High-pressure processing (HPP) is for the food industry a relatively young technology that successfully evolved into one of the most engaging alternatives to conventional thermal processing. One of the earliest high-pressure (HP) applications in the food industry is oyster processing. HPP does not influence the primary and secondary structures of proteins; the tertiary and quaternary structures of globular proteins have been long known to undergo reversible and irreversible changes under HP. HPP enhances lipid oxidation in fish muscle after the treatment and during subsequent chilled storage of cod, carp, and rainbow trout. HPP affects the integrity of cellular structures such as lysosomes and sarcoplasmatic reticulum and favors the release in cytosol of proteolytic enzymatic systems, such as calpains and cathepsins. Texture Oxidation of unsaturated fatty acids or triglycerides in seafood takes place via free radical formation. The taste and flavor of seafood is influenced by the presence of both volatile and nonvolatile components.