Oil body-based one-step multiple phases and hybrid emulsion gels stabilized by sunflower wax and CMC: Application and optimization in 3D printing

In this paper, novel oil body (OB) based emulsion gels were prepared by mixing different ratios of two phases: Carboxymethyl-cellulose-coated OBs (CMC-OB) phase and Sunflower wax-based soybean oil (SW–SO) oleogel phase. The stabilization mechanism of OB emulsion gels was investigated by multiple microscopy techniques, and the decorating ability and 3D printability have been evaluated and optimized combined with the rheology analysis. Multiple phases and hybrid emulsion gels could be prepared by a one-step method due to the natural oil-in-water (O/W) structure of OB. In the first case, an (O1/W1)/O2 type emulsion gel was obtained when the OB-CMC phase content was 50 wt% and below, which with a higher elastic modulus was better for formability in 3D printing. Another case was that the OB-CMC phase was the continuous phase when the OB-CMC phase was 60, 70 wt%, and the emulsion gel system was O2/(O1/W1) structure with a 15 μm emulsion size and an unsatisfactory 3D printing capability. Then, two different approaches to improving the 3D printability of O2/(O1/W1) emulsion gels were compared, namely by increasing the strength of the inner phase and external phase by adding SW and OB content, respectively. With the addition of OBs, more suitable printing ink for 3D printing was obtained for the tight compaction of OBs in the external phase. The OB-based multiple phases and hybrid emulsion gels without low-molecular weight emulsifiers facilitated the broadening of OB applications in healthy, green, sustainable food products and 3D printing.