Comprehensive Characterization of Fruit Volatiles and Nutritional Quality of Three Cucumber (Cucumis sativus L.) Genotypes from Different Geographic Groups after Bagging Treatment

Abstract

Bagging is widely practiced to produce high quality and unblemished fruit; however, little is currently known about the effect of bagging on flavor and nutritional quality of cucumber fruits. Here we determined the influence of bagging on fruit quality of cucumber (Cucumis sativus L.) using three genotypes from different geographic groups. Exocarp chlorophyll and carotenoid levels were significantly decreased by bagging, accompanied by color change. Ascorbate content in bagged fruits decreased to some extent, while contents of soluble sugars, starch, and cellulose were comparable with those of control fruits. Compositions related to fruit flavor quality could be enhanced largely through bagging treatment, with elevation of the relative proportion of C6 aldehyde, as well as (E,Z)-2,6-nonadienal/(E)-2-nonenal ratio, and linoleic/α-linolenic acid ratio. Lipoxygenase and hydroperoxide lyase, two key enzymes in the production of volatiles, displayed distinctive transcript expression patterns and trends in changes of enzymatic activity in the bagged fruits of different genotypes. Overall, this study assesses the information on changing characteristics of fruit volatile composition and nutritional quality among different cucumber genotypes after bagging treatment. Results of this study would contribute to providing reference for mechanism study and cultivation conditions to improve cucumber fruit flavor to a considerable degree.

Role of Lipids in Food Flavor Generation

“…However, various processing methods have a significant effect on the flavor profile of fruits and vegetables. Shan et al [ 44 ] reported that the bagging treatment enhanced the flavor quality of cucumbers, which were related to trans -2, cis -6-nonadienal, and trans -2-nonenal. Similarly, Lomelí-Martín [ 70 ] suggested that high hydrostatic pressure increased the content of aldehydes and ketones and decreased that of alcohols in the fruits and vegetables.…”

Association of Refreshing Perception with Volatile Aroma Compounds, Organic Acids, and Soluble Solids in Freshly Consumed Cucumber Fruit

“…Overall, the most dominant volatiles was (E,Z)-2,6-nonadienal, followed by (E)-2-nonenal, consistent with the literature. 24,29 Results also showed that different cucumber varieties could be differentiated by their volatile content shown in PCA (Figure 3), indicating that volatiles were linked to the genetics of cucumber. As aforementioned, literature specifically pertaining to cucumber volatile variety difference is very limited.…”

“…Information related to volatile profiles in diverse cucumber varieties in the literature is rare, and the literature has a focus on C6 and C9 aldehydes and alcohols. 19,24,25 Cucumber Volatiles and Variety Difference. Within the eight cucumber varieties as shown in Table 1, the most dominant volatiles (at least 50 μg/kg and occurred in all eight cucumber varieties) were acetaldehyde (52.0−70.9 μg/kg, 1.9−2.5% of the total volatiles); hexanal (127.…”

The Formation of Fruit Quality in Cucumis sativus L.

“…Besides, bagging was also an effective measure to improve the fruit quality. Shan et al (2020) demonstrated that cucumber fruits were found to have enhanced fruit flavor quality after bagging, for the elevated relative proportion of C6 aldehyde, ( E,Z )-2,6-nonadienal/( E )-2-nonenal ratio, and linoleic/α-linolenic acid ratio.…”