The invention relates to a feed composition comprising a flavonoid, more particularly an isoflavone such as daidzein or genistein, for example in the form of a fermented soy protein material. The invention also relates to a process for the coloring or pigmenting of various animals such as fish and Crustacea, for increasing the endogenous concentrations of astaxanthin and chanthaxanthin, and for improving the texture of the flesh of said fish or Crustacea.
