Optimization of the extraction of duckweed protein and its application as an antioxidant composite membrane in blueberry preservation

In this paper, response surface methodology (RSM) was used to optimize the extraction process of proteins from duckweed and the protein extraction rate was increased to 24.11 ± 0.04 %. The duckweed protein extract (DP) was mixed with sodium carboxymethyl cellulose (CMC) and glycerol to prepare DP/CMC antioxidant membranes with different additions (0.5 % ∼ 2.5 %), and 2.0 % DP/CMC antioxidant membranes were used in blueberry preservation experiments. The results showed that the moisture permeability of DP/CMC antioxidant membrane was significantly reduced, the thermal stability was significantly improved, and the antioxidant property was significantly higher than that of CMC membrane ( p  < 0.05). The lowest oxygen content in the 2.0 % DP/CMC membrane package compared to PE and CMC membranes may be due to the synergistic effect of aerobic respiration of blueberries and oxidation of antioxidants in the membrane, under which the loss of antioxidants in the blueberries was lowest and the quality of blueberries was effectively maintained. In this study, for the first time, antioxidant membranes with significant freshness preservation effects were prepared using duckweed protein extract (DP), demonstrating its great potential as an active packaging material for food preservation, and opening up a new development direction for the application of DP.