Evaluation Of E. Car Inicauda Freshness Based On Electronic Nose Technique

As the conventional methods for aquatic freshness detection are so tedious and time-consuming that it is difficult to employ them for real-time aquatic freshness detection in our daily life. So, there is a great need to establish a method which is simpler, faster, more scientific and objective. In this paper, the electronic nose was used to evaluate odor changes of E.carinicauda with different freshness during storage at4℃. The model predicting the freshness changing rates of E.carinicauda based on odor model was established.1. Sensory evaluation and physico-chemical inspection methods were used to detect the E.carinicauda of different storage time. The changes of color, pH, TVB-N, colony count of E.carinicauda during the storage were investigated.2. Some experiments were carried out in advance to optimize the paramenters of the operation. In different conditions(different temperature, headspace volume, sample quantity and headspace generation time), samples in different freshness were detected by electronic nose, and the data were analyzed by PCA and variance analysis, and the optimal paramenters were:temperature20℃, space250mL, sample quantity10g, holding time10min.3. In this paper, to analysis odors in E.carinicauda during storage time by solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS).45volatile compounds were identified by comparing their mass spectra with those contained in the NIST mass spectral database,4kinds of acids,8kinds of nitrogen compounds,37kinds of hydrocarbons,6kinds of alcohols,2kinds of ketones,2kinds of phenolic,4kinds of sulfur compounds and heterocyclic compounds were detected. In addition the chemicals found to correlate best with spoilage were trimethylamine (TMA), dimethyl sulfide, and indole over a period of7days.4. The electronic nose was used to evaluate odor changes of E.carinicauda with different freshness during storage at4℃. The model predicting the freshness changing rates of E.carinicauda based on odor was established. The result showed the samples of different freshness could be well distinguished by S6、S7、S8、S9、S10sensors of the electronic nose. The predicting model of freshness was feasible (accuracy≥95%). This study provides a new method for E.carinicauda freshness evaluation and its freshness can be predicted correctly by the model based on odor.