Fruit and Nut Snacks for the 21st Century

California raisins clock in at about 15% to 18% moisture, with low-moisture varieties going as low as 12% to 14%. Even when compared to other fruits with the same moisture content, Payne says, “California raisins generally have a lower water activity than other dried vine fruits, because of their intact skin and fructose-glucose content. This prevents moisture migration to or from other ingredients in preparation and allows them to be added to formulas without concern for adding unneeded moisture.”

Other raisin advantages include firm skins, which hold up during manufacturing and help retain the fruit’s shape and structural integrity. Naturally occurring organic acids, including propionic and tartaric, act as mold inhibitors. And raisins are natural sweeteners and humectants. Their natural sugar content allows raisins to “function as a replacement for refined sugar,” Payne says, “allowing formulators to eliminate or reduce refined sugar in a variety of snack applications. When used in place of sugar, California raisins, as well as raisin paste and raisin juice concentrate, provide not only sweetness, but the advantages of longer shelf life, humectancy and textural contrast.”

Payne, who also represents the U.S. Highbush Blueberry Council, Folsom, CA, sings the praises of those superfruits, too: “Manufacturers have discovered that using blueberries and blueberry formats offers the dual advantage of sweetening and coloring the product naturally, plus the ability to tout the nutritional benefits of their products. Consumers perceive blueberries as a healthy ingredient and are, therefore, drawn to products featuring them.”

Manufacturers can tailor their blueberry choice to the products’ moisture, notes Payne, with options like unsweetened freeze-dried berries at 0% to 2% moisture; dehydrated with 11% to 18% moisture; and osmotically preserved at 40% maximum moisture. The latter, he says, is “an innovative format in which fresh or frozen blueberries are placed in a vacuum chamber and undergo a slow, natural infusion process with a syrup solution or stabilizers, after which they are carefully dried to preserve color and flavor.”

Another dried-fruit innovation that not only conveys the color and flavor of premium fruits, but at lower cost and improved functionality, is real cranberry pieces “disguised” as other fruits—cherries, blueberries, strawberries, orange and mango. They have the processing versatility and tolerance of sweetened, dried cranberries, Borsari says, but the appearance and flavor of the mimicked fruit. “Whether it’s a frozen blueberry or real mango piece,” she explains, “the real fruit is often very difficult to use in manufacturing, or very costly or hard to get. These give them a great alternative.”

How they’re made is fairly straightforward. For a blueberry piece, says Kristin Girard, principal food scientist, Ocean Spray Ingredient Technology Group, “we extract some of the goodies out of the cranberry, mainly the acid, to give it a more-neutral palate. Then we co-infuse sugar and blueberry juice back into the product.” Gentle air-drying finishes it off. “It has blueberry aroma, blueberry color and flavor, and it also has a little bit of a textural difference from the real dried blueberries, which can be grainy and seedy,” she says.

The advantage of dried options is that they help manage moisture in products, possibly the biggest processing consideration with fruits in snacks. The details of how to achieve that management vary with each application. In something like a fruit and nut mix, the dried fruit tends to be the moisture source rather than its sink. So, to keep the product equilibrated and its water activity at a safe 0.39 to 0.46, Girard suggests glycerated fruit to “help maintain a nice, soft piece when you’re adding it to a really dry or low-water-activity environment.”

In a bar, on the other hand, the manufacturing process determines the approach to moisture management. “If the bar is extruded without being cooked,” Girard says, “it would be more of a wet bar.” Then, a formulator needn’t worry about the fruit losing water to the surroundings. “But if it’s a baked bar, like the harder ‘original’ granola bars, those were really low in moisture,” she says, and would require a glycerated piece.

Nuts to you

Nuts present a different set of challenges. Paramount is oxidative stability. “Oxidation is always an issue with all nuts,” says Vicki Nesper, marketing communications manager, Hazelnut Council, Jersey City, NJ. The culprit is the thing that makes nuts such nutritional powerhouses: their unsaturated fats. “Companies can work closely with their suppliers to make sure that they’re purchasing their nuts packaged so as to keep them very fresh until they’re used in the product,” she says.