Microwave-Induced Behavior and Digestive Properties of the Lotus Seed Starch—Chlorogenic Acid Complex

Abstract

The effect of chlorogenic acid (CA) on the dielectric response of lotus seed starch (LS) after microwave treatment, the behavior and digestive characteristics of the resulting starch/chlorogenic acid complex (LS-CA) at different degrees of gelatinization and the inhibition of α-amylase by chlorogenic acid were investigated. The variation in dielectric loss factor, ε″, and dielectric loss tangent, tanδε, of the microwave thermal conversion indicated that LS-CA had a more efficient microwave-energy-to-thermal-energy conversion efficiency than LS. This gelatinized LS-CA to a greater extent at any given temperature between 65 and 85 °C than LS, and it accelerated the degradation of the starch crystalline structure. The greater disruption of the crystal structure decreased the bound water content and increased the thermal stability of LS-CA compared to LS. The simulated in vitro digestion found that the presence of the LS-CA complex improved the slow-digestion property of lotus seed starch by increasing its content of resistant and slowly digested starch. In addition, the release of chlorogenic acid during α-amylase hydrolysis further slowed starch digestion by inhibiting α-amylase activity. These findings provide a foundation for understanding the correlation between the complex behavior and digestive properties of naturally polyphenol-rich, starch-based foods, such as LS, under microwave treatment, which will facilitate the development of starch-based foods with tailored digestion rates, lower final degrees of hydrolysis and glycemic indices.

Formation and Application of Starch–Polyphenol Complexes: Influencing Factors and Rapid Screening Based on Chemometrics

“…Microwave processing is an efficient processing method that utilizes the vibration of polar groups to convert electromagnetic energy into thermal energy for the rapid heating of food products [95]. Microwave processing transfers heat uniformly into the granules through internal heating, accelerating the disruption of starch helices, releasing more starch chains and exposing more binding sites capable of binding polyphenols, which promotes the formation of complexes [9].…”

Recent advancements in bio-based dielectric and piezoelectric polymers and their biomedical applications

“…These factors can influence the mobility and orientation of the starch molecules, affecting their ability to store and transmit electrical charges. [68][69][70][71][72] For instance, Ndife et al 73 studied the effect of moisture and temperature on the dielectric properties of various starches in granular and solution forms. They reported that dielectric values of starch solutions decreased at higher temperatures but rose for granular starches, whereas the dielectric constant and loss factor of all kinds of starches increased with an increase in moisture content.…”

“…These factors can influence the mobility and orientation of the starch molecules, affecting their ability to store and transmit electrical charges. 68–72…”