These free ribose data parallel the visual ob- 

 servations of the progression of the browning; 

 of the snapper flesh. The flesh of the TDP 

 treated fillets, when visually observed, was con- 

 sistently lighter in color at each draw than the 

 flesh of any of the other fillets. 



Taking into account the ribose data, organ- 

 oleptic scores, and visual observations of the 

 progression of browning, the TDP treated fil- 

 lets showed a much better inhibition of brown- 

 ing, as well as preservation of overall quality, 

 than fillets treated with other chemicals. The 

 foregoing combination of observations indi- 

 cates that browning in snapper flesh is that of 

 the Maillard type. 



The skin color deterioration of frozen snap- 

 per fillets is an oxidative process whereby the 

 red skin pigment of snapper, astaxanthin, is 

 converted to astacene or further degradation 

 products. The red pigment in marine fishes 

 is predominantly astaxanthin (Tsukuda and 

 Amano, 1966). In an earlier experiment con- 

 ducted at this laboratory, several of the more 

 common antioxidants used in the food industry 

 were applied to snapper fillets (Love and 

 Thompson, 1969). Application of these anti- 

 oxidants deters the fading of the skin color 

 for only a few months. In the present exper- 

 iment, however, packaging the fillets in Cryo- 

 vac vacuum-sealed plastic bags inhibited the 

 oxidative process sufficiently to increase the 

 frozen storage shelf life to 12 months. After 

 this period, a slight discoloration or fading of 

 the red pigment was noted. This indicated 

 that the oxidative process which converts the 

 red pigment, astaxanthin, to astacene or prod- 

 ucts further down the degradation chain is not 

 entirely due to the presence of air. Enzymatic 

 oxidation also probably plays an important role 

 in the skin color deterioration of red snapper. 



The application of TDP to red snapper fillets 

 followed by Cryovac vacuum packaging and 

 subsequent freezing of the product results in 

 a superior quality product for a 12-month 

 storage period. The TDP can be applied by 

 either dipping or injecting the fillets as was 

 shown by previous experiments at this labora- 

 tory (Thompson and Thompson, 1969) . Either 

 method of application produces the same re- 

 sults. This treatment is by no means a "cure- 

 all" for the snapper industry, but it is a be- 

 ginning since the previous storage life of a 



frozen snapper fillet was somewhere between 

 1 and 3 months. 



LITERATURE CITED 



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