# Distribution of Volatile Compounds in Different Fruit Structures in Four Tomato Cultivars
## 1 Introduction  
Tomato is one of the world's most consumed vegetables, and is known for its unique taste and richness of nutrients, such as lycopene, \(\beta\)-carotene, and lutein which can protect against various cardiovascular diseases and many forms of cancer [1].  
In recent years, there has been an increasing demand for good quality fruit and vegetables, and the tomato is not an exception. More and more consumers are willing to pay extra for good flavor [1]. Fresh tomatoes have a characteristic flavor due to the presence of a complex mixture of sugars, acids, and volatile compounds [2; 3]. Volatile compounds are the main determinant of the special flavor in tomatoes [4]. Scientists have identified more than four hundred volatile compounds in the tomato [5], but less than 10% of them are present in significant concentrations and odor thresholds for determining the tomato flavor [6; 7]. In the past few years, many researchers studied the volatile compounds of the tomato and identified many biosynthetic pathways of essential aromatic volatiles [8]. The volatile compounds are biosynthesized from lipids, amino acids, lignins, and carotenoids [9].  
Previously, many studies have been performed on the volatile components in whole fruit or pericarp tissues [10; 11; 12; 13; 14; 15], and the contents of the volatile components in the peel and internal tissueswere compared. [PERSON] et al. [16] compared the composition of the volatiles between the pericarp and locular gel, and concluded that the locular gel contained lower concentrations of cis-3-hexenal, hexanal, heptanal, octanal, nonanal, cynene, terpinolene, undecane, dodecane, 6-methyl-Shepten-2-one, 2-methyl butyl acetate, 1-nitro-pentane, and 1-nitro-2-phenylethane than the pericarp. However, the locular gel contained higher concentrations of 2-methyl propanal, butanal, 2-methyl butanal, 2-methyl-2-butanal, 2-methyl propanol, 3-methyl butanol, 2-methyl butanol, and 2-butanone than the pericarp [16]. [PERSON] et al. [17] also compared the differences in the volatile components between the peel and internal tissues, and showed that the inner tissues of the tomato fruit contained higher concentrations of 3-methyl butanal, 2-methyl butanal, 3-methyl butanol, and 2-methyl butanol than that of the pericarp, which is probably due to the higher levels of alcohols in the inner tissues [17; 18].  
Previous studies were focused on determining the volatile compositions only in the pericarp and locular gel. Actually, the anatomy of a tomato fruit includes pericarp (PE), septa and columella (SC), locular gel and seeds (LS), and the stem end (SE) (Figure 1), and the volatile compositions in the different inner tissues were not reported. The inner tissues also have a lot of volatile compounds, and they make great contributions to the overall aroma quality. In this study, the rip tomato fruits of \"FL47\", \"Tygress\", \"Tasti-Lee\", and \"Cherokee Purple\" cultivars were used. The volatiles were extracted from PE, SC, LS, and SE, and the organic volatile compounds were identified by Gas Chromatography-Mass Spectrometry (GC-MS). The aim of the paper was to analyze the distribution of volatile compounds in different fruit structures in four tomato cultivars and evaluate the aroma contributions and aroma profile of different tissues based on their odor activity values (OAVs), which would provide substantial information regarding the volatile components in different cultivars and inner tissues.  
Figure 1: Schematic cross-section of (**a**) Tasti-Lee, (**b**) Tygreen, (**c**) FL47, and (**d**) Cherokee Purplea tomato fruit. (1) Pericarp (PE); (2) septa and columella (SC); (3) locular gel and seeds (LS); and (4) stem end (SE).