This paper aims to investigate the physical and 3D printing properties of arrowroot starch (AS), a natural biopolymer with many potential health benefits. Scanning electron microscopy images showed that AS granules had mixed spherical and elongated geometries, with average sizes of 10.5 ± 2.5 μm. The molecular weight of AS measured by gel permeation chromatography (GPC) was 3.24 × 10⁷ g/mol, and the amylose/amylopectin ratio of AS was approximately 4:11. AS has an A-type crystal structure, with a gelatinization temperature of 71.8 ± 0.2 °C. The overlap concentration (C*) of AS in aqueous solutions was 0.42% (w/v). Temperature-dependent dynamic rheological analyses of 10% to 30% (w/v) AS fluids showed that the storage modulus (G’) reached the maximum values around the gelatinization temperatures, while the yield stress (τ_y) and flow stress (τ_f) values all increased with the increase in AS concentration. The printing accuracy of AS gels was found to be associated with the interplay between the G’ values and the restorability after extrusion, determined by the three-interval thixotropy tests (3ITT). The optimum 3D printing condition occurred at 20% (w/v) AS, the nozzle diameter of 0.60 mm, the printing speed of 100 mm/s and the extrusion speed of 100 mm/s. Our research provides a promising biopolymer to be used in the design of novel personalized functional foods.

As a functional polysaccharide, inulin was carboxymethylated and it formed nanocomplexes with bovine serum albumin (BSA). The success of obtaining carboxymethyl inulin (CMI) was confirmed by a combination of Fourier transform Infrared (FT-IR), Raman spectroscopy, gel permeation chromatography (GPC), and titration. The effects of pH and ionic strength on the formation of CMI/BSA nanocomplexes were investigated. Our results showed that the formation of complex coacervate (pH_φ1) and dissolution of CMI/BSA insoluble complexes (pH_φ2) appeared in pH near 4.85 and 2.00 respectively. FT-IR and Raman data confirmed the existence of electrostatic interaction and hydrogen bonding between CMI and BSA. The isothermal titration calorimetry (ITC) results suggested that the process of complex formation was spontaneous and exothermic. The complexation was dominated by enthalpy changes (∆Η < 0, ∆S < 0) at pH 4.00, while it was contributed by enthalpic and entropic changes (∆Η < 0, ∆S > 0) at pH 2.60. Irregularly shaped insoluble complexes and globular soluble nanocomplexes (about 150 nm) were observed in CMI/BSA complexes at pH 4.00 and 2.60 while using optical microscopy and atomic force microscopy, respectively. The sodium chloride suppression effect on CMI/BSA complexes was confirmed by the decrease of incipient pH for soluble complex formation (or pH_c) and pH_φ1 under different sodium chloride concentrations. This research presents a new functional system with the potential for delivering bioactive food ingredients.

Inulin is a prebiotic and an effective texture modifier for emulsion gels, offering considerable commercial value for consumers whose chewing ability changes. This study evaluated the influence of inulin on print precision, structural integrity, and sensory quality of 3D-printed emulsion gels. An inulin-based emulsion gel with desirable texture and freezing stability across −18 °C to 25 °C was successfully developed. Rheological analysis showed a pronounced increase in elasticity with increasing inulin content. In frequency scanning, G′ rose from 2.99 × 10³ Pa (6.7 % inulin) to 1.08 × 10⁴ Pa (20 % inulin), while oscillation scanning showed a rise from 2.27 × 10³ Pa to 7.18 × 10³ Pa. Frequency and thixotropy tests revealed that salt-free gels exhibited the highest G′ and viscosity. Temperature scanning showed peak moduli at −18 °C (G′ = 2.44 × 10⁶ Pa; G″ = 1.09 × 10⁶ Pa). Notably, G′ in 20 % inulin gels declined only 65 % after thawing, compared to 76 % in 6.7 % gels, confirming better freeze–thaw stability. Electronic-nose detection and sensory evaluation indicated that higher inulin levels diminished the characteristic camellia-oil odor. Correlation analysis demonstrated that hardness was inversely related to fatty and smooth sensory attributes, highlighting the predictive value of instrumental measurements for sensory texture in 3D-printed foods.