American consumers possess a passion for pies, a craving for cakes and a taste for treats that are filled, stuffed and piled with sweet fillings. These fillings run the gamut from pumpkin and peach to marshmallow and cherry.

Filled foods have been around since Roman times, when flour milling was perfected to the point that refined flour was combined with a little oil and water to create tender dough that encased a variety of fillings. The Pilgrims brought their pie-baking skills to the New World, and soon, pumpkin and berry pies were satiating the founding fathers of the United States of America.

Pies are synonymous with fruit fillings. Apple is the most popular flavor, with cherry, lemon meringue and coconut cream following closely behind, the American Pie Council says. Beyond pies, fruit fillings are used in applications ranging from cakes and pastries to cookies and bars.

Fruit fillings serve two roles in bakery foods: flavor and function. Besides offering healthful benefits, fruit fillings also mask off flavors in products such as nutrition bars.

Fruitful and fulfilling
Fruits are graded according to U.S. Department of Agriculture standards. The grading process rates the presence of decay, insect and bird damage, injury due to freezing, plus many more variables that affect the quality of fruit.

U.S. No. 1 grade fruits generally are used for fresh consumption, and U.S. No. 2 grade fruits often are used for food processing applications.

Besides standard USDA grades, pitted cherries used in pie fillings also are graded and sold based on the number of pits per shipment. One pit per 400 cherries is the maximum allotment, but new technologies allow processors to reach counts of one pit per as many as 1,000 cherries. This new technology saves fruit suppliers and bakery food manufacturers money in the long run.

One fruit supplier says that at least 10 lawsuits are filed against his company every year as a result of pit damage to consumers’ teeth. Insurance covers this liability, but pie-makers may want to consider paying a premium price to buy fruit that is as close to pit-free as possible.

Larger fruits, such as apples, are available sliced, chopped and diced, with piece sizes purchased according to finished applications. Piece identity is an indicator of quality, with larger pieces more desirable. Pies and open-faced tarts generally require whole slices, and turnovers, snack pies and cookie fillings require smaller pieces. Smaller cuts are available using quality fruits with few fillers and added ingredients.

Cookies and bars may use drum-dried fruit flakes and powders to attain full fruit flavors with soft, moist and chewy consistencies. However, these products lack piece identity. Drum-dried fruits impart cooked “jammy” characteristics to fillings, and supply flavorful additions to whole fruit fillings for pies and pastries. These fillings also enhance flavor while reducing fruit costs.

Manufacturers of bars use a variety of fruit fillings for flavor and function. Meal replacement and nutritional bars traditionally are full of healthful nutrients, such as proteins, vitamins and minerals, phytochemicals, flavonoids and micronutrients.

The presence of fruit fillings in these bars masks off-flavors derived from increased levels of vitamins and minerals. Breakfast bars continue to gain popularity in today’s grab-and-go society. Apple and berry are classic flavors used in breakfast bars, but new flavor combinations, such as tropical fruit blends that use banana, kiwi, coconut and pineapple, also are gaining popularity.

Frozen fruit ingredients are available as Individually Quick Frozen (IQF) or packed in bulk. IQF fruit offers good piece identity, true fruit flavor and the convenience of portion control. IQF fruits often are used straight from the shipping container, allowing for convenient preparation. The heat of the oven thaws the fruit without overcooking it, which reduces boil-out.

Many high-volume bakeries create their own fillings. These filling systems generally contain a combination of ingredients, including fruits, starches, gums, acids, sweeteners and spices.

Frozen fruit is used with a sweetener, either high fructose corn syrup (HFCS) or sugar, in a 5:1 ratio to offer a consistent filling with a stable texture. The sugar in these filling formulas inhibits the formation of ice crystals during freezing and improves the integrity of fruit by inhibiting browning. Frozen fruit fillings must be stored frozen, and thawed before using.

Do-it-yourself
High-volume bakeries create their own fillings with a combination of fruit and other ingredients to make consistent, flavorful fillings. Starches, gums, acids, sweeteners and spices all play important roles in the finished quality of fillings.

Bakery fillings vary widely in their levels of solids, pH and consistencies. Fruit fillings generally contain fruit, sugar, corn syrup, starch and water. These fillings are adjusted by the addition of acid to achieve a pH of 3.7 to 4.5. The manufacturing process affects the desired taste and texture of fillings. For example, starches and gels used in fruit fillings must give a medium to firm gel strength that is not thermally reversible, function at a low pH and not mask the characterizing flavors of the filling.

Cornstarch can be used in pie fillings, but the ingredient’s unrefined state makes it susceptible to shear and may cause the filling to break down in ambient or frozen storage. Cornstarch also breaks down in the presence of high acid levels. Waxy maize starches are refined and modified to be extremely stable in freeze-thaw applications. They thin during the cooking process, and do not re-thicken upon cooling. Cold-water swelling starches (instant starch) are refined starches that do not require cooking.

Prepared fillings should be chilled before filling the bakery food, which reduces boil-out that occurs when fillings boil over and through the crust. Docking crusts helps steam escape during baking, which eliminates soggy crusts.

Sweet fillings
In an effort to broaden the pie-selling season, many pie manufacturers have launched summer pies filled with cream, non-dairy whipped fillings and custards. Cream pies and custards generally use 10% to 20% eggs or egg yolks to thicken the filling, and use a minimal amount of starch. Egg-based fillings rely on exposure to heat and/or acids to thicken.

“Coagulation is a delicate process,” one filling consultant says, and coagulation depends on time, temperature, starch, liquid, sugar, acid and salt, all in the ideal ratio. Too much heat applied too quickly or even low heat applied for too long causes protein molecules to overcoagulate, rupture and squeeze out the moisture from within the structure. This process, called syneresis or weeping, results in droplets of water at the bottom of a finished good.

In starch-based custards, bakers must heat the mixture after adding the egg yolks, to denature alpha amylase found in the yolks. This enzyme destroys starch gels. The more sugar in the mixture, the higher the temperature to deactivate the enzyme. “If not inactivated, this enzyme will turn a custard or cream pie into soup,” one filling supplier says. Liquids added to a custard mixture dilute the filling’s ability to coagulate and form. Added salt assists the coagulation process.

Non-dairy whipped toppings and fillings, which are freeze-thaw stable, offer increased shelf life compared to dairy-based fillings. The filling’s versatility also enhances mouthfeel without imparting greasy tastes.

The market for pies and snacks with fillings shows no signs of stopping. And, as convenience continues to drive new product launches, hand-held meals and snacks are certain to gain in popularity. From early Roman civilizations to Pilgrims to today’s consumers, filled bakery foods offer convenience, satisfaction and sometimes nutrition—three qualities as American as apple pie.