Sauces are like icing for entrées. Whether thick and rich or light and delicate, sauces accent an array of foods and, in some cases, create the distinctive flavor or texture for which a product is known. And in sauces of all sorts—from rich cream sauces that coat your mouth with lingering flavors to fiery marinades that transfer flavors of all sorts to meat, poultry and fish—starches have long been used for textural assistance.
Cold, hard facts
Growing interest in frozen products has, however, presented new challenges for developers. “In general, starches are used in sauces to modify texture, increase emulsification and improve mouthfeel,” says Denise Fallaw, technical manager for meat & convenience, Cargill Texturizing Solutions, Wayzata, MN. “In frozen applications, it is important the starches have good freeze/thaw stability to maintain these characteristics through multiple cycles of temperature fluctuations.” Temperature fluctuations and freeze/thaw cycles are far more numerous than you might think. Rachel Wicklund, food scientist, Tate & Lyle, Decatur, IL, explains that such temperature swings are as likely to be seen in the manufacturing facility as on a distribution vehicle, or in a grocery store display case. “Each time the door to the case is opened, the temperature in the display case goes up and the food may begin to thaw. Then, when the door is closed, the product re-freezes. If you combine that with the repeated freezing and thawing of the food that occurred before the food even reached the display case, with the repeated freezing and thawing that can occur as that food sits in your shopping cart and then your car before ever reaching the freezer at home, it is easy to understand why freeze/thaw is such a concern.”
Baseline
Regardless of origin, starches are made up of two primary components: linear amylose and branched amylopectin, arranged radially into granules. The ratio of amylose to amylopectin will affect the characteristics of the starch during processing. “Starches with a higher proportion of amylopectin will thicken, but do not form a gel as their counterparts with higher levels of amylose,” Fallaw says. “Retrogradation, where starch reverts to a crystalline structure upon cooling, is more likely with higher amylose starches.” Wicklund notes that the origin of a given starch will affect the amylose-to-amylopectin ratio, providing functionalities that make a starch more or less suitable for frozen sauce applications.