Emulsifying starches allow food scientists to use starch as an ingredient to create a noncontinuous phase with a matrix of water, lipid, and starch. They are different from traditional modified starches (like octenyl succinate) which are primarily used as water binders or stabilizers. To maintain water-phase stability in the product, an additional starch or gum is needed. Alkenyl succinates are commonly used for this purpose. Emulsifying starches do not create significant viscosity and are not heat tolerant. They support surface reactions rather than internal absorption.
Encapsulating starches trap lipids (oils) with starch and related products. Octenyl succinic acid anhydride-reacted starch (OSA) is a successful commercial encapsulating starch. This method is approved for modification worldwide. Low- and fat-free pourable dressings were developed using these starches and gums. Oxidized and dextrinized starches are also used. The food scientist should consider the overall characteristics and ultimate effects on the finished product, including flavor and color, and compare them to a standard.
Starch can also be used as an encapsulating agent by including polyvalent metal ions, which produces a water-repellent starch that slows down the release of flavor from encapsulated oils. The starches used for encapsulation can differ.
A new modified starch complex has been developed using legumes (pea) which have a different molecular structure compared to other starch sources. This structure allows for microencapsulation, which involves trapping lipids within the starch. This technology was introduced by Nichols in 2005.
The food scientist needs to think about how quickly the flavors evaporate and then decide which starch to use. For flavors that don’t evaporate easily, maltodextrin can work as a surface coating. However, for flavors that evaporate more easily, a high-amylose starch treated with OSA can be a good choice because it sets quickly and can encapsulate the flavors.