Jurnal Pijar MIPA (e-ISSN: 2460-1500 & p-ISSN: 1907-1744) is an open-access, peer-reviewed scientific journal published by the Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. The journal publishes original research articles and reviews encompassing various topics in natural sciences and science education, particularly in Physics, Chemistry, and Biology. All submitted manuscripts undergo an initial editorial review followed by a rigorous peer-review process. Jurnal Pijar MIPA was first published in 2006, initially releasing two issues per year (March and September) until 2018. In 2019, publication frequency increased to three issues per year. This was expanded further to four issues annually in 2021. Beginning in 2022, Jurnal Pijar MIPA transitioned to a bimonthly publication schedule, with issues released in January, March, May, July, September, and November.
Department of Mathematics and Science Education, Faculty of Teacher Training and Education, University of Mataram. Jurnal Pijar MIPA colaborates with Perkumpulan Pendidik IPA Indonesia Wilayah Nusa Tenggara Barat
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A Life Lost, A Lesson Learned: Ecological and Emotional Impacts of a White-Throated Kingfishers Death
This study presents a reflective account of a personal encounter with a dead White-Throated Kingfisher (Halcyon smyrnensis) during fieldwork, highlighting the ecological and emotional implications of its death. The incident, likely attributed to heat stress exacerbated by climate change, serves as a poignant reminder of the vulnerability of even resilient species to human-induced environmental pressures. Through a species profile, analysis of environmental stressors, and exploration of anthropogenic threats, this study underscores the urgent need for conservation efforts, climate action, and habitat protection. The emotional impact of the encounter emphasizes the importance of recognizing the intrinsic value of wildlife and the interconnectedness of human and environmental well-being. This research aims to contribute to a deeper understanding of the complex relationships between humans and wildlife, inspiring collective action to mitigate the pressing environmental challenges of our time.
Copyright (c) 2025 Deepshikha Shree, Md Abu Imran Mallick, Sima Paik, Kumari Komal, Shiladitya Acharjee, Shaba Alam Ansari, Smitha Pankaj https://creativecommons.org/licenses/by/4.0
Synthesis of Gold Nanoparticles Using Ascorbic Acid as a Bioreductor and the Effect of Uric Acid
Gold nanoparticles (AuNPs), ranging in size from 1 to 100 nm, represent one of the most significant advancements in metal-based technologies in recent years. Their application in the medical field, especially as drug delivery agents, is particularly noteworthy and demonstrates their transformative potential. This study aims to synthesize AuNPs using HAuCl4 as a precursor and ascorbic acid as a bioreductant at a concentration of 20 ppm with a bottom-up method. The result of the synthesis process yields a striking burgundy-colored solution, signifying the successful formation of gold nanoparticles. The results of UV-Vis characterization provided insightful data on the transformation of the HAuCl4 solution. Initially recorded at a wavelength of 314.60 nm, the solution underwent a notable shift to 523.50 nm after the synthesis process, demonstrating an absorbance value of 0.323. Furthermore, the transmission electron microscopy (TEM) analysis illuminated the unique characteristics of the synthesized nanoparticles, revealing an average particle size of 6.23 nm with the highest particle frequency in the range of 6-8 nm. Moreover, the result of clinical trials conducted with ten randomly selected volunteers, who received 20 ppm of AuNPs over a five-week period, demonstrated that seven out of ten participants experienced a significant reduction in uric acid levels, underscoring the therapeutic potential of gold nanoparticles. Microscopic observations following the injection revealed that volunteers with normal uric acid levels exhibited fewer leukocytes than those with elevated uric acid levels, who were noted to have leukocyte counts up to three times higher. In conclusion, the synthesis of AuNPs using ascorbic acid is marked by a wine-red solution and a significant absorption wavelength shift to the 500–600 nm range. The positive results of the clinical trial reflect the ability of AuNPs to lower uric acid levels, thereby paving the way for innovative nanotechnology-based therapeutic strategies in the medical field.
Copyright (c) 2025 Yulle Rachmawati, Titik Taufikurohmah https://creativecommons.org/licenses/by/4.0
Screening Flavonoids of Ethyl Acetate Extract from Matoa Tree Bark (Pometia pinnata) Using UV-Vis Spectrophotometry Method
Matoa tree bark is a plant that contains flavonoid chemical compounds believed to be a traditional medicine in various alternative treatments. Therefore, it is important to measure its flavonoid content. Ethyl acetate extracts were prepared using the maceration method at durations of 3 x 24 hours. The aim of this study was to determine the flavonoid compound content and levels in matoa tree bark (Pometia pinnata) using UV-Vis spectrophotometry. Qualitative analysis was carried out using NaOH reagent and the wilstater cyanidin test, both of which showed positive results for containing flavonoid compounds, indicated by an orange color change. Quantitative analysis using a regression quercetin standard curve with an R2 value of 0,9844 revealed a flavonoid content of 2.712%. These results indicate that matoa tree bark extract has a high flavonoid content and has the potential to be developed as a herbal medicine formulation.
Copyright (c) 2025 Ratno Budiyanto, Ach. Kholis, Taufiqurrahman Taufiqurrahman https://creativecommons.org/licenses/by/4.0
Indonesian Teachers Perspective on the Characteristics and How to Teach Science in Elementary School
Science education plays a critical role in shaping students' scientific literacy and attitudes. Teachers' perspectives on the nature of science (NoS) are central to how science is taught in classrooms, particularly at the elementary level. This study aims to analyse the views of elementary school teachers in Indonesia on the fundamental characteristics of science and how they implement these views in their teaching practices. Using a descriptive quantitative approach, complemented by Focus Group Discussions (FGD), data were collected from 52 teachers across diverse geographical regions, including West Nusa Tenggara, Java, and East Nusa Tenggara. The data were analysed based on four core aspects of the nature of science: science is interesting to study, science is useful in life, science continues to develop, and science is a global human endeavour. The results show that most teachers have very positive views on the first three aspects, while their understanding of the global dimension of science is categorised as good. Further analysis revealed no significant differences in teachers' views based on length of service, gender, or PPG (Teacher Professional Education) status. These findings suggest the need to enhance teachers' pedagogical competence through globally oriented training programs and contextualised science teaching approaches. This study contributes to improving the quality of science education by encouraging a more holistic and globally relevant understanding of science among primary school teachers.
Copyright (c) 2025 Riska Dia Sapitri, Ryya Aulia Atsiri, Rizka Sofia Irawan https://creativecommons.org/licenses/by/4.0
Promoting Students Critical Thinking and Cognitive Learning Outcomes through Problem-Based Learning integrated with Mind-Mapping
Critical thinking and advanced cognitive abilities are vital competencies in 21st-century biology education, especially in complicated subjects like immunology. Innovative pedagogical methods are crucial for helping pupils overcome learning challenges and develop a deep understanding. This study examines the integration of problem-based learning (PBL) with mind-mapping approaches to enhance undergraduates' critical thinking and cognitive learning in immunology education, a field often regarded as complex and interdisciplinary. A quasi-experimental one-group pretest-posttest design was utilized, comprising 23 undergraduate students participating in a fundamental immunology course at the State University of Malang, Indonesia. Data were gathered using essay-based evaluations and evaluated employing paired t-tests, N-gain scores, and effect size computations. The results demonstrated substantial enhancements in both critical thinking and cognitive learning outcomes post-intervention, with impact sizes classified as big to very large. The extent of improvement differed among indicators, exhibiting moderate advancements in applying, evaluating, and analyzing, whereas synthesis showed only modest advancement. The results indicate that PBL combined with mind-mapping can effectively enhance higher-order thinking skills in complex subjects, providing dual scaffolding that aids students in organizing intricate concepts, visualizing relationships, and reinforcing higher-order thinking abilities.
Copyright (c) 2025 Lianto Lianto, Yulista Trias Rohayati https://creativecommons.org/licenses/by/4.0
Development of a Student Worksheet Based on Project-Based Learning to Improve Learning Outcomes of Junior High School Students
This research involves the development of a Student Worksheet based on project-based learning for the solar system sub-material, focusing on improving the learning outcomes of junior high school students. The purpose of this study is to identify the level of validity, practicality, and effectiveness of the project-based learning Student Worksheet. The method employed in this research is Research and Development (R&D), utilising the ADDIE approach as the development model. This study demonstrates that project-based learning, specifically the Student Worksheet on solar system sub-materials, is deemed highly valid, with a validity value of 0.88, aimed at enhancing student learning outcomes. The practicality of the results from a student response questionnaire, with 82.24% of students agreeing, indicates that the Student Worksheet is highly practical. Effectiveness based on knowledge learning outcomes, with the calculation of n-gain from pretest and posttest, obtained an average n-gain of 0.71 with high criteria, attitude learning outcomes obtained an average of 90.67% which is categorised as very good, and learning outcomes skills obtained an average of 91% which is categorized as very good. The results of the study demonstrate that the Student Worksheet project-based learning on the solar system sub-material is feasible for use, as it meets the criteria of validity, practicality, and effectiveness in improving student learning outcomes. The implications of this research suggest that project-based learning Student worksheets can serve as an alternative, innovative teaching material that encourages active student involvement, improves critical thinking skills, and provides educators with a reference for developing learning tools that align with the demands of the Independent Curriculum and 21st-century learning.
Copyright (c) 2025 Yuniarti Khairini Rahmah, Ellyna Hafizah, Syubhan Annur https://creativecommons.org/licenses/by/4.0
Analysis of Leaf Area Index of Shade Trees and Its Relationship with the Discomfort Index: A Case Study at the University of Mataram Campus
The development of shade trees on the Mataram University campus is intended to maintain environmental comfort, as well as add beauty. The microclimate softening function of trees is largely determined by the density of their canopies, known as the leaf area index (LAI). Various LAI measurement methods have been developed, which are generally more suitable for assessing tree productivity but less valid for assessing the ability to soften the microclimate or decrease the discomfort index (DI). This study was conducted to analyze the distribution of LAI of shade trees and their relationship with the DI on the Mataram University campus. To obtain a more valid LAI value, the leaf area variable measured was the leaf area forming the canopy, replacing the leaf area on the canopy surface, as was done in previous studies. Microclimate variables measured to determine the discomfort index (DI) were air temperature and relative humidity. The results showed that the LAI of 108 trees (33 species) spread across 9 zones within the Mataram University campus ranges from 1.2630 (very small category) to 9.6735 (very large category). The DI values under the canopy of trees ranged from 23.225 (quite comfortable category) to 26.869 (somewhat comfortable category). The relationship between LAI of shade trees and DI on the campus of Mataram University was linear and negative, with the resulting regression equation being y = 28.1204-0.4749x. If LAI increased, then DI tended to decrease; conversely, if DI increased, then LAI tended to decrease. The function of campus trees in softening the microclimate can be enhanced by improving their LAI.
Copyright (c) 2025 Suripto Suripto, Rachmawati Noviana Rahayu, Supardiono Supardiono, Lalu Muhammad Aby Dujana, Feby Ayu Genggelang https://creativecommons.org/licenses/by/4.0
Fermentation of Gembili Juice: Innovation in Functional Beverages Based on Lactobacillus plantarum B1765
Gembili tubers (Dioscorea esculenta) are abundant in Indonesia but remain underutilised despite their potential as a functional food. One effort that has been made is to produce a symbiotic fermented beverage, as it is known to contain prebiotic inulin that can be fermented using probiotics. Lactobacillus plantarum B1765 is charactherized by its probiotic potential. This research evaluated the impact of fermentation duration using L. plantarum B1765 starter culture on the quality of gembili juice products, including Total Lactic Acid Bacteria (LAB), pH, Total Titratable Acids (TTA), and organoleptic quality. Gembili juice was made by fermenting gembili juice at 37°C for 0, 6, 12, 18, 24, and 36 hours. The total LAB count was enumerated using the total plate count (TPC) method with MRS-Agar medium containing CaCO3. pH determination was performed using a pH meter. TTA was calculated by acid-base titration, and organoleptic quality was assessed by untrained panellists, who rated the level of liking using a hedonic scale. The total LAB and pH data were analyzed using the Kruskal–Wallis test, while the TTA data were analyzed using a one-way ANOVA to determine the significant differences among the fermentation durations. The fermentation time of gembili fermented beverages had an effect (p < 0.05) on the total number of LAB, pH, and TTA. LAB growth increased and reached an optimum of 7.55 x 10⁸ CFU/mL at 18 hours. However, the pH continued to decrease to 3.84, and the TTA continued to increase to 0.32% until the end of fermentation. Sensory evaluation (hedonic test) showed that fermentation time had no effect (p>0.05) on color and aroma. Still, it had an impact (p < 0.05) on taste, with the highest preference for the 18-hour fermentation. This product complies with SNI standards and is suitable for development as a fermented functional beverage. The inulin and phenolic compounds present in gembili may contribute to its antioxidant activity and α-glucosidase inhibitory effects.
Copyright (c) 2025 Rohilatul Bidayah Amaliyah, Prima Retno Wikandari https://creativecommons.org/licenses/by/4.0
Synthetic Enzyme Engineering In Silico and In Vivo Approaches for Applications in the Halal Food Industry
Recent developments in biotechnology and bioinformatics have opened new possibilities for designing enzymes for the halal food sector. This study employs an integrated framework combining in silico modelling and in vivo validation to create synthetic enzymes that are both effective and compliant with halal standards. Computational analyses were conducted to predict enzyme–substrate interactions and evaluate structural stability, while experimental validation confirmed enzymatic activity, thermal stability, and safety profiles. The results demonstrate that this dual approach improves design efficiency, enhances catalytic performance, and ensures enzymes originate from halal-certified sources, addressing a notable gap in current research where optimization and religious compliance are often addressed separately. This methodology bridges molecular biochemistry with Islamic jurisprudence, providing a scientifically grounded approach for producing bioenzymes suitable for industrial applications. By showing that halal verification can be integrated without compromising enzyme functionality, the study provides a model for ethical and religiously responsible food production. The findings have broad implications for the halal food industry, supporting scalable enzyme manufacturing and laying the groundwork for future research in synthetic biology, regulatory compliance, and the development of innovative functional foods.
Copyright (c) 2025 Welly Anggraini https://creativecommons.org/licenses/by/4.0
Determination of Total Flavonoid Content in Ethanolic Leaf Extract of Calotropis gigantea: A Comparison Between Geothermal and Non-Geothermal Areas
Calotropis gigantea (L.), commonly known as biduri, is a plant recognized for its pharmacological properties, including antioxidant and anti-inflammatory activities, largely attributed to its secondary metabolites, particularly flavonoids. The concentration of these bioactive compounds is strongly influenced by the environmental conditions in which the plant grows. Geothermal manifestation areas, characterized by extreme abiotic conditions, can induce metabolic responses in plants, potentially enhancing flavonoid production. This study aimed to determine and compare the total flavonoid content in ethanolic leaf extracts of C. gigantea collected from geothermal and non-geothermal areas in Aceh Province. Extraction was conducted using 96% ethanol, and total flavonoid content was quantified using UV-Vis spectrophotometry via the aluminum chloride (AlCl₃) complexation method. Quercetin served as the standard, and flavonoid levels were expressed as milligrams of quercetin equivalents per gram of extract (mg QE/g). The calibration curve showed a linear relationship between quercetin concentration and absorbance, with a regression equation of y = 0.0101x – 0.0098 (r = 0.9417). The results demonstrated significant differences in flavonoid content between samples from geothermal and non-geothermal sites. C. gigantea plants from geothermal areas exhibited altered flavonoid levels compared to those from non-geothermal regions, indicating that environmental factors play a role in modulating the biosynthesis of these bioactive compounds.
Copyright (c) 2025 Taufiq Karma https://creativecommons.org/licenses/by/4.0
High School Students Perceptions of Problem-Based Learning (PBL) Integrated with Anthropogenic Phenomena: An Analysis of Engagement and Motivation
The importance of student engagement and motivation in the physics learning process at the high school level, which has often been perceived as a difficult subject and less relevant to real life. Through the integration of anthropogenic phenomena, learning is expected to become more contextual and foster awareness of environmental issues. This study aims to determine students' perceptions of physics learning activities using the Problem-Based Learning (PBL) model integrated with anthropogenic phenomena. The research was conducted at the high school level using a quantitative descriptive approach. The respondents consisted of 108 tenth-grade students who had participated in physics learning using this model. The research instrument was a validated questionnaire. Data were analyzed using a Likert scale and presented in percentage form. The results of the study indicate that students' perceptions of physics learning using the integrated anthropogenic PBL model are in the good and very positive categories. This is demonstrated by the percentage of engagement aspects exceeding 80% and the motivation aspects reaching 86%. Overall, both aspects scored 61% or higher, indicating that the application of this model is effective in enhancing student engagement and motivation in learning. These findings are expected to serve as a reference for teachers in developing contextual physics learning and contribute as supporting literature for future research.
Copyright (c) 2025 Evie Sylviana Dewi, Nurita Apridiana Lestari https://creativecommons.org/licenses/by/4.0
Implementation of Interactive Learning Media on the Blood Circulatory System Towards Science Literacy
Scientific literacy is an important indicator in the implementation of science education, which must be integrated systematically at all levels of education. This study aims to investigate the differences in scientific literacy skills between classes taught using interactive learning media and those taught using conventional learning media, with a focus on the sub-topic of the circulatory system. Additionally, it aims to assess the changes in scientific literacy skills before and after the use of interactive learning media on the sub-topic of the circulatory system. The type of research employed was quasi-experimental, utilising a non-equivalent control group design with data collection techniques that included pretests and posttests of scientific literacy. These tests were used to evaluate the hypothesis through independent sample t-tests and paired sample t-tests. The study's results showed differences in scientific literacy abilities between classes taught using interactive learning media and those taught using conventional learning media in the sub-material of the circulatory system. The results of this study also indicated a difference in scientific literacy skills before and after the use of interactive learning media in the sub-material of the circulatory system. This study demonstrates that the use of interactive learning media that present content related to scientific phenomena can enhance students' scientific literacy skills. This research highlights the importance of utilising interactive learning media for teachers in enhancing students' scientific literacy.
Copyright (c) 2025 Nina Febryanie, Ellyna Hafizah, Maya Istyadji https://creativecommons.org/licenses/by/4.0
The Effect of Project-Based Learning with a STEM Approach on Students Creative Thinking Ability and Science Process Skills
Creative thinking ability is one of the essential demands of 21st-century learning, which needs to be supported by science process skills to foster deeper understanding and meaningful learning experiences. However, science learning in schools is still largely dominated by lecture methods with minimal practical activities, resulting in students being less active, untrained in creative thinking, and rarely engaged in scientific processes. This study aims to investigate the effect of the Project-Based Learning (PjBL) model with a STEM (Science, Technology, Engineering, and Mathematics) approach on students’ creative thinking ability and science process skills in the topic of elements, compounds, and mixtures. The research employed a quasi-experimental method with a pretest-posttest control group design for creative thinking ability and a posttest-only control group design for science process skills. The sample consisted of two eighth-grade classes selected through random sampling, with 30 students in each class. One class was assigned as the experimental group, taught using the STEM-based PjBL model, while the other served as the control group using conventional instruction. Research instruments included essay tests and observation sheets. Data analysis using the t-test revealed a significant effect on creative thinking ability (p = 0.001, p < 0.05) and science process skills (p = 0.004, p < 0.05). The novelty of this study lies in the integration between the design of PjBL and the STEM approach, with systematic measurement of two important indicators of 21st-century learning: creative thinking and science process skills, in the context of applied basic chemistry topics. Thus, the findings affirm that integrating PjBL with STEM is effective in fostering 21st-century skills. Based on these results, it is recommended that innovative and contextually relevant projects be designed to support the development of meaningful science learning.
Copyright (c) 2025 Tri Fitri Cahyati Sidabutar, Ely Djulia, Marlina Sinaga https://creativecommons.org/licenses/by/4.0
Needs Analysis of Ethnoscience-Based STEM Teaching Materials for the Science Education Program
This research is driven by the urgent need to produce university graduates who are not only scientifically competent but also creative and possess a strong appreciation for local wisdom, aligning with the Golden Indonesia 2045 vision and the National Research Master Plan's focus on local knowledge. A preliminary problem analysis identified a gap: the absence of ethnoscience-based STEM (Ethno-STEM) teaching materials specifically designed for university students to enhance their appreciation of local wisdom and creativity. This study aims to analyze the need for Ethno-STEM course materials, which will subsequently be developed into a valid, practical, and effective product. A descriptive mixed-methods approach was employed. Data were collected through document analysis of the semester learning plan, a questionnaire administered to 25 students, and semi-structured interviews with 4 science course lecturers. The results indicate that: (1) The document analysis of the STEM course semester learning plan at UNISLA explicitly mandates the integration of local wisdom and ethnoscience in its learning outcomes. (2) The questionnaire results show that an average of 88% of students expressed a high need for Ethno-STEM teaching materials to improve four key aspects: appreciation of local wisdom, creativity, learning interest, and conceptual understanding. (3) Lecturers confirmed difficulties in finding ready-to-use, structured teaching resources to support the Ethno-STEM project-based learning. The novelty of this study lies in its specific mapping of needs, providing an empirical justification for developing Ethno-STEM teaching materials at the higher education level. It is concluded that there is a valid and urgent need to develop systematic Ethno-STEM teaching materials to support curriculum implementation and enhance the quality of learning in the Science Education Program at UNISLA.
Copyright (c) 2025 Agus Santoso, Khoiro Mahbubah, Qonita Qurotul Aini https://creativecommons.org/licenses/by/4.0
Validation of Instrument to Measure Science Pre-Service Teachers Digital Skills: Confirmatory Factor Analysis
Validating instruments that measure digital skills—such as through Confirmatory Factor Analysis (CFA)—is crucial to ensure that pre-service teachers, particularly those from Generation Z, possess accurate, reliable, and pedagogically meaningful digital competencies. Using a quantitative survey design, data were collected from 349 Generation Z pre-service teachers across four science specializations (chemistry, physics, biology, and general science). The instrument used was adapted from previous studies and translated using the back-translation method to ensure its validity. Confirmatory Factor Analysis (CFA) was employed in AMOS 24 to evaluate both first-order and second-order models to analyze the data. The six dimensions assessed—Access to and Management of Digital Content (AMDC), Use of Digital Means (UDM), Communication Skills (CS), Creative Skills (CrS), Digital Safety Skills (DSS), and Digital Empathy (DES)—demonstrated strong loadings onto the higher-order construct of Digital Skills (standardized regression weights = 0.94–0.97). Model fit indices confirmed the robustness of the structure (χ² = 865.079, RMSEA = 0.075, TLI = 0.908, CFI = 0.923). Reliability was high, with Cronbach’s alpha ranging from 0.674 to 0.966 and Composite Reliability (CR) exceeding 0.70 for most constructs. Correlation analysis revealed strong interrelationships among dimensions (r = 0.779–0.998), underscoring the integrated nature of digital skills. The findings suggest that digital skills among pre-service science teachers can be conceptualized as a unified but multidimensional construct. The validated instrument offers a reliable tool for assessing digital competencies in teacher education. Practically, the results have implications for curriculum development, underscoring the need to integrate digital literacy training into teacher preparation programs. Future research should expand validation to diverse cultural contexts and apply longitudinal approaches to capture changes in digital skill development over time.
Copyright (c) 2025 Dyah Pusptasari Ningthias, Hilman Qudratuddarsi https://creativecommons.org/licenses/by/4.0
The Influence of Wet Aging on pH, Meat Color, Fat Color and Water Holding Capacity of Bali Beef from Traditional Slaughterhouses in Lombok
Beef quality plays a vital role in ensuring consumer satisfaction and market competitiveness, particularly in regions where traditional slaughtering practices remain prevalent. This study aimed to evaluate the physical quality of Bali beef obtained from traditional slaughterhouses on Lombok Island and to determine the effect of wet aging on meat quality. The experiment used longissimus dorsi muscle samples from 1 to 3-year-old male Bali cattle. Physical parameters analyzed included pH, meat color, fat color, and water-holding capacity (WHC). Data were analyzed using a Factorial Completely Randomized Design followed by Duncan’s Multiple Range Test. Results showed that wet aging had a significant effect (p<0.05) on most physical parameters. The pH decreased from 5.85 to 5.57, meat color became slightly darker due to myoglobin oxidation, and fat color became lighter under vacuum conditions. WHC increased from 47.13% to 50.34%, indicating improved water retention. Based on these findings, it can be concluded that beef from traditional slaughterhouses in Lombok still meets the quality standards of fresh meat. Furthermore, the 21-day wet aging process significantly enhanced the physical quality of Bali beef without causing adverse effects, demonstrating its potential as a practical post-slaughter treatment to improve the competitiveness of local beef products.
Copyright (c) 2025 Baik Mesy Darita Fitriani, Dahlanuddin Dahlanuddin, Fahrullah Fahrullah, Bulkaini Bulkaini, M Ashari, Ikhwan Firhamsah, Zaid Al Gifari https://creativecommons.org/licenses/by/4.0
The Potential af Robusta Coffee Leaf Flour (Coffea canephora) as a Functional Food Ingredient: Antioxidant Activity Analysis
Functional food has become a rapidly growing segment in the global food industry, emphasizing the use of natural resources as sources of functional ingredients. One promising candidate for development is Robusta coffee leaf flour. The purpose of this study was to determine the optimal treatment and the effect of drying temperature on the antioxidant activity of Robusta coffee leaf flour. This study employed a one-factor randomized block design (RBD). The treatments consisted of combinations of temperature and time, with six levels: P1T1 = 50°C for 4 hours; P1T2 = 50°C for 5 hours; P1T3 = 50°C for 6 hours; P2T1 = 60°C for 4 hours; P2T2 = 60°C for 5 hours; and P2T3 = 60°C for 6 hours. Each treatment was repeated three times, resulting in a total of 18 experimental units. The data were analyzed using ANOVA and Duncan’s multiple range test for significant results. Findings indicated that the highest antioxidant activity was achieved at 60°C for 6 hours (P2T3), with a value of 73.51 ppm. Robusta coffee leaf flour demonstrates strong potential as a functional food ingredient, with optimal antioxidant activity achieved through specific drying conditions. Further research is recommended to investigate its bioactive compound profile and potential applications in food products.
Anak Agung Ngurah Dwi Ariesta Wijaya Putra
Copyright (c) 2025 Ni Komang Parwati, I Gusti Agung Yogi Rabani RS, Ida Ayu Putu Ary Widnyani, Anak Agung Ngurah Dwi Ariesta Wijaya Putra, Putu Rima Sintyadewi https://creativecommons.org/licenses/by/4.0
Comparative Potential of Antibacterial Activity of Marine Plants for the Development of Natural Antimicrobial Agents: A Review
Antibiotic resistance remains a major global health concern, driven by the misuse and overuse of antibiotics, which has resulted in multidrug-resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum beta-lactamase-producing Escherichia coli (ESBL-E. coli), leading to increased morbidity, mortality, prolonged hospital stays, and rising healthcare costs. To address this challenge, the search for alternative antibacterial agents that are natural, sustainable, and environmentally friendly has become urgent. Marine plants, including red macroalgae (Rhodophyta), brown algae (Phaeophyta), green algae (Chlorophyta), and seagrasses, produce secondary metabolites such as flavonoids, alkaloids, terpenoids, tannins, and sulfated polysaccharides with promising antibacterial properties. This systematic review analyzed 320 articles from PubMed, Google Scholar, and ScienceDirect, of which eight met the inclusion criteria, to compare the antibacterial potential of marine plant extracts against Gram-positive and Gram-negative pathogenic bacteria. The findings indicated that species such as Kappaphycus alvarezii, Corallina officinalis, Eucheuma spinosum, Sargassum polycystum, Caulerpa racemosa, and Padina australis exhibited antibacterial activity ranging from weak to very strong depending on species, extraction methods, solvents, concentrations, and environmental conditions, with K. alvarezii showing the highest inhibition zone of up to 26 mm against Bacillus subtilis and Vibrio species. The antibacterial mechanism is believed to involve membrane disruption, alteration of permeability, and inhibition of protein and DNA synthesis. In conclusion, marine plants demonstrate strong potential as sources of natural antibacterial agents that may reduce dependence on conventional antibiotics and mitigate the global antibiotic resistance crisis, though further research is required to standardize extraction methods, isolate active compounds, and validate efficacy and safety through MIC, MBC, and in vivo studies before clinical and industrial application.
Copyright (c) 2025 Nazila Nazwa Zikria, Nurhadis Nurhadis https://creativecommons.org/licenses/by/4.0
Antioxidant Activity and Organoleptic Tests on Functional Drinks Made from Soursop Leaves (Annona Muricata) with a Combination of Sappan Wood (Biancaea Sappan)
Functional beverages are popular because they have bioactive compounds that contribute to body health. This study aimed to determine the effect of combining soursop leaves (Annona muricata) and sappan wood (Biancaea sappan) on total phenolic content, flavonoid content, antioxidant activity, and sensory characteristics of a functional beverage. The study employed a Complete Randomized Design (CRD) with one factor consisting of seven treatment combinations, which represented different proportions of soursop leaves and sappan wood. The results showed that the 70% soursop leaves and 30% sappan wood combination (A7B7) produced the highest total phenolic content of 3335.97 mg GAE/100g, the flavonoid content of 2180.35 mg QE/100g, and the lowest IC50 value of 62.02 ppm, indicating strong antioxidant activity. Sensory tests showed that treatment (A1B1) in color parameters showed a significant difference (p<0.05), and treatment (A2B2, A3B3, A4, B4, A5B5, and A6B6) in taste, aroma, texture, and preference parameters did not show a significant difference (p<0.05). The A7B7 combination was identified as the best formulation based on antioxidant activity and panelist preferences.
Copyright (c) 2025 Kristina Febrianti Eno, Rima Sintyadewi, Ida Ayu Putu Ary Widnyani, Anak Agung Ngurah Dwi Ariesta Wijaya Putra, I Gusti Agung Yogi Rabani RS https://creativecommons.org/licenses/by/4.0
Optimization of Biodiesel Synthesis from Kapok Seed Oil (Ceiba pentandra) through Transesterification Reaction with a TiO2 Catalyst
Biodiesel represents a renewable, environmentally friendly, and locally producible alternative to conventional diesel fuel. This research synthesized biodiesel from kapok seed oil (Ceiba pentandra) via transesterification using a TiO₂ catalyst, with process parameters optimized to maximize yield. Kapok seed oil was extracted using Soxhlet extraction with n-hexane and purified by vacuum column chromatography. The transesterification process involved systematic variation of the oil-to-methanol molar ratio, catalyst mass, reaction temperature, and reaction time. Optimal conditions were established at a 1:10 molar ratio, 0.20 g of catalyst mass, a reaction temperature of 60 °C, and a reaction time of 90 minutes, resulting in a biodiesel yield of 71.58%. Characterization of the biodiesel revealed a density of 0.88 g/mL, viscosity of 3.10 cSt, acid value of 1.89 mg NaOH/g, and saponification value of 231.879 mg KOH/g. GC-MS analysis identified methyl palmitate, methyl linoleate, and methyl oleate as the principal methyl ester components, with methyl oleate as the predominant species. These findings demonstrate that biodiesel derived from kapok seed oil possesses properties suitable for use as an alternative fuel that meets established quality standards.
Copyright (c) 2025 Mona Rozitawati, Erin Ryantin Gunawan, Dedy Suhendra, Farida Ariani https://creativecommons.org/licenses/by/4.0
Exploration of Salam Leaf Extract (Syzygium polyanthum) as a Natural Indicator for Acid-Base Titration: Color Stability and Endpoint Accuracy
Acid-base indicators play an important role in titration, but the use of synthetic indicators such as phenolphthalein is increasingly criticized for being toxic, carcinogenic, and environmentally unfriendly. Therefore, this study was conducted with the aim of developing bay leaf extract (Syzygium polyanthum) as a safer, natural indicator, thereby supporting the concept of green chemistry. The study was carried out in four stages, namely first, extraction with ethanol: water solvent (70:30 and 50:50), second, color change test in pH 4, 7, and 10 buffer solutions using visual documentation and UV-Vis spectrophotometry. Third, validation of effectiveness in HCl–NaOH titration with phenolphthalein as a comparator. Additionally, stability and reproducibility tests were conducted over a 7-day storage period. The results showed that bay leaf extract remained stable for at least seven days, exhibiting a significant λmax change profile at 405–425 nm, which varied according to pH changes. This indicates the sensitivity of phenolic pigments to acidic, neutral, and basic conditions. In titration validation, the extract with 50/50 solvent showed an identical titrant volume to phenolphthalein (25.0 mL; deviation 0%), while the 70/30 solvent showed a deviation of -14.6%. Stability tests showed that the extract was relatively stable for up to 7 days in dark conditions with a decrease in absorbance <10%, while reproducibility tests produced inter-user variations <5%. These findings suggest that bay leaf extract has strong potential as a reliable, stable, and consistent natural indicator, making it a worthy alternative to synthetic indicators in environmentally sustainable chemistry education and research laboratories.
Copyright (c) 2025 Nasirsah Nasirsah, Fatma Suryani Harahap Fatma, Rabiyatul Adawiyah Siregar, Elda Sari Siregar, Sahlan Tuah https://creativecommons.org/licenses/by/4.0
The Analysis of Students Creative Thinking Ability Using Mind Map on Solution Topic
Creative thinking is one of the key competencies in 21st-century education. This study aimed to analyze students’ creative thinking skills on the topic of solutions using mind maps as an assessment tool. This study used a quantitative descriptive method involving 44 XII-grade students from two senior high schools in Padang City during the 2025/2026 academic year. The instrument used was adapted from Rahayu et al., focusing on four indicators of creative thinking: fluency, flexibility, originality, and elaboration. The results showed that most students (95.45%) were categorized as less creative, while one student (2.27%) was creative, and one (2.27%) was not creative. No students achieved the highly creative level. The highest achievement was in the fluency aspect (86.36%), followed by flexibility (60.90%), originality (38.25%), and elaboration (19.88%). These findings indicate that students were relatively capable of generating ideas but struggled to develop and connect them in more original and detailed ways. This study highlights the novelty of using mind maps as an alternative assessment tool for measuring creative thinking in chemistry learning, specifically in the context of solutions, and suggests the need for creativity-oriented instructional approaches.
Copyright (c) 2025 Melati Wahyuni, Faizah Qurrata Aini https://creativecommons.org/licenses/by/4.0
Analysis of Students Environmental Attitudes as a Contribution to the Sustainable Development Goals (SDGs)
Environmental attitudes among university students play a crucial role in supporting the achievement of the Sustainable Development Goals through the development of responsible and sustainable behaviors. This study aims to analyze university students’ environmental care attitudes in the context of the Sustainable Development Goals (SDGs). A descriptive quantitative approach was employed, involving 121 students from the Chemistry Education Program, Faculty of Teacher Training and Education, Universitas Mataram. Data were collected using a 5-point Likert scale questionnaire covering three primary dimensions of environmental attitude-cognitive, affective, and conative-along with a commitment dimension toward the SDGs. The results indicate that all dimensions fall within high to very high categories, with the highest averages observed in the cognitive (4.32), affective (4,18) and SDGs commitment (4.25) dimensions. The conative dimension scored slightly lower (3.89), suggesting the existence of an attitude–behaviour gap between awareness and actual practice. Students demonstrate strong environmental knowledge and moral commitment, but have not fully translated these into consistent, sustainable behaviors. These findings underscore the need for more contextually relevant and action-oriented learning strategies based on the SDGs, such as project-based learning and eco-campus programs, to translate environmental awareness into tangible actions. Overall, the study emphasizes the strategic role of higher education in cultivating knowledgeable, committed, and sustainable-minded youth aligned with SDG 12, SDG 13, and SDG 15.
Copyright (c) 2025 Syarifah Wahidah Al Idrus, Rahmawati Rahmawati, Abdul Kadir https://creativecommons.org/licenses/by/4.0
Teaching Skills for Students in a Practical Teaching Microteaching Course
The Microteaching course trains students to understand basic teaching skills and apply them in teaching practice with fellow students. The purpose of this study was to determine students' explanation skills during teaching practice in the microteaching course. The study was conducted with Biology Education students enrolled in the Microteaching course, class A, during the 2024/2025 academic year. Data were collected using observation sheets during student teaching practice through peer teaching. The instrument used was derived from indicators' explanation skills, with answer choices on a 1-5 Likert scale. The data were analyzed descriptively by calculating the scores obtained by each indicator on the observed explanation skills, then 5 categories were created: very poor, less good, quite good, good, and very good. The results of observations on all observed explanation skills indicators showed that, on average, students were able to apply explanation skills in teaching practice in micro teaching courses with a good category. However, there were still students with very poor and poor presentations, with an emphasis on important points, and feedback indicators. It can be concluded that, on average, students were able to apply explanation skills in teaching practice; however, they still need to continue practising so that, later, when facing school field practice or when becoming real teachers in schools, they become accustomed to using these skills.
Copyright (c) 2025 Kusmiyati Kusmiyati, I Wayan Merta https://creativecommons.org/licenses/by/4.0
Testing of Soil Moisture and Temperature Sensors in an Automatic Plant Watering System Based on the Internet of Things (IoT)
The implementation of automated plant watering systems in the agricultural sector utilizes sensor technology based on the Internet of Things (IoT). This study aims to evaluate the performance of soil moisture and temperature sensors utilizing the IoT in an automated plant watering system. The sensors used are the YL-69 sensor to determine soil moisture and the DS18B20 temperature sensor to determine soil temperature. Both sensors are connected to the NodeMCU ESP8266 microcontroller. Testing was conducted from 07:00 to 17:00 WITA, with a 1-hour interval for data collection, monitored using the IoT on the blink application on the cellphone. Then, the data obtained is analyzed to determine the values of error and accuracy. The results obtained on the soil moisture sensor have an average error of 0.989% with an average accuracy of 99.011%. Meanwhile, the results obtained on the soil temperature sensor have an average error of 1.240% with an average accuracy level of 98.760%. The lower the error value, the better the sensor performance indicates the sensor's ability to read data that is close to the actual value of the comparison tool. Likewise, the higher the level of sensor accuracy, the better and more reliable the sensor is when used in an IoT-based soil temperature measurement system. This value indicates that the sensor's performance has a very high level of reliability and precision in detecting soil moisture and temperature in real-time. This system can be applied in agricultural technology education and vocational training programs.
Copyright (c) 2025 Susilo Yudoyono, Dewa Gede Eka Setiawan, Muhammad Yunus, Muh. Fachrul Latief, Icha Untari Meidji https://creativecommons.org/licenses/by/4.0
Student Involvement Model in Laboratory Maintenance According to ISO 17025
Student engagement in laboratory quality systems is essential for strengthening maintenance compliance and technical competence, particularly when aligned with international standards such as ISO 17025:2017. This study aims to (1) design a student engagement model that complies with the requirements of clauses 6.2.2 and 7.6 of ISO 17025:2017 and (2) analyze the impact of its implementation on improving equipment maintenance compliance and student technical competence. The research design employs an explanatory sequential mixed-methods approach, with a dominant quantitative component and qualitative support. The research subjects included 22 key informants (laboratory coordinators, laboratory heads, technicians, and students) who were selected with purposive sampling. Data were collected through structured questionnaires, in-depth interviews, FGDs, and participant observation. Quantitative data were analyzed using multiple linear regression using SPSS 25, while qualitative data were analyzed thematically. The results showed that the model designed based on four pillars: training, documented participation SOPs, internal audit simulations, and portfolio systems effectively transformed students from passive learners into competent contributors to the laboratory quality assurance system. The implementation of the model was proven to significantly improve maintenance compliance (mean = +1.81) and technical competence (mean = +1.59). Regression analysis confirmed that the model explained 80.2% of the variance in compliance (R² = 0.802) and 78.1% of the variance in competence (R² = 0.781), with documentation quality (β = 0.462; β = 0.423) as the strongest predictor. Qualitative findings revealed a shift in mindset from obligation to ownership as a key mechanism. This study concludes that the developed model not only aligns with ISO 17025 but also provides a strategic approach to building sustainable quality cultures in educational laboratories.
Copyright (c) 2025 Muhsin Muhsin, Mohammad Liwa Ilhamdi, Lalu Septiadi Wirandanu https://creativecommons.org/licenses/by/4.0
Development of Chemistry Magazine Containing Content on Cross-Aldol Condensation Reaction as Reading Material for Polyfunctional Organic Compounds Lectures
Chemistry magazines have the potential to be effective media because they are able to present material in a more interesting, concise manner, and are supported by visualizations that clarify abstract concepts. The use of chemistry magazines is expected to help students deepen their understanding of the aldol condensation reaction mechanism and other organic materials. This study aims to develop a chemistry magazine that contains content on the cross-aldol condensation reaction mechanism as a supplementary reading for students in the Polyfunctional Organic Compounds course. The type of research used is research and development (R&D) with a 4D model that includes the stages of define, design, develop, and disseminate. The subjects of the study were students from the Chemistry Education Study Program at the University of Mataram, while the object of the research was a chemistry magazine developed based on the results of a student needs analysis. Data were collected through expert validation sheets and student response questionnaires, then analyzed descriptively and quantitatively using Aiken's V formula to measure validity and percentage of agreement (PA) to measure reliability. The results showed that the chemistry magazine obtained an average validity score of 0.93, categorized as “highly valid,” and a reliability level of 94%, categorized as “reliable.” Meanwhile, the results of the practicality test, as obtained by students, achieved a percentage of 85% with the category “very practical”. Thus, the chemistry magazine developed is declared feasible and practical for use as additional reading material to enhance students' understanding of the cross-aldol condensation reaction mechanism in the Polyfunctional Organic Compounds course and to foster an interest in learning chemistry independently.
Copyright (c) 2025 Rahmawati Rahmawati, Weny Amanatul Hidayah, Syarifa Wahidah Al Idrus https://creativecommons.org/licenses/by/4.0
The Utilization of Medicine Plants by the Community of the Traditional Village Dasan Beleq Gumantar Regency, North Lombok, Indonesia
The traditional village community of Dusun Dasan Beleq is the oldest Sasak tribe in Lombok and still maintains local wisdom in using plants as traditional medicine. This study aimed to identify the plant species, parts, and processing methods used by the local community for medicinal plants. This type of research is descriptive. The data were collected through primary research, including semi-structured interviews and non-participatory observations. The respondents were selected by purposive sampling, including traditional leaders and the local community. The stages of data analysis are data reduction (Data Reduction), data presentation (Data Display), and conclusion. The results showed that the people of the Dusun Dasan Beleq Traditional Village had knowledge of 25 species from 22 plant families. Leaves are one of the most commonly used plant parts besides flowers, fruits, seeds, and rhizomes. The processing of medicinal plants used by the people of the Dusun Dasan Beleq Traditional Village involves methods such as pounding, boiling, and squeezing.
Copyright (c) 2025 Nurul Hidayah, Gito Hadiprayitno, Karnan Karnan, Jono Irawan https://creativecommons.org/licenses/by/4.0
The Effect of Different Doses of Compost and Urea Fertilizer on the Growth of Pak Choi (Brassica rapa L.)
Pak Choi is a widely cultivated plant species in Indonesia. To grow optimally, Pak Choi requires a growing medium containing sufficient nutrients. To ensure adequate nutrient levels in the growing medium, fertilization is necessary. Research on the effect of compost and urea fertilizer applications on Pak Choi growth was conducted from March to June 2025. This study aims to analyze the vegetative growth of Pak Choi after being given compost and urea fertilizer treatments. In this study, a completely randomized design with 2 factors was used. The compost application was 0 kg, 0.8 kg, 1.6 kg, and 2,4 kg for 8 kg of soil in a polybag. The urea fertilizer treatment was 0 grams, 0.5 grams, 1 gram, and 1.5 grams for each plant. Each treatment combination was performed with three replications. The results showed that the compost treatment had a significant effect on the fresh weight, number of leaves, plant height, and leaf length of Pok choy. The application of urea fertilizer can increase the fresh weight, number of leaves, plant height, and leaf length of Pak Choi. The interaction between compost and urea fertilizer had no significant effect on fresh weight, leaf number, plant height, or leaf length. The optimal dose of compost was 1.2 kg. The 1.5-gram urea fertilizer treatment resulted in better growth than the other doses.
Copyright (c) 2025 I Wayan Merta, Ahmad Raksun https://creativecommons.org/licenses/by/4.0
Sustainability Analysis of the Vertical Composter as an Innovative Approach for Organic Waste Management and Space-Efficient Urban Food
The waste problem is a never-ending problem, so it is everyone's responsibility to find solutions to the existing waste problem. According to data from the Ministry of Environment and Forestry in 2022, waste in Indonesia is predominantly composed of organic waste, accounting for 41.27% of the total waste. The purpose of this study was to determine plant growth by utilizing used barrels as a vertical composter for organic waste, which is useful for providing small-land farming, and to determine the quality of liquid and solid fertilizers. The method used was a laboratory experiment. The results of the study were as follows: the number of mustard green leaves was 15 cm, and the bok choy leaves were 13 cm. The total height of the mustard greens was 40 cm, and the bok choy was 20 cm. The length and area of ​​the leaves continue to increase by around 0.2 cm or more per day. The highest nutrient content in both compost and liquid fertilizer is P2O5 in Gegelengan Village, 4.223% in compost, and 5.4% in Kediri Village in liquid fertiliser, while the lowest is the N-Total content of 0.5% (compost) and 1.2% (liquid fertilizer). The research results obtained from the initial soil, solid organic fertilizer and liquid organic fertilizer met the quality standards based on the Decree of the Minister of Agriculture No. 261/KPTS/SR.320/M/04/2019.
Copyright (c) 2025 Hijriati Sholehah, Nurhidayah Nurhidayah, Khairul Pahmi Rahmawati https://creativecommons.org/licenses/by/4.0