Influence of Surface pH on Color, Texture and Flavor of 3D Printed Composite Mixture of Soy Protein Isolate, Pumpkin, and Beetroot

This study investigated stimulation at different pH to alter color, texture, and flavor of soy protein isolate, pumpkin, and beetroot mixture as 3D printed food product. Sensory evaluation as well as Fourier transform infrared (FTIR) spectroscopy were also conducted; the results were used to support the aforementioned property evolutions. Color of the printed product was unaffected beyond pH 6. Lower pH resulted in higher hardness and gumminess but in lower springiness and cohesiveness of the printed product. Flavor of the printed product changed only after 5 h of stimulation; desirable change was noted at pH 8 and 10. Treatment at pH 10, however, resulted in higher saltiness of the product. All treated samples possessed higher sensory scores than the freshly printed one. FTIR spectra could be well correlated to physical changes of the treated printed product. Stimulation at pH 6 was noted to give the best overall results.