Prepared Foods - August 2008 - (Page 66)

cover story Due to their different sizes, the three main cyclodextrins, alpha, beta and gamma, can encapsulate different-sized particles. pends particles in a controlled air stream, where they are coated with the material of choice. These systems take many forms and may be utilized for drying, granulating and agglomerating, as well as coating. These systems often are used for hot-melt coatings, such as stearines, fatty acids and waxes, which solidify in cool air and release their core material upon heating or shear. They are used to encapsulate ascorbic acid and sodium bicarbonate leavening used in baked goods (Foster, 2005). 3 Alpha Cyclodextrin O HO O OH HO O OH O HO HO HO OHO OH O OH O OH OH OH O OH OH O OH OH O OH O Molecular Encapsulation Encapsulation at the molecular level, sometimes called the inclusion complexation technique, is best illustrated for food applications with cyclodextrins. Briefly, cyclodextrins that many might call “natural” are produced from starch by the action of cyclodextrin glycosyltransferase, an enzyme produced by several microorganisms. Structurally, cyclodextrins consist of 6, 7 or 8 D-glucopyranose units connected by alpha-(1,4) glycosidic linkages (just like starch). (See the cyclodextrin illustration.) The chemically and physically stable, bucket-shaped polysaccharides (with a hydrophobic interior) form stable complexes sometimes instantaneously, with a variety of different molecules. How well the guest molecule fits into and is released from the host “bucket” is a function of the interplay of a number of different molecular interactions, ranging from Van Der Wals forces to hydrogen bonding to interactions with the solvent medium. Cyclodextrins can effectively entrap aromatic oils, such as those from onions and garlic, or various extracts from herbs and spices, making them more watersoluble and control their release (for example, under the moisture and temperature conditions typically found in the mouth). They also have been shown to entrap various flavonols, such as quercetin and myricetin, a potent antiinflammatory compound and antioxidant, respectively. Both are found naturally in many fruits and vegetables (Lucas-Abellána, 2007a,b).4,5 Some cyclodextrins already are used as carriers for protecting vulnerable natural colors, flavors and vitamins, or serve as a means to solubilize lipids, stabilize oil in water emulsions, or flavor or aroma modifiers in a variety of processed foods. Accelerated and long-term storage stability test results showed that the stability of cyclodextrin-entrapped food ingredients surpassed that of the traditionally formulated ones. Cyclodextrins can offer improved sensory, nutritional and performance properties as a result (Szente and Szejtli, 2004).6 Recent laboratory successes have shown that cyclodextrins can O Photo courtesy of Stanisław Skowron spray-dried ingredient systems, these systems can be incorporated into dry products or powders, and the encapsulated active ingredients will be released upon contact of the product with water. Spray-chilling is another common process in which cool particles of the encapsulate (such as a flavor) are mixed with hot-coating materials (such as a melted fat) to create either a solution or dispersion. This mixture is then atomized into a chamber, where it is contacted with a cool air stream that causes the atomized droplets to solidify, forming a crude encapsulated product. It is then cooled with air to create a powder. Though spray-chilling is a good choice for products that require higher substrate coating levels, up to 80%, there are disadvantages to this process. Drawbacks include interactions between the fat and the active, or the volatilization of lipid-soluble materials over time. Spraychilling is often used for vitamins, acidulants and reactive minerals that need to be protected from reacting with their ingredient environment, such as various iron fortificants. Volatile actives can be lost during both spray-drying and spray-chilling processes. Neither spray-drying, melt extrusion or spray-chilling allow the formation of coated materials that have the ability to release multiple active ingredients in a controlled, consecutive manner; this is desirable for a sustained flavor release. More sophisticated encapsulating technologies are needed to achieve these objectives. Fluid-bed systems for encapsulation are sometimes utilized when the release characteristics of the finished ingredient system are well-defined. The process sus- 66 August 2008 ● www.PreparedFoods.com http://www.PreparedFoods.com

Table of Contents Feed for the Digital Edition of Prepared Foods - August 2008

Prepared Foods - August 2008 Table of Contents Hitting the Shelves Promoting Craveable Foods and Beverages It’s a Small World MarketWatch Regulations: Safety Dance A Taste of Southeast Asia Flavor Secrets: Asian Five-spice Flavor Secrets: The Well-seasoned Potato On the National Menu To Serve and Protect: Flavor and Nutrition Protection Fat Applications in Transition: Creation of Good vs. Bad Fats A Tasteful Formulation Balance Nutrient Density and Dairy Foods R and D Applications Seminar: Formulation Information R and D Applications: Some Flavors Like it Hot R and D Applications: Prebiotics from a Conifer? R and D Applications: Seeing Red (Foods) R and D Applications: A Probiotic with Survival Skills Abstracts

Prepared Foods - August 2008

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