Volume 6
Issue 1
Food Science and Technology
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Available Online: http://www.ejpau.media.pl/volume6/issue1/food/abs-10.html
CHANGES IN HEADED AND GUTTED BALTIC HERRING DURING IMMERSED SALTING IN BRINE WITH THE ADDITION OF ACETIC ACID PART 2. INTENSITY OF PROTEOLYSIS
Edward Kołakowski, Bożena Bednarczyk
ABSTRACT
The amount of and changes in the products of protein hydrolysis (TCA-soluble and TCA-insoluble biuret positive products, brine extractable protein, non-protein nitrogen, amino acid nitrogen and others) were examined in salted flesh of headed and gutted Baltic herring immersed in 16% NaCl brine with the addition of acetic acid (0, 1, 2, 3, 4, 5, 6, 7%), as well as in brine itself, after one and two weeks of storage at a temperature of 8 ± 1°C. The addition of acetic acid into brine accelerated proteolysis in flesh noticeably, at the same time retarding diffusion of muscle protein into brine. After the first week of fish maturation, the maximum proteolysis was observed at a pH of 3.8, and after the second week of maturation—at a pH of 4.2 to 4.8. Within a more acidic pH range, TCA-soluble products prevailed in flesh, with a minimum share of TCA-precipitated brine extractable protein, while in a less acidic range there were proportionately more products from the latter group, even t
Key words:
Baltic herring, immersed salting, acetic acid addition, pH vs. proteolysis.