Study on the Effects of Modified Atmosphere Packaging on the Freshness of Chimonabambusa quadrangularis Shoot Based on Principal Component Analysis

Different modified atmosphere packaging bags combined with low temperature treatment were used to store and preserve freshness of Chimonabambusa quadrangularis shoots to investigate the optimal preservation process of freshness of Chimonabambusa quadrangularis shoots. The freshness of Chimonabambusa quadrangularis shoots were stored in four different modified atmosphere packaging bags (WK, PE20, PE30, PE40) for 50 d in a cool storage facility at (1.0±0.3) ℃. The respiration intensity, hardness, browning index, polyphenols, soluble protein, PAL and POD of freshness of Chimonabambusa quadrangularis shoots were measured by sampling every 10 d during storage. And the effect of preservation of freshness of Chimonabambusa quadrangularis shoots by different modified atmosphere packaging bags was analyzed by combining with principal component analysis. The results showed that: PE20 could effectively reduce the respiration intensity of freshness of Chimonabambusa quadrangularis shoots, inhibit the rise of hardness, delay the change of total color difference value of fresh bamboo shoots, and inhibit the rise of decay rate, browning index, POD activity and PAL activity during storage of fresh bamboo shoots. The nutrients (V_C, soluble protein) of freshness of Chimonabambusa quadrangularis shoots were maintained at a high level. Principal component analysis showed that respiration intensity, medium hardness, and decay rate were the key indicators affecting the freshness of Chimonabambusa quadrangularis shoots. The results of the analysis were subjected to a composite evaluation score, and the composite evaluation score of PE20 packaging at 50 d was higher than that of the other three modified atmosphere packages. The combined index determination and principal component analysis concluded that the treatment with modified atmosphere packaging bags of PE20 was the most effective in preserving freshness of Chimonabambusa quadrangularis shoots.