summarizes the characteristics of the commercial proteases
as well as the composition of the fish powder used as
starting materials to produce fish-like aromas. Fish powder (100 g/L
in water) was hydrolysed for15 h at constant stirring, under
controlled conditions of temperature and pH (60 C at pH 6). The
reactionwas terminated by heating the mixture at 95 C for 20 min
in a water bath. Each protease used was added so all mixtures had
the same enzymatic activity per gram of sample. The conditions of
pH, temperature and time of reaction, as well as the enzymes and
their combinations were selected based on the combination of
those parameters that resulted in the higher concentration of free
amino acids in a preliminary experiment (data not shown). The
resulting slurries were centrifuged at 8000 g for 20 min and aliquots
were analysed to determine the degree of hydrolysis (DH)
and amounts of free amino acids.