tion. These chemicals can also be applied to 

 fillets by a dipping- or injection technique as 

 was demonstrated by this laboratory (Thomp- 

 son and Thompson, 1969). 



Packaging. — All fillets were separately 

 packaged in vacuum-sealed Cryovac plastic 

 bags. 



Storage. — ■ All fillets were stored in a 

 —10° F (—23.3° C) freezer until analyzed. 



Table 1 .--Organoleptic scores for cooked snapper fillets stored 

 at -10° F.JV 



_1/Values presented are averages of scores given for appearance, 

 taste, and texture based on a 5-point scale. 



Organoleptic Evaluation of Fillets 



Fillets were evaluated organoleptically by an 

 8-member expert taste panel at the end of 1, 3, 

 6, 9, and 12 months of frozen storage. The 

 fillets were scored on appearance, taste, and 

 texture. The scoring method consisted of giv- 

 ing a score of from 5 for excellent to for in- 

 edible. 



Table 2. --Appearance scores for cooked snapper fillets stored 

 at -10° F.i/ 



iyvalu.es presented are averages of scores given for appearance 

 by taste panel members based on a 5-point scale. 



Chemical Methods 



Total ribose determination. — Total ribose 

 was extracted from minced snapper flesh ac- 

 cording to the method of Sinnhuber (1966). 

 Total ribose content of the extract was deter- 

 mined by the orcinol method of Mejbum 

 (1939). Heating time was increased to 45 

 min as modified by Albaum and Umbreit 

 (1947). 



Free ribose determination Free ribose 



was extracted from minced snapper flesh ac- 

 cording to the method of Sinnhuber (1966). 

 Bound ribose was removed from this extract 

 using Dowex ion exchange resins according to 

 the method of Tarr and Leroux (1962). Free 

 ribose was then determined by the orcinol meth- 

 od of Mejbum (1939) using an increased heat- 

 ing time of 45 min as modified by Albaum and 

 Umbreit (1947). 



RESULTS 



Organoleptically the glutathione treated fil- 

 lets received the best average score (4.7) at the 

 end of 1 month of storage (Table 1). By the 



Table 3. --Free and total ribose content of snapper flesh stored at 

 -10° ?M 



_1/Values presented are averages of duplicate samples. 

 ^'Sample was lost. 



end of 3 months of storage, the control, gluta- 

 thione, and the Na-FDTA + PG treated fillets 

 all received an average score of 4.0. Not until 

 the 6 month draw was there a considerable dif- 

 ference in organoleptic scores observed. Then 

 both the TDP and glutathione treated fillets 

 received a score of 3.8 while the control fillets 

 received a score of 3.2. By the end of 12 months 

 of storage the TDP treated fillets received the 

 highest score (2.7) while the NA 2 EDTA + PC, 

 treated fillets received the lowest score (1.8). 

 After averaging scores for appearance only 

 (Table 2), the TDP treated fillets received the 



