Larger molecules that tend not to crystallize increase viscosity, and they provide little to moderate humectancy in comparison. In con-fections, these larger molecules provide the chewy texture in taffy, the stringing seen in soft caramels when pulled, or the viscosity needed for efficient hard-candy production. They also are used in various ratios to effectively control crystallization of sugars, such as sucrose, in applications ranging from gummy candy to fudge. Many ingredients used in confections, such as fat or protein, add molecu-lar weight. But, in most cases, the main ingredient that provides these characteristics is corn syrup, and by varying the amount of corn syrup (and its dextrose equivalent) used with sugar, we can significantly affect the characteristics previously mentioned.
Replicating with polyols
Polyols are some of the most-versatile sugar-free ingredients available, especially for confectionery products. The reason for this be-comes clear when examining their origin.
In the United States, polyols start out as traditional corn syrups modified by reducing the reactive sites (aldehyde or ketone) through either one or a combination of the following production methods: catalytic hydrogenation, enzymatic conversion or fermentation. Only the reactive groups are changed, so the polyol retains much of the sugar’s structure, bulk and function. Moreover, all of the polyols are considered either: a food additive, GRAS or self-affirmed GRAS.
Polyols can be divided into three groups: monomers, dimers and polymeric mixtures. The monomers—consisting of one carbohydrate unit—are erythritol, mannitol, sorbitol and xylitol. The dimers—consisting of two bonded carbohydrate units—are isomalt, lactitol and maltitol. The polymeric mixtures are combinations of polyols—varying in lengths of repeating carbohydrate units—that are identified as polyglycitol syrups, also known as hydrogenated starch hydrolysates (HSHs) and maltitol syrups (these are the most similar to corn syr-ups). Nomenclature is determined by the amount of maltitol present (dry basis); a syrup that contains greater than 50% maltitol is con-sidered a maltitol syrup, and anything less is a polyglycitol syrup.
Polyols can exhibit a wide range of physical characteristics beyond that of the typical solubility, molecular weight and sweetness. They have other unique properties, such as cooling effects, which occur when crystalline polyols—exhibiting a negative heat of solution (erythritol, xylitol, and mannitol have the most notable cooling effects)—are dissolved in water (often reducing the temperature of its surroundings). This may be a welcome property in an application such as mints or breath-freshening chewing gum, but not necessarily in traditional dark chocolates.
Another unique property of polyols is their absence of reducing groups, which allows them to be very heat-stable (up to 350F). In hard-candy applications, this is considered a benefit because they produce no off colors (yellow) or off flavors like traditional sugar products. On the other hand, in applications such as caramel, polyols do not react with protein (i.e., Maillard reaction) to produce those desired caramel colors or flavors. Lastly, not all polyols are digested in the same manner, and some are better-tolerated than others (erythritol is well-tolerated, as are the higher-molecular-weight maltitol syrups and polyglycitols). Given the choice of multiple polyols, the serving size can dictate which is better suited. For example, chewing gum has a much-smaller serving size than that of gummy candy—typically 5 grams vs. 40 grams—so a lesser-tolerated polyol would be more appropriate in the chewing-gum product.
Substantial and (a bit) sweet
Another group of bulking ingredients is the “fiber” or “fiber-like” low-digestible carbohydrates. These carbohydrate polymers (higher molecular weight) consist of sugars—such as glucose, mannose and fructose—linked together in such a way that significantly reduces their digestibility, as well as caloric contribution. Their sources are various and can be naturally occurring or man-made. Although these can be used to help obtain a “sugar free” claim, some of them can add another claim: fiber. Depending upon how much fiber is used in the finished food, FDA allows for various types of fiber-related claims where the product can be considered an “excellent source” (5.0 grams of fiber per serving) or “good source” (2.5 grams of fiber).