Nutritional and functional properties of photosynthetic microorganism proteins: A comparison with soy protein isolate and wheat protein

As a widely acknowledged source of sustainable food protein, there has been limited research on the functional properties of photosynthetic microorganism proteins (PsmPs) applied in food. The nutritional and functional attributes for meat analogue production of Spirulina platensis protein (SpirP), Chlorella pyrenoidosa protein (ChloP), and Schizochytrium sp. protein (SchiP) were investigated and compared with two widely utilized proteins: soy protein isolate (SPI) and wheat protein (WheaP). At a neutral pH, SpirP and SchiP exhibited high emulsifying activities of 69 and 66 m2/g, while ChloP (20 m2/g) was comparable to SPI (15 m2/g) and WheaP (19 m2/g). Their remarkable foaming capacity indicated their potentials to produce meat analogues with fibrous structures. The water absorption capacity of PsmPs (4.4–4.8 g water/g protein) was comparable to WheaP (4.7 g water/g protein), while the oil absorption capacity (3.7–4.4 g oil/g protein) was higher than SPI (2.7 g oil/g protein) and WheaP (3.3 g oil/g protein), implying their potential to produce juicy and tasty meat analogues. Besides, the heat-induced photosynthetic microorganism protein gels had stable structures. In summary, SpirP, ChloP, and SchiP emerge as outstanding protein sources and viable alternatives to SPI for the production of meat analogues.