Effects of ultrasonic treatment and homogenization on physicochemical properties of okara dietary fibers for 3D printing cookies.

This paper presents a means to modify the attributes of okara fiber using ultrasonic and high-speed shearing treatment. The results of scanning electron microscopy and differential scanning calorimetry reveal that the modified okara fiber demonstrates small particle size and high thermal stability. When the 500 W-15,000 rpm combination is used for okara-fiber treatment, the latter exhibits excellent swelling (SC) as well as water- and oil-holding capacities. When 6% of modified okara fiber is added to the dough, the resulting cookies demonstrate the best printing performance. Subsequently, the printing parameters can be optimized to obtain the best filling rate of 30%. The corresponding nozzle diameter and printing speed equal 0.8 mm and 50 mm/s, respectively. Finally, the 3D-printed cookies containing okara fiber are compared against those commonly available in the market via sensory evaluation. As observed, the 3D-printed cookies were more acceptable to people. Therefore, the addition of the okara dietary fiber to the cookie dough not only improves the okara utilization rate but also increases the dietary-fiber content in the cookie, thereby alleviating the occurrence of obesity in modern society.

Preparation, characterization, and 3D printing verification of chitosan/halloysite nanotubes/tea polyphenol nanocomposite films.

In this study, chitosan/halloysite nanotubes/tea polyphenol (CS/HNTs/TP) nanocomposite films were prepared by the solution casting method. The scanning electron microscopy (SEM) result showed that the nanocomposite film with a CS/HNTs ratio of 6:4 and a TP content of 10% (C6H4-TP10) had a relatively smooth surface and a dense internal structure. The water vapor barrier property of the nanocomposite film was improved due to the tortuous channels formed by the HNTs. However, the swelling degree and water solubility of the nanocomposite films were decreased. The nanocomposite films have a good antioxidant capacity. Antibacterial experiments showed that the C6H4-TP10 nanocomposite film had certain inhibitory effects on the growth of both E. coli and S. aureus. In addition, we used 3D printer to verify the printability of the optimal formulation of the film-forming solution. Overall, this strategy provides a simple approach to construct promising natural antioxidants and antibacterial food packaging.