15 

 (carbon dioxide or COj-saturated brines) have been used successfully to 

 preserve food quality and extend shelf-life (Barnett et al., 1978; Brown 

 et al., 1980; Bui lard and Collins, 1978; Gee and Brown, 1987a, 1987b; 

 Lannelongue et al., 1982; Longard and Reiger, 1974; Shewan, 1950; Vernath 

 and Robe, 1979; Villemure et al . , 1986; Woyewoda et al., 1984; Yokoseki et 

 al., 1956). Studies of seafood preservation using a modified atmosphere 

 of CO2 showed that the lower internal pH of the tissue was due to exposure 

 of the external COj present and resulted in a rapid acidification of the 

 internal cellular environment (Aickin and Thomas, 1975; Boron and DeWeer, 

 1976; Thomas, 1974; Thomas and Ellis, 1975; Turin and Warner, 1977). 

 Intracellular and extracellular acidification of tissue could produce an 

 antimicrobial effect and also influence many different enzymatic 

 activities (Parkin et al . , 1981). SCF possesses physicochemical 

 properties intermediate between those of liquids and gases which enhance 

 its efficacy as solvents; the higher gas density gives good solvent power, 

 while the lower viscosity and higher diffusivity provide the SCF with 

 higher gas permeability (Rizvi et al . , 1986). Carbon dioxide is used as 

 a solvent for SCF because it is nontoxic, nonflammable, inexpensive and 

 readily available (Hardardottir and Kinsella, 1988) and it has a 

 relatively low critical temperature (33.1°C) and pressure (72 atm) (Rizvi 

 et al., 1986). Eldridge et al . (1986) reported that SCF produced minimal 

 detrimental effects on the functional properties of proteins. The 

 application of SCF using CO2 as a solvent in seafood processing could be 

 a benefit because it possesses characteristics of antimicrobial action, 

 lipid (cholesterol) reduction, and enzymatic inhibitory activities. 



,.v.;; 



