Advances in Science and Technology Vol. 138

Abstract: Gluten is a protein that gives a chewy characteristic to wheat flour-based foods. Gluten consists of glutenin and gliadin linked by disulfide bonds in which gliadin gives the viscosity and extensibility properties of gluten. Based on its properties, gliadin has great potential as a biomaterial and has been widely used in both the pharmaceutical and food industries. The separation between gliadin and glutenin generally uses alcohol such as 60-70% ethanol and 1-propanol. However, this method is inefficient and can cause environmental pollution. Another method is to add a food grade aqueous acidic medium where the separation occurs due to the difference in isoelectric point between gliadin and glutenin. Aim of the research to determine the effect of sodium sulfite with varying concentration on the separation of gliadin from gluten. In this study, gliadin was separated using 98% acetic acid, while sodium sulfite was used as a reducing agent to break the disulfide bond. To precipitate glutenin, the pH of the dispersion was adjusted to 4.4 using 5% ammonium hydroxide. The centrifugation was carried out at 8000 rpm to obtain the gliadin. The FT-IR spectrum showed that gliadin had absorption in the amide I band (C=O), namely α helix for the use of 0.1% and 0.15% of sodium sulfite and β sheet for 0.2% of sodium sulfite. The SDS-PAGE analysis on the use of all concentrations of sodium sulfite contained gliadin with a molecular weight of 25-40 kDa. After comparing it with marker proteins, it was estimated that it contains only α/β gliadin and γ- gliadin. The RP – HPLC chromatogram showed that the use of 0.1% and 0.2% sodium sulfite resulted in ω5 gliadin and ω 1,2 gliadin types, and at 0.15% sodium sulfite resulted in the most complete types, namely ω5 gliadin, ω1,2 gliadin and α /β gliadin, each containing glutamine, proline, phenylalanine, tyrosine and glycine. Overall, the use of 98% acetic acid at a certain pH with sodium sulfite as a reducing agent can separate gliadin from gluten. However, there was a change in the three-dimensional structure of gluten proteins so not all gliadin fractions can be identified completely.Keywords: 98% acetic acid; gliadin; isoelectric point; sodium sulfite

Abstract: Cassava starch is a common food ingredient that has a high carbohydrate content. It can be modified into resistant starch type 3 (RS-3) that has lower glycemic index. The common production of RS-3 includes gelatinization to free the amylose from the granule structure, then followed by cooling to induce retrogradation. The granule structure of cassava starch resists the structure disintegration so that it is unable to produce high resistant starch content in the retrogradation process. In this study, High Shear Mixing (HSM) was used to help the gelatinization process to provide cassava starch structure disintegration. The centrifugation was carried out to separate the low free-amylose and high free-amylose liquid layers. This paper examines the relationship between the effect of variations in rotational speed (rpm) of HSM on the amount of resistant starch as a percentage of dietary fiber. A 1:20 starch-water suspension was processed using an HSM with rotational speeds of 9.000, 10.000, 11.000, and 12.000 at a temperature of 95°C for 15 minutes. After the stirring process, the water starch suspension was separated by centrifugation for 30 minutes. Then the samples were cooled in the refrigerator for 24 hours, then dried under freeze-drying method. The product that has been obtained is then analyzed by Total Dietary Fiber (TDF), amylose, and carbohydrate analysis. From the analysis of the result, this method can increase the TDF content of the product up to 14,66% at 12.000 rpm.

Abstract: Crude palm oil purifying process is an important process in refining vegetable and animal oils to remove the impurities. This process produces spent bleaching earth (SBE) waste which needs to be reprocessed before being released into the environment because it contains 20-30% of oil. However, based on Government Regulation Number 22/2021, SBE was removed from the list of hazardous waste on condition the oil contained is under 3%. In this study, the oil content in SBE was extracted using maceration process. The aim of this study was to measure the remain oil content in de-oiled bleaching earth (de-OBE) using various solvent. The solvents used are n-hexane, acetone, and ethanol with SBE to solvent ration. The highest yield obtained was 22% using n-hexane as a solvent. To determine the quality of the recovered oil, water and free fatty acid contained were analyzed. After being extracted, the remaining oil content in the de-OBE was measured. The remaining oil content in de-OBE for n-hexane and acetone as solvent was under 3% but for ethanol the oil content in de-OBE was high up to 15 %.

Abstract: Paecilomyces variotii is one of the heat-resistant fungi that causes spoilage problems, especially in processed fruit products. Many non-thermal methods have been tested for their efficacy to inactivate spoilage and pathogenic microorganisms. The objectives of this study were to use dense CO₂ (HPCD) and their combination with thermal processing at 50-90oC to reduce the population of P. variotii mold ascospores in orange juice. Application of dense CO₂ between 0.4 to 0.8 MPa for 30 min only reduced <1.0 log of these spores. The highest log reductions achieved (2.24 log) were shown by sequential treatments of 0.8 Mpa pressurized CO₂ for 30 min followed by 90oC-30 min thermal processes. Soluble solid content (10-30oBrix) affected the spore reduction by dense CO₂-assisted thermal processing, being higher at lower oBrix. These results indicate that P. variotii mold ascospores were highly resistant to these treatments. Increasing the pressure of HPCD treatment might improve the log reductions required for food pasteurization.

Abstract: Increased use of coal has an impact on the environment because of the waste from coal combustion residual. It also has an impact on the management of waste due to limited land for the temporary storage of waste owned by the coal user industry. In the Government Regulation of the Republic of Indonesia Number 22 of 2021 concerning the Implementation of Environmental Protection and Management, fly ash and bottom ash are registered as non-hazardous waste. The addition of fly ash to the planting medium can affect soil fertility and biota in the soil. The number of heavy metals contained in the soil to which fly ash is added depends on the amount of fly ash so that it can affect the heavy metals in plants. The number of microbial populations in the soil such as fungi and actinomycetes in the soil decreases with the added concentration of fly ash which is due to changes in soil pH such as denitrifying microbes. In this research, cocopeat, and guano growing media were used in a ratio of 1:1. The addition of fly ash to the planting medium were 20%, 30%, and 40%. In addition, this research also evaluated the effect of the addition of EM4 and the selected microbes on the growing media mixture. The planting medium was aerobically fermented for one week, two weeks, and three weeks. Then it was tested for macro elements, the number of bacteria, moisture, and pH every week. The mixture of planting media was tested on mustard pakcoy for one month to see the growth of the plant indicated by the number of leaves and plant height. From the results of this research, it was found that bacteria affect the growing media (pH, the number of microbes, phosphate, and potassium) and the plant growth in the height and total of leaves. Variations in the addition of fly ash to the growing media affect phosphate and aluminium content.

Abstract: Spodoptera litura is an agricultural pest that attacks almost all types of herbaceous plants, especially vegetable commodities. Spodoptera litura causes serious damage during the immature or larval stage. The attack of Spodoptera litura larvae can cause significant losses to farmers. To deal with these pests, they still use chemicals that have a negative effect on the environment. Therefore, a good solution is required by utilizing biological agents to control agricultural insect pests. It is an alternative strategy that is more environmentally friendly than the use of chemical pesticides. Research on the use of biocontrol agents as biological control agents for insect pests is still being pursued, one of which is the use of entomopathogenic microorganisms. Biological control using entomopathogenic bacteria is an alternative strategy that is effective and environmentally friendly compared to the use of synthetic insecticides. This study aims to determine the mortality rate from the use of organic waste and bacteria against pathogenic pests Spodoptera litura and to determine the activity of pathogenic pests Spodoptera litura after treatment. This study begins with observations to determine the log phase of bacterial growth by culturing bacteria. The tested bacterial cultures were grown on nutrient broth media so that the bacteria were observed and counted using a hemocytometer method to determine the contact time. The next step was to make nutrient broth liquid media and sterilize using an autoclave at 121°C for 15 minutes. Prepare organic waste of coconut water and 10% molasses to be contacted between the substrate and bacteria. Spodoptera litura was collected from Keputran Market Surabaya - Indonesia every day. Spodoptera litura was treated with biopesticide and mustard greens once at t = 0 hours and the activity and mortality rates were observed at 4 hours, 24 hours, 48 hours, and 72 hours. The results showed that the best variable in % mortality was the consortium of bacteria Bacillus thuringiensis, Bacillus cereus, Pseudomonas fluorescens, and the bacterial community of Sidoarjo mud and a mixture of organic waste coconut water with a pathogenicity value of LT50 for 22 hours and mortality rate at 100%.

Abstract: Catalyst is a substance that is widely used in chemical reactions to obtain certain products. This study has been focusing on preparing and employing solid catalyst derived from geothermal sludge (GS) as waste material from Dieng Geothermal Power Plant (PLTPB) activity. The methodology of catalyst preparation was extraction of silica from the sludge by alkali solution, followed by gelling formation and acidification with sulfuric acid solution. The prepared catalyst was then applied in hydrolysis reaction to convert sago flour into glucose.Catalyst properties were assessed in term of morphology, crystallinity, surface area, and activity (hydrolysis reaction). Sample analysis confirmed the produced catalyst was amorphous in general, having 127 m²/g of surface area. In addition, the prepared catalyst contained 78 - 79 % of silica, a significant increase - as a result of preparation - from that of raw material sludge which had 33 - 43 % silica. From the catalyst activity test conducted at 120 - 185°C hydrolysis reaction, as much as 50 % of glucose yield could be obtained from sago starch conversion, indicating prospective catalyst performance.Keyword: Sulfonated SiO₂, Catalyst, Geothermal Sludge Waste, Sago, Hydrolysis

Abstract: Laboratory activities for testing nitrogen levels of natural rubber production are carried out to determine the nitrogen content to meet the Standard Indonesian Rubber (SIR). The test parameters use hazardous chemicals such as strong acids, i.e. sulfuric acid, which have corrosive properties. Testing activities in the laboratory will produce by-products in the form of liquid wastewater containing high sulfate concentrations. A cheap and environmentally friendly wastewater treatment system is required in this research, namely a coagulation-flocculation system using eco-enzyme as a liquid coagulant. Eco-enzyme is a fermented product of household organic waste from the remaining vegetables and fruit peels that are still fresh with a 1:3:10 formula after around 3 months. The purpose of this research was to determine the levels of COD, TDS, and sulfate concentrations as an indicator of wastewater quality standards that are safe for the environment. It is necessary to know the effectiveness of the eco-enzyme as a coagulant in treating laboratory wastewater with various concentrations of 1, 5, 10, 20, and 40% v/v. As well as variations in monitoring time of 5, 10, 15, 20, and 30 days. In this study, laboratory waste treatment with Eco-Enzyme as a coagulant resulted in a decrease in sulfate levels at 29.8 mg/L found at 1% v/v Eco-Enzyme concentration with monitoring for 30 days. With levels of COD 263 mg/L, TDS 39.7 mg/L, and pH 7.01 at a concentration of 40% v/v Eco-Enzyme. The results of this study indicate that Eco-Enzyme can act as a natural coagulant that is environmentally friendly and can degrade laboratory liquid waste so that it meets wastewater quality standards that are safe for the environment.

Abstract: The potential of zircon minerals in Indonesia as valuable adsorbent materials has not been properly developed. Seeing its high potential as an excellent adsorbent for anions/cations in water treatment and industrial wastewater, the raw zircon minerals into zircon oxides which will later be composited with magnetic nanoparticles using one-pot solvothermal processes (Fe₃O₄@ZrO₂). Cadmium is one of the most substances heavy metals toxic at lower concentrations. It is used in many industries, including textiles, paint, and dyes. In drinking water and industrial wastewater, the permissible concentration has been set the concentration level at 0.003 mg/L by the World Health Organization.The adsorbent characterizations of SEM and XRF analysis showed that the Fe₃O₄@ZrO₂ had many different chemical composition and a possibility of high specific surface area due to the nanosize particle for adsorption processes. The Fe₃O₄@ZrO₂ showed high adsorption uptake capacity and selectivity for the cadmium in the aqueous solution. The highest cadmium adsorption capacity was achieved (24.85 mg/g) at pH 6 using the Fe₃O₄@ZrO₂ as adsorbent. The removal efficiency of the Fe₃O₄@ZrO₂ for Cd remains almost 80% after three cycles. Therefore, the Fe₃O₄@ZrO₂ has the potential to be used as an adsorbent in water and wastewater treatment.