Effects of Some Antioxidants and EDTA on the Development 

 of Rancidity in Spanish Mackerel (Scomeromorus maculafus) 



During Frozen Storage 



by 



ROBERT N. FARRAGUT, Chemist' 



National Marine Fisheries Service 



Fishery Products Laboratory 



Pascagoula, Mississippi 39567 



ABSTRACT 



Spanish mackerel {Scomheromoriis maciilatus) were treated with antioxidant so- 

 lutions containing BHA and BHT (Tenox 4); BHA, BHT, PG, citric acid, and pro- 

 pylene glycol (Tenox6); Tenox 4 plus EDTA; Tenox 6 plus EDTA; Ca(Na)2EDTA; 

 (Na)2EDTA; (CA)2EDTA; and (Na)4EDTA both by dipping and injecting methods. 

 Samples analyzed at 3-month intervals showed fillets packed in vacuum and treated 

 with EDTA remained in good condition over the 12-month storage period. However, 

 samples treated with (Na)4EDTA remained superior to other samples throughout the 

 storage period. 



INTRODUCTION 



Spanish mackerel can be found in abundance 

 in waters from the Chesapeake Bay to Texas. 

 Early records indicate major landings of Span- 

 ish mackerel from the Chesapeake Bay during 

 the last part of the 19th century. Around the 

 turn of the century, landings declined in the 

 Chesapeake Bay area but increased in southern 

 Florida waters, where the fishery stabilized and 

 is presently located. The stocks are tremendous 

 but annual landings have remained in the 

 neighborhood of 8 million pounds for the past 

 18 years (Lyies, 1969). 



At present the commercial processing of 

 Spanish mackerel usually is limited to eviscer- 

 ation and freezing of whole fish. The fish are 

 usually marketed in this manner with only a 

 small percentage of the catch sold as boneless 

 fillets or steaks. Mackerel treated in this man- 

 ner begin to show signs of rancidity within as 



' Presently National Marine Fisheries Service, 

 Southeast Fisheries Center Miami Laboratory, Miami, 

 Fla. 33149. 



little time as a 3-month period and ai'e usually 

 rejected by taste panels between the sixth and 

 ninth month of storage. 



As good fish, Spanish mackerel have many 

 assets. The delicate flavor, the good yield of 

 edible boneless fillets, and their availability con- 

 tribute to the demand for good quality Spanish 

 mackerel. A major factor influencing in- 

 creased production and wider markets is the 

 rapid onset of rancidity that occurs prior to 

 and during frozen storage. 



The problem of rancidity in fish has been 

 studied for many years. Reports of the eflfect 

 of various antioxidants on the development of 

 i-ancidity in red spring salmon, haddock fillets, 

 herring, and other species show little or no in- 

 crease in shelf life over the controls. Typical 

 antioxidants used in these experiments included 

 BHT (butylatedhydroxytoluene),BHA (buty- 

 lated hydroxyanisole) , propylene glycol (Voss 

 and Munkmer, 1966), ethyl gallate, ascorbic 

 acid, and a-tocopherol (vitamin E). Castell 

 and Spears (1968) report the induction of ran- 

 cidity by minute quantities of trace minerals 



