Okara is a by-product obtained from soybean milk containing high dietary fiber. This study focused on how to add value to okara by converting it into okara cellulose powder. The feasibility of using mechanical energy from the extrusion process to produce cellulose powder from okara was compared with the traditional mechanical method, hydrothermal and untreated okara powder (SBM). The extrusion process was carried out at different screw speeds (350–450 rpm), amount of water (0.5–1 L per hour), and number of treatment cycles. The physicochemical and functional properties of the okara cellulose powder and specific mechanical energy were analyzed. Results showed that the particle size of samples treated by 6 cycles of extrusion reduced to three times lower than SBM. The sample subjected to hydrothermal and extrusion showed significantly increased swelling ratio, water solubility index (WSI), and antioxidant capacity. However, only the extrusion treatment could improve the rheological properties. Increasing the cycles of extrusion treatment increased the swelling ratio and WSI values. Extrusion altered the color and chemical composition by decreasing the lightness and total dietary fiber. Extrusion treatment was proved to be an effective mechanical method for improving okara properties and converting the by-product into a potentially value-added ingredient for use in future food applications.

This investigation examined the effects of microalgae supplementation on the physicochemical properties, nutritional profile, and digestibility parameters of high-moisture meat analogues (HMMAs). The sustainability and nutritional potential of incorporating three microalgae species—Arthrospira platensis, Haematococcus pluvialis, and Nannochloropsis oculata—into diets were investigated at inclusion levels of 0.5% and 1.5% (w/w). Colour metrics, compositional analysis, antioxidant capacity, textural characteristics, and in vitro protein digestibility were also assessed. The findings demonstrated enhancements in nutritional quality, particularly in protein content. Antioxidant capacity was significantly elevated in the 1.5% inclusion samples. Samples containing 1.5% A. platensis exhibited the highest chlorophyll concentrations at 19.91 mg/mg, while 1.5% H. pluvialis displayed carotenoid levels at 34.59 µg/mg. These improvements correlated with increased efficacy in ABTS and FRAP radical scavenging assays. Colourimetric analysis indicated that elevated microalgae concentrations contributed to darker hues; 1.5% H. pluvialis markedly increased redness (a-value, p < 0.05), with the visual profile similar to conventional meat. Supplementation with 1.5% A. platensis consistently decreased hardness and chewiness, likely attributable to enhanced porosity. Conversely, 1.5% N. oculata promoted a honeycomb-like microstructure, thereby augmenting cut resistance and hardness. The diminished rehydration capacity observed in 1.5% H. pluvialis was ascribed to smaller pore sizes, but maintained a higher oil-holding capacity relative to the control. All microalgae-infused HMMAs retained excellent in vitro protein digestibility. These results underscored the potential of microalgae—particularly 1.5% A. platensis for nutritional and textural enhancements, 1.5% H. pluvialis for improved visual and antioxidant properties, and 1.5% N. oculata for elevated phenolic and chlorophyll contents—in advancing sustainable, plant-based meat alternatives.

Texture perception in extruded snacks is commonly evaluated using force-based measurements, although crispness-related oral sensations arise from fracture, sound emission, and lubrication during mastication. This study developed a mechanistically grounded framework for texture characterization of fiber-enriched extruded snacks by integrating instrumental and sensory analyses within an oral-processing context. Extruded snack samples containing soybean residue (okara; 0%, 29%, and 40%) and commercial benchmarks were evaluated using synchronized mechanical–acoustic testing (five-blade Allo-Kramer shear and three-point bending tests), oral tribology, and sensory evaluation combining intensity rating and ranking. Increasing okara content shifted fracture behavior from brittle, sound-emitting failure toward damped, progressive deformation with approximately 3–5-fold lower acoustic envelope amplitudes and smoother force–time profiles. These changes corresponded to lower perceived Crunchiness and Sound Intensity, reflecting diminished crispness-related perception, and higher Hardness and Grittiness/Coarseness attributes (increases of ~25–45%). Oral tribology revealed cohesive, poorly lubricated boli for okara-rich snacks, requiring higher entrainment parameters (Uη₀ ≈ 1.0 × 10⁵–3.5 × 10⁵) to transition from boundary to mixed lubrication compared with commercial benchmarks (Uη₀ ≈ 7.0 × 10⁴–2.0 × 10⁵). Convergent multivariate analyses established instrumentally defined texture phenotypes that translate mechanical–acoustic and tribological signatures into sensory-interpretable texture categories, providing a practical framework for discriminating and optimizing nutritionally enhanced extruded snack products.