Monitoring of the quality change of cherry tomatoes during storage is very important for the quality control of cherry tomatoes. In this study, the soluble solids content (SSC), reducing sugars (RSs), titratable acids (TAs), ascorbic acid (AA) and lycopene of cherry tomatoes during storage at 0, 4, 10 or 25 °C were measured, and the kinetic models were established. The results showed that the zero-order reaction combined with the Arrhenius kinetic model could be used for the prediction of changes in SS, RS and AA content. The first-order reaction combined with the Arrhenius kinetic model could be used for the prediction of changes in the TA and lycopene content. The volatile compounds of cherry tomatoes were simultaneously determined by the gas chromatography–mass spectrometry (GC–MS) and electronic nose (E-nose). A total of 104 volatile compounds were identified by GC–MS. Orthogonal partial least squares discriminant analysis (OPLS-DA) showed that there were 13 different metabolites among cherry tomatoes with different freshness. The accuracies of Fisher’s models based on E-nose for discriminating freshness of cherry tomatoes stored at 0, 4, 10 and 25 °C were 96%, 100%, 92% and 90%, respectively. This study provides a theoretical basis for the quality control of cherry tomatoes during storage.
A new method combining ultraviolet (UV) spectrophotometry and MoO 3−x nanosheets was developed for the rapid and accurate determination of ascorbic acid (AA) content in fruit and vegetables in this study. MoO 3−x nanosheets were prepared by the liquid exfoliation method using AA as the reducing agent, and the content of AA can be determined by a UV spectrophotometer. Experimental conditions for the MoO 3−x nanosheet method, including grinding time, ethanol concentration, sonication time, and water bath temperature were also optimized.The morphology of MoO 3−x nanosheets was characterized by atomic force microscope. The results showed that the average thickness of MoO 3−x nanosheets was 2.1-5.8 nm. The MoO 3−x nanosheets method had a good linearity in the AA concentration range of 0.01-0.05 mg/ml (R 2 = 0.9996). The limit of detection was 0.031 µg/ml, and the limit of quantitation was 0.095 µg/ml. The spiked recoveries were in the range of 88.79%-116.76%. The MoO 3−x nanosheets method was validated for the determination of AA content in five different fruit and vegetables samples with relative standard deviations less than 2%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.