Microbiological Spoilage of High-Sugar Products

Abstract

The high-sugar products discussed in this chapter are referred to as chocolate, sugar confectionery (non-chocolate), liquid
sugars, sugar syrups, and honey. Products grouped in the sugar confectionery category include hard candy, soft/gummy candy,
caramel, toffee, licorice, marzipan, creams, jellies, and nougats. A common intrinsic parameter associated with high-sugar
products is their low water activity (a
w), which is known to inhibit the growth of most spoilage and pathogenic bacteria. However, spoilage can occur as a result
of the growth of osmophilic yeasts and xerophilic molds (Von Richter, 1912; Anand & Brown, 1968; Brown, 1976). The a
w range for high-sugar products is between 0.20 and 0.80 (Banwart, 1979; Richardson, 1987; Lenovich & Konkel, 1992; ICMSF,
1998; Jay, Loessner, & Golden, 2005). Spoilage of products, such as chocolate-covered cherries, results from the presence
of yeasts in the liquid sugar brine or the cherry. Generally, the spoiled product will develop leakers. The chocolate covering
the cherry would not likely be a source of yeast contamination.