Effect of different post-harvest storage conditions and heat treatment on tomatine content in commercial varieties of green tomatoes

Green tomatoes are rich in tomatine (a natural mixture of α-tomatine and dehydrotomatine, in the 10:1 ratio), which has been shown to have many beneficial effects on human health. The content of tomatine depends on several factors including tomato variety, agricultural processing and post-harvest storage conditions. In the present study, the quantification of α-tomatine and dehydrotomatine contents was performed by reverse phase liquid chromatography, coupled with electrospray ionization tandem mass spectrometry (RP-HPLC-ESI-QqQ-MS/MS), in three commercial varieties (Camone, Merinda, Nerina), post-harvest ripened fruits, which were stored at different temperatures (22 ± 2, 10 ± 1 and -20 ± 1 °C). Data showed that the tomatine concentration decreased as the maturity stage increased. On the other hand, there was an increase observed for long storing periods, after mold occurrence, and a few days at -20 ± 1 °C storage temperature. The content of the two glycoalkaloids in green Camone fruits that underwent heat treatment simulating industrial processing conditions (boiling procedure at 100 °C) showed that thermal treatment did not modify the total tomatine content.