Nondestructive and Rapid Assessment of Intact Tomato Freshness and Lycopene Content Based on a Miniaturized Raman Spectroscopic System and Colorimetry

摘要

Tomatoes and tomato-related products are associated with many health benefits and disease risk reduction. This work was to explore the use of a miniaturized Raman spectroscopic system for rapid and nondestructive quality assessment of intact tomatoes. Combined with colorimetry and spectrophotometry methods, surface color and lycopene content of intact tomatoes were measured as references. The ratio of two chromaticity indices a*/b* of tomato surface increased when their freshness declined; the correlation coefficient (r) of the second-order polynomial curve-fitting was 0.908. The freshness discriminant model developed on Raman spectra gave a correctness of 85.6 %. The quantitative models performed poorly for predicting lycopene content based on Raman spectra. From the results obtained, it can be concluded that the established miniaturized Raman spectroscopic system was feasible for assessing the freshness of intact tomatoes. However, it is difficult to predict the lycopene content accurately.