What does the Incredible Hulk, denizens of Jurassic Park, the Terminator, and hydrocolloids all have in common? Answer: they all deliver novel special effects, usually in a big sort of way.
As any movie-goer knows, special effects have certainly become more sophisticated today, making possible new “realities” on the screen and adding to the overall experience. In the realm of food development, gums—and especially gum blends—are also playing an increasingly sophisticated role in terms of providing texture, stability, fiber enrichment, and other functionality and health benefits. More real than any image we see on the silver screen, the special effects they add to food products include a wide range—thickening probably comes to mind first, but also moisture management, texture modification, freeze/thaw stability, emulsification, gelling, ice crystal control, and sheen/gloss, just to name a few.
These special effects are helping to broaden the applications of gums, making possible the creation of new products or improving on the traditional ones. For example, gums may be employed by the food manufacturer in the formulation of low- or no-fat foods; in the preparation of culinary dishes for the foodservice area or the creation of prepared foods that attempt to realize the gold standard represented by those culinary dishes; and in the formulation of healthy foods where dietary fiber content is important or which may help lower cholesterol levels, have an effect on glucose or insulin levels, and so on. Perhaps, most significant, because of their special properties, gums will probably play an increasingly important role in the healthy reformulation of food products (a theme that has been reoccurring over the past several Ingredients sections)—their functionality and potential health benefits certainly helping to thicken (in more ways than one) the plot of our ongoing ingredients saga.
This month’s Ingredients section will be updating several recent gum developments and how they can provide stability, improve texture, maintain taste integrity, offer potential health benefits, and, yes, even provide possible cost effectiveness due to their lower usage levels in the application.
Gums are polysaccharides (long chains of simple sugars) or their derivatives, which, depending on their type, are dispersible in either hot or cold water to produce viscous materials. They primarily function as water-control agents by increasing viscosity (resistance to flow) or by forming gels.
Although some gums are very old (some may have even been used to help wrap Egyptian mummies), from a food ingredients perspective they offer interesting innovations and other newsworthy developments. Through technology, they have been improved on, with new versions providing characteristics that previous ones did not have. New, dependable, and more consistent sources are being discovered. Gum blends are being customized that provide increased functionality as well as solve specific problems that otherwise might not have been solved.
--- PAGE BREAK ---
Keep in mind, too, that although the word “gum” conjures up in the mind the characteristic of stickiness (its original definition probably applied to gummy natural plant exudates), gums are classified by sources which can include several groups in addition to the natural plant exudates. This article will cover gums derived from seaweeds, plant extracts, plant seeds, and plant exudates, as well as those produced by fermentation means. Also covered in this article are the water-soluble derivatives of cellulose.
These classes of gums have evolved over the years, their boundaries expanding with new discoveries. For example, tara gum derived from seeds has been recently introduced into the United States; since xanthan gum made its debut in the 1960s, new modifications have been added to fermentation-produced gums, including the development of curdlan in the 1990s; new gums produced from seaweeds have been developed; and, overall, efforts continue to be made to improve on the quality and functionality of gums, as well as to specifically tailor these characteristics to food and beverage products.
I think one can easily see how gums have become more sophisticated over the years, much like special effects in the movies have gone from guys in cheesy rubber monster outfits to those generated by computer technology.
Let’s now look at some of these gum developments, which, for convenience, I am organizing by the sources already mentioned. Also, a sidebar (see page 44) will discuss the value of gum blends as well.) It should be noted that because of space considerations, this article is not designed as a complete listing of gums (nor as a comprehensive listing of companies who supply these gums), but rather as an update of some of the significant developments related to these hydrocolloids and their potential impact in product development.
Gums from Plant Seeds
• Guar Gum. A galactomannan obtained from the seed kernel of the guar plant Cyamopsis tetragonoloba, guar gum is dispersible in cold water to form viscous sols which upon heating will develop additional viscosity. A versatile thickener and stabilizer, the ingredient may be used to improve the consistency of ice cream, manage the viscosity of sauces and dressings, stabilize fruit beverages and juices, and retain moisture in breads and frozen foods.
The U.S. reportedly imports more than 96 million lb of guar gum from India and Pakistan annually. To decrease this dependence on imported guar, a domestically produced alternative is now available from the Southwest Guar Cooperative, 1203 E. Hester St., Brownfield, TX 79316 (phone 806-637-8096; fax 806-637-7091; www.swgar.com).
--- PAGE BREAK ---
The producer-owned cooperative grows and processes guar beans in the southwestern U.S., and is said to guarantee a safe, secure, and traceable source of guar for the food industry. The domestic supply offers consistent quality, maintains price stability, and is free of genetic modifications. Southwest Guar’s new processing facility, based in Brownfield, Tex., is now fully operational. Construction of the guar-splitting facility was funded in part by a $500,000 USDA value-added agricultural development grant. The 2003 guar crop is currently being harvested, and samples from the current production run can be obtained by contacting the cooperative. The company is also offering long-term contract commitments which allow customers to secure product for the future.
A high-viscosity, quick-hydrating guar gum powder is available from PL Thomas, 119 Headquarters Plaza, Morristown, NJ 07960 (phone 973-984-0900; fax 973-984-5666; www.plthomas.com). Marketed under the name Ultra Guar, the product is said to display characteristics unlike those of conventional guar gum powders. It is an exceptionally high-viscosity-producing polymer, achieving about 6,000 centerpoise (cP) in about 2 min. It hydrates quickly in both hot and cold aqueous solutions, and because of its concentrated power, less is needed. The rapid hydration speeds up processing times as well. Applications include instant beverages, sauces, dressings and gravies, pet foods, and other products. The supplier reports that the ingredient typically is half as expensive as CMC, one of the primary polymers used.
The functionality benefits of guar gum are well documented, but its health benefits as well are also being looked at in a wide range of studies. A review of these studies have been compiled by TIC Gums, 4609 Richlynn Dr., Belcamp, MD 21017 (phone 410-273-7300; fax 410-273-6469; www.ticgums.com). These studies include lowering cholesterol in rats and humans, effect on glucose and insulin levels, aiding colon-specific drug delivery, speeding ulcer healing, and several others. One interesting study determined if molecular weight or particle size of guar gum impacted metabolic effects.
• Locust bean gum. Also called carob gum, locust bean gum is a galactomannan derived from the seeds of the European carob tree or locust bean tree (Ceratonia siligua). It is suitable in applications where good stabilizing, thickening, and emulsifying properties are required.
--- PAGE BREAK ---
The ingredient is partially soluble in cold water, but requires heat to achieve full hydration and maximum viscosity. “Because it contains a portion that is insoluble in cold water, locust bean gum has very low viscosity in cold water (about 200 cP). For complete hydration and maximum viscosity, locust bean gum requires heating to 180ºF for 2-5 min. Viscosity after heating can be close to 3,000 cP,” noted a representative of TIC Gums, a supplier of several locust bean gum products and blends using the gum. “In contrast, guar gum, a cold-water-soluble gum, has a 1% viscosity or about 3,500 cP without heating.” (The presence of guar gum admixed with locust bean gum can be detected by methods using high-pressure liquid chromatography and other analytical tests.)
The gum provides high viscosity, forms gels with xanthan gum upon heating and cooling of the solution, and functions as a water binder. Gels formed by agar or carrageenan can be made more elastic by the inclusion of locust bean gum. Furthermore, the gum exhibits synergy with other hydrocolloids. For example, it can form heat-reversible flexible gels with xanthan gum or form rigid, sliceable gels with kappa-carrageenan. It can also be used at low concentrations as a component of dairy stabilizer systems.
Because it is low in viscosity in cold water but thickens when heated and cooled, as well as being milk reactive, the gum is very suitable for use in soups, sauces, and processed cheese applications. The gum, when added to wheat flours, can also provide extended shelf life and improve texture and taste. However, its major application is frozen desserts, especially ice cream, where it serves to slow the rate of melt-down and improve storage properties. Ice cream stabilized with locust bean gum contains significantly smaller ice crystals, resists structural changes that can occur during storage and distribution, and has a distinctive mouthfeel and texture.
Although the characteristics of locust bean gum have probably been recognized since ancient times, significant developments keep occurring that can have a positive impact on the ingredient. Recently, Meyprodyn® 200, a cold-water-soluble locust bean gum, was introduced by Rhodia, Inc., 259 Prospect Plains Rd., Cranbury, NJ 08512-7500 (phone 609-860-4000; fax 609-860-0245; www.rhodia-food.com). The texturing and thickening ingredient may be used in applications where no heat is involved during processing.
TIC Gums produces a locust bean gum product, TIC Pretested® Locust Bean Gum POR/A Powder, which is made by a process that eliminates the dark seeds. The resulting gum has fewer specks and a higher viscosity than other grades. Also available is TIC Pretested Prehydrated Locust Bean Gum Powder which eliminates the creation of lumps that are typical of regular locust bean gum when added to hot water.
--- PAGE BREAK ---
• Tara Gum. Another galactomannan, tara gum is a natural seed gum product derived from the fruit of the shrub-like tara bush, Caesalpinia spinosa. Its structure and functionality are said to be similar to those of the more established galactomannans, locust bean gum and guar gum. Like guar, tara gum is cold water soluble and attains maximum viscosity in water, milk, and other low-solid systems within minutes. And like locust bean gum, it acts synergistically with kappa-carrageenan and xanthan gum to increase gel strength and make such gels less prone to syneresis.
Because of its properties, tara gum may be used as a stabilizer, thickener, emulsifier, and gelling agent in a number of food products, especially in the low- or no-fat areas. Applications for the gum include frozen dairy desserts, cultured dairy products, fruits and variegates, functional foods and beverages, baked goods, condiments, sauces, and other products.
At the 1998 IFT Annual Meeting + Food Expo®, the gum was spotlighted (perhaps for the first time at a U.S. food show) by Bunge Foods Ingredient Systems Div., 3582 McCall Place, N.E., Atlanta, GA 30340(phone 404-455-3603; fax 770-986-6282). The company emphasized that tara gum in frozen desserts is said to provide a fat-like texture, excellent eating properties, and heat-shock protection. Mixtures of tara and xanthan gums provide long-term suspensions, suggesting potential in salad dressings, sauces, and similar products.
Since its debut, the gum continues to be promoted by tara suppliers for offering functionality and economic advantages over its more recognizable counterparts, guar and locust bean gums, as well as for its synergistic abilities with a variety of other hydrocolloids.
According to a manufacturer and exporter of tara gum, Exandal Corp., 12766 Jolette Ave., Granada Hills, CA 91344 (phone 818-366-0372; fax 818-363-3980; www.exandal.com), tara gum provides cold-water solubility and viscosity at 75–85°F. The gum reportedly bridges the gap between the cold-water-soluble, highly galactose-substituted guar and cold-water-insoluble and lower galactose-substituted locust bean gum.
The solution viscosities produced by tara gum are highly viscous and short textured compared to the solution viscosities of locust bean gum. Furthermore, the gum provides superior heat-shock protection, imparts a rich butter mouthfeel, requires usage levels of 20–25% less than locust bean gum, and resists breakdown in high-shear processing environments. More information about tara gum can also be obtained from Foreign Domestic Chemicals Corp., 3 Post Rd., Oakland, NJ 07436 (phone 201-651-9700; fax 201-651-9703).
Moreover, tara gum shows interesting synergistic effects with xanthan gum, modified food starch, CMC, carrageenan, and agar. Because it is less expensive than other hydrolloids, it can lead to the development of highly functional but cost-effective blends.
Most recent, tara gum was introduced to the line of Coyote brand plant, marine, and bio gums by Gum Technology Corp., P.O. Box 35206, Tucson, AZ 85705 (phone 800-369-4867; fax 520-888-5585; www.gumtech.com). The ingredient is said to work as an excellent locust bean gum replacement at a more economical price and has a very pleasant mouthfeel.
--- PAGE BREAK ---
• Agar. Obtained from certain species of red algae (Gelidium, Gracilaria, and Eucheuma, class Rhodophyceae), agar-agar, or simply agar in its abbreviated form, is a mixture of the polysaccharides agarose and agaropectin. Although it is known to most people as a medium for growing microorganisms, the algae-derived material has been used for centuries by Asians for making jellies and other food preparations.
Traditional agar is insoluble in cold water, slowly soluble in hot water, and soluble in boiling water, forming a gel upon cooling. Gels are formed at approximately 35°C and do not melt below 85°C. Agar is frequently regarded as superior to other gelling agents, with one supplier calling it “the queen of gelling agents” because its gels have greater transparency, strength, stability over a range of acidity and alkalinity, and reversibility without decomposition of the agar. It also tends to be more expensive than other gelling agents. Today, agar functions as a stabilizer in icings, glazes, and bakery fillings; fish, meat, and poultry products; and in other applications where alternatives to gelatin are wanted.
New technological developments have added to the functionality of agar, creating new opportunities and uses for this gum.
A Japanese sugar refiner, Taito Co. (www.taito-group.co.jp/), recently produced a type of agar that reportedly does not solidify, making it suitable as a natural food-thickening agent. Traditionally, for solidification to occur, two substances in agar must be mixed in a certain ratio. The company has found that by mixing these substances in a different ratio, a version of agar can be created which will not solidify, but rather can be added to foods as a thickening agent. Foods made with this agar tend to be less sticky than those made with other thickening agents. Mitsui & Co., Ltd., a general trading company, is a major shareholder in the Japanese company. For more information about this development, see Taito’s Web site or contact Mitsui & Co., Ltd., 200 Park Ave., New York, NY 10166 (phone 212-878-4403; fax 212-878-4407; www.mitsui.com).
In 1998, Bunge Food Ingredient Systems Div. introduced a specially processed agar which can dissolve at reduced temperatures while exhibiting enhanced gelling capability. Unlike native agars which must be heated to near-boiling temperatures for maximum hydration and gel strength development, this product dissolves easily at about 125°F and produces full-strength gels under these conditions. It may be used in yogurts, puddings, candies, icings, sour cream, nutritional drinks, and a variety of other applications.
--- PAGE BREAK ---
• Carrageenan. One of the most utilized features of carrageenan, a versatile gum extracted from red seaweed, is its ability to form gels in a wide range of strengths and textures. This is made possible by three basic carrageenan types, kappa, iota, and lambda, with each type differing in solubility and gelling properties. The kappa and iota types require hot water for complete solubility and can form thermally reversible gels in the presence of potassium and calcium cations. Kappa gels are brittle and exhibit syneresis, while the iota gels are more elastic without syneresis. The lambda type is cold water soluble and does not form gels. Kappa and iota carrageenans are very reactive with milk protein products.
The selection of these types can create specific gel strength, texture, solubility, and gelling temperature properties. Typically, carrageenan is used in low concentrations to create water-based gel systems, stabilize dairy products, and improve yield and texture in meat and poultry products.
Countries such as Europe, Japan, and North and South America have used carrageenan in meat, poultry, and seafood systems to increase yield, improve texture, and achieve greater profitablity, and its success in these systems has been recognized worldwide.
In recent years, we’re seeing more work being done in developing carrageenan-based ingredients in other applications, especially confectionery and bakery. One area of focus, in particular, is the use of carrageenan as an alternative to gelatin. (See the October Ingredients section for a discussion of a variety of alternative ingredients.)
Product formulations using carrageenan and other hydrolloids to demonstrate increased shelf life and enhanced stability were developed by FMC BioPolymer, 1735 Market St., Philadelphia, PA 19103 (phone 609-951-3756; fax 609-951-3680); www.fmcbiopolymer.com). These formulations using carrageenan-based ingredients include Freeze Thaw Stable Donut Icing and Glaze, Gummy Candies, and Post-Bake Neutral Bakery Fillings.
For example, gummy candies formulated with carrageenan reportedly show an increased shelf life vs traditional stabilizers such as gelatin and starch. Texture profile analyses were measured by means of a Texture Analyzer during storage at 20, 30, and 40°C throughout a shelf life of 6 months. The tests found that gelatin and starch-based gummy candies change much more in texture than carrageenan-based gummies.
--- PAGE BREAK ---
Also, the company developed baking formulations to illustrate the effectiveness of carrageenan and other hydrocolloids. Icings, glazes, and frostings are applied on bakery products to enhance the finished item’s appearance, flavor, and texture. Many of these traditional icings, glazings, and frostings do not retain their original integrity and textural characteristics during storage at fluctuating temperatures and prevailing humid conditions. Using hydrocolloids such as carrageenan can help retain textural integrity, resulting in extended shelf life. Post-bake fillings are neutral fat-based cream fillings that are used in finished products such as filled doughnuts, pancakes, croissants, muffins, and cakes. Shelf life of the finished product is limited due to migration of moisture into the surrounding dough, resulting in an unacceptable product. Using hydrocolloids, such as carrageenan, allows fat-based fillings to be replaced with water-based versions that offer similar properties and the additional benefit of controlled water migration into the dough.
A family of carrageenan products that bring special functional properties to many applications are offered by CP Kelco, 8355 Aero Dr., San Diego, CA 92123 (phone 858-292-4900; fax 858-292-4901; www.cpkelco.com). These include Genutine®, a new carrageenan with gelatin-like properties designed as an alternative to gelatin in a variety of food applications, such as water gels, dairy and aerated desserts, confections, and vegetarian products; Genuvisco, a carrageenan used to thicken and stabilize water-, dairy-, and protein-based formulations (a cold-water-soluble version is offered for instant and beverage applications); Genulacta, a carrageenan primarily used in milk-based systems and suitable for ice cream, chocolate milk, and dairy dessert applications, providing excellent texture, mouthfeel, and shelf-life stability; and several others, including a new technology for meat applications.
Carrageenan Co., 3830 S. Teakwood St., Santa Ana, CA 92707 (phone 714-751-1521; fax 714-850-9865; www.CarrageenanCo.com), has spent research efforts developing blends of gum systems using carrageenan as a base, and has introduced a carrageenan-based ingredient which may be used as an alternative for gelatin in marshmallows and other products.
• Alginates. The term “algin” is used to describe alginic acid and its various inorganic salt forms, which are derived from brown seaweeds. The monovalent salts, often referred to as alginates, are hydrophilic colloids, and these, especially sodium alginate, are widely used in the food industry.
Alginate is a linear copolymer composed of two monomeric units, D-mannuronic acid and L-gulopyranosyluronic acid, whose ratio and block structure influence the properties of alginate solutions, especially gelling ability and resulting gel strength. Polyvalent cations, most commonly calcium, will react and cross-link with alginate polymers. As the polyvalent ion content of the solution is increased, thickening, gelation, and precipation will occur. Alginates work well as stabilizers in a variety of food applications, including restructured fruits and vegetables, ice creams, icings, salad dressings, puddings, and dessert gels.
--- PAGE BREAK ---
Recently, a variety of alginate-based texture systems were introduced by ISP Food Ingredients, 1361 Alps Rd., Wayne, NJ 07470 (phone 973-628-3938; fax 973-872-1583; www.ispcorp.com). For example, a stabilizer system for salad dressings and sauces is composed of propylene glycol alginate and microcrystalline cellulose, which work together synergistically to provide superior stability and a rich, creamy mouthfeel, even in low-oil products. A system for use in nutritional beverages consists of sodium alginate and microcrystalline cellulose, which work together to provide superior stability and a smooth, refreshing mouthfeel.
At present, the company has developed a range of alginate-based systems for a number of applications, including bakery, dairy, sauces, dressings, and other food categories. These lines are marketed under the names Alginade®, Dairiloid®, Kelset®, Lacticol®, and Manucol®.
• Gum Acacia (Gum Arabic). An exudate of the acacia tree, gum acacia was used by the pharoahs more than 3,000 years ago. During the Crusades, Arab merchants organized the trade of acacia gum, which took the name “Arabic gum,” among the African tribes. Hence, the names “acacia” and “arabic” are used interchangeably.
Gum acacia dissolves in hot or cold water, forming clear solutions, and its solubility increases with temperature. It can function as an emulsifier, encapsulator, cloud agent, stabilizer, and a retardant to sugar crystallization. When added to foods and beverages, the ingredient can enhance mouthfeel, lengthen shelf life, deliver flavors and colors, and improve production rates.
A gum acacia product which provides these functionality properties while delivering a level of 90% soluble dietary fiber (dry weight basis, AOAC method) is marketed under the name Fibregum by Colloides Naturels International, 1170 U.S. Highway 22, Ste. 204, Bridgewater, N.J. 08807 (phone 908-707-9400; fax 908-707-9405; www.cniworld.com). The ingredient is available in an instantized form.
In addition to health-promoting properties, the functionality of the ingredient was demonstrated in several food formulations at the 2003 Supply Side West show. The company describes the following benefits:
In nutrition bars, the ingredient may be used to stabilize the texture by controlling the water activity; bind all components (fruit, cereals, and other inclusions) together, providing a short texture without stringiness or stretching; and function as an emulsifier, eliminating the need to add lecithin in the syrup. In extruded snacks, the ingredient can provide a more homogeneous shape and a light, fluffy texture; increased crispiness and crunch; and an extended shelf life, reducing staling and loss of crispness. In fruit beverages, it provides improved acid stability, even at high temperatures; smooth and rounded mouthfeel with reduced astringency; and no taste or smell.
--- PAGE BREAK ---
A gum acacia product which may be used as an alternative to modified starches in encapsulated flavor applications is offered by Importers Service Corp., 233 Suydam Ave., Jersey City, NJ 07304-3399 (phone 201-332-6970; fax 201-332-4152; www.iscgums.com). The company reportedly has developed a method which removes the color and flavor from gum acacia, resulting in a highly functional, tasteless, light-colored product called Superwhite Gum Acacia. This ingredient is said to make feasible the economical replacement of chemically modified food starches with natural gums in encapsulation processes. The lighter-grade gum acacia is suitable for use in light-colored drinks, confections, cereals, soups, frozen meals, and other products desiring a lighter color. A variety of other gum arabic products are also available for providing improved body, texture, and mouthfeel in a range of applications.
• Karaya Gum. The dried exudate from the Sterculia urens tree native to India, karaya gum does not dissolve in water but swells to form a colloidal sol with a rate of hydration depending on mesh size. A 3–4% sol will result in a heavy gel, and for higher concentrations the gum must be cooked under steam pressure to solubilize. It has a pH of 4.5–4.7 and functions as a binder and adhesive.
Although karaya gum has been used in traditional and Indian cooking, its market in foods has been limited. Its main application today has been in the pharmaceutical field. When used as a food ingredient, it can function as a replacer for tragacanth, a gum which, like arabic and karaya, is based on a plant exudate.
It can a provide a feeling of satiety, and consequently may have potential in the formulation of dietary products and nutraceutical products.
According to a major supplier of karaya gum, Alland et Robert, 9 Rue De Saintonge, Paris, France (phone 33 144 59 21 31; fax 33 142 72 54 38; www.allandetrobert.fr), the polysaccharide may be used alone or with other hydrocolloids, and because of its stability it is particularly suitable for the formulation of chilled ready-to-eat food warmed up by the microwave.
The manufacturer maintains that when used in coatings, fillings, dressings, desserts, and emulsified sauces, the gum provides textural improvements and is suitable as a highly soluble fiber. It is said to function as a powerful gelling agent with superior capacities of water binding and swelling potency.
The company has also developed a new flash heat treatment for the decontamination of karaya gum. The treatment induces an improvement of the microbiological quality of the gum, preserving its functional properties.
The gum is available in a variety of forms, ranging from granules to powder.
--- PAGE BREAK ---
• Pectin. Obtained from citrus peel, apple pomace, or other appropriate edible plant material, pectin is a purified carbohydrate product consisting mainly of galacturonic acid and galacturonic acid methyl ester units forming linear polysaccharide chains. It is normally classified according to its degree of esterification—main classifications including high-methyl-ester or HM pectin, and low-methyl-ester or LM pectin. A third type, amidated pectin, is obtained from alkaline de-esterification of HM pectin in the presence of ammonia.
These pectins are said to vary in their reactivity with calcium and what is required to form a gel. HM pectins require a minimum amount of soluble solids and a low pH for gelation. They have a degree of esterification greater than 50%, and form thermally irreversible gels in the presence of sugars at pH less than 3.5.
LM pectins, which have a degree of esterification less than 50%, are not dependent on pH; they do not require a certain level of acid or sugar, but do require the presence of calcium ions for gelation. LM pectins form thermally reversible gels in the presence of Ca+2 ions and function over a broader pH range and at lower soluble soluble solids content. A useful brochure, “Pectins—Thickening Agents for Foods,” is available from ISP Food Ingredients, 1361 Alps Rd., Wayne, NJ 07470 (phone 973-628-3938; fax 973-872-1583; www.ispcorp.com).
Pectin functions as a gelling agent, imparting a gelled texture to products, particularly jams and jellies. However, through their ability to bind water, they are also used as thickeners and stabilizers, finding increasing use as viscosity builders, protective colloids, and stabilizers. Because of these properties, they can impart texture to a wide range of applications, including beverages, yogurt and other dairy products, bakery products, confections, and other products. Its gelling capability is often used in multi-phase foods, either in the final product or at an intermediate stage in the process. As a functional component in stabilizer blends and other food ingredient systems, pectin is compatible with most food gums and other ingredients.
A specialty pectin that functions as a fat replacer is available from CP Kelco. Marketed under the name Slendid, the pectin-based ingredient offers excellent stability to heat, pH, shear, and salt. Slendid 100 is a low-methoxy pectin used as a fat replacer, gelling agent, and viscosifier in products such as mayonnaise, vegetable dips, and dressings. It requires calcium to form gels, and gelation may take place across a wide pH range (2.8–7.0). Slendid 200 is a high-methoxy pectin providing body and smooth mouthfeel. It has been used as a fat replacer in beverages, dairy products, mayonnaise, dressings, spreads, and other products. It does not dissolve, but rather swells instantly into soft particles, creating the fat sensation in the final product. It performs well in cold processing, and at pH lower than 4.
--- PAGE BREAK ---
A pectin-based stabilizer for sorbet has been developed by Degussa Texturant Systems, 3582 McCall Pl., NE, Atlanta, GA 30340 (phone 770-455-3603; fax 770-986-6282; www.texturantsystems.com). Called Unipectine™ FZ 244, the stabilizer reportedly consists of only pectin, not other ingredients such as proteins, emulsifiers, and other combinations of hydrocolloids usually found in stabilizer systems. According to the company, the new stabilizer can provide a refreshing texture to the sorbet while retaining all of the fruit flavors. It is said to be the only stabilizer on the market that is able to foam and texture sorbets, provide overrun, and stabilize while consisting of one single hydrocolloid: pectin. The stabilizer is a nominee for the Food Ingredients Europe 2003 Most Innovative Food Ingredient award.
In a related development, Degussa’s three separate food ingredients units, Flavors & Fruit Systems, BioActives, and Texurant Systems, have recently been combined into a single international unit, Degussa Food Ingredients. This concentration of food activities into a single business unit will improve the company’s ability to meet market requirements for system solutions and tailor-made products and services, one of these, of course, being hydrocolloids such as described above.
• Arabinogalactan. Obtained from larch trees, arabinogalactan is a hot- or cold-water-soluble gum that is stable over a wide pH range. An arabinogalactan-based ingredient called FiberAid is available from Larex, Inc., 4815 White Bear Pkwy., St. Paul, MN 55110 (phone 651-636-2628; fax 651-636-1583; www.larex.com). The water-soluble polymer has a high fiber content combined with low viscosity, properties which make it suitable for use in a variety of health and sports beverages.
The ingredient’s dietary fiber content is said to be comparable to or greater than other soluble gums, and it delivers superior mouthfeel without unpleasant texture. According to the manufacturer, the ingredient can provide moisture retention in baked goods, improve dough handling characteristics, contribute to a finer, more uniform grain, lower water activity in sweetener compositions, and provide film-forming properties.
• Xanthan Gum. A fermentation product of Xanthomonas campestris, xanthan gum first gained FDA approval in 1969, and in 1974 won IFT’s Food Technology Industrial Achievement Award for its developer, Kelco, now CP Kelco, 8344 Aero Dr., San Diego, CA 92123 (phone 858-292-4900; fax 858-292-4901; www.cpkelco.com). Since then, the high-molecular-weight polysaccharide has continued to evolve to meet the needs of the food processing industry, with new improvements in product quality, consistency, and functionality being introduced.
--- PAGE BREAK ---
Xanthan gums function as hydrophilic colloids to thicken and stabilize emulsions, foams, and suspensions. They offer stability to a wide range of food ingredients, and their pseudoplastic rheological properties make them excellent at suspension and stabilization of colloidal systems. Xanthan gums are characterized by their very high viscosity at low concentrations, and xanthan gum solutions are easily pumped and poured. Applications include salad dressings and sauces, dairy products, beverages, fruit preparations, frozen foods, dietetic foods, and many other products.
A wide range of xanthan gum products, marketed under the name Keltrol, are available from CP Kelco. These products are differentiated by their hydration characteristics, novel functional properties, and applications. According to the manufacturer, the functional groups on the side chains of the xanthan gum polymer are controlled during the fermentation process to enhance key functional properties, such as viscosity, acid stability, and galactomannan synergy. These new products are said to achieve higher viscosities than standard xanthan gum and also exhibit better acid stability at elevated temperatures.
New additions to the Keltrol family have included 521, a less dusty product that goes into solution faster under typical plant mixing conditions; 622, a low-dust product that yields transparent solutions; F and TF, fine-mesh versions that hydrate rapidly when well dispersed; HP, a high-viscosity grade with better suspending powder; GM, a granular mesh product that disperses well and develops viscosity gradually; RD, a readily dispersible grade that can be used in systems with poor agitation; and several other innovations.
Most recently developed was 630, a version which can hydrate directly in moderate salt solutions and has improved stability in low-pH applications. This gum is said to be more stable in low-pH environments than standard xanthan gum and has enhanced synergy with galactomannans, such as guar gum and locust bean gum. Specialty xanthan gum products, marketed under the name Kelgum, interact with galactomannans to give synergistic viscosity increases or thermoreversible gels.
• Gellan Gum. A water-soluble polysaccharide produced by fermentation of a Sphingomonas elodea (previously known as Pseudomonas elodea) gellan gum, also earned the Food Technology Industrial Achievement Award for CP Kelco. This multifunctional hydrocolloid can be used at low levels in a wide variety of products that require gelling, texturizing, stabilizing, suspending, film-forming, and structure. The gum is said to be extremely effective at low use levels in forming gels with monovalent and divalent cations. A variety of interesting textures ranging from a fluid gel to soft, elastic gels to brittle gels can be produced using gellan gum. Applications include sugar confectionery, jelly desserts, dairy products, fruit preparations, fluid gels, and many other foods.
Like xanthan gum already discussed, this ingredient has been improved on over traditional versions. For example, Kelcogel HTS, a new high-acyl form of gellan gum, is said to create very elastic, rubbery gels, and offers a cost-effective alternative to carrageenan/locust bean gum combinations.
--- PAGE BREAK ---
A hydrocolloid system made with gellan gum and pectin was recently introduced under the name Kelcogel® PS by CP Kelco. The system has been specially designed to allow long-term stabilization of both cloud and pulp in ready-to-drink fruit juices. Fruit juices made with the ingredient reportedly exhibit a more pseudoplastic rheology, providing excellent suspension properties without adversely impacting mouthfeel. This product is acid stable, with low protein reactivity, which makes it compatible with a variety of juices. The system is easy to disperse and hydrate, and can be used in most juice processing plants without having to add special mixing equipment.
• Curdlan gum. Curdlan became the third microorganism-fermented polysaccharide to be approved by FDA (December 1996). Developed by Takeda Vitamin and Food USA, Inc., this beta-1,3-glucan polymer produced by Alcaligenes faecalis var. myxogenes has a linear structure that makes it resistant to heat and pH between 2 and 10. The ingredient reportedly is capable of forming a gel when heated in an aqueous suspension, unlike other gelling agents which require conditions in addition to heating. Depending upon the degree of heating, a resilient thermo-irreversible gel with retort- and freeze-thaw-resistant properties can be produced.
Curdlan gum can be a valuable textural agent in applications such as low-fat meats, vegetarian dishes, reduced-fat dressings, sauces, and gravies. Its gels are very stable over a wide pH range and under severe food processing conditions. The gels are also bland in taste, color, and odor, which is beneficial in certain food systems such as dairy applications and desserts.
Cellulose, a linear glucose-based polymer linked by beta-14 linkages, can be chemically modified to produce cellulose gums such as carboxymethylcellulose (CMC), hydroxypropylenecellulose (HPC), and microcrystalline cellulose.
Cellulosic gums can play an important role in the development of foods with special textures. For example, cold-water-soluble methylcelluloses exhibit reversible thermal gelation—they gel under heat but resolubilize with reduced temperatures. This special feature allows methylcelluloses to work as fat barriers during frying, as binders, and to retain moisture. Meat analogs and potato-based products are two examples of applications where thermal gelation is required to hold the system together.
HPC for use in whipping cream was developed by Hercules, Inc., Aqualon Div., Hercules Plaza, 1313 N. Market St., Wilmington, DE 19894-0001 (phone 302-594-5000; fax 302-594-5400; www.aqualon.com). Marketed under the name Klucel®, the water-soluble cellulosic is non-ionic, is highly surface active, and provides aqueous thickening and stabilization.
The gum reportedly allows the formulation of reduced-fat whipping cream with excellent foam properties, the creation of well-defined decorative shape, and superior stability over a week in refrigerator storage. In addition, very-low-fat whipping creams of less than 25% fat may be made with good foam properties. According to the manufacturer, in whipped dairy creams, the ingredient provides outstanding foam stability, firm foam structure, improved body and mouthfeel, syneresis control, prevention of shrinkage, and resistance to over whipping.
--- PAGE BREAK ---
The Aqualon Div. of Hercules has also expanded its product lines to include Aquasorb® A-500, a super-absorbent specialty cellulosic material used to control water migration and extend shelf life; a new faster-dissolving CMC designed for use in applications with high solids that need additional viscosity and mouthfeel; and new Benecel® methylcellulose products with varying degrees of hot and cold viscosity/gelation for applications with challenging textural requirements. The super-absorbent CMC helps control water migration. By absorbing water, even at high temperatures, this product can help extend the shelf stability of bakery and two-phase systems.
Cellulosic gums are also offered by The Dow Chemical Co., 1650 N. Swede Rd., Midland, MI 48640 (phone 800-488-5430; fax 989-638-9836; www.methocelfoodgums.com). As of June 30, 2003, Methocel food gums have obtained expanded regualtory approval in meat and poultry products where binders, thickeners, and film formers are allowed at the suitable levels.
The Value of Gums
Recently, a new business unit was established by CP Kelco to identify, develop, and rapidly commercialize new fermentation products. The unit, Kelco Biospecialties Group, is very interested in joint development projects that lead to a broadening of its product portfolio. By developing products with features specially designed for the end user, it can create value for the customer. Furthermore, its scientists understand how to create products to meet specific customer needs and to relate the features of its products to potential customer benefits.
Such an approach toward gums (all gums or gum systems, not just those produced by fermentation) can become increasingly important as we consider the value that these hydrocolloids hold for the future. Let’s consider a few areas.
First, they can play a very important functional role in the reformulating traditional products, making possible the creation of healthier foods that have desirable tastes and textures. Products ranging from hot dogs to pizza toppings, from turkey pastrami to meatballs, from ready-to-drink juice beverages to “dietary fiber” ice creams can all benefit in terms of taste and texture by the functionality properties of gums and gum blends.
Second, gums can play a role in addressing certain health trends such as the current emphasis on low carbohydrates. For example, at the 2003 Worldwide Food Expo, a prototype for a low-carbohydrate ice cream was highlighted by TIC Gums, Inc. Use of a gum system reportedly helped attain a 40% reduction in carbohydrates while delivering the textural qualities of a full-fat ice cream.
Third, films have found themselves in the spotlight lately. Innovative examples might include dissolving breath strips, delivery systems for health components, protective barriers or coatings, and even a way of introducing decorative colors into an application. These applications might not be possible without the use of hydrocolloids, such as pectin, carrageenan, xanthan gum, and other biopolymers which contribute to the inherent stability of the film.
Fourth, gums may be used in food and beverage products where the manufacturer is looking for an alternative ingredient that can provide comparable functionality at cost savings. Furthermore, as was discussed in the October Ingredients section, gums provide the manufacturer with an array of choices, and these combinations make possible gum blends that are tailored to fit certain applications, each designed to deliver certain functional characteristics to that application.
When considering all the possible roles that gums and gum blends can play in future product formulation, these hydrocolloids are truly masters of the special effect—providing the finished product with a wide range of textures and mouthfeels, enhanced appearance, taste improvement, and other benefits.
And like the Terminator in films, hydrocolloids will always be back. Whether they become governor of a major state is another question entirely.
--- PAGE BREAK ---
Gum blends provide new answers in product formulation
Last month’s Ingredients section discussed the synergistic benefits of sweeteners, and how sweetener blends solve specific problems in product formulation as well as create new opportunities. Like sweetener blends, gum blends are also playing an increasingly important role in providing functionality, health, and culinary benefits.
In this month’s Ingredients section, I have organized gums around their specific sources, primarily for convenience as well as clarity. However, you really can’t discuss their value without taking into consideration gum systems, which like sweetener blends, function as a cornerstone in product development. One can easily say that their increasing importance is just one more step in the thickening plot of the ingredients saga.
Throughout this Ingredients article, we see several examples of how gums interact with each other. Some of these combinations include xanthan gum and galactomannans, propylene glycol alginate and microcrystalline cellulose, and gellan gum and pectin. Furthermore, although this article is not covering starches, it must be noted that combinations of starches and gums are also playing an increasingly important role. The August 1999 Ingredients section, “Starches and Gums Move Beyond Fat Replacement,” discussed different combinations of starches and gums, and I recommend a quick review of this section.
Several innovative gums systems were highlighted at the 2003 Worldwide Food Expo. For example, gum blends designed to stabilize a variety of products made with dairy ingredients were spotlighted by TIC Gums. The powdered system (Dairyblend 603 EP Powder), consisting of protein-reactive pectin, an emulsifying hydrocolloid, and deodorized guar (GuarNT® Bland), were incorporated into an orange smoothie. The system allows for consistent viscosity, settle-free emulsification, protection against milk protein breakdown in high-acid formulations, and reduction of any grassy flavor. The orange smoothie was selected as the sample application because of its high-acid citrus base. It was also fortified with soluble dietary fiber.
A new gum system, Dairyblend Choc 46, was incorporated in a chocolate milk beverage. The gum system was developed to inhibit the settling of cocoa solids, improve emulsification and stability, and ensure consistency in extended shelf life UHT and HTST-treated chocolate milk products. Food manufacturers buy the product as a separate dairy powder blend, then add their own cocoa or chocolate powder to create their custom formulations that take into account any milk variations. The system also has proven effective for aseptic and shelf-stable chocolate milks, which have traditionally posed challenges in stability and flavor.
Several dairy formulations highlighting the functionality of gums were showcased by Degussa Food Ingredients, which had recently combined its three business units, including Texturant Systems, into one international unit. For example, a low-carbohydrate strawberry yogurt was stabilized by such hydrocolloids as locust bean gum, pectin, and carrageenan. Degussa supplies a number of texturant systems, which include agars, alginates, carrageenans, galactomannans, pectins, xanthan gum, and hydrocolloid blends.
--- PAGE BREAK ---
Gum blends are also finding potential use in culinary applications. This should not be too surprising, since gum combinations offer a wide array of choices. Traditionally, starches have found application in such preparations, but gums may be used with starches or as alternatives to starches, or they may act synergistically with other hydrocolloids. Interestingly, at the 2003 IFT Food Expo®, TIC Gums chose a culinary approach to demonstrate the effectiveness of gum combinations. The Culinary Concepts column in the November issue of Food Technology, a culinary column (page 18) addressed this aspect.
As companies add to their portfolio of gums, they also find new combinations possible which might solve previously difficult challenges.
A hydrocolloid blend for stabilizing ready-to-drink juice beverages was developed by CP Kelco. Called KecoGel™ PS, the blend consists of high-acyl gellan gum and pectin, and was specially designed to allow long-term stabilization of both cloud and pulp in ready-to-drink fruit juices.
A wide range of stabilizer systems demonstrating synergistic benefits have also been developed by Gum Technology Corp., P.O. Box 35206, Tucson, AZ 85740-5206 (phone 800-369-4867; fax 520-888-5585; www.gumtech.com). For example, Coyote Stabilizer CKLX-MS is a blend of carrageenan, xanthan gum, locust bean gum, and konjac. It can be used as a thickening agent as well as a gelling agent. The gums in the system react synergistically to form a very elastic and strong gel after heating and cooling. Kappa carrageenan forms a very brittle gel by itself, but when konjac, locust bean gum, and xanthan gum are added to the system and hydrate together with the carrageenan, the gel formed is very elastic, strong, and without syneresis.
A water-soluble gum system designed for clear-gelling applications in low-calorie and no-sugar-added jams and jellies has been developed by Gumix International, Inc., 2160 N. Central Rd., Fort Lee, NJ 07024-7552 (phone 201-947-6300; fax 201-947-9265). The components of the system, Gumixall 780 Premium, are said to synergistically interact to create systems with excellent gel strength. Boiling the solutions of this natural gum system causes full hydration.
Since gums offer such a wide array of choices, one can expect to see a wide range of gum systems being customized to provide answers to specific problems.
Next month’s Ingredients section will look at the latest advancements in color and how they can help improve the appearance of foods and beverages.
by DONALD E. PSZCZOLA
Senior Associate Editor