Bioprocessing of rice starch: advances in extraction, modification, and analytical characterization

Rice starch is an important biodegradable biopolymer widely utilized in food, pharmaceutical, and industrial sectors, where its performance depends strongly on its structural and functional properties. This review provides a comprehensive evaluation of current preparative and modification strategies used to isolate and enhance rice starch for diverse biotechnological applications. This review summarizes major preparative methods for rice starch isolation, including alkaline extraction, dimethyl sulfoxide extraction, SDS-NaOH-protease treatment, high-intensity ultrasound processing, and freeze-thaw infusion, emphasizing their efficiency and impact on starch integrity. Key physical (pre-gelatinization, microwave treatment, annealing, heat-moisture treatment, and ultrasound modification), chemical (acetylation, oxidation, hydroxypropylation, carboxymethylation, and cationization), and dual-modification strategies are discussed with respect to their ability to enhance swelling, solubility, viscosity, and thermal stability. Advanced analytical techniques such as X-ray diffraction, nuclear magnetic resonance, FTIR spectroscopy, differential scanning calorimetry, and microscopy are highlighted as essential tools for evaluating structural and functional changes. Overall, this review integrates advances in starch preparation, modification, and characterization, providing a framework for developing high-value, sustainable starch derivatives. Emerging opportunities include environmentally friendly processing, enzyme-guided modification, and optimize starch functionality for future bioprocessing needs.