This study was designed to compare the properties, kinetics and stability of the immobilized lettuce protease with the free one. We also aimed to test the use of the immobilized lettuce protease for the production of novel bile binding and tyrosinase-inhibitory peptides from plant food processing wastes (cauliflower midrib and broad bean leaves). Immobilized lettuce protease was prepared previously from Lactuca sativa (lettuce) seeds. Free lettuce protease was immobilized on alginate-glutraldehyde beads by covalent bond at optimum conditions with high immobilization efficiency. In the present study, immobilized protease showed optimal activity 221.5 U/mg enzyme protein at pH 10 and 70°C, while the free one showed 22 U/mg enzyme protein at pH 7 and 60°C. Km values of the immobilized and free protease toward azocasein were 1.143 and 1.442 mg, and Vmax values were 142.9 and 24.6 U/mg enzyme protein, respectively. Immobilization of lettuce protease resulted in an increase of activation energy (Ea) for azocasein hydrolysis from 9.6 to 23 Kj/mol. Immobilization improved its turnover number Kcat (15.96 Kj/mol) and catalytic efficiency Kcat /Km (13.96 Kj/mol) compared to that of the free one (3.09 and 2.143 Kj/mol, respectively). Deactivation energy (Ed) values were 38.76 and 55.41 for the free and immobilized protease, respectively, confirming the enzyme stability by immobilization. Free protease could be stored for 70 days at 4°C with loss of only 20% of its initial activity, while the immobilized one could be stored for 23 and 46 days with retention of 114 and 74.5% of its initial activity at 9°C, respectively. CaCl2 increased the rigidity, stability and activity of the immobilized enzyme by 125%. Cauliflower peptides were enzymatically prepared from cauliflower protein. It had higher bile binding and tyrosinase inhibitor potency than the parent protein. Immobilized lettuce protease and cauliflower peptides could be applied in food and pharmaceutical industries.