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.
