Encapsulation technology helps bakers manage reactions, protect sensitive ingredients and ensure longer shelf life for products.
Encapsulation technology allows manufacturers to control each step of the baking process, from the fluffiness and longevity of a muffin to how and when ingredients react. Encapsulation protects and delivers unstable or reactive ingredients to products and overcomes ingredient shortcomings. It improves the handling of an ingredient, controls its release and enhances its stability during baking. This control is imperative because reactivity at an inopportune time poses problems for bakers, such as negative effects in the dough or batter.
Encapsulation is a range of technologies that includes fluid bed encapsulation, and spray chilling or spray drying particles and flavors with oil, hot-melt or water-soluble coatings.
“Lipid-based fluid bed-type encapsulation involves taking an ingredient, which is usually water-soluble and spraying it with warm liquid fat. The fat, which solidifies at room temperature to form a hard coating, is hydrophobic, thus providing an effective moisture barrier,” says Kristine Lukasik, PhD, applications manager, Balchem Encapsulates, a division of Balchem Corp., New Hampton, N.Y.
“The delay in solublization imposed by the coating effectively controls the ingredient’s reactivity,” Lukasik says. “The ingredient is released by the combined effects of temperature, physical forces and moisture. Encapsulates can be engineered to have specific release behavior that is appropriate for a given application,” she adds.
In some applications, the oil encapsulating the product melts during baking allowing the ingredient to solubilize and react. In other situations, the particle is encapsulated to protect it throughout baking and distribution. The salt topping a soft pretzel, for example, is encapsulated to remain protected during baking and throughout the product’s shelf life.
Bakers encapsulate sodium bicarbonate (baking soda), leavening acids, preservatives, acidulants, dough conditioners, fortifying ingredients and flavors for many reasons. If some ingredients release too soon, they can have negative effects on yeast activity, dough development or handling. Premature generation of carbon dioxide by chemical leaveners, ingredient degradation or flavor loss during baking also can occur, Lukasik says. Ingredients also are encapsulated to improve the longevity and functionality of the ingredients or the finished products.
“Once you start that leavening process you’re losing gassing,” says Walter Zackowitz, managing director, international sales, Watson Inc., West Haven, Conn. “The in-store baker will take a pail of frozen muffin batter and thaw it out overnight, and in the morning, they’ll start scooping out muffins. Early in the morning they’re making nice big fluffy muffins. If they have poor sales in the morning, by 10 or 11 o’clock the muffins aren’t quite as tall, and they’re more and more dense. So you’re losing quality. You’re losing shelf life. If you were to use an encapsulate, you would retain quality all daylong and you could buy larger more cost efficient pails of batter,” he says.
When formulating a batter containing naturally acidic ingredients, such as buttermilk or blueberries, bakers might experience problems using baking soda as chemical leavening because the baking soda might react with the acid from a ruptured blueberry instead of the free acid in the batter, Lukasik says. She adds ingredients are encapsulated differently depending on desired function. Abscorbic acid (Vitamin C) acts as a nutrient or a dough conditioner depending on how its reactivity is directed. The encapsulation performed on abscorbic acid intended as a dough conditioner is different from that produced if it is to act as a fortifying agent, Lukasik says. When used as a fortifying agent, the encapsulation remains intact through baking to ensure the vitamin’s stability. As a dough conditioner, it needs to react in the dough.
How it works
How a company decides to encapsulate an ingredient depends on both budget and function. When spray drying oil-soluble flavors, manufacturers take an oil-soluble flavor and solublize it into a high-melt point oil. Then they raise the oil a few degrees above the melting point and use an atomized nozzle to spray it into a tower filled with cold air. As the beadlets fall through the air they solidify and harden and the flavor is entrapped in the solid oil matrix, Zackowitz notes. Mixing a water-soluble flavor in a starch matrix and spraying it in a water environment before removing the moisture is another option.
During spray cooling or spray drying, a particle is suspended in a coating matrix and sent up into a tower and sprayed. As the particle is atomized with a hot-melt coating, the coating cools around the particle. Towers cost about $50,000, making the process only moderately expensive. When working with volatile solids, such as onions, spraying the particles into the air can compromise flavor notes or result in off flavors. Manufacturers can instead laminate these particles using a ribbon blender or pan coater, Zackowitz adds. Pan coating runs about $10,000.
Fluid bed encapsulation, costs between $1 million and $1.5 million dollars for a starting unit, including support equipment and a controlled environmental room.
“In fluid-bed encapsulation, the particles are propelled up the center of a cone-shaped unit with the particles cycling down the sides and up again. The operator controls critical parameters of temperature and moisture content of the particles and coating material temperature before starting the top-down coating spray. As the particles travel through the coating zone, the face of [each] particle is going to have a droplet of oil impacting it,” Zackowitz notes.
Temperatures are critical. If it is too cold the droplet will freeze on the particle rather than flow onto the particle’s surface. If the coating is too hot, it will flow over the particle’s surface and will not create the desired, separate laminate-coating layers. Different melt-point coatings or the amount and thickness of coating layers can determine the release time of the encapsulate, as well as its consistency and survival properties.
If too few layers are coated onto an acid or bicarbonate the coating can’t keep the dough from rising, and the result could be a can of cookie dough that bursts open on the store shelf. Or if sodium bicarbonate does not release early enough, or if the melting point is a degree too hot and the moisture was too low to activate the bicarbonate, the cookies will not rise as intended and could be small and dense.
Zackowitz notes these problems are not as common today because computers now control air speed, temperature and other variables, leaving little room for inconsistencies.
In the case of fluid bed encapsulation, Zackowitz says a microscopic particle may have 20 to 25 layers coating it. This allows a dough to remain fresh from makeup to distribution and keeps the dough from leavening until it enters an oven. When the dough hits a certain oven temperature, the oil coating melts into the dough and the encapsulate releases before the dough’s moisture bakes off. “That kind of control takes a $1.5 million unit. You couldn’t get that kind of consistency with spray drying, spray chilling or pan coating,” he says.
Lukasik agrees the method can make all the difference. “It is critical to consider what kind of particle you are starting with, the nature of the coating you are using and the mechanical limitations of the encapsulation reactor,” she says. Two products by different manufacturers might look identical on paper, she adds, but will be vastly different in terms of release behavior and functionality.
Even with their many benefits, encapsulates still can pose challenges. Bakers may need to adjust their formulas to ensure their products receive maximum benefit from the encapsulate. “It isn’t always immediately obvious to [manufacturers] what changes they need to make in their formula [or process] while using encapsulated ingredients,” Lukasik notes. She says a supplier can guide bakers in determining the correct amount or proper time to add the encapsulate.
Now that computers regulate factors, such as temperature, encapsulates are helping create products superior to those from previous decades. Engineering and equipment changes, such as more efficient nozzles, are improving consistency. More control also means more cost-efficient production as manufacturers have fewer bad batches, Zackowitz says.
Encapsulation technologies from the chemical and pharmaceutical industries now also are being used in food industries, says Yi Wu, chief innovation director, The Wright Group, Crowley, La. In addition, more ingredients can be encapsulated without affecting the functionality and sensory attributes of the products, Wu adds.
“In the past, encapsulation technology could only reliably provide what I’d call ‘coated particles’ and not really ‘technical ingredients’. The knowledge base and instrumentation have now evolved to a point [where] one can design materials to be high performance ingredients with very controlled behavior,” Lukasik says. She adds encapsulation design and engineering will continue to be important in bringing new elements of functionality to ingredients for bakers.
Zackowitz agrees. Fifty years ago, Watson Inc. developed gum aerobic-based colored glitter to decorate cakes. In the ‘90s, the company flavored the glitters and cut them into squares that later debuted as breath strips. Called edible film technology, these water-soluble packaging films can deliver everything from flavors to medications. Zackowitz says film strips might act as delivery systems in the future, so consumers can decide what flavor to add to products at home. He predicts the technology will evolve as a way to trap flavors, spices or vitamins as a form of encapsulation.
However it evolves, encapsulation technology “will continue to be successful and necessary because of the increased consumer demands for new and [more healthful] foods,” Wu says.