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Until now there are has not been any concrete utilization of used cooking oil (jelantah). This research seeks to convert this cooking oil waste into biodiesel. According the actual that cooking oil still contains free fatty acids can be converted into methyl esters through transesterification reaction. This effort is in line with the increasing requirement for renewable energy sources. But to achieve maximum reaction results of transesterification without using a catalyst, need supercritical conditions. Even more cooking oil waste is a low quality oil with high levels of free fatty acids and high rancidity. Therefore it is necessary to think about optimum process conditions and needed superior catalysts in the transesterification process. One catalyst that thought to be superior is CaO/CoFe2O4. Eggshell solid waste can be used as a natural source of CaO, through high temperature heating (calcination). The purpose of this study is produces biodiesel from waste cooking oil using CaO/CoFe2O4 from eggshells catalyst. This research objectives were achieved through the following main steps: (1) Synthesis of activation zeolite for rafination process; (2) Pre-treatment of cooking oil waste; (3) Trans-esterification reaction from cooking oil waste using CaO/CoFe2O4 eggshells waste; (4) Optimization of trans-esterification reaction; (5) characterization of methyl esters produced and see their potential as biodiesel. Based on the results of FTIR, yield analysis, GC-MS, the result product is methyl ester and its potency to be biodiesel. The catalyst application in the transesterification reaction made from used cooking oil is expected to provide a conversion is about 80%. [ABSTRACT FROM AUTHOR]

The heterogeneous catalysts in biodiesel synthesis is more environmentally friendly and reusable. Alkaline earth oxides are less alkaline than alkaline oxides. Biodiesel is an alternative fuel, which has been started to be developed as a renewable energy. The aim of this study was to synthesize biodiesel from low-quality crude palm oil (CPO) with heterogeneous catalyst of MgO-K2O using ultrasonic waves. The stages in this study were (a) activation of natural zeolites, (b) refining of low quality of CPO, (c) synthesis of MgO-K2O catalyst at ratio of 10 : 1, 10 : 2, 10 : 3 (MgO : KOH) and (d) transesterification of esterified CPO (variations in the amount of catalyst 10%, 15%, and 20%). This research achieved the optimum conditions for methyl ester synthesis at ratio of 10 : 2 (MgO : KOH) of catalyst composition (15% w/w of oil), and the yield was 88.086%. The character of the methyl ester was in accordance of Indonesian biodiesel standard, therefore, the methyl ester obtained has the potential as biodiesel. The composition of the synthesized methyl ester were 1.96% methyl myristate, 40.42% methyl palmitate, 44.32% methyl oleate, and 7.46% methyl stearate. [ABSTRACT FROM AUTHOR]

The characteristics of yogurt are influenced by the concentration of the starter and incubation time. This study aims to determine the effect of variations in starter concentration and incubation time on the characteristics of yogurt. To achieve this objective, the study was carried out through several stages, namely sample preparation (pasteurization of cow's milk); incubation of cow's milk yogurt with variations in starter concentration and incubation time; characterization of the physical and chemical properties of yogurt. The physical properties were investigated through organoleptic tests of color, aroma, taste, and texture, along with pH and viscosity tests. In contrast, the chemical properties were analyzed from the total acid levels and protein levels. The results show that the variation in the treatment of yogurt production significantly affects the physical and chemical characteristics of the yogurt produced. The produced yogurt's pH is in the range of the standard value set by Food Standards Australia New Zealand (FSANZ). Besides, the amount of produced yogurt's total acid and protein concentration in this study are also met in the standard value set by the Indonesian national standard of yogurt. Moreover, the Mann-Whitney test results show excellent characteristics of yogurt produced. It has a soft texture, a distinctive aroma of yogurt, sour flavor, and white color. [ABSTRACT FROM AUTHOR]

Nowadays gout is still a problem, both nationally and globally. The most widely used commercial drug to treat gout is allopurinol, which act as xanthin oxidase inhibitor, thus inhibiting uric acid synthesis. However, the use of allopurinol in a relatively long time can cause various unwanted side effects. Previous studies have shown that ethanol extract of sugar apple, which is rich flavonoids can inhibit the xanthine oxidase enzyme, but the structure of flavonoid in this fruit is still unknown yet. The aims of this study are to obtain ethanol extracts from the flesh of sugar apple, purify the extract by partitioning techniques using n-hexane and chloroform solvents, test inhibitory activity against xanthine oxidase and identify the flavonoid content using LC-MS/MS analysis. The results have shown that from 800 g the fruit flesh can be obtained 106 g of concentrated ethanol extract. After purification by partitioning using hexane and chloroform purified ethanol extract ed contained flavonoids, with TPC value of 16.11 ± 0.72 (mgGAE/g) and TFC value of 36.79 ± 2.96 (mgQE/g), in the same volume (0.01 mL) has xanthine oxidase inhibitory power by 75.17% compared to 1 mL of allopurinol 100 ppm and one of the dominant flavonoid compound contained was 3',4',7-trimethoxyflavan. [ABSTRACT FROM AUTHOR]

A coral skeleton is one of the biomonitoring agents that is useful to consider the seawater's situation pollutant. It can record contaminants' reconstruction and predict pollution history, especially of Fe3+ and F− ions as the pollutant in the seawater. We investigated Fe in the coral skeleton and added F− ions in seawater as the reconstruction of polluted F− ions. Fluoride content in coral skeleton was determined as a related Na concentration (NaF) using the Flame of Atomic Absorption Atom (FAAS) with spike method. Fe3+ and F− ions were mixed in the reactor with a coral skeleton to understand their effect on the coral growth. The coral absorbs F− ions in the coral growth with their effect on Fe's absorption rate. The addition of 1.5 g/L F− ions significantly reduces the coral growth by 25%. The coral skeleton can be used to control Fe and F− in the seawater. [ABSTRACT FROM AUTHOR]

Indonesian government has committed to increase exploration of wasters potential. Microalgae is an excellent water organism which high potential converted to biodiesel. Moreover, microalgae have a better photosynthetic ability than ordinary plants. Thus, microalgae can take part in preventing global warming by reducing carbon dioxide levels in the atmosphere. Recent research has successfully isolated several microalgae isolates from water area in East Java. However, they had not been characterized yet. Therefore, the aim of this research was to characterize two of those isolates in terms of potential as a feedstock of biodiesel production. The results showed that based on phenotype analysis, it could be concluded that Kelp I and Kelp IV were Prochloron sp. and Chlamydomonas sp. Prochloron sp. grew up optimally within 16-18 days, while Chlamydomonas sp. had an optimum growth at 13-18 days. The lipid yield of dried microalgae is 31.85% and 46.86% for Prochloron sp. and Chlamydomonas sp., respectively. Fatty acids composition in both Prochloron sp. and Chlamydomonas sp. were dominated by palmitic acid, which is very good for biodiesel synthesis. [ABSTRACT FROM AUTHOR]

The 1,8-dioxo-octahydroxantene has many derivates. One of those is 9-(4-hydroxyphenyl)-3,4,6,7-tetrahydro-2H-xanthene-1,8(5H,9H)-dione. This compound has been successfully synthesized from 4-hydroxybenzaldehyde and 1,3-cyclohexanedione. This reaction has been catalyzed by lime and lemon juice under the free solvent condition. It is assumed that citric acid in both materials has a role in catalyzing this reaction. The advantages of using them as catalysts are biodegradable, environmentally safe, and cheap. Besides that, the synthesis of this compound only required one reaction stage, and the product was easily purified. The structure of the pure product was determined by FT-IR, H-NMR, and GC-MS. The antioxidant activity of this compound was investigated by the DPPH method. This compound had an antioxidant activity with inhibition percentage over 53.42%. [ABSTRACT FROM AUTHOR]

Synthesis of 9-(4-bromophenyl)-3,4,5,6,7,9-hexahydro-1H-xanthene-1,8(2H)-dione (compound 1) using lime and lemon juices as catalyst under free solvent condition has been successfully done. Both fruits contained citric acid, which operates as an acidic catalyst. The structure of compound 1 was confirmed by IR, H-NMR, and MS spectra. The use of the natural product as a green catalyst has some advantages, that is eco-friendly, cheap, high availability, and biodegradable. DPPH methods were used as methods to determine the antioxidant properties of compound 1. This compound has properties as antioxidant with inhibition percentage of 59.20%, 65.38%, 67.41%, 68.53%, 70.0% at 2, 4, 6, 8, and 10 ppm respectively. [ABSTRACT FROM AUTHOR]