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Determination of allelopathic potential in mahogany (Swietenia macrophylla King) leaf litter using sandwich method Mukaromah, Arnia Sari; Purwestri, Yekti Asih; Fujii, Yoshiharu
Indonesian Journal of Biotechnology Vol 21, No 2 (2016)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1758.807 KB) | DOI: 10.22146/ijbiotech.16456

Abstract

The sandwich method is a reliable screening bioassay that can be utilized to investigate allelopathic activity of leaf litter leachates. Screening the allelopathic potential of mahogany (Swietenia macrophylla King) leaf litter in plant–plant interaction using the sandwich bioassay method has not been reported. The research objectives were to determine and categorize allelopathic potential of S. macrophylla leaf litter using the sandwich bioassay method, and to determine specific activity (EC550). S. macrophylla leaf litter. The results showed that S. macrophylla leaf litter exhibited strong allelopathic activity when compared with 46 leaf litter species and was included in the top ten of allelopathic leaf litter species. Increasing S. macrophylla leaf litter concentration was concomitant with inhibition of radicle lettuce seedling growth compared with the control. According to the linear regression analysis, the effective concentration (EC50) of S. macrophylla was estimated to be 3.25 mg D.W. eq. mL-1 and was considered to have strong growth-inhibitory activity on lettuce radicle elongation. The results suggest the possibility of allelopathic potential of leaf litter in plant–plant interaction under S. macrophylla trees.
Effect of Soaking Treatment on Anthocyanin, Flavonoid, Phenolic Content and Antioxidant Activities of Dioscorea alata Flour Ratnaningsih, Ratnaningsih; Richana, Nur; Suzuki, Sakae; Fujii, Yoshiharu
Indonesian Journal of Chemistry Vol 18, No 4 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (14.567 KB) | DOI: 10.22146/ijc.23945

Abstract

Purple Dioscorea alata is one kind of tuber crops that rich in polyphenolic compounds. In Indonesia, the utilization of this yam is still very limited because it is easily damaged on the fresh form. Due to its high perishability, then the fresh tuber have to be processed into dried materials to expand its utilization. This study investigated the effect of browning inhibition treatments (immersion in water, Na-bisulfite, and ascorbic acid) on moisture, color, anthocyanin, flavonoid and phenolic content, and determined the antioxidant activities of D. alata flour. The moisture content of D. alata flour ranged between 6.89 to 7.71% db, which still in the range of wheat flour moisture content standards using Codex Standard. Browning inhibition treatment improved the color appearances and provided better values on anthocyanin, phenolic, and flavonoid content of D. alata flour. The color and antioxidant activities of D. alata flour were significantly correlated with its functional properties.