Comprehensive Analysis of Dry Material Content, Moisture Content, and FTIR Spectroscopy in Durian Peel

One of the agricultural wastes that has the potential to become high-value products is durian peel waste. This study aims to analyze the parts of durian peel in terms of dry material content, moisture content and FTIR analysis. The method of this research is starting from the selection of ripe durian and durian peel is divided into four parts and labelled as B (thin neck area of white inner peel), C (thick bottom area of white inner peel), A (green and spiny outer peel), and AC (overall combination of C and A). Each section of durian peel has been studied to determine dry material, moisture, and crude fiber content. The results showed that the A segment had the highest dry material content (15.18 %), the B segment had the highest percentage of moisture content (124.1 %) and the FTIR testing of durian peel samples contained O-H, C-H, C≡C, C=O and C=C functional groups. These data have proven that each segment of durian peel has a significant difference in terms of composition value and that the moisture absorption rate of durian peel affects the functional groups.


Introduction
Durian in scientific language called Durio zibethinus murr is included in the Bombaceae family known as the king of fruits and is a tropical fruit native to Southeast Asia.[1] Durio zibethinus murr and is known as a seasonal fruit of Southeast Asia, especially Malaysia, Thailand, the Philippines, and Indonesia [2] [3] [4] [5].The durian plant is a fruit that originated in Indonesia.Durian has various morphologies, depending on where it grows.In Indonesia, there are seven variations of durian shape.Among them are round, ovoid, oval, round flat tip, long round, ovoid, and obovoid.In general, durian fruit has a fruit peel colour, which is green to brown.In the market there are various types of durian shapes and colours that are sold.Durian has a fruit peel that has sharp, thick, and hexagonal spines.There are several types of durian that are popular in Indonesia.Durian has an attractive flesh colour and distinctive aroma [6].The average weight of a durian fruit is 2 kg to 4 kg and is ovoid to almost round depending on the variety.[7].Durian shell waste until now has not been utilized properly because it is difficult to decompose and can become hazardous biological waste that pollutes the environment.[8] Along with the increase in durian production from year to year, durian shell waste will also increase, and environmental pollution will also continue to increase.So far, there are those who use durian peels as candy, some use durian peels as a mixture of bath soap, some use durian peels by means of high temperature carbonization as an adsorbent, and some use durian peels as charcoal briquettes.Durian fruit consists of 19-36% fruit flesh (aril), 4-17% seeds and 50-70% fruit peel.[9].The hard and thick fruit peel which reaches almost a quarter of the fruit is the part that is thrown away until it finally becomes rotten [10].Durian peels have a high cellulose content of 50-60% and lignin and low starch content of 5% each.The purpose of this study was to determine the dry matter content, moisture content and functional groups in durian peel consisting of four segments of durian peel, namely: yellowish green inner peel segment and spines, white inner peel segment, thin white inner peel segment, thick white inner peel segment, and thick white inner peel segment with yellowish green durian spines [11].

Materials
Durian fruit used in this study is durian fruit obtained from North Sumatra, Indonesia.Durian was split using a knife along the carpel seam in the middle of each segment.Then the aril and seeds were manually removed from the peel.Using a knife, cut the durian skin into 1-2 cm pieces and proceed as shown in Figure 1.Pre-dry weight = Initial weight of durian peel sample before oven drying for 24 hours Dry Weight = Weight of samples that have been dried using an oven for 24 hours 2.2.2 Moisture Content Testing Aluminum foil used in this study as a container was weighed and recorded its weight and labelled D1.Then each locus of durian peel was weighed as much as 1 gram and recorded its weight and labelled D2.Furthermore, each locus of durian peel was dried using an oven at 70℃ for 24 hours.Each durian locus that has been dried before, further dried at 105 ℃ for 3 hours.The final weight of the oven-dried sample was weighed and recorded and labelled D3.Calculation of moisture content can be done by using equation ( 3): 2.2.3 FTIR testing (Fourier Transform Infra-Red) testing.FTIR test was conducted on Durian Leather samples that were still treated with physical activation.The test results can be seen through the relationship of transmittance (%) and wave number (cm -1 ).FTIR test is used to show and identify the functional groups of organic compounds in the sample.

Dry material content testing
Dry material content is the measure of durian fruit maturity of the fruit after the water has been squeezed out. Figure 3 shows the percentage of dry material content of various durian peel segments.Figure 3 shows that the spiny green outer peel segment (A) has the highest dry material content of 15.18% compared to the white inner durian peel segment (thin neck area) labelled B, which is 8.75% and C, which is 8.84%.While the durian peel segment, which is a combination of durian peel segments C and A labelled AC has a percentage of 12.12%.That was explained that dry material content is strongly related to water and dry material accumulation, which indicates that the amount of dry material content is higher in the segment of A of durian peel, which is yellowish green and spiny peel [12].Thus, the segment of A of durian peel which is spiny and yellowish green in colour contains a lot of starch, protein obtained from the process of photosynthesis and translocation in the phloem.Segments of C and B where B is in the thin neck area of the white inner peel, while C is in the thick area of the white inner peel shows a slightly lower amount of dry material content because the parts in this segment contain more water than dry material.

Moisture Content Testing
Most rotten fruits contained significant level of water, making them susceptible to microbial attack.In conducting this test, fresh fruit is selected to determine the wet sample in fresh fruit to calculate precisely.Figure 4 shows that the graph of the difference in the percentage of water content of the durian peel segments.The segment of B the durian peel has a high percentage of moisture content of 124.1%, explaining that the concentration of water in the thin neck area of the white inner peel is higher than the others.Then the percentage level of water content is followed by the segments of C, A and AC which have percentage values of 122.1%, 114.4% and 113.8%, respectively.The thin neck area of the white inner peel of the durian peel is very good at controlling the concentration of water in the durian peel so that it is difficult to experience damage in this section.

Function Group Testing on Fourier Transform Infra Red (FTIR)
FTIR test was conducted on durian peel samples that have not been treated with activation.FTIR test was conducted to determine the functional groups of organic compounds in durian peel.The test results can be seen through the relationship of transmittance (%) and wave number (cm -1 ) below: The results of FTIR testing of durian peels that have not been activated show the absorption of the infrared spectrum and the vibrations of the O-H, C-H, C≡C, C=O and C=C functional groups of aromatic compounds indicated by the presence of absorption bands in the wavelength region 574.78717-3847.98792cm -1 .The band with medium intensity at 3847.98792cm

Conclusion
Based on the results of tests conducted on the durian peel, it was found that the spiny green outer peel segment (A) has the highest dry material content of 15.18% compared to the white inner durian peel segment (thin neck area) labelled B which is 8.75% of the lowest dry material content.In the A segment of durian peel, that is spiny and yellowish green in colour contains a lot of starch, protein obtained from the process of photosynthesis and translocation in the phloem so that it has the highest dry material content.While B is due to this segment containing more water than dry material.In the results of water content testing, the B segment of durian peel has the highest percentage of water content of 124.1%, explaining that the concentration of water in the thin neck area of the white inner peel is higher than the others.In FTIR testing, the vibrations of the O-H, C-H, C≡C, C=O and C=C functional groups of the compound are indicated by the presence of absorption bands in the wavelength region 574.78 -3847.98 cm -1 .

Figure 3 .
Figure 3. Percentage of dry material content of durian peel segments

Figure 4 .
Figure 4. Percentage of Moisture Content of Durian Peel Segments

Figure 5 .
Figure 5. FTIR Results of Durian Peel -1indicates the presence of O-H bond.The band at 3431.36366 cm -1 indicates the presence of C-H bond.The band at 2314.5792 cm -1 indicates the presence of C≡C bond.The band at 1649.13768 cm -1 indicates the presence of C=O bond.The band at 1413.82213 cm -1 indicates the presence of C=C bond.The state of this functional group states that the level of water absorption in durian peel affects the functional group.