Saponification Process Research Articles

From kitchen to cosmetics: Study on the physicochemical and antioxidant properties of waste cooking oil-derived soap

A large amount of used cooking oil (UCO) is improperly disposed of in sewage and rivers, leading to environmental pollution and posing health risks such as carcinogenic diseases. This study explores an eco-friendly approach to addressing this issue by repurposing UCO for laundry soap production, contributing to waste management and environmental decontamination. The soap was prepared by treating UCO with an alkaline solution (NaOH) through a simple saponification process, providing a greener alternative to traditional methods that rely on imported vegetable oils. The prepared soaps were evaluated for cleansing capacity as well as physical, chemical, and physicochemical properties. The results showed moisture content of 9.27 % to 10.34 %, pH ranging from 6.03 to 4.46, chloride percentage from 0.055 % to 0.29 %, free caustic alkali between 0.152 and 0.175, and total alkali content from 0.29 % to 0.73 %. These values meet the requirements of East African Standards (EAS), validating the quality of UCO-based soaps. By diverting UCO from waste streams and utilizing it in soap production, this approach supports waste management, minimizes environmental pollution, and contributes to sustainable production practices.

Deactivation mechanism of catalyst in long-period experiment of 1,1,2-TCE dehydrochlorination

ABSTRACT VDC, as an important raw material for high barrier material PVDC and lithium-ion battery binder PVDF, had an increasing demand. The catalytic dehydrochlorination of 1,1,2-TCE to generate VDC was a green process route that was expected to replace the heavily polluting sodium hydroxide saponification process in industry. There was a certain research foundation for the catalytic dehydrochlorination of 1,1,2-TCE, among which the core problem was that the catalyst was prone to deactivation. Previous studies had calculated the average molecular structure of the spent catalyst surface species when coconut shell activated carbon was used as the support. In subsequent studies, alumina support had been proven to be a better carrier for dehydrochlorination of 1,1,2-TCE, and the selected catalyst had been used in long-period laboratory experiments. The results indicated that the catalyst life had been significantly improved. In the early stage of the reaction, the activity of the catalyst decreased rapidly. In the first 20 h, the conversion of 1,1,2-TCE decreased from 49.35% to 40.36%. From 21 h to 120 h, the conversion of 1,1,2-TCE decreased from 39.96% to 36.18%, tending to stabilize. After 120 h of reaction, the catalyst was extracted and elemental analysis, FTIR, and GPC characterization were performed on the spent catalyst surface species. The average molecular formula of the carbon deposits was obtained as C96.08H50.29Cl36.53. Compared with coconut shell activated carbon support, under the action of activated alumina support, the route of catalyst carbon deposition had changed, and the sediment was more composed of polyvinylidene chloride components. Under certain conditions, sediment formed a dynamic equilibrium, which explained why the activity of the catalyst gradually stabilized. This study revealed the catalytic mechanism of active alumina supported catalyst and the pathway of carbon deposits generation, which was of great significance for improving the lifespan of improved catalyst.

Spinning gold: Unraveling the bioaccessibility and bioavailability of Pitanga’s carotenoid microfibers

The design and development of nanoparticle- and microparticle-based delivery systems incorporating carotenoids into carrier materials offers multiple advantages, including enhancing the bio-efficacy of these compounds due to improving their bioaccessibility and bioavailability. This study introduced pitanga saponified carotenoid extract (PSCE) and pitanga non-saponified carotenoid extract (PSCE) in a 12 % zein/1 %PEO solution and electrospun for fiber production. Then, the fibers were characterized, and their bioaccessibility and bioavailability were also evaluated. The average mean diameter of carotenoid non-saponified microfiber (CNSM) and saponified (CSM) was 5.76 ± 1.7 μm and 4.92 ± 1.4 μm, respectively, indicating that the saponification process reduces the viscosity of the solution resulting in the development of finer microfibers. Carotenoid encapsulation efficiency ranged between 10.3 % and 8.43 % for saponified and non-saponified extracts, respectively. Surprisingly, no carotenoid release was detected from both microfibers after 72 h. Carotenoid bioaccessibility was higher in pitanga pulp compared to both microfibers. The xanthophylls showed higher bioavailability in pitanga pulp. The study’s results suggest that the microfibers’ structure significantly influenced carotenoid release and cellular absorption more than the chemical structure of carotenoids themselves.

Pemberdayaan Masyarakat Pondok Pesantren (Santriwati) dalam Pembuatan Sabun Cuci Pakaian Berbahan Dasar Minyak Jelantah

Waste cooking oil/used cooking oil which is blackish brown is residue from the frying process that still contains fatty acids which have the potential to be used to make soap. At the Al Ihsan Puteri Islamic boarding school, Banjarmasin used cooking oil waste has not been managed well. This activity aims to educate the Islamic boarding school community (santriwati) and boarding school administrators about making washing soap from used cooking oil as a solution so that used cooking oil can be reused in other forms. Participants in the activity were 15 female students at the Al Ihsan Puteri Banjarmasin Islamic Boarding School. This activity consists of discussion (counseling) and direct practice. The chemistry knowledge education material explains the impact of used cooking oil on the body, while the soap-making training material explains the cold saponification method through demonstrations. The service results show that almost 100% of the students who initially did not know how to reuse used cooking oil in soap, now know how to reuse used cooking oil. Students also increase their knowledge and skills in reacting with materials in the saponification process.

Saponification Process and Soap Chemistry

Saponification Process and Soap Chemistry

Investigation of ionic liquid adsorption and interfacial tension reduction using different crude oils; effects of salts, ionic liquid, and pH

The results revealed the significant effect of NaCl, KCl, CaCl2, MgCl2, CaSO4, MgSO4, and Na2SO4 and pH values of 3.5–11 on the interfacial tension (IFT) reduction using three types of neutral, acidic, and basic crude oils, especially for acidic crude oil (crude oil II) as the pH was changed from 3.5 to 11 (due to saponification process). The findings showed the highest impact of pH on the IFT of crude oil II with a reducing trend, especially for the pH 11 when no salts exist. The results revealed that the salts except MgCl2 and CaCl2 led to a similar IFT variation trend for the case of distilled water/crude oil II. For the MgCl2 and CaCl2 solutions, a shifting point for IFT values was inevitable. Besides, the dissolution of 1-dodecyl-3-methyl imidazolium chloride ([C12mim][Cl]) with a concentration of 100–1000 ppm eliminates the effect of pH on IFT which leads to a reducing trend for all the examined crude oils with minimum IFT of 0.08 mN/m. Finally, the [C12mim][Cl] adsorption (under pH values) for crude oils using only Na2SO4 was measured and the minimum adsorption of 0.41 mg surfactant/g Rock under the light of saponification process was obtained.

Ionic liquids adsorption and interfacial tension reduction for synthetic resinous and asphaltenic oils: salinity and pH effects

The effects of sulfate salts under low and high salinity conditions and pH of 3.5–11 on interfacial tension (IFT) reduction and IL adsorption using resinous (RSO) and asphaltenic (8 wt/wt%) synthetic oils are investigated. The measurements showed the increasing effect of pH on the IFT of RSO/DW from 23.5 to 27.3 mN/m (pH = 3.5 → 7) in the first place and a reducing effect (0.4 mN/m) if pH = 7 → 11. Using a high concentration of 50,000 ppm for MgSO4, and Na2SO4 revealed an extensive IFT reduction for a pH value of 11 with the value of 0.20 mN/m for Na2SO4. The measured IFT values showed the significant impact of IL (500 ppm) on the IFT (minimum value of 0.01 mN/m for RSO/50,000 Na2SO4 + 500 ppm 1-decyl-3-methyl imidazolium triflate ([C10mim][TfO])) for pH = 11. The IL adsorption measurements showed the role of in-situ surfactant production (saponification process) on the 1-decyl-3-methyl imidazolium chloride ([C10mim][Cl]) and [C10mim][TfO] adsorption reduction from 3.67 to 2.33 and 4.21 to 3.34 mg IL/g rock, respectively. The performed core flooding experiments using the optimum chemical formulation showed the possibility of tertiary oil recovery with maximum oil recovery of 28.8% based on original oil in place in the presence of 500 ppm.

Comprehensive Analysis of Lutein and Loroxanthin in Scenedesmus obliquus: From Quantification to Isolation.

Carotenoids are hydrophobic pigments produced exclusively by plants, fungi, and specific microbes. Microalgae are well suited for the production of valuable carotenoids due to their rapid growth, efficient isoprenoid production pathway, and ability to store these compounds within their cells. The possible markets for bio-products range from feed additives in aquaculture and agriculture to pharmaceutical uses. The production of carotenoids in microalgae is affected by several environmental conditions, which can be utilized to enhance productivity. The current study focused on optimizing the extraction parameters (time, temperature, and extraction number) to maximize the yield of carotenoids. Additionally, the impact of various nitrogen sources (ammonia, nitrate, nitrite, and urea) on the production of lutein and loroxanthin in Scenedesmus obliquus was examined. To isolate the carotenoids, 0.20 g of biomass was added to 0.20 g of CaCO3 and 10.0 mL of ethanol solution containing 0.01% (w/v) pyrogallol. Subsequently, the extraction was performed using an ultrasonic bath for a duration of 10 min at a temperature of 30 °C. This was followed by a four-hour saponification process using a 10% methanolic KOH solution. The concentration of lutein and loroxanthin was measured using HPLC-DAD at 446 nm, with a flow rate of 1.0 mL/min using a Waters YMC C30 Carotenoid column (4.6 × 250 mm, 5 μm). The confirmation of carotenoids after their isolation using preparative chromatography was achieved using liquid chromatography-tandem mass spectrometry (LC-MS/MS) with an atmospheric pressure chemical ionization (APCI) probe and UV-vis spectroscopy. In summary, S. obliquus shows significant promise for the large-scale extraction of lutein and loroxanthin. The findings of this study provide strong support for the application of this technology to other species.

Pengaruh Penambahan Sodium Lauryl Sulfat terhadap Karakteristik Sabun Padat pada Mata Kuliah Praktikum Analitik Proses

Solid soap as a result from process analysis practicum can be produced using with hot process method using raw material of palm oil and a strong base in the form of NaOH. The aim of this research is that apart from fostering student inquiry regarding the soap making process, they are also able to analyze the parameters of solid soap over a certain period based on variations in the amount of added surfactant. The methods used in practicum activities are dividing practicum groups, making solid soap, and collecting practicum reports. In the activity of making solid soap, the concentration of sodium lauryl sulfate (SLS) was varied for each group, 0, 1, 2 and 3% w/w respectively. The parameters measured in this research were the pH value, water content, ability to form foam, free fatty acid content and ethanol insoluble material in solid soap. The pH characterization of the results of the saponification process shows that soap at all variations in SLS concentration is predominantly alkaline. The characterization carried out showed that the levels of free fatty acids and ethanol insoluble substances met SNI 3532:2016 standards. Water content parameters do not meet these standards because the measurements were carried out during practical activities and without the process of holding the soap product. From the results of observing these parameters, in general it can be concluded that the solid soap products resulting from the practical work have the best quality under the condition of adding SLS with a concentration of 1%.

PEMBUATAN SABUN CUCI TANGAN CAIR BERBASIS BERBAGAI MERK MINYAK ZAITUN DENGAN PENAMBAHAN MINYAK ATSIRI SEREH WANGI (CYMBOPOGON WINTERIANUS JOWITT)

Soap is a product that functions as a cleaner and wash. Hand washing soap in the form of a solution (liquid) is preferred because it looks more attractive and is more practical. Liquid Soap Liquid soap is made through a saponification process using oil and using alkali (KOH). Olive oil contains α-tocopherol (vitamin E) and β-carotene which function as antioxidants. The use of essential oils is good in making perfume, cosmetics, medicines, soap and fragrances, essential oils function as a fixative. The essential oils used are generally patchouli oil, citronella oil, vetiver oil and sandalwood oil. This research aims to make liquid hand washing soap based on various brands of olive oil with the addition of citronella essential oil. The liquid hand washing soap produced is in accordance with SNI, where olive oil-based liquid hand washing soap with brands "B" and "C" has a normal pH, namely 7.03 and 6.98, while brand "A" has a slightly acidic pH, namely 6.01 and brand “D” has a slightly alkaline pH, namely 7.95. The specific gravity produced by brand "A" is 1,027 g/ml, brands "B", "C" and "D" are 1,024 g/ml, 1,096 g/ml and 1,099 g/ml. The liquid hand washing soap based on olive oil with the addition of citronella essential oil produced does not contain microbes with the clean power of brand "B" being higher at 191 FTU turbidity compared to brand "A" at 173 FTU turbidity, brand "C" at 166 FTU turbidity and the “D” brand only has 122 FTU turbidity.

Chemical, Physical and Biological Performances of Natural Antibacterial Soap from Garlic

The aim of producing natural-based soap was to provide an alternative to commercially available antibacterial soaps that contain high levels of chloroxylenol, which can be toxic and harmful to humans at high concentrations. The natural formulated soap contains garlic extract, which has bioactive compounds that contribute to its antibacterial activity. The garlic extract was obtained using an ultrasonication method in water and then infused in virgin coconut oil (VCO) before undergoing saponification process. The performance of the soap was determined through physical, chemical, and biological properties. The foam stability test, moisture content, pH, and free alkali content test were done, and the antibacterial property of the soap was tested using the disk diffusion assay. The disk diffusion test was done on gram-negative and -positive bacteria, namely Escherichia coli (E. coli) (ATCC 25922) and Staphylococcus aureus (S. aureus) (ATCC 25923), respectively. The study found that garlic-infused soap has good foam stability (98.11%) and low moisture content (15.4%) due to its high VCO content. The chemical analysis showed that the soap has an alkaline pH (9.98) and contains enough free alkali (0.861%), which is within the recommended range. The antibacterial performance of the soap was tested, and it was found to inhibit the growth of E. coli as the formation of an inhibition zone (11.5 mm) was observed. The larger the inhibition zone, the stronger the antibacterial properties of the soap. However, the soap had weaker antibacterial properties against S. aureus as the inhibition zones formed were smaller (1.2 mm). Based on these results, it was concluded that garlic-infused soap is a potential substitute for readily available antibacterial soap with comparable physical, chemical, and biological properties The results of this study suggest that garlic-infused soap is a potential alternative to commercial antibacterial soaps with further research to confirm these findings. DONE

Ecological soap production using green chemistry principles

The reuse of fatty materials for soap production is considered a viable alternative to minimize environmental problems such as the eutrophication of lakes and rivers and to reduce the high costs of effluent treatment and domestic water supply. This research presents protocols for ecological soap production from the determination of the saponification index (SI) using the principles of Green Chemistry. The chemical greenness of the produced soap was assessed using mass and holistic metrics. The SI measurement ensured a final product without residues, aligning with the principles of Green Chemistry: principle 1 (waste prevention) with a Factor E of 0 and an Atomic Economy of 100%. Additionally, the Green Matrix and Green Star analyses demonstrated a more sustainable experimental approach for bar soap production, with 45% higher greenness compared to traditional soap and 95% greenness for ash soap. The changes in the saponification process by the principles of green chemistry allowed ecological soap production without residues, an innocuous product to health and the environment. The methodology proposed in this research can contribute to minimizing an environmental problem related to the incorrect disposal of non-biodegradable oil.

A sustainable separation strategy for recovering Sm/Co from SmCo magnets with fatty acid and primary amine

Acidic extractant is a kind of extractants commonly used in critical metal recovery industry, but the saponification wastewater generated during the saponification process inevitably causes environmental pollution. In order to develop a sustainable separation strategy for rare earth, the synergistic effect between lauric acid (LA) and primary amine N1923 (RNH2, with R = C19-C23) was investigated in this paper. The study revealed that the hydrogen bond between LA and RNH2 was helpful to realize the saponification of LA, thereby significantly improving the extraction and separation performance of LA. Unlike the quaternary ammonium or quaternary phosphonium in ionic liquid saponification studied in the previous study, RNH2 can independently combine hydrogen ions to achieve the deprotonation of LA without adding alkali or basic resin, which makes the extraction and separation process more environmentally friendly. Aiming at the recovery of samarium cobalt (SmCo) magnet, the separation of Sm and Co in chloride medium was systematically studied. When LA and RNH2 were combined in equal molar proportions to extract Sm, the extraction system demonstrated a high synergistic coefficient of 61.94, and separation coefficient of Sm and Co was remarkably high at 5326.2. It showed that the LA-RNH2 extraction system for recovering Sm and Co from actual SmCo magnets could achieve 93.19 % recovery of Co, 90.53 % recovery of Sm and 16,222 Sm/Co separation factor. The LA-RNH2 extraction system has shown potential applications in Sm/Co separation and waste SmCo magnet recovery processes. It also provides a novel strategy for the saponification of acidic extractant without alkali consumption and saponification wastewater discharge.

Isolation of carminic acid from essential oil, its characterization and applications towards replacing toxic colourants used in soaps

Wide variety of cosmetics was frequently colored using synthetic coloring agents. They were used despite being harmful due to their brightness and exceptional color clarity. Researchers' attention was drawn to recent experiments that substituted natural colorants with harmful ones. We describe how to include (Miss Current) essential oil (EO) into soap using a straight forward saponification process in this article. It is interesting that the essential oil we added made the soap colored. Carminic acid (CA) was the chemical ingredient in soap that produced the color. From EO, carminic acid was extracted as the sodium salt of carminic acid (NCA), and it was then identified using a variety of spectroscopic methods. Infrared (IR) spectroscopy was used to determine the functional groups in CA. Additionally, the presence of carminic acid (CA) was verified using spectroscopic methods using mass and nuclear magnetic resonance (NMR). Additionally, the antibacterial effectiveness of soap with essential oils was assessed. Additionally, molecular docking studies were used to investigate the affinity of carminic acid (CA) for binding to keratin and alpha-amylase.

Alkaline hydrogen peroxide solutions: expectorant, pyolytic, mucolytic, haemolytic, oxygen-releasing, and decolorizing effects

The local action of hydrogen peroxide solutions on such dense biological masses, such as pus, mucus, sputum, and blood clots, is influenced not only by the concentration of the hydrogen peroxide but also by the alkalinity of the solution and the temperature of the interaction medium. Increasing the solutions temperature from 24C26C to 45C55C and its alkalinity from pH 7.0 to 8.48.5 enhances the pyolytic, mucolytic, hemolytic, bleaching, and oxygen-releasing activity of hydrogen peroxide solutions. Simple heating achieves the desired level of hyperthermia, while the addition of sodium bicarbonate provides the indicated alkalinity.
 Hyperthermia, according to the laws of physics, reduces the viscosity of biological masses, increasing their fluidity, permeability to the antiseptic solution, miscibility, and solubility in it. Furthermore, hyperthermia accelerates the rate of chemical, physicochemical, and biochemical processes, according to the Arrhenius law. The elevated temperature of interacting media speeds up the alkaline saponification process of proteins and protein-lipid complexes, which constitute the colloidal basis of biological masses. Additionally, hyperthermia intensifies the enzymatic decomposition of hydrogen peroxide into water and oxygen gas, facilitated by the enzyme catalase present in most biological masses. The released molecular oxygen generates gas bubbles that mimic cold boiling, leading to the explosion of biological masses, transforming them into a fluffy white foam.
 Oxygen in an alkaline environment oxidizes biological pigments, including hemoglobin and its metabolites of different colors, resulting in their discoloration.

Artificial Neural Network in the Development of Halal Cosmetic Formulation Containing Okara

The development of halal cosmetic formulations presents a challenge to obtain optimised formulations with desirable qualities as it involves many ingredients. The advancement of cosmetic technologies employs multivariate statistical techniques such as artificial neural networks (ANN) to optimise cosmetic formulation, which aims to overcome the shortcomings of traditional formulation methods, which are laborious and cumbersome. Okara is a by-product of the production of soy-based products. Okara has been found to have numerous benefits for many industries and has been discovered as a promising halal cosmetic ingredient. Okara is a plant-derived ingredient; it can be incorporated as a cosmetic ingredient if essential aspects of production are addressed, such as using permissible substances, manufacturing, storage, packaging, and delivery following Shariah requirements. This study aims to develop an optimised halal cosmetic soap formulation containing okara using ANN to achieve the desired hardness of the soap. The influential input variables were the main compositions of the okara soap formulations, containing different fatty acids and oils, and okara through a saponification process. In contrast, the hardness (N) of the soap was the response used as the output. Five different algorithms trained ANN. Generic Algorithm (GA) 6-09-1 was selected as the final optimum model to optimise the halal cosmetic soap formulation. GA modelling was further validated, and the experimentally obtained actual hardness (N) value was close to the predicted value. In conclusion, they were optimised formulating using ANN to produce a soap with desirable properties better than those of commercial ones.

Pembuatan Sabun Padat Berbahan Minyak Atsiri Skala Rumah Tangga

Making this soap aims to provide an explanation for making solid soap made from lemon essential oil as an effort to improve community skills and can be applied by the community in the future as a business. Soap making is done by heating coconut oil at a temperature of 800C. Mix 30% NaOH with heated oil until it becomes homogeneous, stirring continuously until the saponification process is perfect. Add the stearic acid which has been dissolved in the alcohol and stir until smooth, add the white sugar and stir again, add the glycerin while stirring, add the foam booster while continuing to stir until the mixture becomes homogeneous. Add coloring and fragrance, namely lemon oil, which is carried out at 400C. Pour the mixture into the mold and let it sit for 15-30 minutes. The soap has hardened and can be removed from the mold. The tests performed were preference, allergy, aroma, color, froth and density tests. The result shows that solid soap has been successfully made, but still requires some further refinement regarding the density and transparency of the soap. With the procedures for making soap and the analytical test that the author described above, new knowledge and skills can be used for the community as well as solid soap business opportunities

Production and optimisation of used cooking palm oil into protected fat calcium salts by fusion method using response surface methodology (RSM)

Used cooking oil (UCO) is a waste, and creates environmental issues due to its hydrophobic property. UCO, with its high content of fatty acid, can be used as source material for animal feed. However, high unsaturated fatty acid in UCO is harmful to the ruminant’s microflora. This can be resolved by transforming UCO into functional product such as ruminant’s protected fat (PF). In the present work, the production of used cooking oil protected fat (UCOPF) using fusion method via saponification process was investigated. Response surface methodology (RSM) was used to evaluate the effect of calcium oxide concentration (CaO), initial temperature (iTemp.), and percentage of water (H2O) on the solidification score and free fatty acid (FFA) content of PF. Results showed that all the studied parameters significantly affected the responses. The coefficient of determination (R2) for solidification score and FFA were high at 0.9433 and 0.9599, respectively. The optimum condition to produced UCOPF by fusion method was CaO (20%), iTemp. (80°C), and percentage of water (30%), which yielded solidification score and FFA of 5.33 ± 0.53 and 0.85 ± 0.07%, respectively. The FFA content of the optimised PF was lower than permitted; thus, it can be used as animal supplement. In conclusion, the UCO can be converted into PF by using calcium fusion method. However, the property and stability of the produced PF should be assessed prior to commercialisation.

The synergistic effect of waste cooking oil and endod (Phytolacca dodecandra) on the production of high-grade laundry soap

A green viewpoint based on the production of soap using waste products such waste cooking oils (WCOs) and Endod (Phytolacca dodecandra) is presented. The process of saponification, which involves reacting triglycerides with fats and oils in an alkaline solution, produces soap. With the help of WCO and Endod as manufacturing inputs, this study intends to create high-quality, commercially viable eco-friendly soaps. The optimal blend of WCO and Endod with sodium hydroxide solution was used in the current investigation to create laundry soaps. Evaluations were done on the cleansing effects and physico-chemical makeup of prepared soap. As a reference control, the raw oil soaps made without and with frying were employed. The free caustic alkali content, chloride content, moisture content, ethanol-insoluble-matter, total fatty matter, pH, and foam height values of the prepared soap were found to be in the range of 0%, 0%, 16.56–22.52%, 0.1–3.05%, 63.41–75.46%, 9.22–9.82%, and 3.3–8.1 cm respectively. The results obtained by blending fried WCOs and Endod were comparable to the Physico-chemical properties of the Endod-free uncooked/fresh oil soap. The soap made by blending WCO and Endod has higher cleansing power and better lather formation than the prepared soap with WCO without Endod. Moreover, the observed data are comparable with similar data reported in other literature, recommended acceptable standards (EAS, CES), and from many countries including the British, Malaysia, and the Philippines. Cooking oils fried at different temperatures do not have much effect on the quality of soap making. This suggested that the blending of WCOs and Endod can be used as raw materials to prepare high-quality and economically feasible soaps by replacing imported oils and fats.

Betel leaf extract as an anti-bacterial agent in solid soap formulation and characterisation

Used cooking oil is a waste oil derived from plants used as cooking oil. Used cooking oil can be reused by a purification process and used in soap making by a saponification process using a base (KOH or NaOH). Based on this, waste cooking oil is handled as a raw material for making solid soap. This study aimed to characterize solid soap from used cooking oil with betel leaf extract and explain the anti-bacterial ability of solid soap from used cooking oil with betel leaf extract. Solid soap is made by purifying used cooking oil by immersion in 15% NaOH and adding bleaching earth, making betel leaf extract by maceration method. The process of making solid soap with the addition of stearic acid, propylene glycol, glycerin, ethanol, and TEA. Characterization of solid soap by testing water content, amount of fatty acid, free alkaline, free fatty acid, mineral oil, foam stability, acidity test (pH), and anti-bacterial test. Testing the water content and the number of fatty acids shows that all samples did not meet the standards required by SNI 06-3532-1994. All samples in the free alkaline test (except sample F0), free fatty acids, mineral oil, and foam stability were tested to meet the standards required by SNI 06-3532-1994, and the anti-bacterial test of sample F4 has the best anti-bacterial properties because it can reduce the growth of bacteria compared to other samples.