Building Better Breads

March 1, 2003

24 Min Read
Building Better Breads

From plain white and honey wheat to hearty rustic, U.S. consumers are finally discovering the many varieties of breads that Europeans have enjoyed for centuries, as well as the countless eating occasions when they can enjoy it. This long-overdue love affair presents bakers with the chance to design and optimize innovative formulas that improve the quality and nutritional profile of bread, at the same time ensuring its shelf life, ease-of-processing and consistent final-product specifications.

Since all breads must contain somewhat established proportions of the same basic ingredients — flour, fat, leavening, sugar and water — to be characterized as such, bakers are challenged when they want to add new ingredients for functional and nutritional improvements. Even the slightest variation in ingredient quantity or manufacturing procedure can equate to measurable differences in the final baked item.

To prevent discrepancies, most ingredients are weighed, rather than measured by volume. This eliminates potential inconsistencies with measuring dry ingredients, such as flour, due to individual bakers’ variations with sifting and packing procedures. The exception to this is with liquids, which are typically quantified as a volume-of-liquid to weight-of-flour ratio (i.e., 1 pint/lb.).

While exact, consistent ingredient measurement is the first step to building consistent, quality bread, a close second is the knowledge that, once a formula is defined, bakers must use the exact ingredients and the precise amount specified every time. Even the slightest variation in ingredients can produce noticeable changes in the finished bread. For example, because gluten proteins must absorb liquid before they can be developed, water addition is important. Varying the water volume even slightly can have a detrimental effect on bread quality.

Pick a bag of flourWhen it comes to selecting flour for breadmaking, all flours are not created equal. Refined flour, such as regular wheat (all-purpose) flour, contains only the endosperm portion of the grain kernel. Whole-grain flour, on the other hand, includes the grain’s germ and bran, which contain most of the fiber, oil and B vitamins of the kernel. Thus, whole-grain flour has a more nutritious positioning compared to refined flour. However, practical reasons exist for refining wheat. For one, the bran and germ dilute wheat flour’s breadmaking qualities — the ability to be leavened by yeast. Also, large lipid concentrations in wheat’s germ and bran layers make flour more susceptible to oxidation, thus shortening shelf life.

Yeast can leaven wheat-flour dough because wheat endosperm contains the important storage proteins gliadin and glutenin. When these proteins are kneaded with water, they form gluten, a plastic and elastic protein complex that gives bread structure. As dough is kneaded, the gluten forms long, elastic strands. These strands capture the gases produced by the leavening agent in tiny pockets or cells, causing dough to rise. This occurs because gluten stretches under pressure at the same time it resists pressure.

In yeast breads, gluten expands to accommodate gas produced by yeast, containing gases rather than stretching to the point of bursting. If dough were wholly plastic, gas would migrate to the surface and escape; if only elastic, gas would accumulate in a few pressurized pockets and bread would be heavy and coarse. Baking dough coagulates the gluten, giving bread its structure and strength.

Rye is a grain with proteins capable of forming gluten, but compared to wheat gluten, rye gluten is inferior and weak. Barley also contains some gluten. Because the proteins in other grains cannot form sufficient gluten, bakers must combine other grains with wheat flour when making yeast-leavened bread. Otherwise, the end product will be extremely heavy and dense.

Flour’s gluten content is very important to bread bakers. Ingredient quantities and the manufacturing process are determined, in part, by how they affect gluten development, which in turn influences the bread’s structure. Up to a point, the more dough is kneaded, the more the gluten develops. However, it is possible to overdevelop dough. This occurs when dough is kneaded too long and the protein is overstretched. The dough turns into a thick fluid with no elasticity. The goal is to develop highly elastic dough, which means maximum gas retention, loaf volume and fineness of texture, without passing the invisible boundary of overdevelopment. While overworking dough by hand is difficult, it is quite easy in a commercial manufacturing operation. Timing the kneading process ensures consistency in finished baked bread.

Bakers have several methods for adjusting gluten development. The obvious first is with flour selection. Strong flours from hard wheat have high protein contents and are required in all bread formulas. Even a typical U.S. rye bread usually contains only about 30% rye flour, combined with 70% strong wheat flour.

Very strong flours are important in commercial baking operations where high-speed machines work the dough in a very short time. Bakeshop and artisan bakery operations have more flexibility. “A new artisan bread flour is milled exclusively for artisan bakers,” says Kent Lyman, director of packaged brands, ADM Milling Co., Overland Park, KS, a division of Archer Daniels Midland Company (ADM), Decatur, IL. He adds that the product, which is derived from a blend of select clean, sound, hard red winter wheats, “combines excellent fermentation tolerance and great oven spring with easy-to-work dough-handling properties.” The unbleached, unbromated and enriched flour has a protein content of 12.25%, which he says “produces a strong-enough dough for artisan bread makers to add particulate ingredients to breads, such as sun-dried tomato bits, sunflower seeds and raisins. The dough also easily forms into different shapes. Standard loaf pans are not necessary.”

Enzyme accommodationsIn commercial baking applications, protease-enzyme addition helps maintain a consistent schedule when flour-protein levels and, consequently, mix times change. “Proteases are minor, inexpensive ingredients that can have a major impact on profits,” says Peter Moodie, director of sales and marketing for New York-based Enzyme Development Corporation. “For example, assume you have a bakery that is optimized using two mixers for finished doughs and produces one dough every 10 minutes, which is six doughs per hour. If the operation runs 18 hours per day, you are producing 108 doughs per day. If, on any given day, you have to make bread that uses stronger flour instead of the typical flour in the standardized formula, mix time has to be extended to accommodate the higher protein level. Now you are outputting one dough every 12 minutes, instead of every 10 minutes. This equates to only 90 doughs in that same 18 hours. To make the same amount of bread, you need to pay your plant 3.6 hours of overtime. Plus the oven and proof box would run an extra 3.6 hours.” But adding protease to the formula resolves this type of problem. “The added expense of a few dollars per hour in protease is more than justified by the alternate loss in production,” he adds.

Proteases perform two basic types of enzyme action on the protein polymer in bread. The “endo” action is defined as random splitting of the polymer anywhere along the chain. This action contributes most to dough relaxing, preventing dough shrink-back, better bread volume and pan flow, and faster bakery throughput.

Proteases take a long polymer and break it into small bits. In the case of bread dough, “proteases help break down sulfite bonds so gluten develops quicker, enabling a baker to stay on schedule when a stronger flour than normal is used,” Moodie says.

The other type of action is “exo,” defined as specific cleaving of a terminal group on the polymer. In the case of proteins in bread dough, an amino acid, or a di- or tri-peptide is cleaved. “The most common application is to debitter a protein hydrolysate, such as cleaving leucine,” he says. “The free amino acids also contribute to browning and to bread flavor.”

The shortening of itCommercially baked bread usually contains some type of fat ingredient — either solid or liquid — to improve crumb softness, volume and texture. The fat is typically referred to as shortening because its primary role is to “shorten,” or break up, masses of gluten, thus weakening the structure and making the final bread more tender. When mixing the dough, the fat surrounds the gluten particles and lubricates them so they do not stick together. In essence, the fat ingredient acts as a tenderizer. Compared to other baked products, such as cakes, bread formulas generally use little shortening, as bread dough does not require as much tenderization as cake batter.

Another important function of fat in breads is to slow moisture loss by coating the starch granules. This lengthens the bread’s shelf life by reducing staling. Research shows that, compared to formulas with no added shortening, shortening levels of 3.0% to 4.5% of total dough weight will increase final loaf volume by up to 20%, with most of the increase coming at the lower added-shortening level. Some research also indicates that the higher the melting point of the fat, which is associated with solid fats, the more it will increase loaf volume.

Vegetable shortenings and butter, both solid fats, have historically been the shortenings of choice in bread formulas. Unfortunately, traditional vegetable shortenings — which are high in trans fatty acids — and butter — which naturally contains some trans fatty acids and is high in saturated fatty acids — have negative connotations because of the harmful health implications associated with these fatty acids. Saturated-fatty-acid consumption has been linked to raising total blood cholesterol levels, and trans-fatty-acid consumption is associated with increasing total and low-density lipoprotein cholesterol levels (bad cholesterol), suggesting that both fatty acids increase the risk of cardiovascular disease.

These negative health implications have bakers searching for alternatives to using vegetable shortening and butter in bread formulations. Researchers at USDA’s Agricultural Research Service (ARS), Fargo, ND, have identified that a bit of oat oil — which is trans-fatty-acid free — could make bread more heart-healthy. “Oat oil is rich in phospholipids and glycolipids, also called polar lipids,” says Douglas Doehlert, Ph.D., ARS cereal chemist. “This type of oil combines with water to lubricate bread dough, to help it rise evenly, and bake into a loaf that is uniformly soft and springy, even after several days of storage.”

In an experiment at North Dakota State University (NDSU), Fargo, researchers compared bread formulations made with either 3% crude oat oil or the same amount of vegetable shortening. In each case, loaf volume, appearance and resistance to staleness proved the same. The researchers also found they could achieve the same result by replacing the vegetable shortening with just 0.5% polar lipids taken from the oat oil. The polar lipids worked better in bread made from hard red winter-wheat flour than in bread made from hard red spring-wheat flour, since dough from the former needed less shortening to increase loaf volume because of its high gluten content.

In a separate project, ARS researchers bred a new kind of durum wheat, a waxy durum wheat (WDW). Doehlert and NDSU associates found that WDW flour could replace vegetable shortening without losing the desired properties shortening confers to bread. A single bread loaf might have two tablespoons of shortening, so replacing that with WDW flour saves about 26 grams of fat, or 234 calories.

Doehlert credits WDW flour’s fat-replacing capacity to a unique type of starch not present on other wheat grains. Starch, a polymer of glucose molecules, contains both amylose and amylopectin. Amylose is the straight-chain form, while amylopectin is the branched form. Most wheat grains contain about 24% amylose and 76% amylopectin, but WDW starch is nearly 100% amylopectin. “WDW flour works best as a shortening substitute when it comprises 20% of a dough formulation,” he says. “In trials, 0.25-lb. loaves of the experimental bread had the same softness, texture and volume as those containing 100% bread wheat flour and 3.25 grams of shortening. And in tests for freshness, the WDW bread stayed much softer than the nonwaxy wheat bread after five days of storage.”

Enova™ oil — manufactured and marketed in the United States by ADM Kao LLC, Decatur, IL, a joint venture between ADM and Kao Corporation, Tokyo — is a healthful oil with potential bread applications. Tony DeLio, corporate vice president of marketing and external affairs, ADM, notes that breads made with the ingredient taste the same as those made with traditional oil, and that most of the time there is no need for manufacturers to change their processing and mixing parameters.

Enova has essentially the same calories and fat content as the soy and canola oil from which it is converted; however, when consumed, instead of being stored as fat, more of it is metabolized as energy. The oil is mostly composed of diglycerides, which are a glycerol backbone with two fatty acids. Most of these diglycerides have the fatty acids located in the first and third position. DeLio says the oil’s benefits are derived from this unique structure because, compared to other oils, when the body metabolizes the fat in Enova oil, fewer triglycerides appear in blood. This occurs because more of the oil is burned as energy in the liver, rather than stored in fatty tissue in the body. This, he says, results from the number and position of fatty acids carried on the glycerol backbone of the oil.

Salatrim, an acronym for short- and long-chain acyl triglyceride molecules, is another lower-calorie fat with bread applications. New Century, KS-based Danisco USA, Inc. offers salatrim under the name Benefat®. Terese O’Neil, business director for Benefat, notes that since the product is a fat, “it will perform as a one-to-one shortening replacement in yeast breads.” She adds that the ingredient offers a trans-free and lower-calorie alternative to shortenings in baked goods. Salatrim — a mixture of triglycerides consisting of at least one long-chain fatty acid and one short-chain fatty acid per triglyceride molecule — provides just 5 kcal/gram, compared to the 9 kcal/gram found in conventional fats, because of the way the body metabolizes the fatty acids.

Getting into conditionBakeshop bakers have more hands-on control in the breadmaking process than commercial bakery operations, where bakers must rely on the addition of facilitating ingredients to ensure proper bread-structure development and shelf life.

“Manufacturers of wholesale fresh bread do not have the luxury of time when baking yeast-type breads,” says Vernetta Dally, manager of applications and technical support, Balchem Encapsulates, New Hampton, NY. “One ingredient they almost always use is dough conditioner.”

Dough conditioners improve yeast-dough performance during processing and baking, as well as produce a softer crumb and bread that is easy to slice, with fewer crumbs at the slicer. “There are many different ingredients used for dough conditioning,” says Charles Morris, manager of research, ADM Specialty Ingredients, Decatur, IL, a division of ADM. “The ingredients cause a complex reaction with the gluten and starch in the flour, greatly enhancing all aspects of the baking operation.” Morris adds that the most recent advances in dough conditioners involve the use of blends. “This is because no one dough conditioner does everything,” he says.

“A specially formulated, all-vegetable dough strengthener and crumb softener is especially effective in whole-grain and high-fiber specialty breads,” continues Morris. “The conditioner provides dough with the strength to withstand the harsh mechanical treatment encountered during processing, particularly in highly automated systems, where the dough could collapse while being conveyed or loaded into the oven.”

Traditionally, potassium bromate was used as a dough conditioner; however, it is being phased out in breadmaking because of possible health concerns. This oxidizing agent was an ideal conditioner in terms of its slow release profile. A significant amount remained in the dough and was available at the proofing and baking stages to provide good oven spring, which resulted in good loaf volume. Ascorbic acid can replace bromate, but it requires encapsulation. Otherwise, it releases too early in the mixing stage.

“Technological advancements have enabled us to encapsulate dough conditioners to ensure that the facilitating ingredient is not released too early into the dough,” says Dally. “If that happens, the dough gets too tight too early, and mixing time increases. Lipid-encapsulated dough conditioners are timed to release at the end of proofing, right before baking or right at the start of baking.”

The “en” crowdEncapsulation also enables manufacturers to add ingredients that reduce the chance of molding through bread’s shelf life. “Mold inhibitors will also prevent the yeast from fermenting, so it is very important that they not be released into the dough until after the yeast have completed the fermentation process,” Dally says. “Encapsulated mold inhibitors, such as sorbic acid and calcium propionate, are released as a result of exposure to high temperatures during the baking step.”

Morris adds: “Shelf-life extenders can also be enzymes. In fact, use of enzymes in breads is increasing. They are used at very low levels (less than 0.2%), but just a little can have a great impact on the finished bread.”

These ingredients are very specific in their effect on bread. “Early high-heat-stable bacterial alpha enzymes have been shown to extend shelf life from around four days to as many as nine days. Today, blends of different enzymes have given shelf life up to 30 days,” Morris says. “These enzymes work to break down gelatinated starch into simple sugars, creating moisture inside the bread. This helps keep the bread soft and fresh-feeling. As little as 0.12% of a concentrated enzymatic dough conditioner and softener produces bread with a whiter crumb, and finer grain and texture. This extends shelf life by keeping a soft, freshly baked crumb.”

Encapsulation is also a helpful tool for the addition of certain flavors and nutrients. “To cut down on fermentation time and to assist in making bread with a consistent sourdough flavor profile, bakers can replace traditional sourdough cultures with encapsulated sourdough flavors,” Dally says. “Unencapsulated sourdough flavors cannot be added directly to the dough, as these flavors are acids and will kill yeast before it ferments. Encapsulation releases the flavor at the right time during baking, after the fermentation is complete, to get a close-to-natural sourdough flavor profile.”

Interestingly, the principle flavor component in cinnamon — a spice frequently added to nonsandwich breads, and often in conjunction with raisins or other dried fruit — has an inhibitory effect on many microorganisms, including yeast. The component — cinnamic aldehyde — can inhibit yeast performance during proofing, resulting in underleavening and volume loss. To prevent this, bakers sometimes refrain from adding cinnamon to dough and apply it in the form of a topical crumble or sprinkle. Increasing yeast levels can counter cinnamon’s inhibitory effect; however, this is usually cost-prohibitive, as well as limited for sensory reasons.

“Microencapsulation is another option,” says Dally. “We developed an encapsulated cinnamon ingredient, which, in a yeast-bread application, proved to perform as expected.” She adds that bread made with the company’s encapsulated cinnamon was comparable in height to yeast bread made with no cinnamon, whereas yeast bread made with raw cinnamon was 16% to 25% lower in height.

Fitting fiber inConsumers aware of the healthful benefits of a diet high in fiber (i.e., a reduced risk of heart disease, hypertension, cancer, diabetes and obesity) know that switching from white to whole-wheat bread helps. Whole-grain products, in general, are many consumers’ preferred medium for boosting their daily dietary-fiber intakes.

ARS researchers were able to make whole-wheat bread more palatable to consumers when they used an ultra-fine, ground whole-wheat flour developed by ConAgra Foods Inc., Omaha, NE. According to scientists, bread baked with this flour had a taste and texture very similar to white bread, as well as six times more fiber. The flour is being used in some commercial breads, as well as other grain-based products, according to Glen Weaver, vice president of technical services for ConAgra Grain Processing Group, Omaha, NE. But the market is limited because the flour is made from white wheat, rather than more plentiful red wheat. ConAgra is working to gear up U.S. production of white wheat so the company can market the flour more widely.

Whole grains are not the only way to boost bread’s fiber content. Bakers can add specialty fiber ingredients to bread with minimal to no effect on the final product when formulas are adjusted for gluten and liquid levels.

National Starch and Chemical Co., Bridgewater, NJ, markets a line of specialty resistant starches under the Novelose® label. Rhonda Witwer, nutrition business development manager, notes Novelose 260 has application in all types of bread. “It has a clean, neutral taste and is white in appearance, which allows incorporation into all types of breads — even white — where it is undetectable by the consumer,” she says. She adds that, while most fiber ingredients change the bread’s texture, the starch “actually improves the quality of bread at the same time it boosts fiber content.” And since the starch contains 60% total dietary fiber, bakers can add enough to bread formulas to allow the final product to carry a “good” or “high” source of fiber claim.

David Huang, market development manager, National Starch, says the resistant starch “can be added to any fiber-bread formulation, replacing an equal amount of flour. Some adjustment in the water may be needed, as well as possibly the addition of some wheat gluten.” He adds that the company made a basic white bread containing 8.4% of the ingredient. “This bread qualifies as a ‘good’ source of fiber because it contains 2.5 grams of fiber per 50-gram serving,” he says. “If bakers wants to produce a ‘high-fiber’ bread, they need to replace 16.8% of flour with resistant starch.”

Novelose 260 holds significantly less water than other fiber sources. High water absorption can cause problems, such as stickiness during dough processing, which result in difficult-to-handle dough that does not expand sufficiently during the rising process. “Because it holds less water, it does not compete for the water needed by other ingredients, such as the proteins that form gluten,” Witwer says. She adds that the entire line of resistant starches “are composed of small crystalline particles, which contribute to uniform cell size in bread dough, thereby improving structure. This avoids the heavy, dense structure associated with high-fiber bread.”

As an additional benefit, resistant starches also lower glycemic response when substituted for flour and other rapidly digested carbohydrates. Witwer says the products “assist in maintaining healthy blood-glucose levels and healthy digestive systems, potentially reducing the risk of developing chronic conditions such as diabetes, obesity and cancer.”

Boosting nutritional profilesU.S. bakers are somewhat limited in the nutrients that can be directly added to breads, as the term “enriched bread” is standardized by FDA in Title 21 of the Code of Federal Regulations (CFR), section 136.115. However, the nutrient profile of bread can indirectly receive a boost through the addition of other ingredients, such as fruits, nuts and seeds.

“Bread bakers who choose to formulate enriched breads typically use nutrient premixes to simplify — and have better control over — the fortification process,” says Ram Chaudhari, senior executive vice president of research and development, Fortitech, Inc., Schenectady, NY. “By law, enriched bread contains 1.8 mg thiamin, 1.1 mg riboflavin, 15 mg niacin, 12.5 mg iron and 0.43 mg folic acid per pound of baked bread. The law also allows a maximum of 600 mg calcium per pound of baked bread. Most premixes are custom-blended for bakers — and often for specific bread formulas — as other added ingredients can contribute to nutrient profiles and, thus, the premix might need more or less of certain nutrients, depending on the desired final nutrient profile. Nutrient premixes are added to the formula with the other dry ingredients. They typically are microencapsulated with a lipid-based system to withstand the extreme temperatures encountered during baking. The encapsulating ingredient melts near the end of baking, releasing the nutrient into the finished bread.”

When fruits, such as raisins, are added to breads, they contribute to overall iron, thiamin, magnesium, potassium and copper levels. Raisins also contain dietary fiber, including soluble fiber. “In fact, 100 grams of California raisins contain 5.3 grams of fiber, 59% of which is soluble fiber,” says Tom Payne, industry specialist for the California Raisin Marketing Board, San Mateo, CA. “In addition, California raisins contain phenolic compounds, several of which function as antioxidants because they have been shown to slow the potentially damaging cell-oxidation process. Recent research indicates a potential role of phenolic compounds in reducing the risk for both heart disease and cancer.”

Adding raisins to bread also helps ensure shelf life naturally. “Raisins help keep products in a state of equilibrium, allowing a baker to reduce or eliminate the use of preservatives and additives. This is because raisins contain high levels of propionic acid, a natural preservative,” says Payne. “The pocket of moisture in raisins inside the loaf will slow down staling of bread, keeping the loaf fresh and tasty.

“A naturally occurring organic acid in the grape called tartaric acid actually enhances the flavor of the bread, and makes the spices and flavors taste crisper and more flavorful,” adds Payne. “Raisins allow bakers to reduce or eliminate the amount of salt needed to keep the bread from tasting bland.”

Flaxseed is another “other” ingredient packed full of good-for-you nutrients. Slightly larger than a sesame seed, it is harvested from the flax plant, a versatile, blue-flowered crop. The seed is shiny, reddish-brown in color, with a crisp and chewy texture, and a nutty flavor profile.

Fat and dietary-fiber content are probably flaxseed’s most attractive attributes. About 42% of flaxseed is oil; however, the oil’s fatty-acid profile is unique compared to other fats. It is very low in saturated fatty acids (around 9%) and extremely high in the omega-3 polyunsaturated fatty acid alpha linolenic. Omega-3 fatty acids are associated with retina and brain development in infants, and in adults, have been shown to reduce the risk of certain cancers, hypertension, cardiovascular disease and stroke.

Flaxseed’s generous quantities of both soluble and insoluble fiber also make it standout. Dietary fiber, in total, accounts for about 28% of the dry weight of full-fat flaxseed. Of that, about one-third is soluble fiber, which is associated with lowering blood cholesterol. The other two-thirds is insoluble fiber, associated with preventing constipation.

Flaxseed is sold as the intact whole seed, which can be used in or on top of breads — much like nuts and seeds — or as milled flaxseed, also called ground flaxseed. Milled flaxseed is the most commonly used form in American breads. When formulating rustic, hearty breads or European artisan varieties, whole seed is often added. When whole seed is used, a one- to two-hour presoak in water is recommended for easier blending. This causes some of the soluble gums on the seed surface to dissolve, so to make the most of flaxseed’s healthful benefits, use the soaking water as part of the liquid component for dough formation.

Research shows little difference due to flaxseed variety in the physical and sensory qualities of finished yeast breads; however, amount used does have an impact. In a basic yeast-bread formulation, where milled flaxseed replaced 10%, 20% and 30% of all-purpose wheat flour, the formulas with flaxseed levels of 10% and 20% compared favorably with commercial breads — such as dark rye, pumpernickel and whole-wheat — producing a standard crumb structure with small- to medium-sized cells, and a nutty flavor profile. At 30% flaxseed, the bread was not considered of optimum quality, due to lower volume, crumb firmness, gray crumb color and oily mouthcoat.

Keep in mind that this was a basic formula without dough conditioners or other baking aids, and that shortening levels were not adjusted to compensate for the fat content of the flaxseed. Formulation modifications should yield significant improvements and allow for higher flaxseed usage levels.

Bakers can use the ingredients mentioned in this article — which just touch on some of the options available — to create variety and, at the same time, ensure machineability and quality, consistent, finished product. Indeed, it is this variety that will keep consumers enamored with bread.

Donna Berry, president of Chicago-based Dairy & Food Communications, Inc., a network of professionals in business-to-business technical and trade communications, has been writing on product development and marketing for nine years. Prior to that, she worked for Kraft Foods in the natural-cheese division. She has a B.S. in food science from the University of Illinois in Urbana-Champaign. She can be reached at [email protected].

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