Abstract: The present invention relates to the use of unpigmented skin from flat fish as novel industrial source of collagen. As unpigmented skin, the ventral skin is used in particular, from sole, dab, turbot, brill. Native acid-soluble collagen is advantageously extracted and separated by precipitation from the supernatant. The invention makes it possible to improve the collagen yield at reduced cost while preserving the native properties of the protein, and in a reproducible manner.

Abstract: This invention relates to a process and apparatus for freeze-drying, said apparatus comprising freeze-drying shelves disposed inside a freeze-drying enclosure, on which may be placed products or solutions to be freeze-dried, which may be contained in open recipients, as well as cooling and/or heating means associated with and preferably incorporated in said shelves, wherein means forming a thermal shield are disposed between said freeze-drying shelves, thus making it possible to slow down the heat exchanges between the surface of the product to be freeze-dried and the heating and/or cooling elements associated with the shelves. More homogeneous freeze-dried products are obtained in this way.