High-pressure homogenization combined with alcohol treatment is effective in improving the sensory and techno-functional characteristics of Chlorella pyrenoidosa

Chlorella pyrenoidosa (CP) is a microalga that has been used as a sustainable protein and food source. However, its green color from chlorophyll and low processability have limited its broad application in food. This study aimed to evaluate the effectiveness of high-pressure homogenization (HPH) in conjunction with alcohol treatment in removing chlorophyll from CP and its impact on the quality and techno-functionality of the resulting decolorized CP meal. The method was found to be efficient, eco-friendly, and allowed easy recovery of CP components and solvents. It removed chlorophyll effectively and increased CP whiteness from 43.5 +/- 1.26 to 86.6 +/- 0.55. The combination processing strategy also significantly (p < 0.05) improved the protein quality (e.g., essential amino acid ratio) and functionality (e.g., foaming, emulsification, and gelation) of CP. The results of morphological and electrophoretic analyses indicated that the aggregation behavior of CP molecules was altered in the decolorized sample. Thermochemical and infrared analyses revealed that the decolorization processing reduced CP's heating enthalpy and disrupted hydrophilic beta-turns on its globulin surface, causing more random coils. These findings suggest that HPH combined with alcohol treatment can enhance CP sensory characteristics and functionality, which would facilitate its application in the food industry.