Engineering Headway Vol. 24

Abstract: Microbial resistance has become a threat that causes thousands of deaths yearly; therefore, efforts are required to address this problem. One of the promising methods used to inhibit bacterial growth is photocatalyst technology. In this research, CaTiO₃ compounds was synthesized using the molten salt method and tested for antibacterial activity in both UV-unexposed and UV-exposed conditions on Staphylococcus aureus bacteria. The diffractogram showed that the CaTiO₃ compound was successfully synthesized without impurities that indicated by the characteristic peaks at 2θ (^o) = 23.29; 33.18; 47.52; 59.33; 69.48; 79.17. The micrograph results showed that the CaTiO₃ compound had a regular polyhedral shape and was agglomerated with particle sizes in the 0.2941 ± 0.0144 µm range. The UV-Vis DRS spectra showed that the CaTiO₃ compound had a bandgap energy of 3.48 eV (315 nm). In the antibacterial activity test results under UV irradiation, the growth of Staphylococcus aureus decreased by 3.95, 0.91, and 1.45 CFU/mL.

Abstract: Sulforaphane and iberin, the isothiocyanate compounds found mainly in Brassica oleracea, are well-reported as anticancer agents. This study examined the potential of sulforaphane and iberin to inhibit proteins implicated in cancer-signaling pathways, such as NF-κB, TGF-β Receptor, Wnt/β-catenin, and MAPK. The presence of sulforaphane and iberin in Brassica oleracea was previously analyzed using LCMS. Subsequently, molecular docking simulation using PyRx Virtual Screening Tool were conducted to assess their binding affinities and interactions with protein targets (3RZF, 5EBZ, 5E8V, 3TZM, 1H8F, 1M17, and 3I81). LCMS analysis revealed the presence of sulforaphane and iberin compounds in Brassica oleracea, identified by their respective abundance peaks in the chromatogram at molecular weights of 177 and 164 g/mol. Furthermore, our results consistently demonstrated that sulforaphane exhibits a higher binding affinity for multiple target proteins than iberin, as evidenced by its lower binding energy values and greater number of amino acid interactions. In conclusion, these findings suggest that sulforaphane and iberin may serve as promising inhibitor ligands for cancer treatment.

Abstract: Immobilized enzymes have higher resistance to environmental changes and can be easily obtained/re-recovered/reusable compared with their free form after use in the biocatalysis process. The main benefit of immobilization is that it protects the enzyme from harsh environmental conditions (e.g. high temperatures, extreme pH values, etc.). However, the enzyme immobilization process is not easy and cheap. Most cellulases used in Indonesia are single-use enzymes and are unstable. This causes the use of cellulase on an industrial scale to be expensive and difficult to store for a long time. Therefore, a solution is needed to mobilize cellulase with a simple and inexpensive process, namely by utilizing activated carbon from the shell of a Calophyllum inophyllum seed. This study aimed to investigate the potential of activated carbon made from C. inophyllum shell as an immobilizer for the production of cellulase. An optimal, easy, and simple enzyme immobilization method is required to ensure sufficient cellulase quality and quantity for industrial scale. In general, the four stages of research were as follows: a) the synthesis of activated carbon made from C. inophyllum shell; b) cellular immobilization synthesis; c) stability test of immobilized cellulase against pH and temperature; and d) reusability analysis of immobilized enzymes. This study examined the effect of carbon particle size (60 and 100 mesh) and concentration of ZnCl₂ activator (1, 2, and 3 M). The results indicate that the optimal manufacturing of C. inophyllum shell activated carbon is by using a size of 100 Mesh with a concentration of ZnCl₂ activator of 2 M, which has an enzyme activity in the range of ±0.25 units/mL, and the immobilized cellulase remains effective for up to 5 reuse cycles.

Abstract: Frozen shrimp companies in Indonesia produce a large amount of shrimp waste. Shrimp waste can be processed into chitin and hydrolysate through the deproteinization process. In this study, deproteinization uses an enzymatic method with a pH of 2.5 ± 0.1 conditioned by using sulfuric acid. Shrimp waste was incubated for 3 or 5 d using acidic water and filtrate from the previous incubation. The Kjeldahl method determined the total nitrogen content of the residue and hydrolysate. The total nitrogen content of the hydrolysate was converted to obtain the protein content. The nitrogen content results in residue obtained at incubation times of 3 and 5 d using acidic water solution, which was 6.98% and 6.64%. Meanwhile, the total nitrogen content soaked in the previous filtrate for 6, 9, 10, and 15 d was 6.57, 6.36, 6.24, and 6.13%, respectively. The protein content obtained at incubation times of 3 and 5 d using acidic water solution was 6.78 and 8.4%. Meanwhile, the total protein levels soaked in the previous filtrate for 6, 9, 10, and 15 d were 9.33, 10.57, 11.12, and 12.49%, respectively. The incubation time decreases the total nitrogen content in the residue and the increase in protein content in the hydrolysate. Keywords: Shrimp Waste, Deproteinization Enzymatic, N total Chitin, Protein Hydrolisate

Abstract: Pectin is a water-soluble fiber that can increase the fiber content of cookies. The pectin used comes from cocoa pod husk extract which was previously only used as animal feed and became waste. This research aims to utilize the content of cocoa pod husks in the form of pectin as a food additive applied to cookies. This research uses quantitative analysis with the help of SPSS on the physical and chemical properties of cookies and their digestibility. Extraction was carried out with 5% (w/v) citric acid solvent for 5 hours at a temperature of 95°C. The extract obtained was analyzed using FTIR and the spectrum was compared with pure pectin used to IPPA (International Pectin Producer Association). Cocoa pod husk pectin extract has the same functional groups as pure pectin. The product, cookies with pectin substitution were tested for physical properties (color, texture), chemical properties (water content, crude fiber content) and digestibility. This study obtained results that the water content, color, texture, crude fiber content, and digestibility of cookies with pectin substitution were different from cookies without pectin. Pectin substitution in cookies was varied at 1, 4 and 7% (w/w) then compared with the control. The effect of pectin is known from the highest water content (6.01%), hard texture (79.57 g/mm), the highest crude fiber content (60.39%) and decreased digestibility (15.44 g/100 mg) at a variation of 7%. Pectin did not affect the color of cookies with no significant differences shown.