Journal of Biobased Chemicals

Effect of Time, pH, and Yeast Concentration on Bioethanol Levels in the Ulva sp. Fermentation Process

Aina Christalia Rinastiti — 2022-12-30

Bioethanol is a form of renewable energy that is used to reduce dependence on the use of fossil fuels which cause various negative impacts on the environment. Ulva sp. contains high carbohydrates so it has the potential as a raw material for bioethanol production. This study aims to determine the optimum conditions of the fermentation process with the variables used time, pH, and yeast concentration. This study used the results of hydrolysis of Ulva sp. with optimum operating conditions of 0.1 N HCl concentration, 80 mesh particle size, and 450 watt microwave power. Measurement of bioethanol levels was carried out using an alcoholmeter. The results showed that the optimal conditions for fermentation were 7 days of fermentation, pH 5.5, and yeast concentration of 1.5% which resulted in a bioethanol content of 7.55%.

Extraction Method of Ultrasound-Assisted Extraction (UAE) of Robusta Coffee Skin Waste using 96% Ethanol Solution in Tanah Wulan Village, Maesan District, Bondowoso Regency

Miftakhul Ulum — 2022-12-30

Argopuro Mountains, Tanah Wulan Village, Maesan District, Bondowoso Regency, East Java, Indonesia is one of the Robusta coffee-producing areas. Robusta coffee beans that are processed can produce quite a lot of by-products in the form of underutilized waste. It is known that coffee skin waste still has a lot of remaining content and it is possible to take these bioactive compounds using extraction methods. Bioactive compounds in natural materials can be done by extraction. Extraction is the process of separating substances in a sample based on different solubilities. The extraction method used is the ultrasonication method (nonconventional). Extraction of the ultrasonication method only requires a relatively shorter time with the help of an ultrasonicator. There is a lot of content in the coffee skin waste powder that needs further testing. The results of this study are expected to provide economic value to robusta coffee husk waste.

Effect of Ethanol Solvents in the Extraction Process of Bioactive Compounds from Brown Seaweed (Sargassum sp.) with the Ultrasound Assisted Extraction Method

Slamet Pujianto — 2022-12-30

Sargassum sp., part of brown algae, is traditionally used as animal feed. Nonetheless, Sargassum contains phenolic compounds that promise to be the raw material of natural antioxidants. The work is to extract phenolic compounds from Sargassum sp. in ethanol and to investigate the effect of the process on phenol yields. Several dried Sargassum sp. are milled in a certain size and extraction using ultrasound assisted extraction with ethanol solvent. Process variables are the extraction time (30-50 minutes) and the Ratio of Sargassum sp. to ethanol which is 5:100-15:100 (b/v), and power of 170-190 watts. Phenol compounds are quantified using the error acid method. The DPPH method is performed to check the antioxidant activity. To investigate the influence of the process, surface response methods based on central composite designs are applied in this work. 153.334 mgGAE/g in 30-minute extraction conditions, 170 watts of power, and a ratio between masses and solvents of 0.05. The antioxidant activity (IC₅₀) of Sargassum sp. extract is 87.57 ppm.

Microwave Assisted Hydrolysis Ulva sp. Using HCl for the Production of Bioethanol Raw Materials

Bekti Palupi — 2022-12-30

The challenges faced by the Indonesian state are increasing greenhouse gases, climate change, and depleting fossil fuel reserves. This requires the exploration of alternative energy that is environmentally friendly and sustainable. Algae biomass, especially Ulva sp. is one of the resources that have the potential for bioethanol production as an alternative energy producer. The purpose of this study is to determine the potential of Ulva sp. as raw material for bioethanol and to determine the effect of particle size, solvent concentration, and power on the hydrolysis process. This study used Ulva sp. as raw material. hydrolyzed with HCl solvent using the microwave assisted hydrolysis method. Hydrolysis with HCl concentrations of 0.1 N, 1 N, 2 N, variations of microwave power 150 watts, 300 watts, 450 watts, and particle sizes of 60 mesh, 80 mesh, and 100 mesh. Measurement of reducing sugar levels was carried out using the dinitro salicylic acid (DNS) method. The results showed that the best conditions for hydrolysis were when the HCl concentration was 0.1 N, the microwave power was 450 watts, and the particle size was 80 mesh which resulted in a reducing sugar content of 20.751 mg/mL.

Effect of Ethanol Solution Concentration in the Extraction Process of Centella asiatica L. Bioactive Components Using Microwave-Assisted Extraction (MAE) Method

Fira Ulvatur Rohmah — 2022-12-30

The Pegagan plant has a scientific name in the form of Centella asiatica L. which is included in the Centella genus, Apiaceae family, and kingdom Plantae. Pegagan (Centella asiatica L.) has distinctive bioactive components, namely triterpene ester glycoside compounds in the form of asiaticoside and madecassoside, and triterpene group compounds in the form of Asiatic acid and madecassic acid. In this study, the extraction of bioactive components from pegagan was carried out using the Microwave-Assisted Extraction (MAE) method and will study the effect of ethanol solvent concentration in the extraction of bioactive compounds. Analysis of the extracted bioactive content was carried out by analyzing the total phenol content using the Folin-Ciocalteau reagent and ANOVA analysis. The results obtained from the study were in the form of total phenol content as an indication of the presence of bioactive compounds, namely at operating conditions of 450 watts of power, 50% ethanol concentration with a radiation time of 15 minutes which resulted in a total phenol content of 21.9244 mg AGE/g sample. In the ANOVA analysis with ethanol solvent, variables that gave a significant response to the total phenol content were microwave power, radiation time, and ethanol concentration with an R-square value of 95.31%. The effect of ethanol concentration on the total phenol content produced, namely the concentration of pure ethanol solvent will produce extracts with the smallest total phenol content, the effect of extraction time on total phenol content, namely the longer extraction time will increase the total phenol content. Maximum total phenol content using ethanol solvent that is, at operating conditions of 450 watts of power, 10% ethanol concentration with a radiation time of 15 minutes which resulted in a total phenol content of 520 mg AGE/g sample.