Pizza: It's Not Delivery--It's From the Grocer

In gluten-free crusts, nonfat dry milk can provide additional solids. Yeast can add flavor. However, the dough does not go through a proofing stage. Instead of yeast, to give the crust an Italian flavor, some pizza manufacturers add spices, such as garlic, onion, parsley, rosemary, thyme, basil, oregano and marjoram.

Customizing the dough

Commercial frozen-pizza manufacturers often rely on optional ingredients to assist the dough manufacture. “The main ingredients for improving process tolerance and the final baked product are DATEM (diacetyl tartaric acid ester of monoglyceride) and enzymes with amylase and xylanase activities,” says Kay. “These ingredients compensate for variations in flour quality, facilitate easier handling and improve dough stability during production. They also provide for uniform volume and texture.

“DATEM works as a dough strengthener primarily due to its ability to interact with gluten, forming the homogenous network important to the crust-making process,” continues Kay. “The improved gluten network increases gas retention in dough and results in increased volume. DATEM also alters the water-binding properties of dough, resulting in a drier surface. This, together with improved dough stability, results in easier dough handling and machinability, since the dough will not stick to the equipment.”

Typical DATEM usage is 0.2% to 0.5%, based on flour (baking percent). Industrial operations often use a liquid version, as it is pumpable and easy to add. Powder and flake forms are also available.

DATEM is usually not used in microwavable frozen pizza, as it can have a softening effect. Microwave cooking tends to soften foods anyway, because it prevents moisture from evaporating.

Enzymes containing amylases, which hydrolyze damaged starch, result in a drop in viscosity, whereas enzymes containing xylanase will change the water absorption of the arabinoxylan part, resulting in higher dough viscosity.

“Danisco’s bakery enzymes have been specially developed to modify the starch and arabinoxylan in flour for optimal baking performance,” adds Kay. “The results are improved dough-handling properties and a better gluten structure with an improved ability to retain the gas produced by the yeast during fermentation.” Usage level is in the range of 100 to 200 ppm.

“Use of both DATEM and bakery enzymes give the pizza manufacturer a high degree of flexibility during the crust-making process,” says Kay. “The combination of the two results in a dough that is more tolerant to the whole baking process, including variations in processing times.” This is particularly important when considering the range of oven conditions the pizza will encounter when the consumer bakes it at home.

For standard parbaked crusts, dough is proofed at 35 to 45°C, which enables the yeast to ferment and produce carbon dioxide. The dough is then stretched, shaped and baked at about 400°F, with baking times ranging from 2½ to 4 minutes. Variables that must be considered when parbaking crusts include the variety of ovens: deck, conveyor, rotating, wood-burning, etc. After baking, the crusts are typically cooled prior to topping.

Some upscale frozen pizzas use classic Italian methods, which include baking the crust in specially designed stone or brick ovens that reach temperatures exceeding 800°F. This produces a crust that is tender on the inside and crispy on the bottom.

When dough enters the oven, it is exposed to significantly higher temperatures compared to the proofing cabinet, which is usually held at about 95 to 110ºF. This causes rapid expansion of the gas trapped in the gluten network and the subsequent rising of the crust.

“The mechanical handling of proofed doughs on conveyor belts or racks is often highly vigorous,” says Kay. “The improved dough tolerance obtained using DATEM and enzymes stabilizes the dough and improves all-around shock stability.”

Dough for frozen self-rising crusts is proofed, but the yeast is protected to ensure that all of the dough rising takes place in consumers’ ovens.

Protecting the crust

Before getting creative with sauces and toppings, many pizza manufacturers choose to seal the top of the crust to help maintain its integrity. Many barrier options are available, including a basic liquid egg-white wash. Various hydrocolloid and emulsifier sprays also can provide a moisture barrier.

For example, an innovative blend of a vegetable-based emulsifier—acetylated monodiglyceride—and beeswax forms an imperceptible layer that melts and becomes invisible to the consumer when the pizza is baked in the oven or cooked in the microwave. Beeswax’s water-barrier properties combine with the emulsifier’s film-forming properties to form a flexible barrier that can withstand mechanical stress without breaking.

This watertight barrier prevents liquid migration into the pizza base from high-moisture toppings. “This way, the base does not become soggy, and the overall pizza maintains its freshly made appearance and eating qualities,” says Kay. The barrier is sprayed directly onto the surface of a parbaked pizza after it has cooled. The cooler it is, the faster the barrier film solidifies. The temperature of the crust must not be higher than 113°F.

Danisco has teamed up with Spraying Systems Co., Carol Stream, IL, to develop the optimum spraying solution for this application. To ensure even coverage and prevent clogged nozzles, the temperature of the barrier is precisely maintained throughout the system. Advanced spray-control algorithms automatically adjust for variations in line speed, providing accurate intermittent spraying without overspray.

“For refrigerated take-and-bake pizza, the barrier extends the shelf life of the pizza and ensures overall pizza quality and topping integrity,” says Kay. “Toppings maintain their original colors, taste and shape throughout refrigerated shelf life.”

A modified food starch from Grain Processing Corporation is also an option. “This ingredient can be used to increase the crispy texture in pizza crust,” says Lopez. “It works well in raw, parbaked and fully baked pizza crust by helping slow down and reduce absorption of the sauce into the crust. As a result, the pizza is less likely to get soggy.”

Just say cheese

Cheese is an essential ingredient on pizza. But with pizza, cheese stretch is key. Whether or not a cheese melts or stretches, and how well it melts and stretches, depends on the chemistry and thermodynamic properties of its casein network.

Most cheesemakers influence the chemistry and physics of cheese melt and stretch when they adjust the following factors: the milk’s heat treatment, pH during cheese manufacture, cheese composition, the lowest pH obtained in the cheese, and proteolysis, or the breakdown of intact casein. Stretch is the ability of the casein network to maintain its integrity and not break when pressure is applied to the cheese.

“Observing the elasticity, or stringy behavior, of mozzarella baked on a pizza is a simple way to see stretch,” says Mark Johnson, senior scientist, Wisconsin Center for Dairy Research, University of Wisconsin-Madison. “Stretch is also responsible for the blisters that form when cheese is baked. Stretch is most often associated with high temperatures but, like melt, it can occur at much cooler temperatures.

“The melt and stretch properties of cheese are based on the number of interactions between casein molecules, the major milk protein. The fewer the interactions, the greater the melt,” continues Johnson. “Stretch requires an intact, interconnected casein network and is lost as the interactions between casein molecules—or aggregates—decrease. Stretch is the result of casein-casein interactions that are broken easily, but also readily reform at different locations in the casein network.”

Melt is important in the release of milkfat from cheese during baking. “If the flow or melt of the cheese is restricted, the release of the fat is also restricted,” says Johnson. “The faster and greater the rate of flow of a cheese, the greater the release of milkfat.” The consumer sees this as oiling-off.

“Since cheese is a network of interconnecting molecules of casein, the hydrolysis, or breaking, of bonds within the casein molecule will increase melt, but decrease stretch,” continues Johnson. “Proteolysis can be slowed by using less coagulant, or in the case of Swiss, Parmesan, Romano and mozzarella, higher cook temperatures or mixer-molder temperatures can inactivate some of the coagulant. Some coagulants are more sensitive to heat than others.”

Jo Smewing, applications manager, Stable Micro Systems, Surrey, England, says: “The extensibility of cheese is an important textural characteristic in a wide range of food applications—in particular, pizza. Freezing, shredding, thawing and even cooking cheese can have a significant impact on its textural characteristics. Reduced-fat products also display very different characteristics compared to full-fat versions. All of this may result in a texture with undesirable mouthfeel.

“Previously, one of the most-common ways to test the stretchability of cheese was to manually lift it with a fork and assess the force required to stretch it, as well as the length to which it stretches,” adds Smewing. “This method is inherently subjective and unreliable.” To provide an objective, repeatable test method, the company developed a rig to use with a texture analyzer. The rig includes a microwavable vessel, sample retainer and double-sided fork probe. To use, cheese is cut into small cubes and then microwaved in the vessel until molten. The sample retainer is slotted into the vessel, which is securely fastened to the base of the texture analyzer. After the fork probe is attached, the arm of the texture analyzer pulls the fork upward through the molten cheese and software measures the force required to stretch the cheese and the distance to breakpoint.

Cheese choices

There’s no doubt that mozzarella is the preferred melting and browning cheese for pizza. Mozzarella and Cheddar, and Italian four-cheese blends (adding Romano, Parmesan and provolone) are commonly used to give a little extra punch. But don’t stop there.

“Mozzarella readily blends with most other cheeses, and a little bit of those other cheeses can really give pizza a signature flavor,” says Patrick Geoghegan, senior vice president of corporate communications, Wisconsin Milk Marketing Board, Madison. “The strong flavor of blue cheese has become a secret for many gourmet pizzerias.”

Blue cheese is an expensive topping for pizza, but for many, well worth the investment. “It brings a bit of bite to pizza, something no other cheese can do,” says Geoghegan, adding that “industrial pizza manufacturers can get a jump-start on their competition” by blending cheeses.

Painting the canvas

Under the cheese, most pizza is topped with some sort of Italian-spiced tomato sauce. However, select pizzerias also offer a white, creamy Alfredo sauce option. Barbecue sauce provides a variety of flavor sensations, including sour, sweet, spicy and tangy. Sometimes, smoky flavor is included, which complements a brick-oven baking process.

Pizza sauce should not be slow cooked—it shouldn’t taste like marinara sauce. It’s also a good idea to have a smooth sauce. Chunky sauces break down, leading to a watery top. Pizza sauce tends to be highly seasoned, as compared to marinara, with a higher solids content of 14% to 18%.

Top picks

Toppings run the gamut and provide opportunities for measuring up to delivery, as well as points of differentiation.

Roasted and sautéed fruits and vegetables add color, flavor, nutrients and texture to frozen pizza. Jon-Lin Foods, a division of McCain Foods USA, Inc., Lisle, IL, uses direct heat with no water blanching (which can add moisture) to deliver individually quick-frozen (IQF) fruits and vegetables with high solids and negligible moisture loss. It creates caramelized options by slow-cooking the fruits and vegetables in natural juices or soybean oil. Fire-roasted and smokehouse-roasted products are cooked over direct fire in natural juices or extra-virgin olive oil to create authentic grill marks and sear-in natural flavors.

To battle the ill effects of vegetable moisture loss, Gilroy Foods, a division of ConAgra Foods, Omaha, NE, offers controlled-moisture vegetables that “work extremely well in frozen-pizza applications, particularly pizzas intended for the microwave,” says Dan Hemming, manager, research & development. “Because of the short cooking time in microwave ovens, vegetables weep moisture into the pizza, making it soggy and less desirable. Because controlled-moisture vegetables are lower in moisture, they don’t lose water, retaining their bold color and strong flavor, resulting in a more-authentic and flavorful pizzeria-style pizza. These vegetables come in fire-roasted and grilled varieties, fitting well in the trends toward bolder flavors and innovative pizza toppings. A barbecue-style pizza, for example, may benefit from some flavorful controlled-moisture onions with distinct grill marks and slightly charred flavor.”

All types of cooked meat can top pizza. The best sausage is irregularly shaped and chunked. There’s a trend in upscaling pizza with steak topping. This premium topping adds a juicy flavor profile to pizzas. Steaks may be grilled, pan-fried or broiled, and marry well with other ingredients and sauces.

“Meat toppings on pizza can be a key element in developing a pizza’s flavor profile,” says Sean Craig, senior executive chef, Gilroy Foods. “Barbecue chicken pizza works well, because the meat not only carries the flavor of the barbecue sauce, but also the grill.” Companies can develop meat toppings that bring out the flavor of a cooking method, along with flavors from marinades and seasoning blends. “Italian sausage, for example, can add a hint of smoke flavor, along with a spicy touch of fennel, for a gourmet twist,” he says.

Amy Marr, vice president of marketing, Gilroy Foods, says: “With smoke, we’re expecting the popularity to continue to grow beyond barbecues. How about a pizza topped with smoked cheese, or a special applewood-smoked bacon pizza? With North African flavors, it’s all about bold flavor combinations. Wouldn’t it be interesting to see Moroccan flavors like a harissa as a sauce base on one of America’s traditional favorite foods—pizza?”

For a Latin influence, try chorizo with onions and jalapeños. Other Latin trends include topping the dough with a black-bean sauce. A side of sour cream and guacamole can readily be added into the frozen pizza package.

Nuts, too, can enhance pizza with flavor and texture. Most nut ingredients come in a variety of forms, which enables their inclusion in pizza in numerous ways. For example, nutmeats can be ground into various consistencies. A coarse grind produces nut meal; a finer grind results in nut flour. Both can serve as a partial substitute for wheat flour. Sliced, diced or chopped versions can top pizza right along with other toppings.

For thin- and medium-crust pizzas, toppings should go to within 1 in. of the edge. The rim of the dough keeps the toppings from bubbling over the edge of the pizza. Because the center of the pie always takes the longest to bake, the thickest amount of toppings should be toward the edge of the pizza rather than in the middle. If there is a heavy concentration of toppings—including sauce—in the center, the outer edges may overcook before the center is done. Once topped, pizzas should be quick-frozen to prevent any moisture from seeping into the dough.

But sometimes, to get your business plans in order in terms of frozen-pizza endeavors, it’s best to take a step back in time to where America’s passion for pizza began: Naples. This is where pizza was nothing more than a simple slab of irregularly shaped, leftover dough smeared with tomatoes and dressed with cheese and whatever fresh ingredients were lying around.

Think nothing more and nothing less.

Donna Berry, president of Chicago-based Dairy & Food Communications, Inc., a network of professionals in business-to-business technical and trade communications, has been writing about product development and marketing for 13 years. Prior to that, she worked for Kraft Foods in the natural-cheese division. She has a B.S. in Food Science from the University of Illinois in Urbana-Champaign. She can be reached at donnaberry@dairy-food.com.

Pizza From the Deli

A supermarket alternative to frozen pizza is take-and-bake refrigerated pizza. Such pizza is typically sold in the self-service deli and can be prepared at the store. However, like many deli-counter offerings, refrigerated pizzas are delivered to the store prepared and packaged for merchandising. Sometimes they are even delivered in frozen form.

The Kroger Co., Cincinnati, is in the midst of phasing out a never-frozen refrigerated deli take-and-bake pizza line and replacing it with one that is now shipped to stores frozen. According to the company, the quality and variety available through frozen-fresh deli pizza better meets the needs of its shoppers.

Long a player in frozen pizzas with brands such as Freschetta, Red Baron, Tony’s and, most recently, Wolfgang Puck, Schwan’s Consumer Brands North America, Bloomington, MN, entered the refrigerated self-service deli pizza business in 2006 with the introduction of Belafino Take & Bake Pizza. “Only premium ingredients are used, including 100% real cheese, specially formulated sauce, no fake proteins and special, super-moist crust,” says Peggy Copeland, Belafino spokeswoman, Schwan’s. The product is shrink-wrapped on a cardboard tray and presented with “high-end and impact packaging graphics,” she says. “It’s available in a pizzeria-style crush-proof box or overwrapped with a label in bulk.” It’s shipped to stores in a boxed six-pack case or a bulk nine-pack case. The product has a 10-day refrigerated shelf life and 180 days frozen.

Pizza Sales Still Rising

According to the June 30, 2007 “Nielsen Market Summary Mid-Year Report,” ACNielsen, New York, household penetration for frozen pizza is 70.9%. Further, frozen pizza accounted for $2.⁸ billion in sales at supermarkets in 2007, a 4.3% increase from the previous year, according to Information Resources Inc., Chicago.

Innovation in process, package and product is driving growth in the category. Quality ingredients, often in unique combinations, team up with advanced baking and cooking technologies. Controlled-atmosphere packaging, sometimes with special, disposable baking accessories, allows for frozen pizza to fool some of the most-discerning pizza eaters.