Abstract:

In order to evaluate the freshness of farmed grass carp stored at 4 ℃, changes in total viable count (TVC), total
volatile basic nitrogen (TVB-N), pH value, K value, and related values were investigated. Meanwhile, electronic nose was
used to analyze the volatile components. The results showed that total viable count and TVB-N value increased gradually
during storage and these changes were correlated with storage time. The values of K, Ki, Fr, G and P firstly increased and
then stabilized. These changes were correlated significantly with storage time with correlation coefficients of 0.955, 0.953,
－0.953, 0.958, and 0.957, respectively. Neither H value nor pH showed a significant correlation with each of the other
parameters . The TVC, K value and the other related values except H value of grass carp could be distinguished effectively
during different storage periods. Compared with TVC and TVB-N value, electronic nose as well as K value and the other
related values except H value were more sensitive to freshness evaluation, while pH value and H value were not appropriate
for the freshness evaluation. The shelf life of grass carp during 4 ℃ storage was 8 days, and fish samples stored for 12 days
reached the upper limit of processing and edibility.

Key words: grass carp, refrigeration, freshness