Chusnul Hidayat

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.

Process Intensification of Enzymatic Fatty Acid Butyl Ester Synthesis Using a Continuous Centrifugal Contactor Separator

Fatty acid butyl esters were synthesized from sunflower oil with 1-butanol using a homogeneous Rhizomucor miehei lipase in a biphasic organic (triglyceride, 1-butanol, hexane)– water (with enzyme) system in a continuous setup consisting of a cascade of a stirred tank reactor and a continuous centrifugal contactor separator (CCCS), the latter being used for integrated reaction and liquid–liquid separation. A fatty acid butyl ester yield up to 93% was obtained in the cascade when operated in a once-through mode. The cascade was run for 8 h without operational issues. Enzyme recycling was studied by reintroduction of the water phase from the CCCS outlet to the stirred tank reactor. Product yield decreased over time to an average of 50% of the initial value, likely due to accumulation of 1-butanol in water phase, loss of enzyme due to agglomeration, and the formation of a separate enzyme layer.

Enzymatic glycerolysis–interesterification of palm stearin–olein blend for synthesis structured lipid containing high mono- and diacylglycerol

The objective of this research was to evaluate enzymatic glycerolysis–interesterification to synthesize structured lipids (SLs) containing high monoacylglycerol (MAG) and diacylglycerol (DAG) from a palm stearin–olein blend (PS–PO blend). The results showed that the optimum conditions for the solvent to fat ratio, glycerol to fat ratio, and enzyme concentration were 2:1 (v/w), 1.5:1, and 15% (w/w), respectively. The conversion rate of MAG and DAG decreased at a high glycerol to fat ratio, low solvent to fat ratio, and high enzyme concentration due to an increase in viscosity and low agitation effectiveness. The emulsion capacity and stability of the SLs were 60.19% and 96.80%, respectively. The hardness of the SLs increased about 3.1-fold. The MAG, DAG, and triacylglycerol conversion rates were 0.45, 0.48, and 1.02%/h, respectively. Thus, glycerolysis–interesterification of a PS–PO blend increased DAG and MAG concentrations and further improved the hardness, emulsion capacity, and emulsion stability of the SLs.

Simultaneous Hydrolysis and Fermentation of Sweet Sorghum Varieties (FS501 and KCS105) into Bioethanol Using Saccharomyces steineri – A Kinetics Study

In this study, kinetics of bioethanol production by fermentation of three different substrates, which were artificial substrate and the juice of two sweet sorghum varieties (FS501 and KCS105) using Saccharomyces steineri, were examined using two proposed models by assuming that simultaneous hydrolysis and fermentation occurred. Fermentation of the substrate of FS501 and KCS105 juices showed better data fitting by using the modified version of the kinetics model while the fermentation of artificial substrate which was free of any other components followed Philippidis’s kinetics model. This difference was caused by the change of the yeast behavior in the form of the reduction of both the rate of fructose and/or glucose consumption by the yeast and the rate of fructose and or glucose conversion into ethanol during lag phase. As the consequence, sucrose hydrolysis seems very dominant in the FS501 and KCS105 juices fermentation during the lag phase. The change of behavior of the yeast was estimated being caused by the existence of “impurities” such as acetic acid, glycerol, nitrogen, phosphor, and potassium in the FS501 and KCS105 juices. From statistical analysis using correlation coefficient (between kinetics parameters and “impurities”), acetic acid was the most influential component to change the behavior.

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...

Kinetic oxidation of protein and fat in snapper (Lutjanus sp) fillet during storage

Fillet of snapper (Lutjanus sp) contains oil and proteins that are easily oxidized during storage. The kinetic model can determine oxidation reaction rate. The objective of this research was to evaluate kinetic oxidation reaction of both oil and protein in fillet of snapper. Fillet of snapper was stored at 0, 10, 20, 30 and 40 °C. The reaction rate constant (k) and activation energy were further determined. Results showed that the value of k increased from 0.28 mg/kg per day to 10.27 mg/kg per day at temperatures from 0 to 40 °C for the peroxide value. For the acid value, TBA value and carbonyl value were rate constants 0.05 mg/kg per day becomes 3.56, mg/kg per day, 0.29 mg/kg per day to 8.91 mg/kg per day, and 0.38 nmol/gr per day becomes 12.06 nmol/gr per day, respectively. The activation energy (Ea) of oxidation reaction peroxide value 65.69 kJ/ mol.K, while the acid value, the TBA value and carbonyl value, 84.80 K/mol.K, 62.99 K/mol.K and 63.64 K/mol.K, respectively. Fish fillet started to deteriorat...

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.