Journal of Material and Process Technologies

Physicochemical, antioxidant, antinutritional and sensory –properties of Tamarind (Tamarindus indica)

Kidist Taksene — 2024-09-08

The sweet, acidic pulp of the tropical fruit known as the tamarind (Tamarindus indica, Fabaceae), which is found throughout Africa and Asia, is highly prized. Ethiopia's Dire Dawa is home to a large tamarind consumption. This study aimed to investigate the physicochemical, antioxidant, antibacterial, antinutritional, and sensory properties of tamarind indica pulp under different processing conditions (roasted and soaking). As a remedy, tamarind pulp that had been raw, steeped, and roasted was utilized. These treatments were examined for their antinutritional capabilities using the disc diffusion method, their proximate composition using gravimetric analysis, their antioxidant and antinutritional components using UV spectrophotometry, and their sugar profile using HPLC. All but crude fat showed a significant (p<0.05) difference in proximate composition between the soaked, roasted, and control samples. The mineral profile revealed the presence of calcium, magnesium, manganese, sodium, and potassium, and a significant difference (p < 0.05) was found between the treatments. The antinutritional analysis showed that both soaked and roasted tamarind had a significant reduction in tannin, phytate, and oxalate. Tamarind fruit extract had 76.12 µg/mL, 79.86 µg/mL, and 105.51 µg/mL antioxidant activity in the DPPH assay for control, soaked, and roasted treatments, respectively. In comparison to the control treatment, the results showed that soaking and roasting enhanced the nutritional profile, antioxidant and sensory qualities, and decreased the antinutritional aspects. This could be helpful input for making the most of and promoting the traditional uses of tamarind in the community.

Dual COX/ 5-LOX inhibitory potential and antioxidant activities by extracts isolated from Melia Azedarach L. leaves

Ibrahim Nasser Ahmed — 2024-09-08

This study was aimed at evaluating the dual cyclooxygenase (COX) and 5-Lipoxygenase (5-LOX) enzyme inhibition and antioxidant activity of the crude extract (CE) and various solvent fractions from Melia azedarach leaves. Multiple solvents were used to fractionate the 80% ethanolic extract of the leaves, which was then examined for enzyme inhibitory effectiveness against COX and 5-LOX enzymes. All fractions and CE were examined for antioxidant activity, and phenolic acids and flavonoids were identified using Reverse-Phase High-Performance Liquid Chromatography (RP-HPLC). The ethyl acetate fraction (EaF) had the greatest COX/5-LOX inhibitory impact among tested fractions. In vitro, COX activity studies showed that EaF and butanol fraction (BF) possess a higher COX-2 selectivity index than Indomethacin. Besides, the EaF exhibited the highest reduction potential among the control and the CE when tested for antioxidant activities. These findings support the traditional use of Melia azedarach as an anti-inflammatory drug, as the plant inhibited both COX/5-LOX and COX-2 with high selectivity.

Separation of benzene and cyclohexane azeotrope mixture using 1-ethyl-3-methylimidazolium ethyl sulfate ionic liquid using extractive distillation

Girma Gonfa — 2024-09-08

Most of the cyclohexane used for various industrial applications is largely produced through catalytic hydrogenation of benzene and the separation of cyclohexane from the unreacted benzene is industrially significant. However, it is tough to separate cyclohexane from benzene by conventional distillation processes since these components have close boiling points and form an azeotrope mixture. Currently, extractive distillation is commercially used for the separation of cyclohexane from benzene using conventional solvents (entrainers) such as sulfolane, dimethyl sulfoxide, N-formylmorpholine, and N-methylpyrrolidone. However, separating benzene and cyclohexane with extractive distillation with these solvents makes the process complex and consumes high energy. On the other hand, ionic liquids are considered green and potentially environmentally friendly, hence have been attracting attention in replacing conventional solvents (entrainers) in extractive distillation because of their unique properties. In this work, 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO₄]) was used for the separation of cyclohexane from benzene using extractive distillation. The performance of [EMIM][EtSO₄] was evaluated by measuring the isothermal vapour-liquid equilibrium (VLE) for benzene, cyclohexane, and [EMIM][EtSO₄] ternary mixture at 353.15 K. The isothermal VLE was measured using Head Space Gas Chromatography (HS-GC). Moreover, the VLE data was also predicted using COSMO-RS and compared with the experimental values. The addition of [EMIM][EtSO₄] eliminated the azeotrope and increased the relative volatilities of benzene and cyclohexane resulting in their separation. The performance of [EMIM][EtSO₄] on the benzene and cyclohexane system was compared with dimethyl sulfoxide. The current ionic liquid shows higher relative volatility compared to dimethyl sulfoxide showing this ionic liquid can be used for the separation of benzene and cyclohexane using extractive distillation.

Nano-metakaolin-enhanced fly ash and cement-based geopolymer mortar

Eyerusalem Aschenaki Gebremariam — 2024-09-08

The addition of Nanomaterials to Geopolymer mortar causes substantial modification in the kinetic of polymerization. The purpose of this research is to study, the effect of nano metakaolin in cement-based fly ash geopolymer mortar. The ratio of alkaline activators and molar concentration of NaOH was kept constant at 1.5 and 12M respectively, while the proportion of Portland cement and fly ash constitutes 30% and 70% of the total starting materials respectively. The replacement level of nano metakaolin was (0%, 5%, 10%, 15%, and 20% by weight of binders). Mortar mechanical and microstructural Properties were evaluated by conduct compressive strength, flexural strength, ultrasonic pulse velocity, scanning electron microscope (SEM) and x-ray diffraction (XRD) analysis. The result shows significant improvement in mechanical performance and denser morphology than the control mix. Therefore, geopolymer mortar containing 10% replacement of nano metakaolin has shown particularly good results and enhancement in various aspects of the material performance and properties, indicating its potential for wider implementation in the construction industry.

Effects of lignocellulose structure on single fiber tensile characteristics portrayal: a case of enset fiber

Abebayehu Abdela Gelgelu — 2024-09-08

Fiber-level tensile characteristics are vital for micromechanical analysis and mechanical modelling of materials and their composites. This portrayal depends on diameter estimation accuracy, as the applied load is determined from the testing machine. Inline, natural fibers possess an internal cavity; the diameter found using microscopy denotes the external diameter which is larger than the diameter pertaining to actual load-carrying cross-section. This study presents a new approach that estimates diameter considering lignocellulose structure and hydrophilicity, thereby enabling the portrayal of more accurate tensile strength values. First, the fibers’ diameter is measured using a laser microscope, on various spots axially and the internal cavity was then considered to determine the actual diameter. The density of milled fibers is measured using Pycnometry. The diameter which relates to a solid load-carrying cross-section is identified using the relationship between density, mass and volume. The experiment design was framed and analyzed using Python and JMP Pro 13. The measured density of Enset is 1.38 g/cm3. The average overestimation of microscopy result is significant; it is 27.7µm which is about 21.8%. This underrates the actual tensile strength of Enset fiber by about 37.5%. That is σext=0.627σact. This, in turn, would affect micromechanical analyses and mechanical modelling. Thus, the need to consider lignocellulose structure for testing the tensile strength of Enset fiber is inevitable and the method utilized in this study can be used for other natural fibers of the same nature customizing the context.

Optimization of crude rotenone oil extraction from birbira plant (Milletia ferruginea) seed by Soxhlet and maceration methods

Amsalu Gosu Adigo — 2024-09-08

The extraction of active compounds from plant materials is one of the most critical processes in the commercial development of natural products for pharmaceutical, herbicide or pesticide production. The focus of this study was extraction of crude rotenone oil (CRO) from Birbira plant (Milletia ferruginea) seed. The extraction was done using maceration and a Soxhlet extractor using organic solvents, such as ethanol, hexane, and chloroform. For the efficient extraction of crude rotenone oil from Birbira plant seed the effect of parameters, such as extraction method, solvent type, extraction time and size of crushed Birbira seed were investigated. Based on the experimental results obtained Soxhlet extraction method was more efficient (41.6% CRO yield) compared to the maceration extraction method (25.1 % CRO yield). The extraction results for both Soxhlet and maceration methods indicated that chloroform is more efficient compared to ethanol and hexane solvents. On the other hand, the effects of crashed seed size and extraction time on the % CRO yield were also investigated. The results showed that medium size (0.1–0.35 mm) for both Soxhlet and maceration extraction was the optimum size leading to the highest % CRO yield compared to fine and coarse ground seed size. The highest % CRO yield was obtained during 4 to 5 h of Soxhlet extraction and 25 to 30 h of maceration extraction method. Therefore, the Soxhlet extraction method is the fastest and efficient method for the extraction of CRO from plant materials. The characterization of Birbira seed powder and CRO was done with FTIR and Rheology test equipment. The FTIR result revealed that CRO is composed of aliphatic, olefin, polyphenol and alcohol functional groups, in which polyphenol functional groups are the most essential flavonoid components available in crude rotenone oil.