Optimization of ultrasonic extraction and physicochemical characterization of starch from Phalaris canariensis L. seeds

Ultrasonic extraction has emerged as an effective technique for producing modified starches. This study investigates the use of ultrasound to improve the functional properties of canary starch for industrial applications. The efficiency of combining ultrasound with alkaline treatment for extracting canary starch was studied and compared with conventional alkaline extraction (CAE). Ultrasound-assisted alkaline extraction (UAE) conditions were optimized using single factorial experiments and response surface methodology (RSM) to maximize efficiency and yield. The highest starch yield (45.53%) was obtained with UAE under the following conditions: solid-to-liquid ratio of 1:5 (w/v), 0.25% NaOH, 39 °C, and 30 min. The starch was also evaluated for the morphological, structural, and physicochemical characteristics. UAE process resulted in canary starch exhibiting higher amylose content (19.47%), increased bulk density 0.79 (g/cm³), superior water absorption capacity (0.42 to 1.02 g/g), improved oil absorption capacity 1.51 (g/g), and enhanced swelling power (1.4 to 6.6 g/g at 75 °C), compared to the CAE. Additionally, the morphology of starch granules was altered, and the transmittance of the starch suspension was more stable in the US treated samples, peaking at 6.91% at 72 h, indicating improved clarity and structural integrity. However, the molecular structure and crystal type of the starch remained unaffected. In conclusion, UAE offers a rapid, eco-friendly, and efficient method for producing canary starch with enhanced functional properties, making it a promising alternative for applications requiring high gelation efficiency, swelling capacity, and water absorption.