In Vitro Digestibility of Starch Gel in Cooked Rice Prepared with Thermo-Reversible Short-Chain Glucan Aggregates...

Area of Science:

• Food Science
• Nutritional Science
• Material Science

Background:

• Soluble corn fiber (SCGAs) are increasingly explored for functional food applications.
• Understanding their behavior during food processing is crucial for optimizing their use.
• Investigating SCGAs' thermo-reversibility and digestibility in starch gels is key to enhancing food applicability.

Purpose of the Study:

• To investigate the thermo-reversible behavior of SCGAs post-cooking.
• To evaluate the in vitro digestibility of starch gels incorporating SCGAs in cooked rice.
• To assess the impact of SCGAs on the physicochemical properties of cooked rice.

Main Methods:

• Differential scanning calorimetry (DSC) to analyze thermo-reversibility.
• In vitro digestibility assays to determine slowly digestible starch (SDS) and resistant starch (RS) content.
• Analysis of cooked rice appearance, texture, and glycemic index (eGI).

Main Results:

• SCGAs exhibited thermo-reversibility, with decreased enthalpy and crystallinity after cooking, but increased upon cooling.
• Cooling SCGAs to 30°C increased SDS and RS content, indicating lower digestibility and glycemic index.
• Incorporating SCGAs into cooked rice increased RS content, with further increases after freeze-thaw cycles.
• No adverse effects on rice appearance or texture were observed up to 20% SCGA addition.

Conclusions:

• SCGAs demonstrate unique thermo-reversibility and low digestibility, making them suitable for thermally processed starch gel foods.
• The addition of SCGAs to cooked rice enhances its nutritional profile by increasing SDS and RS content.
• SCGAs show potential as a functional ingredient for developing healthier food products with reduced glycemic impact.