Microalgal flour
Compositions of microalgae-derived flour are disclosed from multiple genera, species, and strains of edible microalgae. Microalgae used in the invention are free of algal toxins and contain varying levels of primarily monounsaturated triglyceride oil. Flours disclosed herein are formulated as free flowing blendable powders, mixed food ingredients, oxidation stabilized, homogenized and micronized, and combinations therein. Flours disclosed herein also form self stabilizing emulsions in slurries with manageable viscosities. Innovative methods of formulating flours and incorporating them into food compositions are also disclosed. The invention also comprises flours with significant digestible protein and unique dietary fiber content and associated water binding, texturizing, and healthy oil delivery attributes. Novel methods of oil and fat replacement using flours of the invention are also disclosed. Flours of the invention can be manufactured from edible and inedible heterotrophic fermentation feedstocks, including corn starch, sugar cane, glycerol, and depolymerized cellulose.
1. A method of making a microalgal flour as a food ingredient, comprising:
(a) providing microalgal cells containing at least 10% by dry weight triglyceride oil, wherein the microalgal cells are of the genus Chlorella;
(b) disrupting the cells to provide particles having a particle size and reducing the particle size to produce an aqueous homogenate; and
(c) drying the homogenate to produce microalgal flour comprising at least 10% by dry weight triglyceride oil, wherein the triglyceride oil is 1-4% C18:0.
2. The method of claim 1 , wherein the microalgal cells are Chlorella protothecoides.
3. A method of making a microalgal powder as a food ingredient, comprising:
(a) providing microalgal cells containing at least 10% by dry weight triglyceride oil, wherein the microalgal cells are of the genus Chlorella , and
(b) drying the cells to produce microalgal powder comprising at least 10% by dry weight triglyceride oil, wherein the triglyceride oil is 1-4% C18:0.
4. The method of claim 3 , wherein the microalgal cells are Chlorella protothecoides.
5. The method of claim 2 , further comprising separating the microalgal cells from culture media before disrupting the cells.
6. The method of claim 2 , wherein the disruption is performed using a pressure disrupter, French press, or ball mill.
7. The method of claim 2 , wherein the drying is performed using a flash dryer or a spray dryer.
8. The method of claim 2 , wherein the microalgal cells contain from 50% to 70% by dry weight oil.
9. The method of claim 2 , further comprising adding a flow agent prior to the drying step.
10. The method of claim 2 , wherein the average particle size of the microalgal flour is less than 10 um.
11. The method of claim 2 , wherein the microalgal flour of microalgal powder has a moisture content of 10% or less by weight.
12. The method of claim 2 , wherein 50%-73.83% of the oil is an 18:1 lipid in a glycerolipid form.
13. The method of claim 2 , wherein the microalgal cells are cultivated heterotrophically in the absence of light.
14. The method of claim 13 , wherein the microalgal cells are cultivated in the presence of glucose.
15. The method of claim 13 , wherein the microalgal cells are cultivated in the presence of a limiting amount of a nutrient for a portion of the culture period.
16. The method of claim 15 , wherein the nutrient is nitrogen.
17. The method of claim 2 , wherein the aqueous homogenate comprises more than 50% lysed cells.
18. The method of claim 17 , wherein the aqueous homogenate comprises more than 90% lysed cells.
19. The method of claim 7 , wherein the drying is performed using a spray dryer.
20. The method of claim 2 , wherein the microalgal flour of microalgal powder has a moisture content of 5% or less by weight.
21. The method of claim 17 , wherein the aqueous homogenate comprises more than 75% lysed cells.
22. The method of claim 10 , wherein less than 10% by weight of the triglyceride oil is docosahexanoic acid (DHA) (C22:6).
23. The method of claim 3 , wherein less than 10% by weight of the triglyceride oil is docosahexanoic acid (DHA) (C22:6).
24. The method of claim 1 , wherein the triglyceride oil is 10-16% C18:2.
25. The method of claim 3 , wherein the triglyceride oil is 10-16% C18:2.