# Investigation of the Maturity Changes of Cherry Tomato Using Magnetic Resonance Imaging
## 3 Results  
### Qualitative MR Image Analysis  
Qualitative image analysis of internal structure changes with different maturity stages were performed. Figure 5a,b shows a center slice image from a 3D MR image set of a cherry tomato at green and red maturity stages, respectively. Usually, the fruit consists of three main parts, including pericarp, locule, and placenta. Pericarp is the fruit wall including flesh and vascular bundles, locule surrounded by pericarp contains seeds and vascular bundles, and placenta is the fleshy part containing vascular bundles only. Additional investigation of the MR image signal intensity variations was done using a 1D image profile of the samples. Figure 5c shows a 1D signal intensity profile graph along a line in Figure 5a. Figure 5d shows a 1D signal intensity profile graph along a line in Figure 5b. Strong signal intensity from pericarp and locule regions was observed from the sample. However, the signal intensity from the placenta region is low compared to pericarp and locule regions, except intensity spikes due to vascular bundles within the placenta. Very strong signal intensity from vascular bundles was observed from the placenta region in cherry tomato. Also, signal intensity variations were observed from three different parts: pericarp, locule, and placenta, of the fruit. These three parts will be changed depending on fruit maturity stage.  
Figure 6 is a center slice of representative MR images of Tiara TY cultivar cherry tomato at three maturity stages: green, pink, and red. At the green maturity stage, the inner (endocarp) and outer (exocarp) pericarp parts are separated visually. A stronger signal is generated from the exocarp region than from the endocarp region, and locule and pericarp parts are distinguished. The signal intensity difference between endocarp and exocarp is less at the pink maturity stage. Also, locule and pericarp parts are distinguished clearly at this stage. However, signal intensity difference between pericarp and locule is about the same at the red maturity stage. It means water distribution inside the tomato is even at the final maturity stage. Figure 7 shows representative MR images of three cherry tomato cultivars with different maturity stages. There is no clear difference on internal structure changes among the cultivars. Generally, pericarp and locule parts are clearly distinguished at all maturity stages, except the red maturity stage, regardless of cultivars.  
Figure 4: Signal calculation regions with rectangular box from an MR image.  
Figure 5: Center slice image of acquired MR images of Tiara cherry tomato. (**a**) Original gray scale MR image of cherry tomato at green maturity stage, including oil reference with a line along x imaging axis, (**b**) original gray scale MR image of cherry tomato at red maturity stage, including oil reference with a line along x imaging axis. (**c**) One-dimensional (1D) signal intensity profile graph along a line in (**a**), (**d**) 1D signal intensity profile graph along a line in (**b**).  
Figure 6: Representative MR images of Tiara TY cultivar cherry tomato only at three maturity stages: green, pink, and red.  
The water distribution of cherry tomatoes appears even at the final maturity stage, regardless of cultivar. However, water content appears evenly distributed in the pericarp region from breaker to light red maturity stages. MR signal intensity changes when different maturity stages are observed. Especially, signal intensity variation between the pericarp and locale regions is observed. Therefore, quantitative analysis of MSI variations of three main parts (pericarp, locule, and placenta), oil reference, and the background noise is justified.