Microalgal flour

Abstract

The present invention relates to microalgal food products with acceptable sensory characteristics and methods of producing the food products. The flour can be produced by cultivating microalgal cells of a strain of Chlorella protothecoides under conditions of acceptable pH and dissolved oxygen to produce a desired amount of lipid. The microalgal cells can be lysed, heat-treated, washed and dried to produce a microalgal flour that can be incorporated into a variety of products.

1 - 36 . (canceled) 
     
     
         37 . A method for producing microalgal biomass or flour with reduced off-flavor, the method comprising:
 (a) culturing microalgal cells heterotrophically in the dark;   (b) applying a high-temperature-short time (HTST) pasteurization treatment for a duration of from 10 to 180 seconds, wherein the temperature of the HTST pasteurization treatment is from 70 to 95° C.; and   (c) washing the microalgal cells.   
     
     
         38 . The method of  claim 37 , further comprising drying the cells. 
     
     
         39 . The method of  claim 37 , comprising washing the microalgal cells with a volume of wash liquid that is as great or greater than the volume of the microalgal cells. 
     
     
         40 . The method of  claim 39 , wherein the volume of wash liquid is about twice or at least three times the volume of the cells. 
     
     
         41 . The method of  claim 37 , further comprising adding an antioxidant to the microalgal cells. 
     
     
         42 . The method of  claim 37 , wherein culturing microalgal cells heterotrophically comprises culturing the microalgal cells in the presence of a dissolved oxygen concentration of 30% or more. 
     
     
         43 . The method of  claim 37 , wherein culturing microalgal cells heterotrophically comprises culturing the microalgal cells in the presence of a dissolved oxygen concentration of 60% or more. 
     
     
         44 . The method of  claim 37 , wherein the microalgal biomass or flour is white or off-white. 
     
     
         45 . The method of  claim 37 , further comprising lysing the cells. 
     
     
         46 . The method of  claim 45 , comprising lysing from 30 to 75% of the microalgal cells. 
     
     
         47 . The method of  claim 45 , comprising lysing from 60 to 90% of the microalgal cells. 
     
     
         48 . The method of  claim 37 , wherein the microalgal biomass or flour comprises less than 200 ppm of chlorophyll. 
     
     
         49 . The method of  claim 37 , wherein the method produces microalgal biomass or flour with undetectable off-flavor. 
     
     
         50 . The method of  claim 49 , wherein the method produces microalgal biomass or flour which retains the lower level of off-flavor for at least 2 weeks when stored in the dark at room temperature in moisture and oxygen-impermeable packaging. 
     
     
         51 . The method of  claim 37 , wherein the method produces microalgal biomass or flour with undetectable fish and cabbage flavor when diluted 1:20 by volume in water, as detected by a tasting panel. 
     
     
         52 . The method of  claim 37 , wherein the microalgal biomass or flour is of the genus  Chlorella.    
     
     
         53 . The method of  claim 37 , wherein the microalgal biomass or flour is of the species  Chlorella protothecoides.    
     
     
         54 . A microalgal biomass or flour produced by the method of  claim 37 , comprising undecalactone (400-1800 ppb), 3-methyl butanal (0-11,000 ppb), pentanal (160-10,700 ppb), 2-methyl butanal (0-2500 ppb), 2-pentanone (39-10,600 ppb), 3-pentene-2-one (0-1500 ppb). 
     
     
         55 . A microalgal biomass or flour produced by the method of  claim 37 , with less than threshold amounts of pyrrole, pyrazine, or pyridines-containing compounds. 
     
     
         56 . A microalgal biomass or flour produced by the method of  claim 37 , with undetectable fish and cabbage flavor, when diluted 1:20 by volume in water, as detected by a tasting panel.