Article: Taming Texture -- May 2008
May 1, 2008
Synergies Between HydrocolloidsHydrocolloids are ingredients used in food systems to help control water. Hydrocolloid synergies occur when two ingredients together work more effectively than either ingredient separately. Some examples are carrageenan and galactomannans, like locust bean gum (LBG) or tara. Xanthan gum and LBG are also synergistic together.
Carrageenan and LBG together can produce sparkling, crystal clear gels of various textures. They are an excellent choice for gummy candies, dessert gels and fruit roll-ups. This system can be expensive, however, and subject to seasonal supply problems with LBG.
An alternative is tara gum. Carrageenan and tara gum give the same synergistic (albeit slightly weaker) reaction as carrageenan and LBG. Carrageenan and tara may also be used in applications where high gel strength and elasticity are required. The gels are translucent, and the system is typically less than half the expense.
Another synergistic combination of ingredients is iota carrageenan with starch. This combination is cost effective, as starch can be reduced up to 40%, while still maintaining moisture retention. Minimal addition of iota carrageenan significantly reduces process viscosity inherent to starch systems alone. Various combinations offer improved organoleptic qualities and resistance to shear degradation. Addition of levels of as little as 0.035% iota carrageenan enhances body and texture of starch-based puddings. Starch reduction results in a cleaner mouthfeel, a shorter texture and is less sticky.
In marinated whole chicken, iota carrageenan and starch combinations provide excellent moisture retention with minimal “drip” loss. A natural texture is maintained without gumminess, and it is easily incorporated into the meat muscle via injection.
Xanthan and galactomannan combinations also work well. In barbecue sauce, xanthan and guar—at a typical stabilizer use level—provide additional thickening and cling, with smoother flow characteristics and improved economics. In cheese spread, a combination of xanthan and guar gum can economically eliminate “whey-off” and reduce flavor masking.
It is estimated that about 30% of the total hydrocolloid market is sold in the form of blends. Blends are developed to take advantage of hydrocolloid synergies, helping food formulators to manipulate texture, rheology and organoleptic properties in a variety of foods. The proper combinations and ratios are typically application-specific, requiring bench experimentation and possible assistance from a supplier.
“Hydrocolloid Synergies: Their Applications in Foods,” Kevin Johndro, laboratory manager, Ingredient Solutions Inc., firstname.lastname@example.org, www.isinc.to
--Elizabeth Mannie, Contributing Editor
Spray-dried Emulsified Powdered SystemsEmulsified powders are useful in a variety of product classes. Non-dairy creamers, powdered vegetable shortenings, whipped toppings and dessert bases, milk replacers, emulsifier systems, yogurt powders and other spray-dried systems are complete systems designed with multiple, functional components.
Creaming agents add creaminess and opacity, enhance color and flavor, improve texture and mouthfeel, create structure and stability, while delivering nutritional properties. Powdered shortenings are >70% fat, adding creaminess and opacity. They are easy to weigh and enhance fat distribution in dry mixes.
Whipped topping and dessert bases are convenient, with easy storage and handling. They add aeration, volume and structure, while enhancing texture and mouthfeel. Healthy options include fat-, cholesterol- or sugar-free; no trans or hydrogenated fats; medium-chain triglycerides; low-glycemic; high-fiber and -protein; non-allergenic; non-GMO; and natural or organic.
The functional fat components of a spray-dried system could be the lauric fats of coconut oil or palm kernel oil, or hydrogenated soy or canola, or for a nutritional function, the powder could incorporate CLA, DHA, EPA, MCT or other healthy oils.
Functional carbohydrates in spray-dried systems may include sugars like sucrose and lactose, corn syrup (typically 20-30 DE) or 10 DE maltodextrin. For sugar replacement, polydextrose sugar alcohol could be included; also, inulin (a soluble fiber) could play a role.
Emulsifiers often are useful in spray-dried systems and their key function is to coat the fat particles and keep them from coalescing together. Each ingredient, like casein, starch, or wheat protein, provides a different type of emulsion with unique functionality. Casein is, by far, the most functional and prevalent primary emulsifier in these systems. Minor ingredients in spray-dried systems include phosphates, secondary emulsifiers like monoglycerides, lecithin, gums, flavors and colors.
Emulsions are spray-dried, because powder is a convenient form. Spray-drying also increases whiteness or opacity and improves texture. Refrigerated storage is no longer necessary and shelflife is increased to one year or more. Drying also protects against oxidative degradation. A one-step, more accurate weigh is accomplished at a lower shipping cost.
End-use applications for spray-dried emulsification systems are dairy, beverages, healthy foods, processed foods, bakery, confectionery, desserts, seasonings and flavors, in both the retail and foodservice segments.
“Designing Healthful Spray Dried Emulsified Powdered Systems,” Dennis Reid, vice president, marketing and technology, Diehl Food Ingredients Inc., email@example.com, www.diehlinc.com, www.sensoryeffects.com
--Elizabeth Mannie, Contributing Editor
Wheat Proteins in FoodsWheat gluten is a highly functional ingredient that promotes long mix times and chewy, tougher, denser textures. It absorbs high amounts of water and promotes longer bake times but can be difficult to incorporate in delicate systems.
Vital wheat gluten can be processed to produce unique properties for specific applications (increased protein levels, faster hydration, higher water absorption, stronger vitality, or less “cereal” flavor).
Wheat protein isolates have been developed to further enhance taste, texture and appearance. They can improve softness and crumb texture in traditional and reduced-sugar or low-calorie baked goods, both fresh and frozen. Other benefits are mimicking fat properties by maintaining softness, replacing or extending egg and dairy proteins, and enhancing whole-grain products by improving taste, dough rheology and texture.
Not all gluten is created equally. Gluten quality can vary, based on source and process. A higher quality gluten can allow the amount required to be decreased. Water management is essential in obtaining optimum performance.
Gluten index is a quality parameter that describes the quality of the gluten and gives a picture of the amount of extensibility vs. elasticity. Wet gluten relates to quantity. The wet gluten is approximately the amount of protein plus the water it holds. Various instruments, such as the Mixograph, Farinograph and Alveograph, are used to measure various properties of gluten.
In cake, wheat protein isolate (WPI) functions to tenderize. When using WPI, the amount of fat and sugar can be reduced, improving the nutrition label. The overall quality, texture and mouthfeel are improved, and the cake remains tender through frozen storage and shelflife. Gluten also adds structure, reducing or removing egg and dairy proteins. In frostings and fillings, WPI reduces modified starches, sugar and fat, increases protein, improves whipping/aeration, improves mouthfeel and creaminess, and replaces higher cost proteins.
In biscuits, gluten tightens cell structure, reduces fat, improves and maintains softness, while replacing sodium caseinate or other dairy-based ingredients. For pizza, flatbread and tortillas, wheat protein isolate improves dough handling, eases sheeting and reduces cracking. Breads, rolls and buns also show improved freeze/thaw stability and microwave quality and tolerance.
Improvements also are made with adhesion for coatings, whole-grain product quality, vegetarian quality and microwave baking.
“Formulating with Wheat Proteins,” Brook Carson, technical product manager, ADM Milling Co., firstname.lastname@example.org, www.admworld.com
--Elizabeth Mannie, Contributing Editor
Using Thermal Gelling HydrocolloidsImportant sauce characteristics include “cling” during cooking and at eating temperatures, suspension, foaming, freeze/thaw stability and foodservice needs. Stabilizers often come in handy to assist in achieving and maintaining these characteristics. Stabilizers often used in sauces include starches, emulsifiers and gums. Considerations when adding stabilizers to sauces are moisture and fat content, pH, processing conditions and other ingredients present like salts, proteins, or fruits and vegetables.
Cellulose-derived ingredients such as methylcellulose (MC) and hydropropylmethylcellulose (HPMC) can provide good stabilization to sauce formulas. MC and HPMC characteristics depend on source, substitution type and uniformity, level of substitution, molecular weight and particle size. Substitution refers to the addition of methyl or hydroxypropyl groups along the cellulose backbone. Varying cellulose derivatives act differently with the application of heat--some thinning, some thickening or flocculating--but all are reversible except starch.
MC and HPMC share some key characteristics in that they are non-ionic, thicken at cold temperatures, gel when hot, have surface-active properties, are good film formers and interact with starch. In sauce applications, they provide thickening and thermal stability. In fillings, they prevent boil-out. In extrusion, they bind. As a pre-dust, they promote adhesion. In batters, they reduce oil pick-up. In gluten-free products, they provide volume and structure. Other benefits include foam promotion and stabilization of whipped toppings.
MC and HPMC thermal gelling properties are thermo-reversible. The rate of heating and other ingredients present can affect their function. At higher rates of heating, they have a higher gel temperature. Adding salts, sugars and other solids lowers gel temperature, while alcohol increases gel temperature.
The thermal gel strength of MC and HPMC solutions depends upon substitution type and level. For example, a solution made of cellulose modified through methyl substitution only will gel as a hard, brittle gel upon heating. In contrast, HPMC solutions, or those made from cellulose modified with methyl and hydroxypropyl substitution, produce softer, more pliable gels upon heating.
Cooking sauces require easy flow during application, good cling during cooking and an attractive appearance for serving. HPMC combined with starch helps achieve these properties. In a cooking sauce formula, HPMC would typically be used at 0.3-0.5% and starch at 1.25%. Sauces containing HPMC increase in viscosity upon heating, giving body and allowing good cling during cooking.
To choose either an MC or HPMC, consider the desired gelling temperature, gel texture, other ingredients, viscosity, handling and processing conditions. When dispersing and dissolving, water may be heated to a range of 60-80°C and the ingredient stirs in easily. Then with agitation, cold water may be added, and it will start to thicken as it cools.
“Formulating Winning Sauces with Thermal Gelling Hydrocolloids,” Mary Jean Cash, senior staff scientist, Aqualon, a business unit of Hercules Inc., email@example.com, www.aqualon.com
--Summary by Elizabeth Mannie, Contributing Editor
Benefits and Properties of Soy Fiber (Okara)One proprietary soy fiber ingredient contains 56% total dietary fiber, contributes 28% high-quality protein and 1.32mg/g isoflavones. Soy protein contains all of the essential amino acids. The protein has emulsifying properties, and its functionality is improved when exposed to heat and shear.
In meat systems, the ingredient improves yield, binds water and oil, improves juiciness, aids in freeze/thaw stability, hydrates rapidly, is easily incorporated and requires no special processing steps. In pork sausage, using soy fiber as the only binder results in a 5-8% increase in cook yields during processing, due to improved moisture retention. Soy fiber replaces the use of conventional binders, such as modified food starch, non-fat dry milk solids, cereal flours, maltodextrins and other soy protein products. It delivers a better nutritional profile, with a lower fat content and higher fiber content than conventional cooked pork sausage.
Labeling nomenclature in USDA-related products would be “isolated soy product” or “modified soy product,” when used in both non-standard and standard of identity products where binders are permitted. Standard of identity products where binders are permitted (up to 3.5%) include fresh, frozen and cooked sausages, frankfurters, hot dogs, bologna and knockwurst. Beef patties, chili con carne, and spaghetti and meatballs can incorporate soy fiber, also. Chili con carne can use up to 8% and spaghetti and meatballs up to 12%. The USDA specifies use level on a product-type basis. In FDA-regulated products, labeling nomenclature would be “soy fiber” or “okara.”
Soy fiber also can be used in gluten-free cookies as a one-ingredient solution substitution of wheat in wire-cut cookies. When compared with conventional wheat flour, soy fiber adds a clean, neutral flavor, is easily customizable and also provides a non-gritty texture, clean ingredient statement and a better nutritional profile. The free-flowing powder is easy to handle and cost-effective.
In fresh-frozen pasta, soy fiber can be used in both the dough and filling. It facilitates sheeting and provides increased cook yields. In pasta filling, it functions as a binder and allows for a cost-effective binder, replacing bread crumbs or modified starch.
“Nutritional and Functional Benefits of Soy Fiber in Various Food Systems,” Melanie Dineen, applications specialist, Sun Opta Ingredients Group, firstname.lastname@example.org, www.sunopta.com
--Elizabeth Mannie, Contributing Editor