Abstract:Leaf protein concentrates were extracted from mulberry Da10 by water, and the leaf proteins were precipitated using the heating method, acid method, acid-heating method, and salting-out method to yield the corresponding protein samples RC, SC, SR, and LC, respectively. The functional properties of the obtained samples were measured and compared with those of soy protein isolate (SPI) in order to determine the functional characteristics of each sample. The results showed that isoleucine and lysine were the first and second limiting amino acids, respectively, in mulberry leaf flour. The precipitation methods had significant impacts on the functional properties of the mulberry leaf proeins. The LC sample showed the highest solubility, foaming capacity, emulsifying activity, and oil absorption capacity, which were significantly better than those of SC, SR, and RC (p < 0.05). SR displayed a higher water holding capacity than SC and RC but showed relatively poor emulsifying activity and foaming capacity. LC and RC had the best gelling property. Compared with SPI, the four samples exhibited better oil absorption capacity, significantly lower water holding capacity, and poor gelling property. The best emulsion stability (68.57%) and foaming capacity (40%) were found in the LC and SC samples, respectively, which were significantly better than those of SPI (54.86%, 37.67%, p < 0.05). The emulsion stability and foaming capacity of RC were comparable to those of SPI while the two properties were the lowest for SR and were significantly lower than those of SPI (p < 0.05). The scanning electron microscopy result showed that LC had a typical honeycomb structure.
