Abstract Lycopene, the red colored carotenoid in tomatoes, has various health benefits for humans due to its capability of scavenging free radicals. Traditionally, the quantification of lycopene requires an elaborate extraction process combined with HPLC analysis within the laboratory. Recent studies focused simpler methods for determining lycopene and utilized spectroscopic measurement methods. The aim of this study was to compare non-destructive methods for the prediction of lycopene by using color values from colorimeter measurements and Vis/NIR spectra recorded with three commercially available and portable Vis/NIR spectrometers, so called food-scanners. Tomatoes of five different ripening stages (green to red) as well as tomatoes stored up to 22 days after harvest were used for modeling. After measurement of color values and collection of Vis/NIR spectra the corresponding lycopene content was analyzed spectrophotometrically. Applying exponential regression models yielded very good prediction of lycopene for color values L*, a*, a*/b* and the tomato color index of 0.94, 0.90, 0.90 and 0.91, respectively. Color value b* was not a suitable predictor for lycopene content, whereas the (a*/b*)² value had the best linear fit of 0.87. In comparison to color measurements, the cross-validated prediction models developed for all three food-scanners had coefficients of determination (r²CV) ranging from 0.92 to 0.96. Food-scanners also can be used for additional measurements of internal fruit quality, and therefore have great potential for fruit quality assessment by measuring a multitude of important fruit traits in one single scan.

中文翻译：

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色度计和不同便携式食品扫描仪用于无损预测番茄果实中番茄红素含量的比较

摘要 番茄红素是西红柿中的红色类胡萝卜素，由于其清除自由基的能力，对人体具有多种健康益处。传统上，番茄红素的定量需要在实验室内结合 HPLC 分析进行复杂的提取过程。最近的研究侧重于确定番茄红素的更简单的方法，并利用光谱测量方法。本研究的目的是通过使用色度计测量的颜色值和三个市售和便携式 Vis/NIR 光谱仪（所谓的食品扫描仪）记录的 Vis/NIR 光谱来比较预测番茄红素的非破坏性方法。五个不同成熟阶段（绿色到红色）的西红柿以及在收获后储存长达 22 天的西红柿用于建模。在测量颜色值和收集 Vis/NIR 光谱后，通过分光光度法分析相应的番茄红素含量。应用指数回归模型可以很好地预测番茄红素的颜色值 L*、a*、a*/b* 和番茄颜色指数分别为 0.94、0.90、0.90 和 0.91。颜色值 b* 不是番茄红素含量的合适预测指标，而 (a*/b*)² 值的最佳线性拟合为 0.87。与颜色测量相比，为所有三种食物扫描仪开发的交叉验证预测模型的决定系数 (r²CV) 范围从 0.92 到 0.96。食品扫描仪还可用于额外测量内部水果质量，因此通过在一次扫描中测量多种重要水果性状，在水果质量评估方面具有巨大潜力。