Abstract:Almond protein was subjected to enzymatic hydrolysis with trypsin and cellulase （4∶1,mass ratio）.With the degree of hydrolysis （DH） and peptide yield as key indicators,response surface methodology was employed to optimize the enzymatic hydrolysis conditions based on single-factor experiments.The enzymatic hydrolysis conditions were optimized as follows：substrate concentration of 4.8%,trypsin addition of 14%,hydrolysis duration of 8 h,and hydrolysis temperature of 54 ℃.Under these conditions,the DH was （55.22±0.56）%and the peptide yield reached （77.92±0.92）%.The hydrolysates were separated and purified through ultrafiltration and Sephadex G-25 column chromatography.Almond peptides with acetylcholinesterase （AChE） inhibitory activity and molecular weights less than 3 kDa were screened out with the AChE inhibition rate as the screening criterion.The median inhibition concentration values of the peptides for scavenging DPPH radicals,hydroxyl radicals,and superoxide anion radicals were 5.11,4.34,and 28.74 mg/mL,respectively,and the total antioxidant capacity was determined to be 1.23 mmol/L.The results indicated that the almond peptide fraction（<3 kDa）,which demonstrated both AChE inhibitory and antioxidant activities,primarily consisted of peptides with molecular weights below 1 kDa,which accounted for 62.73% of the fraction.