KOVALEN: Jurnal Riset Kimia

In Silico Analysis of Pinocembrin Inclusion Complexes with beta-Cyclodextrin and Hydroxypropyl-beta-Cyclodextrin Using DFT and Molecular Docking

2026-08-31T14:51:34+00:00

Fe Removal by Pistia stratiotes Under Mixed-Metal Conditions: Evaluating Ionic Competition During Phytoremediation

2026-08-31T14:51:34+00:00

Ethanolic Soxhlet Extract of Harendong Leaf (Melastoma malabathricum): A Study of Total Phenolic Content and Antioxidant Activity

2026-08-31T14:51:34+00:00

Effect of Spent Coffee Grounds on the Organoleptic Properties, pH, Moisturizing Effect, and Skin Irritation of Body Scrub Formulated with Waste Cooking-Olive Oils Liquid Soap

2026-08-31T14:51:35+00:00

Spent coffee grounds (SCG) have potential as a sustainable exfoliating material for body scrub formulations. This study evaluated the effects of systematically varying the proportions of SCG and liquid soap derived from waste cooking oil and olive oil on the organoleptic properties, pH, moisturizing effect, and skin irritation responses of body scrubs. Three formulations containing 3% cornstarch were prepared with SCG and liquid soap proportions of 40:57% (V1), 50:47% (V2), and 60:37% (V3), respectively. Organoleptic properties were evaluated descriptively, pH was measured in triplicate, and moisturizing and irritation responses were assessed observationally in 13 respondents. Increasing SCG progressively changed the texture from smooth (V1) to moderately coarse (V2) and coarse (V3), while all formulations exhibited a coffee odor and black color. The pH values were 7.87 0.23, 7.70 0.07, and 7.38 0.38 for V1, V2, and V3, respectively, all within the pH range of 4.5–8.0 adopted according to SNI 16-4399-1996, with no significant differences among formulations [one-way ANOVA, F(2,6) = 2.781, p = 0.140]. Positive moisturizing responses were observed in all respondents for V1 and V2 (13/13; 100%), but not for V3 (0/13; 0%). No itching, erythema, or edema was observed for any formulation during the 30-min observation period. Overall, V1 exhibited the most favorable combination of characteristics among the formulations evaluated. These findings indicate that the SCG–liquid soap compositional balance is an important formulation factor influencing the physicochemical and observed skin-response characteristics of SCG-based body scrubs.

Microwave-Assisted Synthesis of Nanohydroxyapatite Using a Biotemplate

2026-08-31T14:51:35+00:00

Formulation of Encapsulated Extracts from Local Palu Red Onion Bulbs (Allium cepa var. aggregatum L.) Using Carrageenan Coating: Characterization, Stability, and Antioxidant Activity

2026-08-31T14:51:35+00:00

This study aimed to identify the optimal concentration of carrageenan as a coating matrix for extracts of local Palu red onion bulbs (Allium cepa var. aggregatum L.) using the ion gelation method to characterise their properties, stability and antioxidant activity. The technique of converting liquid samples into small particles is known as microencapsulation. Carrageenan was formulated at varying concentrations (0.1%, 0.2%, 0.3%) with the addition of 0.1% Na-TPP. Testing of antioxidant activity at a concentration of 0.3% yielded the highest antioxidant activity of 87.59%. The ANOVA test results showed that the matrix concentration had a significant effect (<0.05) on antioxidant activity. A total phenolic content of 49.61 mg GAE/g was observed in the 0.3% carrageenan sample. Carrageenan was stable at temperatures of 25°C and 40°C. FTIR characterisation of the encapsulation process indicated the presence of spectra showing interactions between the coating matrix and the extract, revealing changes in functional groups. PSA analysis indicated a particle size of 2100 µm.

Design and Optimization of Fe Doped TiO2 Photocatalytic Reactors for Pollutant Degradation: A Systematic Literature Review

2026-08-31T14:51:36+00:00

Environmental pollution caused by industrial wastewater containing persistent organic compounds has become a major global concern. Photocatalytic technology based on titanium dioxide (TiO₂) has attracted significant attention due to its strong oxidation capability, chemical stability, and environmental compatibility. However, the relatively wide band gap of TiO₂ limits its activity mainly to ultraviolet light. Metal doping, particularly with iron (Fe), has been widely investigated as a strategy to enhance visible light absorption and suppress electron–hole recombination, thereby improving photocatalytic performance. This study aims to analyze the development and optimization of Fe-doped TiO₂ photocatalytic reactors for pollutant degradation through a systematic literature review. The review followed the PRISMA guidelines, and relevant articles were collected from three major scientific databases: Scopus, Web of Science, and ScienceDirect. A total of 166 articles were initially identified, and after screening and eligibility assessment, 18 studies were included in the final analysis. The results show that synthesis methods such as sol–gel and hydrothermal techniques significantly influence catalyst properties and photocatalytic activity. In addition, reactor configurations including packed-bed, fluidized-bed, and photocatalytic membrane reactors play an important role in improving degradation efficiency through optimized light distribution and mass transfer. Reported pollutant degradation efficiencies ranged from approximately 45% to over 99%, depending on operating conditions and reactor design. Despite promising laboratory-scale results, further research is required to improve reactor scalability, catalyst stability, and energy efficiency for large-scale environmental applications.