Industrialization of sauerkraut production in Poland will need to solve the problem associated with disposing of highly acidic waste effluents. Late sauerkraut brine present the greatest problem with respect to treatment because of their high BOD and low pH. Degradation rate of sauerkraut brine by Kluyveromyces marxianus yeast - depends on concentration of the brine in the medium. The removal of lactic acid in shake flask experiments varied from 98.95 to 56.75 % after 48 h at 30°C. The immobilization of yeast in sodium alginate improved the lactic acid degradation rate and allow to treat the very acid brine directly. Lactic acid was fully used in diluted brine in 24 h and the content in undiluted brine was reduced by 90.17 to 81.2 to % in the following runs after 48 h.
Headed and gutted Baltic herring were immersed in 16 % brine containing 0, 1, 2, 3, 4, 5, 6 or 7 % acetic acid. Weight ratio of fish to brine was 1:1. Samples were stored for two weeks at a temperature of 8 ± 1°C. Changes were investigated in fish weight, weight and volume of brine, pH of flesh and brine, color parameters of flesh and its sensory properties after one and two weeks of maturation. It was demonstrated that fish brined in a 16 % solution of NaCl with an addition of 1% acetic acid were of the best quality. In the flesh of these fish, no sour (briny) flavor could be detected, and the delicate, slightly elastic, texture was evaluated as very desirable. The addition of acetic acid into the brine improved the lightness of flesh substantially; at the same time, however, it increased weight losses of fish after brining, mainly on account of a decrease in the water content in fish flesh.