Process waters generated during production of acid marinated and old fashion marinated herring at the primary and the secondary producers were subjected to compositional analyses and fractionation. Samples were taken whilst storing, filleting, brining and marinating herring. The strategies followed a targeted approach for specific process water streams. Ceramic membrane technology (Utrafiltration, UF) as well as electrochemistry (Electrofloculation, EF) were tested separately and in combination to recover biomolecules from the richest process waters. The performance of the two technologies UF & EF were compared and the most promising technology (UF) was scaled up and investigated further at the pilot scale on site for selected process waters.

Compounds such as fatty acids, protein, peptides amino acids, vitamins, trace elements, salt and pH were quantified in the process waters before and after the EF and UF separation treatments. In two studies, fractions recovered during UF-treatment were separated further and characterized for peptides, polyphenols and antioxidant capacity in vitro (test tubes) and in food systems as herring glazing agents or as additives in herring mince. The quality of the fractions was also estimated by performing a selection of functionality tests including emulsifying, and foaming properties. Permeates from UF-separation were considered for biotechnological applications since they are highly dense in nutrients. Experiments were performed to evaluate the fractions as growth media for microalgae. The cost for implementing UF using ceramic membranes was investigated. A full cost benefit analysis was performed aligned with the cost of technology installation and the cost of effluent discharge and treatment. In addition the market potential for recovered biomolecules in the Nordic countries was evaluated for herring producers and for other fish feed or food processing companies.