**3.2 Starch analysis of parenchyma and vascular bundle of oil palm trunk**

**Figure 6** showed the percentage of starch content for separated sample (parenchyma and vascular bundle) and non-separated (mixture parenchyma and vascular bundle) sample from inner to outer of oil palm disks. The duration of the storage time was determined between 0, 45 and 60 days were used similar as the determination of sugar content of oil palm trunk.

Based on this study, the middle part of the oil palm trunk had the highest starch content compared to the outer and the inner part. The amount of the starch content in the middle part showed with a range 3–5%, whereas in the inner part in a range 2–4% and in the outer part around 3–4% in the 0 days. Parenchyma at the bottom part in the middle part showed the highest starch content compared to others which is 4.54% at 0 days whereas parenchyma at the top part in the inner part showed the highest starch content which is 3.5% at 45 days. Referring to previous studies on the starch content for a 0 day, as indicated by Tomimura (1992), the starch content for separated sample of vascular bundle and parenchyma was 2.4% while in parenchyma was 55.5% respectively.

The pattern results of starch content for all samples were reduced as the duration of storage increased. Based on the findings of this study, the starch content at day 0 initially to increase and decrease rapidly around day 45 to 60 and became almost negligible after 60 days. This changing pattern may happened because of the starch probably been converted to glucose and other fermentable sugar by enzyme

#### **Figure 6.**

*Amount of starch content at different part of the oil palm trunk during storage time. P-B, parenchyma-bottom; VB-B, vascular bundle-bottom; P–T, parenchyma-top; VB-T, vascular bundle-top; X, bottom non-separated; Y, top non-separated.*

activities. These activities probably involve degrading enzyme and sucrose metabolism enzymes [10]. In this study we only focused on 0, 45 and 60 day because it is the optimal day according to the previous study.

This research showed that the higher starch content had been found in the parenchyma comparatively to vascular bundle. Abundant amount of parenchymatous tissue which is rich in starch content accumulates in these parts [32]. According to [32] study, the carbohydrate content in oil palm trunks reported that peripheral cortex contains high starch level. This study showed that the middle part contained the highest starch content which is being different from the previous study. This may be due to the different types of cultivar has been used.

*Chemical Composition of Parenchyma and Vascular Bundle from* Elaeis guineensis *DOI: http://dx.doi.org/10.5772/intechopen.98421*

According [32] found that high level of starch content was located dominantly in the top part of oil palm trunk. This phenomenon relates to an older cells distribute in basal part of the oil palm trunk compared to top part that contain young cells. As young cells, it needs a lot of carbohydrates which is consisting of the abundant amount of starch content, reserved for the growing process [33]. This statement was supported by [31] in his report that starch stored in the upper part of the tree is purposely used for flowering process.
