基于电子鼻对水蜜桃货架期评价的研究

利用PEN3 电子鼻系统对早熟“久保”水蜜桃采后7d 货架期内的芳香成分进行检测分析，先通过电子鼻系统动态采集水蜜桃芳香成分并得到了电子鼻的响应值，再利用PCA(主成分分析)、LAD(线性判别)模式识别方法进行数据分析。结果表明LDA 方法能够更好地区分第1 天、第2～4 天和第5～7 天货架期的水蜜桃，进行交叉确认分析后，对第1 天、第2～4 天和第5～7 天的水蜜桃货架期区分准确率达91%，同时采用负荷加载(Loading )分析方法可以得知，传感器W1S(甲烷)、W2S(乙醇)、W2W(硫化氢类)对水蜜桃货架期的评价起主要作用，这为进一步优化传感器以及探索方便快捷的水蜜桃无损检测技术提供了依据。

Freshness Evaluation of Juicy Peach by Electronic Nose

In this study, a portable electronic nose PEN3 was used for the aroma analysis of Jiubao juicy peach, an early-ripening cultivar in order to provide experimental references for the evaluation of its freshness. Dynamic aroma sampling was achieved using PEN3 and the response values of the instrument were obtained. This was followed by data analysis using principal component analysis (PCA) and linear discrimination analysis (LDA). The results showed that the use of LDA was able to better discriminate peaches on the 1st, 2nd to 4th, and 5th to 7th days of postharvest storage in polyethylene bags under the conditions of (20 ±0.5 )℃ and 65%－70% relative humidity. According to cross-validation analysis, the discrimination accuracy among these samples stored for different storage periods was as high as 91%. Meanwhile, it was indicated by loading analysis that sensors W1S, W2S and W2W played a central role in evaluating the freshness of juicy peach, which provides useful evidences for the optimization of sensors and exploration into a simple and convenient non-destructive technique for the evaluation of juicy peach freshness.