Abstract: A nutritious animal protein-derived peptide beverage was prepared from an enzymatic hydrolysis of duck liver protein with white sugar and pectin added. Optimization of the major factors (ingredients) affecting the stability of the beverage was optimized using one-factor-at-a-time method and response surface methodology. It was found that incorporation of 2.0% duck liver peptide, 8% white sugar and 0.09% pectin gave a product with the highest stability (stability coefficient 99.1%). Amino acid composition analysis indicated that the peptide was rich in amino acids and had high nutritional value. After autoclaving, E. coli, mold and pathogens were not detected for 30 days. Sensory evaluation showed that the beverage was uniform and stabile. The results of antioxidant assays showed that the IC50 values of the beverage for 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging and ferrous iron chelating were 0.035 and 0.101 mg/mL, respectively. The results indicated that the peptide beverage had good antioxidant activity and stability. This study can provide experimental evidence for deep processing and high-value utilization of meat processing by-products.

Key words: duck liver peptide beverage, response surface optimization, antioxidant effect