Chemical and sensory changes associated Yu-lu fermentation process – A traditional Chinese fish sauce

The production of ‘Yu-lu’, a Chinese traditional fermented fish sauce, was replicated in the laboratory with little adaption in order to study the chemical, microorganism and sensory changes associated with the process. Yu-lu was made by incubating mixtures of small anchovies and 30% salt (salt/fish, w/w) at 30 ± 5 °C for 180 days, then rising the incubation temperature to 50 °C for 7 days. Changes in total soluble nitrogen (TSN), TCA (trichloroacetic acid) soluble peptides, formaldehyde nitrogen, total acid, total volatile base nitrogen (TVB-N), trimethylamine nitrogen (TMA-N), composition of amino acid, the non-enzymatic browning index and total plate counts of Yu-lu were observed. TSN, formaldehyde nitrogen, TCA soluble peptides, total titratable acid and non-enzymatic browning index increased throughout the fermentation period. Glutamic acid, lysine, leucine and valine were prominent in Yu-lu. The results from QDA test showed that incubation after 180 days for a week can accelerate the flavor formation of Yu-lu.