Enzyme-assisted aqueous extraction of oil and protein hydrolysate from sesame seed

Abstract

In this work, sesame oil and protein hydrolysates were extracted via the enzyme-assisted aqueous extraction (EAAE) process using Neutrase (a commercial protease), Pectinex (a commercial carbohydrate-hydrolyzing enzyme) and a 1:1 mix of Neutrase and Pectinex. All the extractions were performed at 50 °C and the optimum pH of the enzymes for 6 h, and the water to sesame ratio was raged between 1:1 and 6:1. The highest oil recoveries were obtained at 2:1 water to sesame ratio for each treatment and the Neutrase-Pectinex treatment gave the max recovery (89.7%, p < 0.05). The oil extracted using Neutrase-Pectinex treatment, contained the highest amount of unsaponifiables, total phenolic compounds, lignans and showed the highest oxidative stability, color indices and sensory attributes, even higher than the solvent-extracted oil (p < 0.05). However, oils obtained using different treatments were not significantly different in terms of free fatty acids content, iodine value, peroxide value, saponification value and anisidine value (p > 0.05). Protein hydrolysates obtained using Neutrase-Pectinex treatment (NPPH) had lower protein and higher carbohydrate content than that obtained using Neutrase treatment (NPH). The lowest solubility, emulsifying activity and stability indices, foam capacity and foam stability of NPPH and NPH was found to be at pH 4.0. The solubility of NPPH was higher than the NPH, but the emulsification properties of the NPH was better than NPPH at pH 2–10 (p < 0.05). NPPH and NPH were not significantly different in terms of foaming properties (p > 0.05).