| Abstract |
The “Mao” compiled fruits (Antidesma thwaitesianum Muell. Arg.) found in wild tropical forests are used as commercially available local products of juice and wine in Thailand, particularly its 100% juice contains a very rich source of antioxidants including polyphenols. This study aimed to determine total phenolic content and antioxidant activity in the juice sample. The amount of total phenolics was determined using Folin-Ciocalteu assay. The antioxidant activity was evaluated by four different spectrophotometric methods including 1,1-diphenyl-2-picryl-hydrazyl (DPPH), 2,2´-azinobis(3-ethylbenzothiazoline 6-sulphonate (ABTS), N,N-dimethyl-p-phenylenediamine dihydrochloride (DMPD) and ferric reducing-antioxidant power (FRAP). It was found that the phenolic content of the juice was 5121.3 ± 43.3 mg GAE/100 mL sample. Their antioxidant activity against DPPH assay was 2655.6 ± 31.3 mg BHT/100 mL sample. ABTS and DMPD ones gave 6382.3 ± 1.3 and 2735.4 ± 9.8 mg Trolox/100 mL sample, respectively. While FRAP assay gave 277.3 ± 0.02 mM Fe2+/100 mL sample. In addition, thermal stability of total phenolic compounds of the juice sample was also investigated by heating at various temperatures (60-100C) for 30 min prior to analysis. The antioxidant activity of the juice under heating at 60C was not affected, but slightly loss of its antioxidant activity of 3.02% at 80C was observed as the phenolic contents decreased to be 6.22%. Therefore, the antioxidant activity related to total phenolics of the mao juice was not much thermally labile. |
Publication
Journal Publication
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