PROPERTIES OF THE ARGENTINE ANCHOVY AND WHITEMOUTH CROAKER MUSCLE PROTEINS OBTAINED BY ALKALI SOLUBILIZATION PROCESS

The aim of this study was to evaluate functional properties and microbiological characteristics of recovered proteins of anchovy (Engraulis anchoita) and whitemouth croaker (Micropogonias furnieri) through the process of alkaline solubilization and isoelectric precipitation, using different solubilization at pH 11 (NaOH and KOH) and precipitation at pH 5.5 (HCl and H3PO4) reagents. Analyses of water holding capacity were carried out (at pH 3,5,7,9 and 11), oil holding capacity and Salmonella sp, Escherichia coli and Staphylococcus aureus. The water holding capacity was lowest at pH 5. The low value of the proteins recovered by alkaline solubilization process also indicates changes in the protein. The highest oil holding capacity was observed in whitemouth croaker concentrates (NaOH/H3PO4) at 5.6 ml oil. g protein(-1). As for microbiological analyses, results showed no Salmonella in 25 g for all treatments and maximum count of 2.75 x 10(2) CFU.g(-1) for coagulase positive Staphylococcus for the muscle of anchovy concentrated. The protein concentrate obtained by combining NaOH/H3PO4 showed better functional quality. This process is an alternative to recover fish protein of low commercial value that may be used as an ingredient in foods.