The Potential Source of Natural Antioxidant Agent of Casia alata Microgreen ,,, The potential source of natural antioxidant agent of Casia alata microgreen

Commonly, plant was cultivated by microgreen have potentially source of natural antioxidant agents. This study was conducted to utilize Cassia alata (C. alata) as a microgreen and evaluated the potential of Microgreen gelinggang as the source of natural antioxidant agents . The seed of Cassia alata was cultivated in Rockwool at room temperature (27±1 o C). At the appearance of the first true leaves, about 21 days, microgreens were harvested from a triplicate of trays with sterilized scissors. The antioxidant activity assay using the DPPH (2,2-difenil-1-pikrilhidrazil) radical scavenging activity method . It was analyzed using spectrophotometry UV-VIS. The result showed that the IC 50 values of Microgreen gelinggang were 1.789x10 3 ±0.0 µg/mL. It was a weak category antioxidant. This study indicated that the extract of Microgreen gelinggang has a potential source of natural antioxidant agents.

C. alata (Casia alata) is a native plant from Argentina.In Indonesia, it is known as "Ketepeng Cina" (Fatmawati et al., 2020).This plant can grow in the tropics, mainly in South Kalimantan.C. alata is a type of herb plant (Chatterjee, 2012).In South Kalimantan, the extract of C. alata leaves is commonly used as the traditional herb for skin disease.According to Oladeji et al. (2020), the extract of C. alata leaves is commonly used as the traditional herb for typhoid, diabetes, malaria, asthma, ringworms, tinea infections, scabies, blotch, herpes, and eczema.The seeds and leaves of C. alata can be used as an antimicrobial (Abdulwaliyu et al., 2013), anti-inflammatory (Wongkaew & Sinsiri, 2014), antidiabetic (Abdulwaliyu et al., 2013), and antifungal (Wongkaew & Sinsiri, 2014).
Several studies have shown that C. alata is rich in antioxidants (Fatmawati et al., 2020), such as ascorbic acid, flavonoid, tocopherol, anthraquinone, and carotene (Chatterjee, 2012).Thus, this study was conducted to the utilization of Cassia alata as a microgreen.The aim of this study evaluates potencial of Cassia alata microgreen as source of natural antioxidant agents.

Plant Material
The seed of Cassia alata L. was obtained from PT. Sari Kaya Sega Utama, Banjarbaru, South Kalimantan.This study was adopted from Ghoora et al. (2020).The seed was cultivated in Rockwool for 21 days at room temperature (27±1 o C).Before the seed was cultivated, it must be soaked in water for 5 hours.At the appearance of the first true leaves microgreens were harvested from a triplicate of trays with sterilized scissors.Microgreens were washed to remove extraneous dirt, washed with deionized water, and fan-dried for 5-10 min.Cleaned microgreens were frozen at -20±1oC before used.

Statistical analysis
The data obtained was then analyzed using ANOVA with a p value of 5%.Results that showed the differences were further tested using the Duncan Multiple Range Test alpha 5%.The potential source of natural antioxidant agent of Casia alata microgreen… Table 1 shows the measuring antioxidant activity using the DPPH free radicals scavenging method.The results showed that the absorption formed a calibration curve with a concentration range of 1.00; 1.33; 1.66; 1.99, and 2.33 mg/mL at 517 nm..The results gave a linear relationship within the concentration and % free radical scavenging (%), described in the form of a linear regression equation y = 21.24x+ 12.01 with R2 0.991 (Figure 1).IC50 on microgreen C. alata was obtained by transforming the absorbance data (y) into %-free radical scavenging (%).The IC50 value of C. alata Microgreen was 1.789x103 ±0.01 µg/mL.This result is higher than the study by Senevirathne et al. (2019), like finger millet and green peas, contain DPPH antioxidant activity IC50 4339 ± 86, and 1830 ± 109 µg/mL, respectively.The IC50 value is the parameter of antioxidant activity.The higher antioxidant activity, the lower IC50 (Rivero-cruz et al., 2020).According to (Qusti et al., 2010), the category of antioxidants is classified very strong (IC50<0.01mg/mL), strong (0.01 mg/ml< IC50<1 mg/mL), moderate (1 mg/ml< IC50<7 mg/mL), and weak (IC50>7 mg/mL).Meanwhile, according to (Molyneux, 2018), the antioxidants are weak because of IC50 values 200-1000 µg/mL and it is considered a source of antioxidants..

RESULT AND DISCUSSION
Based on this research, gelinggang microgreen is classified as a weak antioxidant.The extraction technique and lack of stages of harvest maturity is one of factor that causing this.Sultana et al. (2009) showed that the solvent and technique extraction can influence antioxidant activity.Similar results were observed by Hill et al. (2019).El-Nakhel et al. (2020) showed that the level of harvest maturity can influence the antioxidant capacity of microgreens.

CONCLUSION
This paper utilized C. alata to microgreen and determined the potential of C. alata microgreen as the source of natural antioxidant agents.C. alata microgreen had the IC50 1.789x103 ±0.01 µg/mL and was classified as a weak antioxidant.
Thus, it would be recommended to optimization the extraction technique and complement mature leafy by microgreen to derive maximum antioxidant activity.

Figure 1
Figure 1 shows the C. alata microgreen leaves at 21 days.It will be extracted for an antioxidant activity assay.Based on this study, C. alata microgreen was classified as a weak antioxidant.Among factors contributing to weak antioxidant are extraction technique and stages of harvest maturity.According to Sultana et al. (2009), the extraction solvent and technique used can affect the antioxidant activity.Similar results were observed by and Hill et al. (2019).The study of El-Nakhel et al. (2020) conducted, the stage of harvest maturity can affect the antioxidant capacity of microgreens.Antioxidants are compounds that act to neutralize free radicals and prevent the damage of the normal cell.The performance of antioxidant activity is determined based on its ability to free radicals scavenging.Commonly, 2,2-diphenyl-1-picrylhydrazyl (DPPH) is a free radical that is used(Albaar, 2015).

Figure 2 .
Figure 2. Correlation of concentration and % inhibitory radical scavenging