Sri Raharjo

The Effect of Size Reduction and Preparation Duration on The Antioxidant Activity of White Saffron (Curcuma mangga Val.)

An UV spectrophotometric area under curve method was developed for the estimation of Levofloxacin Hemihydrate in its mono component tablets. The spectrophotometric method for estimation employed Area under curve method for analysis using 0.1M Sodium Hydroxide as solvent for the drug Levofloxacin Hemihydrate at the wavelength range of 285-295nm. Levofloxacin Hemihydrate obeys Beer’s law in concentration range 10-50µg/ml. The recovery studies ascertained accuracy of the proposed method and the result validated according to ICH guideline. Results of analysis have been valid statistically by recovery studies. The method was successfully for evaluation of Levofloxacin Hemihydrate in tablet dosage form without the interference of common excipients.

Antiphotooxidative Effect of Ascorbic Acid Microemulsion in Virgin Coconut Oil

This study was intended to determine the effectiveness of ascorbic acid microemulsion for inhibiting photooxidation of virgin coconut oil (VCO). The ascorbic acid microemulsion was prepared by mixing ascorbic acid, deionized water, surfactant mixture, and VCO as continuous phase. Ascorbic acid microemulsion at 50, 100, 150, 200, or 250 ppm was dispersed into VCO. The same level of ascorbyl palmitate, TBHQ (tertiary butylhydroquinone), and BHA (butylated hidroxyanisole) were added into VCO and used for comparison. All of these samples were subsequently subjected to photooxidation under fluorescent light exposure (4,000 lux) for up to 8 hours at room temperature (30 ± 1 °C). Peroxide values and p-anisidine values of photooxidized samples were measured at 1 hour interval. The result indicated that at the level of 250 ppm, ascorbic acid which was included into the microemulsion system effectively inhibited photooxidation of VCO in comparison with the other antioxidants. This study confirmed that a highly hydrophilic singlet oxygen quencher (SOQ) such as ascorbic acid can be successfully incorporated into the microemulsion system and the addition of ascorbic acid microemulsion effectively inhibited photooxidation of VCO during storage under fluorescent light.

The potential of palm kernel shell activated carbon as an adsorbent for β-carotene recovery from crude palm oil

The study aimed to obtain of palm kernel shell activated carbon (PKSAC) potentially as an adsorbent for recovery of β-carotene from crude palm oil. Activation of palm kernel shell carbon was done chemically using phosphoric acid at impregnation ratio of 3 (ml/g) for 24 hours and carbonization at 500 °C for 30 min and 60 min called PKSAC30 and PKSAC60 respectively. The results showed that the yield of PKSAC30 and PKSAC60 were 48.82% and 47.67%, the surface area were 1665.823 and 1680.877 m2/g respectively, whereas surface area of decolorized activated charcoal (DAC) as control activated carbon was 1068.391 m2/g. PKSAC30 able to adsorb β-carotene in isopropyl alcohol at the equilibrium as much as 14.32 mg/g, while the DAC as much as 21.58 mg/g. Desorption of β-carotene from DAC using tetrahydrofuran reached 49.99%, while from PKSAC30 reached 28.30%.

Identification of flavonoid from leaves of gedi (Abelmoschus manihot L.) and its antioxidant activity

A flavonoid compound had been isolated from Abelmoschus manihotL. leaves. The leaves extract was obtained by maceration in methanol to obtain n-hexane-acetone-methanol sequential extracts. Further separation was done by flash chromatography using silica gel G - 60 as a stationary phase. The column was eluted subsequently using several mixture solvents including ethyl acetate, ethyl acetate/methanol (3:1,v/v,), ethyl acetate/methanol (1:1, v/v), ethyl acetate/methanol (1:3) and methanol at 2 mL/min flow rate. At the end of this fractionation, 112 fractions of 10 mL each was collected. Using bioassay-guided fractionation, seven isolates from fraction four were obtained. The isolate five showed the highest antioxidant activity in the 2,2-diphenyl-1-picrylhydarzyl (DPPH) radical scavenging test and then it was chosen for structure elucidation. The structure of the compound was determined based on spectroscopic data of UV, IR, 1H-NMR, and 13C-NMR. The isolated compound was proposed as 3,3’,5’ trihydroxy-4’ met...

Formulasi untuk Memperbaiki Flovor Bubur Buah Alpukat (Persea americana Mill) Hasil Restrukturisasi

The objective of this experiment was to develop novel restructured products from fresh avocado fruits puree and calcium-alginate gel forming method (internal setting). Gel forming by internal setting the calcium is released under controlled conditions simultaneously throughout the system. Restructuredfruit products were evaluated for pH, color, and sensory properties. Sodium chloride (0.5% and 1.0%) did not give better flavor for restructured avocado compare to product without it. The addition of sodium chloride precisely increases the sourness of the product. Restructured avocado product with citric acid concentration 0.05% and 0.1% were much preferred than product with citric acid concentration 0.5%. The addition of sugar (5%) to the restructured product significantly reduced the sourness. Compared to the addition of sodium chloride (0.5%), products with addition of sugar (2.5% and 5%) were significantly more preferable and the flavors were closer to fresh-cut avocado fruit.