Ultrasonic-assisted extraction of nanocellulose from sweet potato residue and its application in noodles.

Enhancing the amount of dietary fiber without compromising the quality of noodles remains a challenge in the food industry. This study aimed to optimize the ultrasound-assisted extraction parameters to enhance the yield of nanocellulose from sweet potato residue (SPR) using a response surface methodology. The impact of SPR nanocellulose on noodles' physicochemical properties was also explored. Results showed that the optimal extraction conditions for nanocellulose from SPR were identified as 180.73 U/mL cellulase concentration, 4.28 h ultrasonic time, 444.12 W ultrasonic power, and 14.17 h enzymatic hydrolysis time. The max yield of nanocellulose was 15.93% at optimum extraction conditions. Increasing the amount of SPR nanocellulose resulted in a reduction in the optimal cooking time, water absorption, elongation index, and springiness, as well as an increase in the breaking rate, cooking loss, hardness, gumminess, and chewiness of the noodles. Sensory analysis revealed higher acceptability of the noodles with 6%-12% SPR nanocellulose compared to other treatments. Microstructure demonstrated that noodles with 0%-18% SPR nanocellulose exhibited fewer holes and denser network structures, but higher SPR nanocellulose damaged the protein network. Those findings suggested that noodles with less than 12% SPR nanocellulose exhibited higher quality. This research provided the foundation for the development of nanocellulose-enriched foods.