# Properties of Different Varieties of Durian
## 3 Results and Discussion
### Antioxidant Properties of Durian Cultivars  
The values of five different antioxidant assays are presented in Figure 3. The results of the DPPH assay were the lowest and of ORAC are the highest. The results of antioxidant activities were expressed in uM TE/g DW and showed the following numbers: DPPH--from 4.58 \(\pm\) 0.43 to 7.05 \(\pm\) 0.22; FRAP--from 6.82 \(\pm\) 0.29 to 11.69 \(\pm\) 0.31; ABTS--from 11.37 \(\pm\) 0.15 to 15.88 \(\pm\) 0.37; CUTRAC--from 39.76 \(\pm\) 7.21 to 56.18 \(\pm\) 5.89 and ORAC--from 360.87 \(\pm\) 14.38 to 377.64 \(\pm\) 18.11. In DPPH and ABTS assays, where the antioxidant activity was determined as percentages of inhibition, showed the same relationships in the investigated durian cultivars as using the estimation of the antioxidant activities of these assays in uM TE/g DW. All used methods estimated that the Monthong cultivar was the strongest between investigated  
Figure 3: Antioxidant activities values (uM TE/g DW) of DPPH (1,1-Diphenyl-2-picrylhydrazyl method); FRAP (Ferric-reducing/antioxidant power); ABTS [(2,2-Azino-bis(3-ethyl-benzothazoline-6-sulfonic acid)diammonium salt); CUTRAC (Cupric reducing antioxidant capacity); ORAC (Oxygen radical absorbance capacity); antioxidant activities by DPPH and ABTS assays (% of inhibition) in durian cultivars. Values are means \(\pm\) SD per g dry weight (DW); n = 5 samples per cultivar, each subsampled and analyzed 5 times. Abbreviations: TE, Trolox equivalent; PM, Puangmanee; MT, Monthong; CN, Chanee. cultivars, showing in most cases significant differences (Figure 3). As mentioned previously, there are many methods for total antioxidant potential determination, and each has its limitations [45]. As can be concluded from the present results that some of these antioxidant assays give different antioxidant activity trends [45], but all presented methods showed that Monthong variety was higher than others. The obtained results are in line with other investigations [42; 46; 47; 48; 14]. So, DPPH (\(\mu\)M TE/g FW) showed 0.98--13.66 and 1.28-2.46 for MT and CN, respectively. FRAP estimation (\(\mu\)M TE/g FW) was 0.72-7.49, 2.32-4.57 and 2.45 for MT, CN and PM, respectively. ORAC assay (\(\mu\)M TE/g FW) for Thai durian cultivars is not applied widely, then for MT is 19.03 and for CN is 23.04, respectively [4]. CUPRAC (\(\mu\)M TE/g FW) varied between the varieties and showed the following numbers: 4.28-10.76, 9.55 and 9.45 for MT, CN and PM, respectively. The obtained results of ABTS (\(\mu\)M TE/g FW) are in agreement with most of the reports and show 2.66-23.53, 20.91, and 20.20 for MT, CN and PM, respectively. Some results were obtained from unknown varieties of durian fruit, as FRAP values of 7.41 \(\mu\)M Fe\({}^{2+}\)/g FW and TEAC values of 4.98 \(\mu\)M TE/g FW [42; 44]. Durian varieties [47] showed antioxidant activities measured by DPPH, FRAP, and ORAC as followed: (4-8, 11-16 and 62-73 \(\mu\)M TE/g DW, respectively). These values were in the same range as the rip Monthong variety measured by DPPH and FRAP which were proved by present results and reported [48; 14]. The ORAC values shown in this report were lower than those found in the present study. The present results of durian extracts (361-378 \(\mu\)M TE/g by ORAC assay) can be compared to other fruits such as _Phylanthus emblica_ [PERSON] (455 \(\mu\)mol TE/g by ORAC assay) and _Spondias pinnata_ (L.f.) [PERSON] (241 \(\mu\)mol TE/g by ORAC assay). Durian extract was prepared using the mixture of ethanol and 0.2 M HCl (1:1, \(v/v\)) exhibited the highest total phenolics value of 116.55 \(\pm\) 1.51 mg GAE/g extract and the highest total flavonoid value of 92.37 \(\pm\) 9.27 mg rutin equivalent (RE)/g extract. In antioxidant studies, the ABTS assay of durian fruit extract showed a greater value in antioxidant activity against control [33]. The results derived from DPPH, FRAP, and other assays showed lower antioxidant potential compared to the standard.