burger market to grow by about 15% a year. They are used to make meat analogs that resemble meat, seafood or poultry after rehydration. TSP is made by thermoplastic extrusion or steam texturization of soy flour using several methods, some of which are proprietary.
Soy protein isolates (ISP) are the most highly refined of the soy proteins and represent the major protein fraction of the soybean. They contain no less than 90% protein. The isolate is often neutralized with sodium or potassium to make it more soluble and enhance its functional characteristics. Isolates are used in infant formulas, meats and other protein-enriched foods.
In October 1999, the FDA granted approval for health-claim labeling of foods that contain 6.25 grams of soy protein per serving; less than 3 grams of fat; less than 1 gram of saturated fat; less than 20 mg of cholesterol; and less than 480 mg of sodium. Products meeting the criteria can make the following labeling claim: "diets low in saturated fat and cholesterol that include 25 grams of soy protein a day may reduce the risk of heart disease."
While the difficulties of getting 6.25 grams of soy into a serving of bread are still being overcome, pasta seems to be a natural fit according to Russ Egbert, Ph.D., director, protein applications research, Archer Daniels Midland, Decatur, IL.
"Pasta shows a very good potential for meeting these claims, as the product can easily incorporate soy protein at a level of up to 20%," says Egbert. "Soy protein is experiencing a significant growth in the functional food area, particularly in light of the allowable claims that were approved by the FDA last year."
An ancient grain that has been a staple for centuries, rice provides ingredients with unique functional characteristics and health benefits. Some innovative rice ingredients are blends of rice components or blends of rice and soy that complement each other. For example, in beverages, soy protein isolate can add protein, however it is not very soluble for instant beverages. The addition of gelatinized, hydrolyzed rice flour serves as a stabilizer to keep protein insolubles suspended in solution, similar to the action of emulsifiers like lecithin. Rice starch also has a high glucose index for quick energy and maintains viscosity in a shakes and smoothies.
High-protein crisp rice is being extruded from a blend of soy and rice components. This blended crisp works in health bars and cereals formulated for FDA soy claims. The bland neutral flavor of rice dilutes the distinctive flavor of soy protein, and with 50% soy protein, it is not difficult to get 12 to 13 grams of these grainy crisps into a bar or cereal.
Neal Hammond, Ph.D., principal scientist food nutrition, Pacific Grain Products, Woodland, CA, explains the unique functionality that rice ingredient blends can add to the meat industry, "PAC-PRO improves meat products in several interesting ways.
"In muscle meat, injection of a blend of rice flour and naturally occurring rice bran oil fixes the hemoglobin and improves the color of the meat. It also serves as a tenderizer, for which the mechanism is still unknown, but has been confirmed at several universities including the University of California-Davis and University of Minnesota," he says. An additional benefit is the elimination of a warmed-over flavor in precooked meats, due to the action of the antioxidants in the rice bran oil. A blend of rice flour and naturally occurring rice bran oil fixes the hemoglobin and improves the color of the meat. "
A typical formulation includes up to 3.5% of the rice ingredient, which appears on the label as rice flour, rice bran, and BHT. Recommended uses are in sausages, hot dogs, jerky, and formed meats.
Rice bran is one of the most nutritious cereal fibers when its fat content is intact. The RiceX Company, El Dorado Hills, CA developed technology to stabilize the oil-rich bran, which is said to contain more than 70 antioxidants. A nutraceutical product derived from stabilized rice bran is high in polyunsaturated fatty acids, water- and fat-soluble vitamins and protein. It has a sweet, malt-like taste and is available in a fine powder. RiceX recently entered into an agreement with the newly created nutraceutical company NutraStar, who will develop therapeutic delivery systems for oil-rich rice bran such as food bars that will be distributed via the Internet. Health benefits are being investigated for treatment of atherosclerosis, hyperlipidemia and diabetes, some in collaboration with the University of California, Los Angeles Harbor Medical Center.
Flaxseed, an ancient high-fiber grain, was cultivated and praised by the Babylonians, Greeks, Romans and East Indians. Flax was adapted to the soil and climate of the Canadian prairies in the 1600s, making Canada one of the largest flax producers in the world. Flaxseed's shape and size are similar to sesame seeds (1000 seeds weigh 5 to 7 grams) and it has a rich, reddish-brown color and a nutty flavor. In high-flaxseed formulas, it can double as a primary flavoring agent.
Its high soluble- and insoluble-fiber content (22% to 29%) and equally high protein content (17% to 22%) make it a favorite in the health-food industry. Recently, however, its high polyunsaturated fatty-acid content gives it increased desirability among the health-food crowd. Flaxseed has up to 45% fat, 57% of which is omega-3 polyunsaturated fatty acid, with the remaining portion divided between monounsaturated and omega-6 polyunsaturated fatty acids. This makes the alpha-linolenic-rich flaxseed a higher source of these cardiovascular-health promoters than any other oilseed. It also is a rich source of the phytochemical, lignan.
Flaxseed is available in whole form or milled. Like sesame seed, product designers can use it as an ingredient or as a garnish. Milled flaxseed is sold in two forms of flaxseed flour, regular and defatted. Regular milled flaxseed has a granular texture with a similar flow to wheat bran. Its high oil content allows it to replace some fat when incorporated into doughs. Defatted flax flour has a finer texture to add fiber and nutrition to low-fat baked goods.
According to the Flax Institute of the United States, North Dakota State University, Fargo, flaxseed should be ground or milled to get the maximum nutritional value. Some nutrition will be released during chewing, but it could pass through the gut undigested except for the seedcoat's soluble gum. The Institute recommends a daily dose of ground flaxseed of 35 grams per 150 lbs. body weight. This can be consumed in one muffin, provided the muffin is 75% flax flour. As with most high-fat grains, regular flax flour must be stored in refrigerated or frozen conditions to prevent oxidation of its polyunsaturated fatty acids, although good results have been reported for whole seeds at room temperature for 6 months.
Whole flaxseed has found a natural home in the baking industry, and in whole grain breads it can be substituted for flour at levels of 10% to 15%. Healthy snacks and cereal bars have incorporated flaxseed at levels up to 30% to 40%. When used as a baked-goods garnish, flaxseed requires pre-soaking before adhering to the product with an egg, water, or starch wash. When exposed to high temperatures, flaxseeds roast and darken, so a moderate baking temperature is recommended.
Milled flaxseed can act as a flour substitute, and offers additional functional benefits to dough rheology. The soluble fiber in milled flax flour resembles gum arabic, and can improve loaf volume when added from 8% by weight of dry ingredients to 15% on a flour basis. Its excellent water-binding properties requires an increase in water by 75% of the weight of flax flour. In yeast breads, yeast is increased by 25% to maintain proof time, texture and consistency. Shortening should also be decreased by calculating the amount of oil contributed by the flaxseed flour.
Barley was a staple in the ancient city of Jericho as long ago as 8000 BC, and the Babylonians were brewing with it in 2500 BC. To prepare barley for human consumption, the hull is removed by abrasion in a process called pearling, hence the familiar form known as pearl barley, a common thickener in soups. A variety of barley in which the hull falls off during threshing is termed hull-less, or naked, barley. It requires no pearling and the important nutrients found in the outer layer of the endosperm are preserved. Many varieties of barley are grown, including naked, waxy and non-waxy. Waxy hull-less barley may have 6% to 9% soluble fiber, versus barley that is hulled, which has only 2% to 4% soluble fiber.
The starches in various types of barley have distinctly different behaviors, and research is continuing to help food processors identify the cultivars that give the best results in specific applications.
Barley can be purchased in several forms in addition to pearl barley, such as pot barley, barley flakes, and rolled barley. Flour from barley can be whole grain - a lighter-color flour - or a darker-colored malted barley flour. Barley malt flour, like its malted analog, is rich in enzymatic activity and can be added to baked goods. The lack of gluten restricts its use in leavened bread to 10%, or appearance of loaf volume is affected. Barley flour has a 2.5-fold water-holding capacity compared to wheat, making it an ideal food thickener, binder or ingredient in oriental noodles. Washington State University, Pullman, has conducted research on utilizing barley flour to make udon noodles from wheat/barley flour blends. Adding barley flour improved taste and had no adverse effects on texture. Quick breads can contain up to 30% barley flour. Cakes, cookies, donuts, muffins and pancakes can be made from 100% barley flour.
Whole barley is generally soaked overnight before cooking, and one cup expands to four times its original size during cooking. For rice pilaf or risotto dishes that incorporate barley, a quick-cooking form can be prepared in 10 to 15 minutes. Near East Food Products, Chicago, has introduced precooked long grain brown rice, barley, and pearled red wheat with flavors and herbs in their Creative Grains line of side dishes.
Barley, rich in beta-glucans, can lower cholesterol when consumed in a variety of baked products. Its beta-glucan is more soluble than oat or wheat beta-glucan, and can be extracted and concentrated for use as a dietary-fiber supplement. Nutritional attributes vary, but most forms of whole barley are a good source of protein, B vitamins, and dietary fiber. Whole barley flour is 13.5% dietary fiber, compared to whole wheat's 9%.
Oats and rye were both weeds that grew in wheat and barley fields. European farmers allowed rye to grow with the wheat and harvested them together as a mixed crop called maslin that was milled into a combination flour. Like barley and soybeans, animals eat almost 90% of the oats grown domestically in the United States.
Old-fashioned rolled oats consist of hulled oats (groats) that are toasted, steamed and flaked to a precise, uniform thickness. Rye can also be rolled and processed in this manner. Toasting develops the characteristic oat flavor and also inactivates native enzymes that can cause off-flavors.
Rolled oats are an important component of granola cereals and can create specialty-bread topping. Oatmeal is also a popular grain for traditional cookies and muffins. There are several sizes of oat flakes, from "baby oats" for achieving a smooth texture to large flakes that preserve the whole-grain identity. Steel-cut oats are prized for their nutlike flavor.
The whole groat contains an outer pericarp, which holds the oat bran. Oat bran, high in the same soluble beta-glucans found in barley, has been incorporated into many baked goods for its cholesterol-lowering ability. Oat flour contributes protein, fiber and moisture retention in finished bakery goods. The beta-glucan is used to mimic fat, as it exhibits similar functional properties. For example, like fat, oat bran gels at room temperature but liquefies at cooking temperature. Oat flour starch is hydrolyzed to a standardized dextrose equivalent and dried to a powder. Once reconstituted with water, it forms a gel that can be used in salad dressings, gravies, dips, soups and coatings. Softer-gelling varieties are recommended for drink mixes and as fat replacers for baked products.
Rye flour is obtained from milling rye meal. The dark and light varieties of rye flour are interchangeable in recipes, but the dark rye flour has a stronger flavor. Rye has strong gluten proteins that are important to forming doughs in baked goods.
Wheat berry is a clever marketing term for unprocessed whole wheat. Orowheat Wheat Berry bread, Entenmann's, Bay Shore, NY has established this specialty bread as an industry standard; the whole wheat lends a characteristic mild, nutty flavor. This ingredient can top crackers and other bakery goods.
Germinating or sprouting the wheat kernel improves digestibility and increases bioavailability of protein, carbohydrates and vitamins. Sprouted wheat is subsequently toasted and used in breads to moisten the crumb and to lend a rich, malted flavor. The natural sweetness allows ready-to-eat cereal manufacturers to decrease the quantity of sweeteners in granola and museli. Wheat berries are being utilized in pilaf and in quick-cooking whole-grain side dishes. In cereals, wheat flakes form the basis of many leading brands. Several forms that add interest are pearled wheat, cut wheat, wheat flakes, quick wheat flakes, and instant wheat flakes.
Wheat protein is used as a binder and textural ingredient in meat analogs. Its fibrous structure mimics the texture of beef, chicken or pork, and it produces a bland flavor profile. When rehydrated, it has outstanding water-binding capacity that maintains structural integrity. Most veggie burgers incorporate texturized wheat gluten with soy protein concentrate to simulate ground beef. In coatings, wheat protein increases batter adhesion and viscosity and provides a film-forming barrier to fat and moisture. Technologists at Midwest Grain, Atchison, KS, discovered that wheat proteins are also ideal for replacing egg whites in pasta to maintain structural integrity after retorting. When added to pasta made from soft wheat flour, the noodles behaved as though they were made from durum flour.
Aside from the many wheat varieties grown for their gluten-rich flour that lends leavened bread its loft, ancient varieties are making a comeback. None is more colorful in its folklore than Kamut (pronounced ka-moot), an ancient relative of durum wheat, but with 20% to 40% more protein, which was recognized by the USDA in 1990.
The story of how the Quinn family of Fort Benton, MT obtained the remaining jar of Kamut, or "King Tut's Wheat," is part of the charm of this resurrected variety. Following World War II, a U.S. airman claimed to have taken some grains from an Egyptian tomb, which were then mailed to a friend's father, a Montana wheat farmer, who displayed the wheat as a novelty at the county fair. This was obtained by the Quinns, who propagated the crop and trademarked the name Kamut, which is thought to be the ancient Egyptian word for wheat. A less colorful explanation offered for its origin is that it is an obscure grain passed down by farmers in Egypt and Asia Minor.
Larger than its durum relative, (its taxonomic classification is in dispute), Kamut is prized for its sweet flavor, natural firmness, and possible hypoallergenicity. Kamut wheat is reported to make excellent pasta, and is certified organic, which is important to Eden Foods, Clinton, MI, which sell Eden Organic Pasta Company's Kamut Spirals, containing 10 grams of protein and 6 grams of fiber per 55-gram serving.
The Egyptians, as it turns out, were not the only ones hoarding traditional varieties of wheat. Spelt, the primary wheat grown in the United States and Europe in the 19th century, is one of the oldest cereal grains known to man, a mere 9,000 years at the minimum. It takes its name from its taxonomic classification, Triticum spelta. Tuscany breads contain spelt, which is ground into farina. Spelt is said to have an almost hazelnut flavor. Some claim that spelt is less allergenic that conventional wheat, but like Kamut, it contains wheat gluten.
Quinoa, pronounced keen-wah, is not a true cereal grain, but like buckwheat, it is the botanical fruit of an herb. Quinoa was considered the "mother grain" by the ancient Incas in the West Andes Mountains of South America. It has regained popularity in the Space Age due to its high protein content (15%) rich in the amino acid lysine.
Quinoa appears as small yellow, flattened spheres that resemble millet, ranging from 1.5 to 2.0 mm in diameter. It is often prepared by toasting in a pan for five minutes, after which it is cooked similarly to rice with a 2:1 ratio of water to grains. A variety of colors are available from dark brown to nearly white. Quinoa processors are now offering a number of ingredients including quinoa flour, puffed quinoa, and quinoa flakes.
Recommended uses include hot breakfast cereal; as a rice replacement or added ingredient to rice dishes such as pilaf; and to add nutrition and interest to soups and salads. The pericarp, or seedcoat, of quinoa is high in saponin. Saponins impart a bitter taste, but this can be easily removed by rinsing the seeds in cold alkaline water. Quinoa is also high in calcium, phosphorous and vitamins B and E. It has a rich, delicate flavor and the leaves can also be eaten. It is perhaps for these reasons that it has been chosen as a candidate food source for NASA's Controlled Ecological Life Support System for long-term space exploration.
Ingredients from grains, whether they are ancient whole grains that tantalize the imagination or new varieties with enhanced functionality, will continue to occupy the principal role in feeding the world. It is no small wonder then, that the food industry continues to find new nutritional benefits from incorporating grains and their ingredients into product lines that offer the consumer a cost-effective basis for sound nutrition and health maintenance.
Suanne Klahorst is associate director of the California Institute of Food and Agricultural Research (CIFAR) at the University of California-Davis. CIFAR serves as an informational clearing house for research programs and results related to food, nutrition, and human health at that campus. She can be contacted at sjklahorst@ucdavis.edu.
• Photo: USA Dry Pea Lentil Council
• Photo: Northharvest Bean Growers Association
• Photo: National Turkey Federation
• Photo: National Starch and Chemical
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