PENENTUAN TOTAL FENOLIK, ASAM ASKORBAT DAN AKTIVITAS ANTIOKSIDAN TANAMAN KAILAN (Brassica oleracea var. Alboglabra) YANG DIRAWAT DENGAN EKSTRAK TANAMAN TERFERMENTASI

Abstract

Kailan (Brassica oleracea var. Alboglabra) is a family of cabbages (Brasicaceae) which contain nutrients and high antioxidant activities. The cultivation system organically and conventionally can influence the nutrients and antioxidant contents. In this study, the total phenolic content, flavonoid, ascorbic acid, and antioxidant activity of ethanolic of kailan extract were carried out. Fresh weight and height of the plant as well as the percentage of damaged leaves of kailan were determine too as physical analysis. There were three different watering treatments on cultivation of kailan such as, organic kailan treated with Fermented Plant Extract (FPE), control (just water) and conventional treatment. FPE was prepared from mixture of rumput paitan (Paspalum conjugatum B), babadotan (Ageratum conyzoides L), and effective microorganism 5 (EM5). The results showed that the weight of plant, the height of plant and percentage of damaged leaves were not significantly different in all treatments. Total phenolic of organic kailan (6,866 AGE mg/g dry weight) was not significantly different from conventional treatment (6,396 AGE mg/g dry weight). Conventional kailan (0,343 QE mg/g dry weight) has the highest flavonoid content. The highest ascorbic acid content was given by organic (0,589 AAE mg/gr dry weight) and conventional kailan (0,448 AAE mg/g dry weight). For antioxidant activities, all treatments gave the same inhibition on free radical in FTC assay, and IC value in DPPH assay. Antioxidant activity in FRAP assay from conventional kailan (0,132 mol/g) could reduce Fe3+ become Fe2+ more efficient than other treatments. IC50 value in NO radical scavenging assay of organic kailan (4,009 mg/ml) was not significantly different from control treatment. This study showed that the cultivation of kailan organically by using FPE treatment could increase the total phenolic, flavonoid content, ascorbic acid and antioxidant activity and thus it could be used as alternative for replacing the pesticide.