Freeze drying is standard practice in many laboratories that conduct body composition (tissue composition) analysis. I have found no differences in total lipid composition of tissues that are dried using heat or freeze dried before extraction.

As Loren has stated, freeze-drying is a common step in lipid extraction in many analytical method. Neither acylglycerides, nor phosphoglycerides, nor most compounds from the unsaponifiable fraction are removed from the sample at the presure/temperature conditions during freeze-drying. Perhaps some short chain free fatty acids will be removed, but those are not that common in fish, and I doubt this will influence total lipid content at all.

Thanks Loren and Jorge for these answer, that are consistent with my thoughts.

Are you aware of some papers supporting this idea, or is this from your personal lab experience?

doi:10.1016/j.foodchem.2013.08.131

doi:10.1016/j.meatsci.2014.12.011

 I have found no difference in total lipid content in tissues (gonad, muscle, digestive) of either earth or marine in vertebrates using freeze-drying or moderate heat..  As other coleagues have stated it is common practise.

Total lipid content is not influenced by freeze drying.

Jorge,

it seem that the doi you provided are erroneous ? Would you mind providing the complete references ?

Thanks for your help

HI Jean Michel

Thanks for this reference !