Bowl 'em over

 

Bowl 'em over
June 1997 -- Cover Story

By: Elaine Knehr
Contributing Editor

    It's breakfast time. Dad's eating a bacon-and-egg sandwich while Mom munches on a bagel. Johnnie just wolfed down a couple of waffles and Susie is devouring a doughnut. But where are the cereal bowls?

  With so much competition at the table, it's no wonder cereal manufacturers want to add consumer appeal to grain-based RTE (ready-to-eat) breakfast cereals. Carbohydrates supply the main source of calories. Starch is the primary carbohydrate, followed by sugars and some fiber. Most cereals are low-fat. Added ingredients - geared toward improving nutrition, flavor and appearance - provide opportunities for the food designer to turn this simple food into a real "eye opener."

A nutritious start

  Fortifying cereals with vitamins and minerals holds popular consumer appeal. According to a 1992 survey taken by Opinion Research Corporation for Arthur D. Little Inc., Cambridge, MA, 44% of consumers consider the option of fortifying "basic foods such as bread or flour" to be "very appealing". Breakfast cereal could logically fall into this category.

  Cereals are typically fortified "with vitamins and minerals, for which there is an established RDI (Recommended Daily Intake)," says Audra Davies, director of product development, nutritional products division, Watson Foods, West Haven, CT. "In most cereals, vitamins are added at a level of 25% to 35% RDI, and minerals at 15% to 25% RDI."

  The following factors should be considered when determining the level of vitamins and minerals to add to a cereal: safety, flavor, stability and effect on the finished product.

  "Extremely high levels of vitamins A and D can be harmful," Davies notes. "These vitamins are not water-soluble and excess amounts are retained by the body. Vitamins A and D may be added at a lower amount since cereal is generally eaten with milk, which is commonly fortified with both A and D.

  "High levels of minerals can cause sensory and stability problems," she warns. Too much iron, for example, might result in a metallic taste. A high calcium level may create a chalky mouthfeel. Metal ions can promote oxidative rancidity.

  Antioxidant nutrients, such as beta carotene and vitamins C and E, are commonly added to foods because of widespread evidence that they enhance immune-system responses. Unlike vitamin A, its precursor, beta carotene, doesn't cause toxicity at high levels. At high levels, however, color becomes a factor. Adding regular beta carotene, in the amount required to provide 100% RDI of vitamin A, would make the product bright orange. Encapsulated versions are commercially available that will cut down on the color impact.

  Vitamin C is often added to cereal, although processing allowances must be made for its low heat stability. Vitamin E is relatively heat-stable, but oxygen can accelerate its loss.

  "Fortification is matrix-dependent," Davies stresses. "The use of honey or molasses, for example, could mask the metallic flavor of a high mineral content." (For more details on specific vitamins and minerals, see "Fortifying Breakfast Cereals," April 1994 Food Product Design.)

  Adding vitamins and minerals is commonly accomplished in two phases. "The more stable nutrients are added at the beginning of the mix," Davies says. "These include the minerals and some vitamins, such as niacin and vitamins E and B6. By adding these at the start, maximum dispersion is achieved. Less stable nutrients, e.g., vitamins A, C and thiamine, are sprayed on at the end of the manufacturing process. The sensitive vitamins are typically delivered in a spray solution, consisting of sugar and water, which is then dried."

  Premixes simplify fortification by ensuring adequate dispersion of nutrients and consistent level of delivery. They allow manufacturers to add multiple nutrients at desired quantities as a single ingredient. Overages can be built into the mixes to compensate for variations in application and vitamin losses during processing and/or storage. Most manufacturers look to their suppliers to provide technical assistance for developing the ideal premix.

  "The cost of fortification is minimal, especially when the improved marketing appeal is considered," Davies says. "Fortification allows the cereal designer to develop a product to meet the needs of a certain population segment. As the competition increases, product differentiation becomes more important."

Fiber facts

  RTE cereals contain varying fiber levels depending on the ingredients used. Fiber content can range from zero to 8 grams or more total dietary fiber (TDF) per serving. Higher levels can provide the opportunity for positive label claims. The Nutrition Labeling and Education Act of 1990 states that foods labeled a "good source" of TDF must provide at least 2.5 grams of fiber per serving. An "excellent source" would contain 5.0 grams per serving.

  Earlier this year, the U.S. Food and Drug Administration approved health claims relating to foods containing beta-glucan soluble fiber from whole oats. If a whole-oat-containing product provides at least 0.75 grams of soluble fiber per serving, companies can claim the food - as part of a diet low in saturated fat and cholesterol - may reduce risk of heart disease.

  Dietary fiber is comprised of soluble and insoluble fiber. "Soluble fiber is metabolized in the body and thus is a source of calories," Davies says. "Beta-glucan, the soluble fiber in oats, helps lower cholesterol level. Insoluble fiber does not contribute calories to the diet. This fiber has been associated with shorter gastrointestinal times and may help prevent some gastrointestinal diseases."

  Many products can increase RTE cereals' fiber content, according to Steve Feinberg, president, Mid America Food Sales, Ltd., Northbrook, IL. Wheat bran and whole wheat are good insoluble-fiber sources. Oat bran contains soluble fiber, while the oat hull provides an insoluble-fiber source. Other fibers, such as pea and sugar beet, contain both soluble and insoluble fiber.

  "Fiber products can provide different characteristics to the end product," Feinberg says. "An apple fiber could impart a slight flavor and may affect the color of the cereal." A high fiber level could result in objectional flavors and gritty mouthfeel. "The choice of fiber should reflect the cost, availability and desired end product."

  In extruded cereals, a cooked starch matrix provides most of the structure. Added fiber to this matrix affects the structure, according to Eric Sevatson, food technologist, Wenger Manufacturing Inc., Sabetha, KS. "Fiber can strengthen the mixture, up to a point," he says. "Fiber, however, acts as an avenue of breakage. If too much fiber is used, there is nothing to hold the product together. It is difficult to maintain the shape of the cereal piece.

  "Fiber granulation affects manufacturing," he says. "A coarsely ground fiber is more difficult to work with, but gives the final product more fiber appearance. A fine granulation produces a less gritty and more durable cereal. Adding fiber to achieve 5.0 grams per serving is attainable. The small loss in texture and durability can be overcome with processing conditions."

  Fiber can also be added through the use of resistant starches, Sevatson notes. These starches are specially processed to alter the structure of the molecule. "The starch is bound so tightly that it cannot be digested. The body treats it like a fiber. If resistant starches are used, a fiber claim can be made on the label. Manufacturing is simplified because, to a degree, the extruder treats the material like starch. The shape of the final product is maintained. One drawback is that the ingredient is expensive."

Fortified with fruit

  Since consumers often put fruit on their cereal, including dried fruit in a RTE is a "natural." Most fruit products contain a high fiber content and less than 0.5% fat. Dried fruits are low in sodium, high in potassium and contain vitamins A and C. Dried fruits provide a natural source of sweetness in addition to distinct flavor, color and texture characteristics.

  Apples, raisins, figs, dates, cranberries and blueberries - these are some of the dried fruits available to the food designer. An assortment of sizes can provide different visual qualities. Products range from powders and granules to flakes, dices and slices.

  Low-moisture apple granules and powders are typically used as part of a coating system, according to Scott Summers, director, technical services, Tree Top, Inc., Selah, WA. "If a particulate is desired in the cereal, a low moisture flake or dice can be used," he says. "A puffed dice has a desirable low density which imparts a crunchy texture. The puffs can be easily colored and flavored to expand their range of application. Intermediate moisture apples are generally used in a granola-type product. The pieces are pressed into a multiple fruit cluster which might include fig and cranberry bits."

  Minimal levels of preservatives are used in dried fruit. "Most apples are sulfured at a low level to preserve color and extend the shelf life," Summers notes.

  Dried fruits used in cereals can range from a low moisture of approximately 2% to an intermediate level of 15% to 18%. Intermediate level fruits include raisins, figs and some apples. The cereal itself contains about 3% moisture. When a higher moisture ingredient is added to the cereal, the system tries to attain equilibrium. Various factors help prevent moisture in fruit from being acquired by the cereal pieces.

  Dried fruits have a low water activity (Aw). Aw is the free, unbound water available for microbial growth in food. The bound water also resists migration. The sugars in the fruit assist in binding the available water.

  Barrier coatings also can limit moisture migration. Raisins, for example, are coated in vegetable oil, followed by a dusting of sugar. Date pieces might have a coating of oat flour. The coatings also reduce stickiness.

  Extruded fruit pieces can be used in RTE cereal. "These bits are in the semi-moist range of 15% to 20% moisture," Sevatson says. "Ingredients include fruit puree and sucrose or dextrose, which are good humectants. This results in a low Aw product. The pieces are dusted with dextrose to prevent clumping. Flavor and color can be added to simulate any desired fruit."

  Freeze-dried fruits may provide good appearance, but are very hygroscopic and expensive. This limits their use in RTE cereals.

Go nuts!

  Nuts can improve RTE cereal appeal by providing nutritional benefits, distinctive flavors, and an interesting texture and crunch. Varieties include walnuts, almonds, pecans, cashews, hazelnuts, pistachios and macadamia nuts. While each nut possesses an individual profile, some generalizations hold true.

  Naturally cholesterol-free, nuts contain 5% to 11% by weight of dietary fiber and 10% to 25% by weight of plant protein. They supply important vitamins, such as E and B6, plus iron and potassium.

  Although high in fat, nuts are low in saturated fats. Monounsaturated and polyunsaturated fats enjoy a heart-friendly reputation. One study, conducted at Loma Linda University, Loma Linda, CA, and reported in the March 4, 1993, New England Journal of Medicine, indicated that walnuts are beneficial in reducing blood cholesterol levels and protecting against heart disease.

  Nuts supply different sensory attributes to cereals. Kernels can be diced, sliced and slivered. The choice of size depends primarily on the application and the desired end product. Sliced almonds, for example, give good visual nut identity to a cereal. Small walnut pieces could disperse flavor and crunch throughout a product. Ground nuts can act as part of a coating system.

  Nuts don't appear to settle in cereal packages, according to Thomas J. Payne Market Development, Burlingame, CA. Walnuts have a fairly low specific gravity as compared to other ingredients used in cereal, such as raisins.

  Nuts require proper storage, both prior to manufacture and when used in cereal. Their high fat content makes the kernels susceptible to odor absorption and rancidity. Storing nuts in cool, dry, dark areas and inside protective containers protects them. Cereal manufacturers often specify BHA- and BHT-treated walnuts. But nuts also benefit from the presence of several natural antioxidants.

  For example, in addition to naturally occurring antioxidants, such as tocopherols, walnuts also have been shown to contain ellagic acid, an active oxidant, according to Nicole Kenyon, consultant to the Walnut Marketing Board, for Thomas J. Payne Market Development. The presence of the other antioxidants, such as gallic acid, methyl gallate, juglone, purpurogallin and tannin also have been reported.

Sweet awakenings

  Some consumers perceive added sugars in cereal as a negative, but in addition to enhancing taste, sweeteners also provide many functional properties.

  Topical application gives presweetened cereals their high sweetness level. Surface application means an immediate, intense taste. Sucrose is often used, since it can be crystallized to either a white, "frosted" surface or a hard, clear glaze. Functionally, a topical sweetener system can act as a flavor carrier, deliver added nutrients and bind dry ingredients -such as nuts - to the cereal's surface.

  When used internally, sweeteners have a significant effect on functionality. "(The) sugars in the formula compete with the starch for available water," Sevatson says. "This can affect proper starch hydration. The internal sugar content should not exceed 16% to 18%." Reducing sugars, such as those in corn sweeteners, undergo Maillard browning reactions during heat processing. This results in a desirable golden color.

  (For detailed information on sweetener usage, see "Sugar in the Mornin': Sweeteners in Breakfast Cereals," June 1996 Food Product Design.)

  For a natural label claim, honey can sweeten a product. Although it is available in liquid and dried forms, the food industry typically opts for the fluid version.

  The source influences honey's color and flavor. A light honey, such as clover, typically has a mild, delicate flavor. Darker honey, such as buckwheat, might possess a stronger taste. Manufacturers generally use a honey blend to ensure consistent color and flavor.

  Flow agents keep dried honey free-flowing. In this form, honey is easily blended with other dry ingredients.

  Researchers at Kansas State University, Manhattan, KS, conducted a 1993 study funded by the National Honey Board to gauge the functional and organoleptic effects of formulating an extruded honey-graham cereal using various levels of honey. First, a trained sensory panel concluded that a combination of high honey levels (15.4% dry weight basis) and low extruder speeds (282 rpm) produced the best flavor, texture and appearance. Further testing with untrained consumers revealed a significant flavor and overall preference for products with higher levels of honey (10.0% to 15.5% dry weight basis vs. 4.5%). According to the research. Consumers scored the crispness level of the highest level (15.5%) of dark amber honey significantly higher than that of the lowest level (4.0%). However the same effect was not noted when white honey was used.

  Manufacturing extruded cereals with high levels of honey is a difficult process, Sevatson says. He recommends a formulation level of 10% to 12% internal sugar when honey is the only added sweetener. Higher amounts of honey can cause sticking problems during manufacturing and storage. With high internal honey levels, the cereal won't cut after the extruder, Sevatson says.

  Topical sweetener systems might utilize liquid honey. However, at levels greater than 5% of the finished product, the coated cereal becomes difficult to handle during processing and packaging, Sevatson says. Honey's approximate composition is 36% fructose, 31% glucose, 7% maltose and 1.5% sucrose. Fructose is hygroscopic, so a product with a high level of honey remains sticky after drying. Packaging cereals made with honey in a foil liner helps eliminate moisture pickup.

Floor 'em with flavors

  If an RTE cereal doesn't taste good, it's not going to be eaten. Added flavors can make a cereal more appetizing. The effect can be obvious, like a distinctively flavored fruit shape. Or, enhancers might subtly round out the taste of the grain, providing a more pleasant flavor.

  The type of flavor used in a cereal depends on the designer's objective. "When developing a flavored cereal, it is important to specify the product parameters," says Pauline Rathjen, manager, bakery/cereal applications, Givaudan-Roure, Clifton, NJ. "This includes the processing conditions, whether a natural and/or artificial flavor is desired, and the cost." The flavor house will then work to meet these specifications.

  Flavors are available as artificial, natural, natural WONF (with other natural flavors) and enhancers. "Artificial flavors are stronger than naturals, and usually hold up better," Rathjen notes. "There are many new natural flavor chemicals, however, with good stability. Cereals commonly use a natural and artificial flavoring."

  If a natural concept is desired, a natural WONF is almost always used. To be simply called "natural," the flavoring must be derived solely from the flavor source. Vanilla extract is an example of a natural flavor. Most natural flavorings are WONFs. This means that the flavoring contains the base flavor derived from the source itself, such as strawberry, plus other natural chemicals that enhance the flavor.

  Most cereal flavorings are added to the coating that is applied to the cereal piece. One method involves simply spraying the flavor onto the cereal, using oil as the carrier. For sweetened cereals, flavoring is added to the sugar coating.

  "Applying a sugar coating is similar to candy processing," Rathjen says. "The manufacturer decides how much sugar is desired on the cereal. A syrup is made, usually comprised of sucrose with some corn syrup. The syrup is heated to a specific temperature, depending on the desired end product (such as a frosted or clear coating). The flavoring added to the syrup must be able to withstand the processing temperature."

  Ingredients such as ground cinnamon, honey and malt can add flavor to cereals naturally. Oftentimes, however, additional flavoring is needed to boost these flavors and minimize processing problems that might occur from excessive levels of these types of ingredients - for example, drying difficulties encountered with high honey levels. Adding a honey flavor or enhancer reduces the amount of honey required to achieve a particular flavor level, reducing or eliminating the problem.

  Encapsulated flavors are finding applications in RTE cereals. "(Manufacturers have) expressed an interest in adding flavor in the extruder," Rathjen says. "Encapsulation would help the flavor survive the heat and pressure of the extruder. There has been some success in Europe with getting fruit, vanilla and chocolate flavors to come through in the extruded material." Encapsulated flavors are generally not used in a coating system, since these are not exposed to high levels of heat.

Color my world

  How can color be used to improve consumer appeal? "Widen the rainbow," says Byron Madkins, chemist, Warner-Jenkinson Company, Inc., St. Louis, MO. "Different and unusual colors, used in some sweetened cereals, make eating fun." Only the food designer's own imagination limits the color of the final product.

  Food colors fall into two main categories: certified and exempt from certification. The certified colors are the artificial or synthetic colorants. These include FD&C Red 40, Yellow 6, etc. Artificial colors must be declared by name on the label. The exempt, or noncertified, colors are considered the "natural" colors, including annatto, caramel color and turmeric.

  "(These colors) cannot be listed as 'natural' on the finished product label," Madkins notes. "The natural colors must be labeled 'artificial color' or 'color added' or by name, since they are added to the product and are not inherent in the product."

  "The FDA has used the term 'natural' as a general adjective in referring to caramel color, but not as a label claim," says Dean Bodnar, vice president and technical director, Sethness Products Company, Clinton, IA. Still, because the common name can be used on the label, caramel color, (as well as the other non-certified colors), offers processors a label-friendly alternative to the FD&C dyes.

  Synthetic colors are cost-effective; they are stable under almost all conditions and can be used at low levels, such as 30 to 100 ppm. They are typically used for bright, "candy-like" cereals, especially greens and blues which have no "natural" alternatives.

  Some natural colors, such as turmeric, are affected by exposure to light, or change with changes in pH. However, they are generally stable in normal cereal processing and packaging. Generally, naturals require higher levels to achieve the same color levels as their artificial counterparts.

  Many natural colors excel at imparting the golden or brownish hues associated with grain-based products. For example, adding caramel color to an extruded cereal can provide a golden color associated with toasting or baking to a to a product where it may be lacking. "It's a matter of concentration," says Bodnar. "You would use the products that provide the yellow tones at low levels. However as one increases the level of caramel color, you can get a dark brown. Unless you are looking at the very dark, almost black colors, using caramel color is very feasible."

  "The amount of colorant used is a small cost of the cereal," Madkins says. "Colors are usually added to an extruded cereal. Flaked products are colored less often.

  "Colors are available as a dry powder or granular form or a liquid," he says. "If a dry ingredient is used, and the color is blended into the dry mix, when the water is added, it may be difficult for all of the color to completely dissolve as it competes with other dry ingredients for the water. A liquid system typically works better since the color is pre-dissolved before it is added to the mix in the extruder."

  Although a liquid can be more expensive, ease of use can outweigh cost. Dust in the air, for example, is eliminated.

  Using colors in cereals not only improves appearance, it can reduce the level of expensive or difficult-to-use ingredients, such as cocoa, maple syrup or cinnamon. "Adding caramel color can allow you to reduce the level of cocoa and enhance the color," says Richard Daehler, senior chemist at Sethness. "I've seen liquid caramel color used in both the cereal base and the coating. In some applications, you might combine it with FD&C dyes to provide a nice, dark chocolate appearance."

  "(In some instances) it is even possible to reduce the amount of color used when switching from a dry to a liquid product," Madkins observes. "In cases where a dry color is not completely dissolving during cereal manufacture, it is possible to reduce the amount of colorant used by introducing the color in a liquid system."

  While there's lots of competition at the breakfast table, cereal is still one of the simplest ways to start the day. Pour it in the bowl, add a splash of milk - and breakfast is served. When value is added to this simple product, consumers will have to agree that cereals are ... grrrreat!!!

  Free-lance technical writer Elaine Knehr holds a bachelor's degree in food technology and a master's degree in business. Her 10 years of experience in product development covers a wide range of food products.

Back to top