Method of reducing the self-heating propensity of biomass

A PUFA-containing composition comprising:

• a fermented biomass of cells comprising at least 20 wt % of at least one type of polyunsaturated fatty acid (PUFA) having at least 20 carbon atoms and at least three double bonds, wherein
• the PUFA-containing composition has a reduced self-heating propensity sufficient to cause a temperature of the PUFA-containing composition to not spontaneously be increased to 180° C. or more in an oven when the PUFA-containing composition is placed in a 100 mm sample cube and is heated in the oven at 120° C. for 24 hours,
• wherein the reduced self-heating propensity is obtained by:
• (i) limiting fermentation of the biomass to less than 6 days,
• (ii) omitting a pasteurization step after fermentation,
• (iii) conducting a drum drying step instead of a lyophilzation step,
• (iv) adding at least one type of natural antioxidant and at least one type of synthetic antioxidant to a fermentation broth at the end of fermentation, or
• (v) including at least 50 g/L sugar to a fermentation broth at the end of fermentation.