Identification and characterisation of headspace volatiles of fish miso, a Japanese fish meat based fermented paste, with special emphasis on effect of fish species and meat washing

The present study investigated the suitability of four species of trash fishes for the production of fish miso, a Japanese fermented fish meat paste compared with soy and rice miso from the point of view of product aroma. The effect of washing fish meat on finished product was also evaluated. Headspace volatiles for different miso samples were analyzed by using solid phase microextraction (SPME) technique. A total of 107 volatile compounds have been identified, where 94 were common for all the miso samples. Considering the lower threshold perception and higher odour active values 2-methylbutanal, 3-methylbutanal, methional, isoamyl acetate, dimethyl disulfide, dimethyl trisulfide, 2,3-butanedione, 3-methylethyl butanoate, 3-methyl-1-butanol, ethyl hexanoate, 1-octen-3-ol, heptanol, heptanal and 2-undecanone were identified as key compounds for the miso products. Principal components analysis (PCA) and hierarchical cluster analysis (HCA) of headspace volatiles clearly elucidated the relationship amongst different miso samples based on fish species and effect of fresh water washing of meat on aroma of finished product.