Decisions, decisions. For many, a trip to the local ice cream shop requires the intense consideration of a corporate takeover. Regular or low fat? One scoop, two, or -- dare I -- three? And should it be rocky road, cookies and cream or triple berry jamboree?
The International Ice Cream Association (IICA), Washington D.C., estimates that the United States produced 1.5 billion gallons of ice cream and related frozen dessert last year. While vanilla remains the most popular flavor (approximately 28%) ice cream varieties containing various inclusions make up a sizable portion of the market. Additionally, most of the growth has been in the high-end products, affording product designers the opportunity to flex their creativity by developing varieties that tempt the consumer.
Ice cream inclusions can come in two different forms: pieces or variegates. Pieces range from small flecks of vanilla bean to partial or whole bite-size pieces of material like fruits and nuts. Variegates often are used instead of, or in addition to, pieces. In the finished ice cream, variegates appear as a ribbon. This effect is achieved by swirling or injecting the sauce-like ingredient through the ice cream while it is still semisoft, but before it is hardened.
It should come as no surprise, however, that there is more to the process than merely dumping standard ingredients into an ice cream base. Not only does the freezing process change the ingredient, but often the ingredient impacts the ice cream itself. Because of this, the products added to frozen dairy desserts often must be modified to produce a suitable finished product.
"There are a lot of people who just want to add standard products, especially candy bars, to ice cream," observes David Holderman, group leader, R&D, Fantasy-BlankeBaer, Carol Stream, IL. "Sometimes it works; sometimes it doesn't. You can't rule anything out, but often you need to reformulate to get the proper characteristics."
A number of factors come into play when working with ingredients for ice cream. The first step is defining the target and deciding what contribution the inclusion gives to the product. This is no different than with any other food product: how should the product look, taste and eat?
Because ice cream inclusions promote a value-added image, most should appear in high contrast to the ice cream itself. With a chunk-type piece, this often means bigger is better. But looking at it on a weight basis: the bigger the piece, the fewer their number on a volume basis.
Ideally, the consumer should find a piece in every bite or at least several per scoop. The piece size often becomes a matter of economics since the inclusions usually cost more than the mix. The higher the grade (premium, super premium) the more likely the economic feasibility of adding bigger pieces, or greater numbers of smaller pieces.
Another appearance factor to consider is the integrity of the piece itself. A sandwich cookie piece should contain both creme and basecake. A candy bar piece should contain the filling as well as the chocolate coating.
"Often when you grind a candy bar, you'll lose the continuity of the chocolate and whatever is inside," warns Gordon Kivi, Fantasy-BlankeBaer's operation manager. "Look at something like a Butterfinger. There's a kind of honeycomb structure, so it produces a lot of fines and the chocolate tends to go off by itself into another piece. In a case like that, we feel to do it right you have to reinvent the wheel: make a center that matches the mouthfeel and taste of the bar, then coat it with a chocolate formulated to protect the center and melt in your mouth without waxiness."
Color bleed or smearing also affects the appearance. Depending on the manufacturer's requirements, however, this may not necessarily come across as a negative.
"We have two types of cherries -- bleeding and non-bleeding," explains Robert Anderson, frozen dessert industry manager, Fantasy BlankeBaer. "Some people like the bleeding effect, some don't. Likewise with variegates, if you want to form a ribbon without any bleeding into the ice cream you have to consider the formulation and processing parameters. There are ways to overcome or at least reduce it. If the base is colored it is certainly less of a problem."
The degree to which an inclusion flavors the ice cream varies. Sometimes -- as in the case of some fruit purees, or other ingredients added to the mix -- the inclusion acts as the source of flavor for the entire product. Other times, it must blend together with other ingredients to give the illusion of a particular product such as "pecan pie." And often, while blending with the other flavors, it creates a specific flavor impact of its own. The ingredient used needs to deliver the correct flavor intensity for its intended purpose.
"Normally we prefer to add some background flavor to the mix," says Holderman. "If you just flavor the fruit prep, the flavor may be too intense in the fruit pieces, so we try to balance it by adding the same flavor to the ice cream. It's not like an unfrozen yogurt; once ice cream is frozen, any flavor migration is very slow."
On the other hand, a product not formulated expressly for ice cream may not deliver the impact required once it is mixed in.
"Things in ice cream often need to be more highly flavored," Kivi remarks. "There are a limited number of pieces, so when you get one, you need a burst of flavor. Whereas, if you're eating a candy bar and have the same flavor intensity, you would be burnt out after a few bites."
This often represents one of the biggest challenges when working with ice cream inclusions. The target texture varies as widely as the number of ingredients and the number of ice cream manufacturers. Whatever the target, the piece must exhibit and maintain an acceptable texture under frozen conditions.
Two main aspects drive the texture requirements: what texture the inclusion shows under frozen conditions, and what happens over extended storage as an ice cream component. These vary with the ingredient and this feature story will explore some specifics further on. There are, nevertheless, some general considerations:
- Fat characteristics: The melt point of the fat greatly impacts its texture in ice cream. Fats that have a higher melt point, such as cocoa butter, often produce a waxy or brittle texture under frozen conditions. Lowering the melt point of a fat produces a softer, more creamy mouthfeel. The type and amount of fat influence the texture of everything from high-fat products such as chocolate, to fats used in baked products, or as an oil for nut roasting.
- Sweetener system: The sweetener used in the inclusion affects the texture by depressing the freezing point. Disaccharides like sugar tend to produce ice crystals. Using corn sweeteners that contain a high level of monosaccharides, on the other hand, results in a less icy product. This is true for both the initial freezing process as well as any subsequent freeze/thaw cycles. While the product should be soft enough to provide a desirable eating texture, if the solids are too high, the ingredient will not freeze. A high level of solids creates other problems as well: The inclusion, including variegates, can fall to the bottom of the carton before the ice cream freezes solidly.
- Stabilizers: The stabilizer system must be appropriate for a frozen system. It not only must exhibit the desired characteristics under frozen conditions, but it must not break down or significantly change when it undergoes freeze/thaw cycling. The target texture also influences the selection. Chocolate fudge is somewhat chewy, a fruit variegate typically is not. According to Joseph Kuo, R&D manager, frozen applications, Ramsey Laboratories, Inc., Cleveland, OH, ice cream manufacturers often want to use the same type of stabilizers in the inclusions as the ice cream mix or specify particular ones for labeling or functional purposes. "You often use pectin as a stabilizer in fruit products because it gives the product a 'natural' connotation," Kuo remarks. "Other times they wish to keep the list of ingredients, especially those the consumer may not understand, as short as possible. Many like carrageenan because it reacts with the milk proteins."
- Moisture: When water freezes, it becomes ice. Consequently, high moisture, low-solids inclusions such as natural fruit become rock hard in ice cream. On the other hand, because of the dissolved solids in ice cream, a significant portion of the water in ice cream remains unfrozen and can migrate into ingredients like nuts and cookie crumbs. Surrounding the piece with a moisture barrier such as a fat helps to retard this process so the inclusion remains crisp.
- Effect on the ice cream: What goes into the ice cream becomes a part of the whole, so a product designer needs to gauge the effect on the entire product. While changes in color due to bleeding and moisture migration fit into this category, several other potential problems can arise.
- Stabilizer synergy: While stabilizer synergies often provide significant advantages, in the case of ice cream they can ruin the product. Particularly if the inclusion is dispersed throughout the mix as in the case of a fruit prep, the wrong stabilizing system can create a hard, gummy, unacceptable product. "This is a frequent problem in developing these products. Under ideal situations, we would like to have the customer's mix to work with in order to make certain the two are completely compatible, especially for fruit feeder products," observes Anderson. "Variegates are not as important, because they stand alone. But things like locust bean gum and xanthan gum are synergistic and together they would give you far more viscosity than either would alone."
- Shelf life: Moisture migration is one phenomenon that influences shelf life. Rancidity also causes problems, particularly in high-fat ingredients such as nuts. This tends to be more of a raw material storage and handling issue. And while oxidative rancidity progresses rather slowly under frozen conditions, a high moisture, aerated environment like ice cream certainly will not improve the overall situation.
- Ice cream processing limitations: Often the process puts constraints on the inclusion specifications and properties. For products incorporated through a fruit feeder, the manufacturer can use as large a piece as practically feasible. If the product goes through a variegating pump, it restricts the size of any chunks. "Some manufacturers may have large enough tubes to handle a piece up to about 3/8 inch," notes Holderman. "Others can't handle much more than a puree." The size of the auger in the fruit feeder may restrict the size of the piece, but in practical terms, is not the limiting factor according to Kuo. The size of the feeder and auger correlate to the speed of the freezer. Therefore, with an exceptionally large piece, you could not feed a high enough volume to produce an acceptable distribution of pieces through the ice cream. Even if it were possible, the cost of the finished product would probably be unacceptable. If the auger speed, and consequently the feed rate, are relatively high it may have a negative effect of the more fragile inclusions by increasing the amount of fines, causing the chocolate to flake off, etc. The viscosity of the variegating sauces needs to be tailored to the system. A sauce that is too thick will not pump properly. One that is too thin will result in smeared or runny deposits instead of a clean, discrete ribbon through the ice cream. The temperature of the inclusion is another important consideration. If the pieces or variegating sauce are too warm, the ice cream may melt. Subsequent refreezing causes a decline in quality of the ice cream. The composition of the inclusion also affects the temperature at which they are added. In the case of low melting point fats, for example, lower temperatures keep the pieces from sticking together during the operation. This results in better distribution in the finished product.
Thinking about the type
Often the type of product or size of the pack dictates the parameters of the inclusion. From a processing standpoint as well as a purely aesthetic view, the size requirement of the piece may change depending on the size of the pack.
"If the ice cream is going into pints, you'll want to see more than one piece in there," advises Kivi. "Unless you're a premium manufacturer who believes bigger is better, you may want to go to smaller pieces rather than increase the total amount. Sometimes people that are using a 1/2- to 3/4 inch piece in half gallons will find that the same size can produce problems in a high speed capping line for pints. The pieces can hang up on the sides."
Cost and end use can also affect the size and number of inclusions. Super premium varieties have much more leeway than economy versions. What works in products intended for home is not necessarily appropriate for foodservice.
"Color and eye appeal have a lot to do with products sold in shops because there's a glass front on the freezer cabinet," Anderson points out. "The customer must see as well as taste the inclusion in each scoop. These formulas tend to have more inclusions than we would normally recommend for store-bought ice cream. On the other hand, store or private label brands are very cost sensitive, so they tend to stay away from fancy flavors and higher cost inclusions."
Ice cream inclusions often need some processing or formulation enhancements from the ingredient manufacturer's perspective. These impact the finished inclusion's quality as well as its practical use.
"We can pack our products in 5-gallon pails, or in 1,000- or 2,000 pound totes," explains Kuo. "The totes can be aseptically packed with pasteurized product while the pails must be hot-filled. The aseptic process is less harsh than the hot-fill heat treatment. However, not every manufacturing facility is set up to use large containers. We also encourage people to use totes, because they're environmentally friendly and do not generate as much waste.
"When you put the product in totes, the stabilizing system becomes very important," continues Kuo. "The liquid portion has around 30% solids, while the fruit is only 6% to 8% solids. one of the challenges is to formulate so the fruit does not float to the top. Usually we can use the same stabilizers that are used in ice cream, but we may have to use different combinations or larger quantities."
Ice cream novelties can present a host of new considerations. Typically, they need to contain smaller pieces than regular ice cream. A designer may need to adjust the formula to meet processing requirements. For example, when extruding a caramel or similar ingredient into a bar, it must cut off cleanly and not tail off.
"We have customers that use our cookie crumbs for coatings on novelty products, but they only require the basecake crumbs, not the creme center," notes Dicki Lulay, director, business development, Nabisco Foods Group, Food Service Division, Parsippany, NJ.
Another area that demands special attention is low- or no-fat products. Since the inclusion contributes a significant portion of the ingredients -- anywhere from 5% to 12% and upwards -- it also may contribute a significant amount of fat. This does not create a problem in the case of fruit, but many of the confectionery ingredients depend on fat to give the correct texture and mouthfeel under frozen conditions.
"We often need to formulate special products for these categories," Kivi says. "You've got to be aware of how much fat is contributed by your inclusions and ribbons. With some products we need to have some room for additional fat, so the fat content of the mix should be lower than the target level. Sometimes you can meet low-fat requirements just by reducing the usage level of the inclusion."
Garden of earthly delights
While we're certain someone, somewhere has looked at it, broccoli would not be a big seller as an ice cream inclusion. The ingredients added to increase ice cream appeal fall into various sweet or sweet-compatible categories: fruit, nuts, confectionery, and sweet baked goods such as cookies and cakes. Depending on the manufacturers requirements, they may act as all or part of the flavoring and coloring system. They tend to be highly visible, although something like a peach puree, may not produce distinct, discrete particles. Each category has some special formulation, manufacturing and usage requirements.
According to the IICA, fruit varieties make up the second most popular ice cream category, about 15% of the total. Ice cream Manufacturers add fruit in a number of ways. They can feed it directly into the mix or as a variegate. They can use natural fruit, sugared fruit or specially formulated fruit preps.
As previously mentioned, using natural fruit in ice cream presents a number of problems including iciness and floating. Even sugared, frozen fruits may not produce the desired quality. The sugar used may promote graininess in the finished product and the solids level of standard packs such as 4+1 (four parts fruit to one part sugar by weight) may not match the ice cream mix and can vary with the crop. This is why ice cream fruit preps are widely used.
"With a fruit prep, you need to have a total solids, or degrees Brix as it's sometimes called, to prevent the fruit from getting icy," Holderman explains. "This is true of both fruit preps that go directly into the ice cream as well as variegating sauces. For those used in the ice cream mix, you need to have the total solids match up fairly closely to that of the mix. The type of sweeteners are important, not only for sweetness, but for how they affect the freezing point."
Caramels, marshmallow, chocolate and fudge are commonly used as variegating sauces. From both a textural and shelf life standpoint, the percent solids need to be higher than a fruit prep. According to Kuo, the correct viscosity to deposit successfully through a variegating pump yet display the correct textural attributes in the finished product falls in approximately the 80,000 to 100,000 centipoise range.
"With caramels and chocolates, people really like a textural contrast," Holderman remarks. "With a fairly high partially hydrogenated vegetable oil level, you can make a chewy type. Something lower in fat with sweeteners that depress the freezing point would give a more syrupy texture. By varying the formula, you can develop products with a wide range of textures."
Caramels can be tricky to produce. With a true caramel, the characteristic color and flavor is developed during the cooking process.
"The sugar, water and milk protein all combine and caramelize during cooking," Kuo explains. "If you cook too long, you get a burnt flavor and dark color. If you don't cook long enough, the color is too light and the flavor is weak. The viscosity is also influenced by the cooking. The longer you cook, the thicker it gets because you denature the protein more. That's why its important to closely monitor the process."
A marshmallow creme may be added in either whipped or unwhipped versions. An unwhipped version gives the manufacturer the option to aerate it to the level they require.
"Many marshmallow creme products are formulated specifically for the ice cream industry," states Bob Bianca, section manager, Kraft Food Ingredients, Specialty Products, Memphis, TN. "They contain stabilizers that allow the manufacturers to process it and to maintain a soft, fluffy texture. If you tried to work with a standard marshmallow creme, it wouldn't function in the ice cream maker's equipment."
Some ice cream products contain actual marshmallows. They can be standard moisture products, approximately 16%, or dehydrated versions that, with storage and subsequent moisture migration, soften to the required consistency by the time it reaches the consumer. The size can vary based on customer requirements. According to Bianca, many manufacturers add the standard moisture products in a frozen state to facilitate handling.
Adding nuts to ice cream is another popular option. Adding nuts to ice cream creates two potential problems. Nuts typically contain high levels of unstable fat and are, therefore, subject to rancidity. Moisture migration can quickly make nuts lose their crunch.
"If you add nuts to ice cream, they need to be coated with some kind of barrier or they become soggy and rancid," advises Rick Meredith, vice president of Paramount Farms, Bakersfield, CA. "This can be done by oil roasting the nuts or by using an actual coating like chocolate or praline."
This again may require special consideration for ice cream inclusions. The melt point of the fat used has to exhibit the right mouthfeel characteristics as well as hold up during processing. But if the melting point is too low, the nuts may stick together during the feed operation.
A praline coating helps to keep the oxygen, and to some extent, the moisture out. It consists of a panned sugar coating applied to an oil roasted nut. Because it is sugar, it will dissolve in the ice cream over an extended period of time.
Chocolate and other confections
As noted, the melt point of fat plays a critical role in the texture. Since a sizable portion of chocolate or compound "chocolate" consists of fat, the type of fat dictates the texture in the finished ice cream product.
"Chocolate is normally made with cocoa butter having a relative melt point of 88 to 92°F," observes Kivi. "In ice cream you want to suppress that melt point by adding a fat like peanut or coconut oil. Otherwise you get a waxy mouthfeel and that waxiness suppresses the flavor release."
Altering the composition of chocolate to improve the frozen texture creates one potential problem. Often, the result cannot be legally called chocolate. That may be a stumbling block for manufacturers who wish to use "real" or `'all-natural" ingredients.
This problem extends itself to other candy products. The texture of not only the chocolate, but the other candy components often hardens to an unacceptable level in a frozen state.
"Candies are often very high in solids and low in moisture and that doesn't necessarily translate well in ice cream," warns Kivi. "It may be too hard to chew through. You have to think of what happens if you stick a particular candy bar into the freezer." Again formula modifications can produce a candy that is acceptable for ice cream use.
Cookies, cakes and brownies all find their way into ice cream. Again, it's a matter of sometimes standard products work, sometimes they don't.
"The product we sell for ice cream is no different from our regular Oreo(r) Cookies," declares Lulay. "But they don't turn mushy in ice cream and they maintain their product integrity -- we don't see a lot of decapping, where the cookies break away from the creme. That's inherent in the product -- twisting the sandwich to separate it. But we didn't design any of it specifically for ice cream. It just turned out that way. You may not see the same attributes in other cookies, even some of our other brands."
Often bakery products need to be modified to give the desired result in ice cream. Many will absorb moisture and soften. While some manufacturers and consumers want a soft cookie piece, others prefer them crunchy. With a cake or brownie piece they should be soft, but not mushy.
Two methods can produce the desired texture. A piece with a crunchy texture can be coated with a moisture barrier, such as fat, to maintain their crispness. A cake or brownie can be formulated and processed so that the initial piece is low in moisture and relatively hard. By the time it reaches the consumer, enough moisture has migrated into the piece to give the desired texture. The harder pieces also tend to withstand the process without breaking apart.
"An excessive amount of fines can change the color of your ice cream and make it look dirty," says Lulay.
Cookie dough for ice cream is another product that usually requires special formulation considerations. The formula may be similar to regular cookie dough, but in different proportions to achieve the desired texture and flavor. There is no need to add leavening, since the dough is not being made into a cookie. But since the product is not baked, the manufactures may want to omit ingredients such as eggs because of the microbial concerns.
"You want to tie the cookie dough together with fat, " notes Kivi. "You need to form it. But, you have to control your process so that the chocolate chips don't melt; otherwise it looks like chocolate dough instead of the typical chocolate chip cookie dough."
Freeze that thought
Back when fudge ripple was considered somewhat avant garde, if a person wanted something with their ice cream, they made a sundae. That's one of the ways that manufacturers get their ideas.
"One of the fastest selling children's dessert concepts in the food service area is the 'dish of dirt' -- a flowerpot with Oreo Cookie pieces for dirt, ice cream and gummy worms with a flower stuck into it," notes Lulay. "The kids love it."
While the thought of gummy worms in ice cream may be a bit outrageous for most adults, at least one manufacturer has capitalized on its kid-appeal. In fact, many ice cream producers seem to be focusing on products for children. While this was always a popular market for ice cream novelties, it is expanding to include regular ice cream. On the other hand, many novelty products are now being designed for adults. According to the IICA, children 2 to 17 years of age and adults over 45 eat the most ice cream.
"The thought is that all ice cream is geared toward kids, anyway," proposes Anderson. "About three years ago at DFISA, we had a special section in our booth showing kids' flavors. Either we were ahead of our time or we started people thinking."
Those in the industry suggest other ways to identify market potential.
"If an ice cream manufacturer is looking for sales in the South, for instance, we might look at adding one of our products that does well in that region," suggests Lulay. "We've been asking potential customers: 'What is your strategic plan? Who is the focus?', and then compare that with the demographics of our products."
According to the group at Fantasy-BlankeBaer, focusing on trends that can be incorporated into ice cream is another way to generate ideas. They listed coffee shop flavors, ethnic and hot flavors as several areas that are currently receiving attention.
No matter what the preference, there's an ice cream inclusion designed for every taste. But although getting the right combination of ingredients may just be a case of serendipity, in most cases, it requires a high degree of expertise and a lot of hard work.