Aroma Evaluation of Transgenic, Thaumatin II‐Producing Cucumber Fruits

Abstract

Fruits of transgenic cucumber lines expressing preprothaumatin II gene were evaluated concerning their aroma. Four homozygous lines, that is, 210 06, 212 01, 224 09, and 225 03 with different levels of transgene expression were selected. Recipient line cv. Borszczagowski, which was formed by inbred line of Cucumis sativus L., was used as a control. The experiment was carried out in a greenhouse and an outdoor experimental plot. The aroma of cucumber fruits was evaluated by GC/MS, as well as GC/MS/TOF in the distillates and by SPME. Irrespective of the isolation/separation technique used, the differences between aroma compounds in transgenic cucumbers and the control were quantitative, and not qualitative. Modified samples showed higher concentrations of volatiles, particularly of the main cucumber fruits odorant (E, Z)-2,6 nonadienal. Transgenic expression of the thaumatin II gene resulted not only in a sweeter taste of fruits in comparison with the control, but also higher aroma acceptability. This was shown by sensory profile analysis. Also electronic nose measurements differentiated between transgenic lines and the control.

Application of high‐pressure argon for improving postharvest quality of cherry tomato

“…Fruit and vegetables can produce aroma volatile compounds to form characteristic flavor, which are associated with quality changes during storage (Zawirska‐Wojtasiak, Gośliński, Szwacka, Gajc‐Wolska, & Mildner‐Szkudlarz, ). GC–MS is a typical method for volatile organic compounds, and has been applied well in various food analyses (Lee, Jeong, & Ku, ; Sun, Zhang, Chen, Zheng, & Fang, ).…”

Foodomics strategies for the analysis of transgenic foods

“…In another study on the profiles of aroma compounds of four lines of GM cucumber using GC-MS, solid-phase microextraction provided better results in terms of number of extracted volatile compounds than microdistillation [90]. The analysis of cucumber extracts using GC-EI-Q-MS and GC-EI-TOF-MS suggested that the significant differences found between GM and non-GM varieties were quantitative rather than qualitative, regardless of the MS-based technique used.…”

Metabolic engineering of aroma components in fruits

“…In cucumber (Cucumis sativus), the concentration of the volatile that mainly contributes to its aroma, (E, Z)-2,6 nonadienal (Table 1), was increased by overexpressing preprothaumatin II (thaumatin II is initially translated as preprothaumatin with peptides in C terminus that are cleaved off when the protein matures). Transgenic fruits presented a higher sensory perception of fruit flavor and increased levels of this aldehyde and other volatiles [66].…”