Investigation of Nutrition and Printability of Orange Juice Sacs Applied to Heterogeneous 3D Printing: Influence of Pretreatment-Assisted Impregnation

The osmotically dehydrated orange juice sacs can serve as materials for heterogeneous 3D printing. Moreover, physical field-assisted such as ultrasound and vacuum, along with their combined application, were employed to enhance the impregnation of green tea polyphenol (GTP) and ascorbic acid (AA) during osmotic dehydration of orange juice sacs. This innovative approach not only compensates for the loss of water-soluble bioactive substances but also enhances the functional properties of heterogeneous 3D-printed food. The study assessed the impregnation effect of ultrasound (UOD), vacuum (VOD), and their synergistic pretreatment (UVOD) on the osmotic dehydration of orange juice sacs. Results indicated that the VOD-treated product exhibited the highest AA impregnation at 294.20 mg/100 g, while the UVOD-treated product demonstrated the best retention of phenolic compounds at 29.55 mg/g and also with best antioxidant activity. Quality attribute evaluation revealed that the UOVD-treated product displayed the lowest water content (66.44%), the softest texture, and superior color and aroma retention compared to the untreated orange juice sacs. In printing experiments, it was observed that the addition of 1–3% orange juice sacs resulted in successful printing using a 2.5 mm printing nozzle, achieving high precision and aesthetically pleasing outcomes.