Freshness is a key indicator for assessing the nutritional and safety qualities of fish products. This study aims to apply the convolutional neural network (CNN) for modeling the Raman spectra data, for the rapid classification of the freshness grades of sea bass ( Lateolabrax japonicus ) fillets. Results suggested that the classification accuracy of CNN model was superior to principal component analysis (PCA), partial least squares discriminant analysis (PLS-DA), and support vector machine (SVM) based on Raman spectra data. In addition, analysis of variance (ANOVA) was demonstrated effective for extracting the Raman spectral features for CNN modeling. Based on the feature-selected CNN model using ANOVA, the average accuracy for identifying sea bass fillets freshness was improved to 90.6% and the testing time was reduced to 0.44 s. In particular, the classification accuracy for the second-grade freshness was significantly improved to 80.2% compared with the CNN model with full-band Raman spectra. This research provided an exemplar for combining the portable Raman spectrometer with deep learning for the rapid and non-destructive analysis of food quality.
There has been a growing interest in employing active films for fish preservation due to the environmental concern of plastic packaging and the high perishability of fish. This work aimed to develop active films (CPB 0.8 ) based on chitosan/polyvinyl alcohol integrated with ginger essential oil (GEO) -loaded bacterial cellulose, and to evaluate the preservation effect of the films on refrigerated sea bass fillets. Different active films were obtained by the solution blending method. It was evaluated by measuring microbiological indicators, physicochemical indexes, and water loss of sea bass fillets. The sample wrapped by CPB 0.8 film had a lower microbial load after 12 days of storage. The results showed that the sample wrapped by CPB 0.8 film had a lower microbial load after 12 days of storage compared to the active film sample without GEO and the control sample. Besides, the reduction of hardness and springiness of fillets packaged with CPB 0.8 film was markedly inhibited. Additionally, the fillets wrapped by CPB 0.8 film indicated a lower K-value (56.54%) under the rejection limit (60%) on the 10th day, which confirmed that CPB 0.8 films extended the shelf-life of fillets to 10 days. Also, the active packaging could preserve fish quality by controlling water migration and lipid oxidation. Overall, these findings indicate that CPB 0.8 films can be useful for the preservation of fish and effectively reduce petroleum-based plastics.
危险品化学品经营许可证（带存储）