Starch, derived from cassava, corn, sorghum, and wheat, serves various roles in food as thickeners, gelling agents, and flow agents. However, the inherent limitations of native starches, such as retrogradation and texture changes, hinder their broad application. This article explores the modifications employed in the specialty starch industry, delving into techniques like crosslinking, derivatizations, and physical alterations to enhance the properties of starch for optimal functionality in diverse food applications.
Why Starch is Modified
Starch modification is undertaken to enhance the appearance, texture, and utility of starch in food processing and distribution. Modified starches, in comparison to unmodified counterparts, maintain freshness, exhibit improved texture, and can be tailored to meet specific processing requirements. This section explores derivatizations such as crosslinking, monosubstitutions, and octenylsuccinylation to highlight their impact on starch properties.
Derivatizations
Crosslinking: A detailed examination of crosslinking elucidates how this process strengthens starch granules, rendering them resistant to acidic, hot, and shear conditions prevalent in food processing. The article explains how crosslinking affects the texture, gelatinization temperature, and resistance to digestive enzymes of starch, emphasizing its role in improving freeze-thaw stability.
Monosubstitutions (Stabilizations): The concept of monosubstitution as a method to prevent retrogradation by introducing blocking substitutes to starch hydroxyl groups is explored. This section covers various types of monosubstitution, including starch acetates, starch hydroxypropyl ethers, starch monophosphate esters, and starch sodium octenylsuccinates, and their impact on freeze-thaw capabilities, gel formation, and cold temperature stability.
Octenylsuccinylation: The article delves into the use of octenylsuccinic anhydride to esterify starch, creating hydrophobic substituents that find application in emulsification and encapsulation. The allowed level of treatment, its impact on stability, and the versatility of octenylsuccinylation are discussed.
Conversions: A comprehensive overview of conversion processes, including fluidity starches, dextrins, and oxidation, provides insights into how these processes affect the properties of starch. The article explores the diverse applications of converted starches in food products.
Physical Modifications
The section on physical modifications covers altered flow properties, pregelatinization, cold-water-swelling starches, and various heat treatments. Detailed explanations of these physical modifications, their impact on starch properties, and their applications in different food processes are provided.
Conclusion
Concluding the article, the importance of natural food ingredients is acknowledged, prompting the exploration of native starch thickeners. The evolving demands of consumers for clean label or healthy ingredients are discussed, along with various approaches, such as alkaline pH adjustment and lipid complexation, to achieve process-tolerant thickening without chemical additives.