Pudji Hastuti

Method of phorbol ester degradation in Jatropha curcas L. seed cake using rice bran lipase

A novel enzymatic degradation of phorbol esters (PE) in the jatropha seed cake was developed using lipase. Cihera rice bran lipase had the highest ability to hydrolyze PE, and reduced PE to a safe level after 8 h of incubation. Enzymatic degradation may be a promising method for PE degradation.

Effect of ethanol concentrations on rice bran protease activity and ester synthesis during enzymatic synthesis of oleic acid ethyl ester in a fed-batch system using crude rice bran (Oryza sativa) lipase

Abstract Crude rice bran lipase was used for the enzymatic synthesis of Oleic Acid Ethyl Ester (OAEE) in a fed-batch system. It was found that rice bran contains protease (4.19 U/g) and lipase (324.03 U/g). The results show that protease inhibits lipase at a low concentration of ethanol (5 μmol/ml), in which lipase esterification activity was only 45.02 U/g. However, protease activity decreased about 11 times at a higher concentration of ethanol (5–50 μmol/ml). It resulted in an increase in the esterification activity of lipase (324.03 U/g). This finding could be used for explaining the effects of ethanol on the enzymatic synthesis of OAEE using crude rice bran lipase in a fed-batch system. When the ethanol concentration in the reaction system was low (≤ 4 μmol/ml), the final OAEE conversion was only 30%. It was caused both by the inhibition of lipase by rice bran protease and by the effect of low ethanol concentration on the equilibrium position of the lipase-catalysed esterification reaction. However, the final OAEE conversion reached 76–92% when higher ethanol concentrations (12.5–50 μmol/ml) were added at initial reaction. It is suggested that the addition of higher ethanol concentrations (12.5–50 μmol/ml) into the reaction system may reduce protease activity and also increase ethanol concentration in the reaction system to be converted into OAEE.

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.

Hydrolysis of Nyamplung (Calophylluminophyllum) protein and their antioxidant activity

The seedcake of nyamplung seeds still contains high protein. Recent studies show that protein hydrolysate has many useful effects, such as an antioxidant. The protein was isolated by the isoelectric precipitation method, further on hydrolysed into short chain peptides. The chemical composition of seedcake and the protein content of extract were analysed. The hydrolysis of the extract was carried out in a various condition such as substrate concentration, pH, and temperature for a different length of hydrolysis and the degree of hydrolysis was determine by TNBS method. The protein isolation process performed on the defatted seedcake produced 52.84 ± 0.07% of protein extract with a brownish colour. The degree of hydrolysis (DH) was increased by increasing the length of hydrolysis and showed the optimum DH with 6.15mg/mL substrate concentration. The increase of temperature also increased the DH, however at 70°C with 240 min time reaction, the DH tended to decrease. The pH of reaction between papain showed th...

Effect of storage temperature on the stability of microencapsulated essential oil from cinnamon (Cinnamomum burmanii)

Cinnamon is a spice that widely available in Indonesia. The scent of cinnamon bark makes this spice plants are becoming popular as a flavor for cakes and drinks. The major component in its essential oil is cinnamaldehyde. The use of cinnamon is generally in the form of insoluble cinnamon powder or liquid essential oil which sensitive to light, heat, and oxygen, therefore it has to be encapsulated in order to extend its shelf life. The encapsulate composition determines the functional properties of the microcapsules. The combination of Arabic gum and maltodextrin is known giving the better encapsulation efficiency and stability than Arabic gum itself. Therefore, this research aims to discover the appropriate ratio of maltodextrin and Arabic gum as well as to evaluate the microcapsule stability of cinnamon essential oil against storage temperature. The essential oils were processed into microcapsules by a spray drying technique with the loading rate of 5 ml/min and with the inlet temperature of 120 °C. The ...

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%.

Novel source of protein extract from nyamplung (Calophyllum inophyllum)

Biodiesel from the seed of nyamplung (Calophyllum inophyllum) is a promising business Indonesia, and large scale production is being developed. Even though the waste is still high protein content, the application is still limited. It is because of lack of information about the protein characteristic. The protein isolation process performed on the defatted seedcake to produce 22.09 ± 0.87 dB of protein concentrate with a brownish color, and the following Lab values are 44.37 ± 1.29, 9.68 ± 0.3 and 12.4 ± 0.78, respectively. The functional group of the extract and molecular weight were determined by FTIR and SDS-PAGE respectively. Chromatogram of FTIR showed that the protein concentrate of nyamplung has a group as a characterize of amide are C=O stretching at1658.78cm−1, N-H stretching at 3371.57cm−1, and NH bending at1543.05cm−1. The molecular size analysis showed the protein of nyamplung relatively have molecular weight were between 9.73 until 37.96 kDa.

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...

Evaluasi Sensoris Odor Bubuk Merica Hitam (Pipernigrum L) Selama Penyimpanan Dengan Olfaktometer Statik

The purpose of the study was to enhance objectivity of sensory evaluation by static olfactometry of black pepper powder odor. Five trained assessors evaluate periodically the odor of black pepper powder stored at 50°C during 30 days by test tube and static olfactometry.. Individual repeatability of assessors was higher by static olfactometry than by the test tube. The group perfomed better in discriminating odor character changes using static olfactometry than test tube. They were able to detect an unfamiliar odor but unable to describe it as indicated by the low reproducibility. It follows that static olfactometry can be use as a tool to discriminate black pepper powder character odor changes.