Flavoring Systems

 

Flavoring Systems
for Savory Snacks
May 1997 -- Applications

By: Lynn A. Kuntz
Editor

    As in any other food category, a snack food's success depends on its flavor.  To enhance flavor, product designers rely on several different flavoring systems. Some of the systems and technology for flavoring snacks have been around for many years; others have recently broken into the market (with varying degrees of success); and some still fall into the experimental realm.  Not all snack foods depend on added flavors to enhance their appeal. In fact, according to the 1996 State of the Snack Food Industry Report,published by the Snack Food Association (SFA), Alexandria, VA, the unflavored varieties lead the pack in terms of sales in most major snack categories - pretzels, nuts, potato chips or crisps, and corn and tortilla chips. These products depend only on the inherent flavor of the substrate; the flavor of the frying oil; flavors developed through frying or other manufacturing processes; and generally, salt.  However, the No. 2 spot doesn't require an elaborate justification for its existence. Potato chips and tortilla chips combined to create an $8 million market in the United States in 1995, according to the SFA report. Since about 37% of that was in flavored varieties, it's not difficult to see why designing flavored snacks receives considerable emphasis.  For some categories - extruded snacks, and ready-to-eat and microwavable popcorn - most products sold contain added flavors or seasonings. To keep many consumers' interest, these fairly bland base products require some "dressing up." That challenge falls to the product designer.  "Everything today, from a seasoning and flavor point of view, must be customized," says Otto Schroeder, vice president, snack food business development for Bush Boake Allen Seasoning, Carlton, TX. "The relationship between the processor and the flavorist has to be close - the more communication and the earlier the communication, the better the result will be."The added attractions  Variety seems to be the theme for snack-food manufacturers. Ideas come from many sources: ethnic classics, other culinary trends, condiments and cobranding. Recent snack-food introductions include: hot flavors, such as salsa and chili; a myriad of barbecue flavors, including branded versions; and ethnic or regional favorites such as vinegar, pizza and black bean. Fusion flavors and authentic (not Americanized) flavors hold promise.  Many companies are looking for hotter, spicier, higher impact flavors, according to Jean Kuster, director of marketing, Burns Philp Food Ingredients, Des Moines, IA. Flavors are becoming more complex. A survey of snack-food manufacturers in the SFA report advises that these companies are looking for new snack-food seasonings including Cajun, cinnamon, chocolate, honey-baked ham, ketchup, peanut, taco, herb and dill.  Regional tastes often drive preference for a particular flavor profile. Salt-and-vinegar was a popular flavor in the eastern United States long before it migrated to the rest of the country. Pork rinds are popular in the South, but don't generate sales in most of the rest of the country.  "There are more regional opportunities, now that most of the national snack manufacturers are gone," Kuster says. "An example is the success a number of manufacturers have had with Carolina barbecue in the South. It has a vinegary-sweet flavor that mirrors the type of barbecue sauce that's popular in that area."  And companies targeting the international market can have a difficult time because foreign consumers may not be tuned in to U.S. taste profiles. For example, John Phillips, associate technical marketing manager at Land O'Lakes, Minneapolis, points out that cream-cheese flavors, including those combined with fruit, are popular for European snack foods.Making the perfect match  "One of the hottest areas is the 'better-for-you' snacks - reduced-fat platforms, such as baked chips, pretzels, rice and popcorn cakes," Schroeder says. "Fortunately, snack foods also naturally fall into one of the biggest trends today - convenience.  "Higher quality is important across the board," he continues. "Companies are improving their classic best-selling products - sour cream-and-onion, nacho, barbecue. They are making them as good as they can be - from both a flavor system standpoint as well as a base standpoint."  Consumer trends initially influence the type of seasoning or flavor system used for snacks, but many other factors affect their design. Sometimes, flavor compatibility or delivery issues arise because of the base.  Some seasonings, such as ranch, appear to complement any number of bases. Cheese seems to go with almost any snack. And, while other types of cheese may be blended in for flavor emphasis, in this country, "cheese" means Cheddar style.  "In general, the market doesn't stray too far away from the traditional Cheddar flavor," Phillips says. "Nacho is a play off of Cheddar, with Parmesan and Romano. Plus, Cheddar is one of the more economical cheeses. It's certainly easier to process."  There's been some interest in other types of cheeses, Phillips notes, such as Parmesan with garlic or herbs. However, Parmesan is not currently a mainstream flavor; it also is one of the more expensive cheese products.  However, one exception to this seemingly universal cheese compatibility has been the multigrain snack. The base typically has such a strong flavor that typical Cheddar-cheese snack-seasoning clashed, rather than complemented. This type of base generally goes better with a sweeter flavor or spice or herb flavor. Companies are starting to examine other, nontraditional bases, Kuster says.  "When you are looking at some of the extruded products that use potato or rice as a base, they come with a very strong taste," adds Burns Philp's Tricia Laning, product development food technologist. "Manufacturers often want you to cover that taste up, and have the flavors come through. That can be a real challenge: to create a flavor that has a good flavor intensity, that's not overwhelming, but will still cover up that base flavor. For example, an extruded potato product may have a cooked, baked-potato flavor, and that might not work with a nacho cheese flavor."  Because the baked product is subjected to a different set of cooking parameters, including time and temperature, different flavor compounds are developed in baking vs. frying.  Flavor delivery issues also might arise. These can result from the size and/or volume of the substrate; reduction or elimination of fat; and the method of production (such as "baked, not fried"). A product such as a rice cake might require an inordinate (and uneconomical) amount of seasoning to overcome the "cardboard-like" image. And food product designers all have been down that fat vs. no-fat flavor road by now.Following tradition  Traditionally, snack-food-flavoring systems consist of topically applied seasonings at levels from approximately 6% to 12%. The dry seasoning is applied to the still-liquid fat of a fried snack, or an oil-coated nonfried snack, or applied as an oil-based slurry. The exact method depends on a number of factors: the level of coating required; the amount of liquid surface oil present at the seasoning step; the fragility of the product; and the equipment used.  Most traditional snack seasonings are powders. Often, they will be blended with carriers or extenders such as salt, flour, corn syrup solids, maltodextrin or whey to aid with dispersion or to moderate cost.  Carriers also are used for plating liquid flavors, such as spice oleoresins, that could prevent the powder from being free-flowing. Another way to prevent caking is adding flow agents, such as sodium silicoaluminate, silica dioxides and magnesium carbonate. These are limited by law to less than 2% in the finished product.  One important factor affecting adhesion of topical seasonings is particle size and shape. Smaller particles tend to adhere better than larger particles in traditional as well as low-fat applications. This is due to their light bulk density and the high surface-to-volume ratio that provides more contact surface. Another is the surface of the snack; seasoned pretzels are popular, but their smooth surface reduces adhesion.  The seasoning can be engineered to enhance application and adhesion. "You can build different properties into a cheese product - its dispersability, if it goes into a slurry system, how well it holds up there," Phillips says.  "Dairy products in general, especially cheese, require a high level of expertise, because they are not like many of the other dry seasonings - they have their own inherent difficulties," Phillips notes. "The flavors are more volatile. They can have problems with flowability and hygroscopicity and how they react with other flavors."  As an alternative to powdered seasonings, some manufacturers use flavored oils. An oil-soluble flavor will migrate throughout the product and help out those bases that suffer from the "chewing-on-cardboard syndrome" once the topical seasoning is gone. This can work well with flavors like hickory smoke or butter. In some cases, depending on the stability of the flavor, these types of oils can be used as a frying medium.The inside track  "There's been a heightened interest in using flavor systems that incorporate flavors in the product itself," Laning says. "That's one way pretzel manufacturers are looking to formulate a low-fat product instead of using an oil slurry."  An internal flavor system can either augment a topical seasoning or replace it. In some cases, the internal flavor ingredients may be a complementary flavor or could be one inherent to the base, such as extra corn or potato flavor. But using an internal flavor system can be tricky, for a number of reasons.  One of the biggest problems is flavor stability. Most snacks are low-moisture products, manufactured with exposure to high heat processes. Subject a highly volatile compound (which applies to most flavors) to heat, and most of them perfume the production floor, instead of flavoring the product.  Heat can completely distill off the flavor or only part of the flavor notes, depending on the individual compounds' boiling points. The former can leave a tasteless product; the latter, a product that doesn't taste right. Using encapsulated flavors has proven somewhat successful in countering this dilemma. These can be more costly, but a higher flavor level may come through, as compared to an unencapsulated product.  The other big problem is flavor delivery. A topical flavor gives a strong, immediate impact, while an internal system tends to give a mellower profile (think cheese curls vs. cheese crackers). However, this can be an advantage if the two systems are used in tandem - the internal system acts as the background flavor once the initial flavor "hit" has diminished.  "For low-fat in particular, an internal system can be part of the solution," Schroeder says. "We need to develop technology that allows flavors or flavor precursors to be added in the base matrix before dehydration, that yield a product with a pleasant taste, for example. That last part of the chip you swallow has to be as indulgent as the first. Right now, it isn't."  Internal flavor systems also can affect the process and end-product. Adding cheese may cause excessive browning. Other flavoring agents, such as tomato powder and HVP, are highly hygroscopic and can affect how well a product bakes or fries to the appropriate moisture level, and also can affect the resulting texture.Low or no fat  "People love their fried products - the flavor, the mouthfeel, the texture," Schroeder says, "and therein lies the challenge." He lists a number of important issues to address: flavor; extending the flavor delivery; masking of baked flavor profiles; adhesion; and lubricity. "A lack of lubricity can make eating just one serving size uncomfortable," he says.  In most standard products, solidified fat acts as the seasoning adhesive, so a new system must be found. The other change occurring when fat is cut is the same encountered in other no- and low-fat foods: changes in flavor perception. Neither of these problems is easy to solve.  To help a topical seasoning adhere, food technologists have turned to aqueous, generally carbohydrate-based systems that are sprayed onto the snack after baking or extrusion. As in oil-application methods, the snack can first be coated with the adhesive, then a seasoning applied. Or, the whole system can be designed for a slurry application.  These possess an inherent drawback. To make a crunchy, low-moisture food, the product must be redried after application. This means additional equipment, additional processing and additional cost. Most adhesion systems use gums, starches or other humectant carbohydrates for adhesion. These ingredients tend to hold onto water, making it difficult to dry to the required moisture. This can drive off some of the flavor, depending on heat level and duration. Also, if excessive moisture is used, it can adversely affect the texture. If excessive heat is used to speed drying time, it can adversely affect the topping by driving off volatiles or promoting browning.  Despite the drawbacks, water-based systems have been used with some success. First of all, they allow a seasoning level comparable to that of fried snacks. The application equipment is the same or similar to that used for oil-based systems - sprayers, drips, cascades, tumblers, etc.  Many different ingredients have been used for this application - starch, maltodextrins, sugars and such gums as gum arabic, guar and gum acacia. Choice depends on several factors, including:viscosity;film-forming abilities;appearance (glossy appearance resembles that of oil);ease of drying;flavor;flavor-masking qualities;solubility requirements.  Still, because these can require increased capital costs and don't create the same flavor delivery as fat, snack-food manufacturers are seeking improvements.  "Low fat can affect both flavor and functionality," Phillips says. "Take adhesion; some improvements can be made in terms of the way the product is manufactured. Dairy products have some inherent adhesion properties based on their composition. You can vary the process and make a finer product. It has less density, so it is less prone to fall off. However, if you change the product, you have to be prepared for other things that might change. If you change the particle size, for example, you may need to adjust the dairy solids in the product, because the flavor will come across stronger."  Fat coats the mouth, modifying intensity and duration of the flavor release. This means that although a topical system is used, it must be designed to account for the reduction in fat. This means rebalancing, as well as increasing, intensity.  "The low-fat versions of traditional flavors on the baked bases have to be very high-impact, bold flavors," Laning says. "Flavors that aren't associated with a fatty mouthfeel, such as barbecue and salsa, can be more successful in low-fat products."  Even more problematic can be differences in flavor and mouthfeel occurring when a product is "baked, not fried." Although added fried-type flavors can put back some of the flavor nuances, they certainly won't contribute any subtle or noticeable textural differences. And depending on the type of sensory research done, this can manifest itself as a "flavor" difference.A super idea  For those looking for other options, Syed Rizvi, Ph.D., and Steven Mulvaney, Ph.D., (researchers at the Institute of Food Science at Cornell University in Ithaca, NY) have discovered a technique called supercritical fluid extrusion (SFX). This patented method combines supercritical fluids with extrusion processing, and can allow the use of heat-sensitive flavors (as well as other ingredients) in extruded products, including snacks.  Standard high-temperature, high-shear extrusion is not a kind environment for flavor volatiles. This has limited the use of in-dough flavor systems for extruded snacks. In cooker-extruders, temperatures can reach up to 250(C with pressures of 25 Mpa, according to Rizvi. When the dough (which contains steam) exits the die, the release in pressure causes the superheated steam in the dough to flash off and the dough to expand, causing the characteristic porous structure. As the water flashes off, so do the flavor volatiles.  Instead of relying on steam, or in some cases, steam and CO2 gas (formed by adding sodium bicarbonate and acid), this process uses supercritical fluid, preferably CO2. A supercritical fluid is one that is above its critical temperature and pressure, and exhibits characteristics between those of a liquid and a gas.  SFX allows expanded products to be manufactured at temperatures below 100(C. This allows the simultaneous low-temperature mixing of flavors and other heat-sensitive ingredients, such as vitamins or colors. The CO2 is injected into the cooling section of the extruder after the gas-holding properties of the dough have been developed through mixing (gluten formation) or cooking (starch gelatinization). Manipulating the temperature and/or pressure induces bubble nucleation and influences rate of formation. When dough exits the extruder, these CO2 bubbles act as a blowing agent.  In addition to the low process temperature, this process has several other advantages. CO2 can act as a flavor solvent and be used to introduce the flavor into the dough. And while not related to flavor, the inventors also say that this process produces controlled expansion that can lead to unique physiochemical, sensory and textural characteristics. They also propose that the CO2-filled cells exclude oxygen, possibly having a positive effect on product quality.  High tech may prove valuable in the future, but it's also necessary to focus on what's being worked on today. Whether a snack flavor system consists of traditional methods or new technology, it's important to work together with the ingredient suppliers and those familiar with the snack-flavoring process.  "Companies who are willing to work with suppliers will do themselves a world of good," Phillips says. "Some companies just give us bits of information on what kind of performance characteristics they are looking for on the product we supply. With no- and low-fat in particular, they want to keep things close. The questions we would ask our customers are: What kind of base, what kind of process are you working with? How it is being used? What temperatures, what kinds of agitation, what kinds of factors are going on with the application? That can be the secret to solving any problems that arise."Back to top