草鱼冷藏过程中新鲜度的综合评价

为研究养殖草鱼冷藏过程中的鲜度变化，以菌落总数、挥发性盐基氮（total volatile basic nitrogen，TVB-N）含量、pH值以及表征新鲜度的K、Ki、Fr、G、H、P值为指标，并结合电子鼻分析其新鲜度。结果表明，草鱼4 ℃冷藏过程中，随贮藏时间的延长，菌落总数和TVB-N含量呈增长趋势，与贮藏时间分别呈极显著相关
（r=0.977）和显著相关（r=0.897）；K、Ki、Fr、G值和P值均与贮藏时间呈极显著相关，相关系数r分别为0.955、0.953、－0.953、0.958和0.957；H值和pH值与其他实验指标相关性均不显著。菌落总数、TVB-N含量、K值及相关值（H值除外）和电子鼻结果能有效区分不同贮藏时间的草鱼。电子鼻检测结果和K值及相关值（H值除外）较菌落总数和TVB-N含量对新鲜度评价更为灵敏，pH值和H值不适宜作为冷藏草鱼的新鲜度评价指标。4 ℃冷藏条件下的草鱼，货架期为8 d，12 d后不可加工和食用。

Comprehensive Freshness Evaluation of Grass Carp (Ctenopharyngodon idellus) during Refrigerated Storage

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.