Effect of Chlorella Pyrenoidosa and Spirulina Platensis Powder on the Physicochemical, Structural, and Rheological Properties of Rice Starch: A Comparative Study

The effect of Chlorella pyrenoidosa (CP) and Spirulina platensis (SP) at concentrations of 0 %–12 % on the properties of rice starch (RS) was investigated. Compared with pure RS, the addition of CP and SP powder decreased the viscosity, increased the gelatinization temperature, and promoted the retrogradation of RS gel. However, when CP was added at 12 % and SP at 8 %, retrogradation inhibition was reduced. At these concentrations, the relative crystallinity of the CP mixture increased by 57.37 %, whereas that of SP increased by 48.13 %. Scanning electron microscopy revealed that the addition of low amount of CP and SP reduced porosity. CP and SP powder facilitated the conversion of bound water to free water and contributed to the weakening of the viscoelasticity of the RS gel. CP powder likely had a more detrimental effect on the short-term storage properties of RS than SP powder. These results provide theoretical support for the development of RS-based products and the innovative utilization of microalgae.