基于主成分分析验证气调对番茄品质的影响

研究低温环境下不同体积分数的混合气体对番茄感官品质、营养价值的影响。以番茄作为试验研究对象，通过预冷处理，选择开孔率5%的聚乙烯食品包装袋包装，放在温度为8 ℃ CO2体积分数为6%的气调箱内，用N2调节O2体积分数为2%、4%、6%、8%和10%。每隔2 d检测一次番茄品质（质量损失率、色差L*值、TSS、TA及主观评价）之后对6个评价指标进行标准化处理，采用主成分分析法建立得分函数，并用传统感官评价验证得分模型。试验研究表明：4% O2+6% CO2气调环境下番茄各项指标可以维持较好的水平。综合函数评价得分显示在长期气调保鲜过程中，低氧环境有利于番茄保持较高品质。传统感官评价方式与综合函数有一致性。主成分分析法表明4% O2+6% CO2的气调环境下具有较高的得分水平，可以显著维持保鲜过程中番茄的营养价值，并延长气调保鲜周期。

Impact of Air on the Quality of Tomato Based on Principal Component Analysis and Validation

The effects of mixed gases with different volume fractions in the low temperature environment on the sensory quality and nutritional value of tomato were studied. Tomato was used as the experimental model, and the samples were processed by precooling treatment, packed in polyethylene food packaging bags with an open cell content of 5%, and placed in a controlled atmospheric chamber at 8°C with the carbon dioxide volume fraction of 6%. Nitrogen was used to adjust the oxygen volume fraction at 2, 4, 6, 8, or 10%. After the quality indexes of tomato (weight loss rate, color difference L* value, total soluble solids (TSS) content, titratable acidity (TA), and subjective evaluation) were measured every two days, the data of six evaluation indexes were processed by a standardized method, principal component analysis (PCA) method was used to establish the score function, and the traditional sensory evaluation was performed to validate the score model. The experimental results showed that the indexes of tomato could be maintained at a good level under 6% carbon dioxide+4% oxygen controlled atmospheric environment. The comprehensive function evaluation score indicated that in the process of long-term preservation under controlled atmosphere, the low oxygen environment was conducive for the maintenance of the high quality of tomato. The results from the traditional sensory evaluation method were consistent with those from the comprehensive function analysis. The PCA method indicated that the 6% carbon dioxide+4% oxygen controlled atmospheric environment had a relatively high score level, and could maintain the nutritional value of the tomato during the preservation and thereby improve the preservation quality.