Oil and meal from waste fodder radish seed press cake via maceration extraction: Composition, optimization, kinetics, and thermodynamic analysis

The residual oil was extracted from fodder radish seed press cake via maceration using n -hexane. The effects of maceration temperature (20–70 °C), solvent/cake ratio (3–10 mL/g), and time (up to 15 min) on oil yield were studied. Optimization was performed with response surface methodology and a historical design. A quadratic equation modeled the relationship between yield and process factors, with strong predictive capability ( R ² > 0.93) and minimal deviation (± 0.7%). The maximum oil yield of 24.26 ± 0.02% was achieved at 61–70 °C, 8–10 mL/g solvent/cake ratio, and 11–15 min. At 70 °C, 10 mL/g, and 15 min, the actual yield was 24.2%, aligning with the predicted value. The maceration process was endothermic and irreversible, described by both phenomenological and exponential models. The oil was rich in monounsaturated (60.8%) and polyunsaturated (28.0%) fatty acids, with lower saturated fats (8.3%), and contained beneficial compounds like proteins, tocopherols, carotenoids, and chlorophyll. Defatted press cake had higher concentrations of proteins, sugars, and phenolic compounds than the press cake.