Palm oil mill effluent (POME) is a remarkably contaminating effluent that generated from three principle processes such as the sterilization, condensation, and hydrocyclone of palm oil in mills. The high biological oxygen demand (BOD), chemical oxygen demand (COD) and acidic pH of POME create an environmental issue if it is discharged into the aquatic and terrestrial ecosystem without treatment. However, by proper handling POME is also considered as a potential substrate for a renewable energy source. Biogas consisting mostly of methane and carbon dioxide has been produced using anaerobic digestion of POME. The process of biogas production involves the indigenous microbial community through hydrolysis, acidogenesis, acetogenesis, and methanogenesis. This study will elaborate on the potential of POME as a renewable energy source as well as the challenges and opportunities to develop biogas from POME in Indonesia. By proper handling and technology, from around (31 to 41) × 10⁶ t of palm oil products in Indonesia from the year 2015 to 2017 it is theoretically calculated that 150.93 MW, 173.37 MW, and 203.92 MW of power plant capacity can be generated, respectively.

Research background. Encapsulating lemuru fish protein hydrolysate is important to maintain its stability. However, optimal conditions for the encapsulation process of lemuru fish protein hydrolysate using statistical methods remain unexplored. This study aims to address this problem by optimizing the encapsulation conditions. Experimental approach. Maltodextrin and gum Arabic were used as carrier agents, with mass per volume ratio ranging from 10 to 30 %, and spray dryer inlet temperatures between 90 and 100 °C. In this study, we analysed the main interactions of these variables using response surface methodology (RSM). Results and conclusions. Our results show that mass per volume ratio of maltodextrin of 25 % and inlet temperature of 100 °C are the optimal conditions for the encapsulation of fish protein hydrolysate. The optimal conditions resulted in a high desirability index of 0.864, indicating an effective balance between yield, solubility and hygroscopicity. The actual results also fall well within the confidence interval of the predicted values, confirming the robustness of the model and the reliability of the predicted optimal encapsulation conditions. Encapsulated fish protein hydrolysate was compared with its non-encapsulated counterpart and characterised using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and particle size analyser (PSA) to validate the results. The encapsulated fish protein hydrolysate showed distinct properties, such as the presence of functional groups from maltodextrin, interconnected particle and more homogeneous and narrower particle size distribution. Novelty and scientific contribution. The encapsulation of lemuru fish protein hydrolysate using maltodextrin with mass per volume ratio of 25 % and inlet temperature 100 °C was successful in improving the properties of the protein hydrolysate. Further research should explore the functional properties of fish protein hydrolysate.