Structural and physicochemical characteristics of lycoris starch treated with different physical methods

Area of Science:

• Food Science
• Biochemistry
• Materials Science

Background:

• Lycoris starch (LS) is a native starch with specific structural properties.
• Understanding starch modification is crucial for optimizing its applications in food and industrial products.

Purpose of the Study:

• To investigate the structural and physicochemical changes in lycoris starch (LS) after microwave treatment (MT), heat-moisture treatment (HMT), and autoclaving treatment (GT).
• To compare the effects of different thermal modifications on starch properties.

Main Methods:

• Lycoris starch was subjected to microwave treatment (MT), heat-moisture treatment (HMT), and autoclaving treatment (GT).
• Structural analysis included particle morphology and X-ray diffraction (XRD).
• Physicochemical properties such as solubility, swelling power, and rheological behavior (RVA, G', G″) were evaluated.

Main Results:

• HMT and GT treatments resulted in larger, rougher, block-like starch particles compared to native LS.
• XRD analysis indicated a conversion from native A-type to B-type starch structure following HMT and GT.
• Solubility and swelling power decreased at higher temperatures (65°C and 95°C) but increased at 55°C for treated starches.
• Treated starches exhibited lower breakdown and setback values in RVA, indicating reduced retrogradation.
• Storage modulus (G') and loss modulus (G″) were lower in treated starches, suggesting weaker gel structures.

Conclusions:

• HMT and GT significantly alter the crystalline structure and morphology of lycoris starch.
• Thermal treatments reduce the retrogradation tendency and gel strength of lycoris starch.
• The observed changes suggest potential for modified lycoris starch in applications requiring altered pasting and gelling properties.