Jurnal Akademika Kimia
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Analysis of Levels of Phosphorus and Magnesium in Beef Bones from Kaledo Waste
Get PDFThe Kaili tribe is a tribe with a very distinctive and well-known culinary heritage in Indonesia, one of which is Kaledo (donggala soft leg). The large number of restaurants and restaurants that provide Kaledo menus raises problems, namely the lack of utilization of beef bones from Kaledo waste, causing environmental issues. The community does not know much about the types of minerals contained in the beef bones. Among them are the minerals contained in beef bones, namely phosphorus and magnesium. This study aims to determine the levels of phosphorus and magnesium in beef bones from Kaledo waste taken randomly from Kaledo restaurants in Palu City. Determination of phosphorus and magnesium levels in beef bones from Kaledo waste using a Uv-Vis spectrophotometer and an atomic absorption spectrophotometer (AAS). The results showed that the analysis of the phosphorus content of beef bones from Kaledo waste obtained 95.125 mg / 100 g, and the magnesium content was 102.9 mg / 100 g. The results of this study are expected to be a source of information about the levels of phosphorus and magnesium contained in beef bones from Kaledo waste and can be used further as a substance in the utilization of beef bones from Kaledo waste
The Relationship Between Interest in Learning and Critical Thinking Skills of Junior High Students in Science Learning
Get PDFThis study aims to determine the relationship between interest (X1) and critical thinking skills of seventh-grade students in science learning at SMP Negeri 4 Tanantovea. This study is a descriptive correlational study. The research sample was selected using total sampling, comprising all seventh-grade students from two classes, totalling 36 students. The instruments used in this study were a questionnaire on students' interest in learning and a critical thinking test. The questionnaire on interest in learning and the critical thinking test were subjected to content and construct validity tests. A field trial was conducted with 36 students, comprising 19 female and 17 male students. The instruments used in this study were a critical thinking test and a questionnaire on students' learning interests. The questionnaire on learning interest consisted of 20 statements, while the critical thinking test consisted of 10 essay questions. All instruments underwent content validity testing by experts, empirical validity testing using Pearson product-moment correlation, and reliability testing using Cronbach's Alpha. Prerequisite tests were conducted using the Shapiro-Wilk normality and linearity tests with SPSS 22 software. The study results in Grade VII of junior high school concluded a relationship between interest and critical thinking ability, with a correlation value of 0.402 and a regression equation of Ŷ = Y = 57.813 + 0.165X1. Furthermore, based on the calculated r value of 0.442, the criteria for the strength of the relationship between the variables of interest and critical thinking indicate a fairly strong relationship
Mass Balance of Hydrocarbons Fuel from Waste Cooking Oil and Plastic by Co-Pyrolysis
Get PDFIndonesia has committed to climate change mitigation through a sustainable energy transition. Currently, the share of renewable energy in Indonesia’s energy mix only reaches 12 %. One type of renewable energy that the Indonesian government is focusing on is biofuel to reduce consumption and dependence on fossil fuels. Bio-oil produced through pyrolysis has the potential to be used as a biofuel. The chosen pyrolysis process is Co-Pyrolysis, which involves two or more feedstocks. In this study, the process was carried out using waste cooking oil (WCO) and HDPE waste as feedstocks. The process was conducted at 450°C for 30 minutes, with varying masses of both feedstocks. The data obtained were analyzed using mass balance and yield analysis to determine the optimal conditions for producing bio-oil as a hydrocarbon fuel. The optimal condition was found at a mass ratio of HDPE: WCO = 1:4, with a bio-oil yield of 78%. Under these optimal conditions, the conversion of HDPE plastic into heptadecane was 29.39%, and the conversion of oleic acid in waste cooking oil into heptadecane was 38.8%. This also serves as an initial step toward developing a pilot plant-scale process using HDPE plastic waste and waste cooking oil
The Effect of Purple Sweet Potato (Ipomea Batatas L.) Fermentation Time on Carbohydrate and Protein Levels
Get PDFYogurt is a fermented milk product produced by Lactobacillus bulgaricus and Streptococcus thermophilus, which confer a distinctive sour taste. Lactic acid bacteria require a carbohydrate source during growth, which can be obtained from purple sweet potatoes. This study aimed to determine the effect of fermentation time on carbohydrate and protein levels in purple sweet potato yoghurt. This study comprises 3 samples: sample A (yoghurt fermented for 7 hours), sample B (yoghurt fermented for 14 hours), and sample C (yoghurt fermented for 21 hours). The study employed a quantitative design, with carbohydrate testing using the Luff-Schoorl method and protein testing using the Kjeldahl method. The carbohydrate content was 10.36% in sample A, 10.41% in sample B, and 10.02% in sample C; the protein content was 2.23% in sample A, 3.93% in sample B, and 4,03% in sample C
Silico Study of Alpha-Glucosidase Inhibitory Activity of Triterpenoid Compounds from Ethanol Leaf Extract of Manilkara Kauki
Get PDFDiabetes mellitus type 2 is the most common form of diabetes, characterized by insulin resistance and hyperglycemia. One strategy for managing blood glucose levels is to inhibit the enzyme α-glucosidase, which plays a role in breaking down carbohydrates into glucose. Synthetic inhibitors such as acarbose have been widely used, but they often cause gastrointestinal side effects. Therefore, there is a need to identify alternative inhibitors from safer natural sources. The leaves of Manilkara kauki are known to contain triterpenoid compounds with potential antidiabetic properties. This study aims to evaluate the activity of triterpenoid compounds from the ethanol extract of M. kauki leaves as α-glucosidase inhibitors using an in silico approach via molecular docking. The target protein used was 5NN8, with acarbose as the reference ligand. Docking results showed that two compounds, β1-barrigenol and barringtogenol C, exhibited good binding affinity with energy values of -7.74 and -7.75 kcal/mol, respectively. Both compounds were also able to interact with essential residues at the active site of α-glucosidase, such as ASP616, ARG281, MET519, and TRP376. These results indicate that triterpenoids from Manilkara kauki have the potential as natural α-glucosidase inhibitor candidates
Analysis of Calcium (Ca) and Potassium (K) Contents in Tin Fruits (Ficus carica Linn)
No full textTin Fruits (Ficus carica Linn) are typical Middle Eastern plants that have been cultivated in Indonesia. Tin fruits are rich in minerals, especially calcium and potassium. In addition, they also contain benzaldehyde which is beneficial against cancer cells. This study aimed to determine the concentrations of calcium and potassium contained in tin fruits. Determination of calcium and potassium contents using an atomic absorption spectrophotometer (AAS). The results showed an analysis of the water content of the sample obtained was 89.065 %, ash content was 1.0165 % and biomass content was 9.9185 %. While the analysis of calcium contents at a wavelength of 422.7 nm and potassium at a wavelength of 766.5 nm respectively obtained that an average yield of calcium was 354.97 mg/100g and 752.68 mg/100g for potassium. The results of this study are expected to be able to attract the interest of the community to cultivate tin fruits, especially in Central Sulawesi
Bioactive Compound Contents and Antioxidant Activity of Purified Red Sorghum Pericarp Extract by Membrane Ultrafiltration Process
No full textSorghum plants contain bioactive compounds such as phenolic compounds and proanthocyanidins. The presence of these compounds is extremely valuable for use as antioxidants in health care. This study aims to determine the total phenolic content, total proanthocyanidin content, and antioxidant activity of purified red sorghum extract using the ultrafiltration membrane method with different transmembrane pressure. At pressures of 8, 9, and 10 Bar, an ultrafiltration process was carried out using a polyethersulfone (PES) membrane with a molecular weight cut-off size of 10 kDa. The total phenolic content was determined using the Folin-Ciocalteu method and identified using UV-Vis spectrophotometry at 760 nm. Total proanthocyanidin content was measured using the acid-butanol method and then analyzed using UV-Vis spectrophotometry at 550 nm. The DPPH (2,2-diphenyl-2-picrylhydrazyl) method will be used to determine the antioxidant activity of purified red sorghum extract. The results of the measurements show that the higher the transmembrane pressure, the higher the concentration of phenolic and proanthocyanidins content, and that the purified red sorghum extract has a high antioxidant value (IC50 = 66.852 ppm)
Determination of Secondary Metabolites and Antioxidant Activity of Robusta Coffee Bean Ethanol Extract by UV-Vis Spectrophotometry
No full textRobusta coffee beans (Coffea canephora Pierre ex.A.Froehner) have antioxidant, antidiabetic, and antihypertensive effects and can prevent coronary heart disease. This study aims to determine the compound content and total levels of secondary metabolites and to determine the antioxidant activity of robusta coffee bean extract. UV-Vis spectrophotometer was used to determine the total levels of secondary metabolites and antioxidant assay using DPPH reagent. The results obtained for the positive qualitative test contain secondary metabolites of alkaloids, flavonoids, saponins, and tannins and do not contain steroid compounds while for the quantitative test, the total alkaloid content is 0.1973% w/w (caffeine equivalent), flavonoids are 1.2106% w/w (equivalent to quercetin), saponins 0.536% w/w (equivalent to sapogenins), tannins at 9.7103% w/w (equivalent to tannic acid). The IC50 result for the antioxidant activity of the ethanolic extract of robusta coffee beans is 55.16 µg/mL which is included in the category of strong antioxidants
Impact of the Concentration Ethylenediamine on Optical Properties of Carbon Dots from Jengkol Peel (Archinendron pauciflorum)
No full textCarbon dots (CDs) are a new member of fluorescent nano carbons that have attracted attention because of their potential applications derived from their optical, chemical, and electrical properties. CDs from jengkol peel via the solvothermal method at 200 oC for 7 h with the addition of ethylenediamine (EDA) as a heteroatom dopant have been successfully carried out. This study aims to determine the effect of concentration EDA on the optical properties of CDs for the possible reason. The results revealed that the CDs solution has fluorescence properties; that bluish-green glow can be observed under ultraviolet radiation (365 nm). The UV - Vis absorption peaks did not depend on the CDs concentration, but the absorbance intensity decreased with increasing EDA concentration. The best fluorescence properties were possessed by 10 % EDA in CDs which produced λex/λem of 370 nm/518 nm, respectively, with a quantum yield of 42 %. The FTIR spectra of all samples showed that the CDs surface had functional groups such as carboxylic acids, hydroxyl, and amines. The obtained CDs have the potential to be used as heavy metal ion detectors, bioimaging, and antibacterial agents
Urang Aring (Eclipta alba (L.) Hassk) Leaf Extract as Natural Dyes for Making Pomade
No full textDyes have an important role in the industrial sector to increase consumer interest in a product. Urang aring is a plant with color pigments that can be used as natural dyes. This study aims to utilize urang aring leaf extract as a natural hair dye for the manufacture of pomade by producing the quality of pomade preparations according to standards. The research method was carried out experimentally including determining the water content and ash content of urang aring leaves and optimizing the time of dye extraction and storage of urang aring leaf extract using a UV-Vis spectrophotometer, then making pomade based on the formulation of urang aring leaf extract and beeswax, namely: formulation I (3:3), II (5:3), and III (10:3). Pomade quality test includes: organoleptic test, homogeneity test, pH test, freeze-thaw test, and color stability test against sunlight. Based on the results of the study, it was found that urang aring leaf extract can be used as a natural dye for the manufacture of pomade with formulation III which meets the standards in the pomade quality test because it has a soft dense texture, blackish green color, and has no odor with a pH of 6 which is ideal for hair. Pomade formulation III also has a texture that does not separate at extreme temperatures and good color stability under direct sunlight for 5 hours