Effect of technological processing on the safety of Indian mackerel (Rastrelliger kangurata) from Suez, Egypt

Abstract

This study investigated the effect of different fish processing technologies on the bacteriological safety and heavy metal contents of Indian mackerel fish products. Mackerel was processed by salting (dry salt 15%), hot marinating (2.5% acetic acid and 3% NaCl) or canning (hot vegetable oil, brine 3% or tomato sauce 8%). Fresh, chilled fish from the local market had an aerobic colony count of 5.1± 0.2 logs CFU/g and the presence of Salmonella enterica was confirmed using API diagnostics and 16S rDNA. Marination and salting resulted in 4 and 1.3 logs CFU/g reduction in aerobic colony counts, respectively. Canning eliminated all viable bacterial growth, regardless of filling medium (vegetable oil, brine or tomato sauce). Processing technologies had no effect on the heavy metal (Hg, Cd, Pb, and Cu) content of the fish products.The estimated daily and weekly intake values of Pb and Cd from fresh fish and their products were below the recommended safety regulations. Canning, followed by marination, were the safer options for the preservation of Indian mackerel (compared to salting).