# Comparative Study on Physicochemical and Nutritional Qualities of Kiwifruit Varieties
## 3 Results
### Aroma Substance  
Aroma characteristics are among the most important organoleptic characteristics for kiwifruit quality and are one of the crucial concerns of consumers. As shown in Figure 5, in this study, a total of 45 volatile compounds were identified in 14 kiwifruits, including 9 alcohols, 1 alkane, 6 esters, 3 aldehydes, 14 alkenes, 5 ketones and 7 other types. Among them, 17, 16, 14, 14, 13, 13, 12, 11, 11, 10, 10, 9, 8 and 7 volatile components were identified in G6 ('Huate'), Y2 ('G3'), Y3 ('Jinta'), Y5 ('Jinmei'), R1 ('Hongyang'), G5 ('MHYX'), Y6 ('Jinyan'), G3 ('Hayward'), G2 ('Xuxiang'), Y4 ('Jinyuan'), Y1 ('16A'), G1 ('Cuiyu'), G4 ('Jinkui') and R2 ('Donghong'), respectively. Volatile substance is one of the important physical characters in kiwifruit, and different compounds and contents lead to various aromas. In the three flesh color groups, there were 12 common compounds, which were eucalypt, linalool oxide, terpinene-4-ol, n-hexaldehyde, 2-hexenal, \(\alpha\)-pinene, \(\beta\)-pinene, \(\gamma\)-terpinene, D-limonene, \(\alpha\)-terpinene, terpinolene and p-cymene. In addition, 1-pentanol, trans-2-hexen-1-ol, n-hexane  
Figure 4: The contents of VE, VC, VB1, VB2 and VB6. ‘G’—green-fleshed kiwifruit. ‘R’—red-fleshed kiwifruit. (**A**) The contents of VE in different flesh color. (**B**) The contents of VC in different flesh color. (**C**) The contents of VB1 in different flesh color. (**D**) The contents of VB2 in different flesh color (**E**) The contents of VB6 in different flesh color. (**F**) The contents of VE in species. (**G**) The contents of VC in species. (**H**) The contents of VB1 in species. (**I**) The contents of VB2 in species. (**J**) The contents of VB6 in species. ‘Y’—yellow-fleshed kiwifruit. ‘A’—_A. chinensis. ‘B’—_A. chinensis_ var. _delicious_. ‘C’—_A. eriantha_. ‘D’—_A. eriantha_\(\times\)_A. chinensis_. Values are means \(\pm\) SD of three individual biological reproductions. Different lowercase letters indicated statistically significant differences ([PERSON]’s multiple range test, \(p<0.05\)) among different kiwifruit cultivars.  
and styrene were present only in red-fleshed kiwifruits. Therefore, they could be used as a characteristic fragrance for red-fleshed kiwifruits.  
It was reported that one of the main aroma compounds was n-hexanaldehyde in 'Hayward' (_A. chinensis_ var. _deliciosa_) and 'Hort16A' (_A. chinensis_) [35]. According to our study, n-hexanaldehyde was also present as a main compound in _A. eriantha_ and _A. eriantha_\(\times\)_A. chinensis_. A previous study found that two compounds, 1-methoxy-2-methyl-benzene and (E, E)-2,4-heptadienal, were only present in _A. chinensis_ var. _deliciosa_[18]. In this study, we found six compounds that were only present in _A. chinensis_ var. _deliciosa_. The reasons for this might be that the previous research involved one sample in _A. chinensis_ var. _deliciosa_, and that limitations in the plant materials led to that conclusion. Another study identified ethyl butyrate, 2-hexenal and n-hexanaldehyde as the three volatile components likely to determine the aroma of 'Jinyan' kiwifruit [36]. In this study, n-hexaldehyde and 2-hexenal were present in 'Jinyan' kiwifruit, which could narrow down the specific aroma of 'Jinyan' kiwifruit.