Use of exogenous enzymes to elaborate the Roman fish sauce 'garum'

A fermented fish sauce, which tries to imitate the ancient Roman 'garum', was developed from tuna (Tunnus thynnus) liver and mackerel (Scomber scombrus). Exogenous proteolytic enzymes were used to accelerate the elaboration process, and various fermentation technological parameters (salt percentage, temperature, enzyme dose, continuous stirring) were assayed in order to optimise the process and obtain the best yield. Best conditions were 10% salt (5% added at the start of the process and the 5% after 24 h of fermentation), 35-37degreesC and Neutrase (an endoprotease from Bacillus subtilis) at 0.125 Anson Units per 100 g. The fermentation process was carried out in 48 h. The obtained product (filtered and diluted with a guar gum solution) was a thick sauce with 21 mgNg(-1), 5.9% salt and 10% fat. The lipidic fraction showed a very interesting fatty acid profile, especially in relation to its omega-3 fatty acids (PUFA/SFA ratio 0.98; 4.2 g eicosapentaenoic acid and 11.3 g docosahexaenoic acid per 100 g fat). The developed garum was rather different from fish sauces that are manufactured nowadays in South East Asian countries. (C) 2001 Society of Chemical Industry.