Temperature Of 50oC Research Articles

Shear Bond Strength of Orthodontic Stainless Steel Bracket in Bovine Teeth Submitted to Bleaching Agents

The purpose of this in vitro study was to determine the influence of bleaching agents in the shear bond strength of orthodontic stainless steel bracket. The samples were composed by 90 bovine lower central incisors, which were divided into three groups named G1 (not submitted to bleaching), G2 (bleached with carbamide peroxide at 16%-Whiteness HP - FGM ®) and G3 (bleached with hydrogen peroxide at 35%-Whiteness HP, FGM ®). The teeth were stored in distilled water at a temperature of 37oC for 24 hours and 30 days was expected for the bonding of brackets Gemini 3M (3M - Unitek ®), after a wait period of 30 days the brackets were placed to all groups of samples, applied with the composite Transbond XT (3M/ESPE®). The shear bond test was performed in material testing machine EMIC DL 2000, carried under a deformation speed of 0.5 mm / min. The G1 presented an average strength of 6,05 (±3,47) MPa, while the G2 presented an average resistance of 2,52 (±1,69) MPa, and the G3 demonstrated 1,58 (±1,17) MPa. The results concluded that the dental bleaching induced, in the experimental model used, significant reduction of shear strength of brackets bonded to dental elements subjected to both in-home and in-clinic bleaching. These findings suggest that adherence of the resin used in the placement of the brackets was damaged by bleaching. Therefore, the most affected in the analysis of shear bond strength was first the in-clinic bleaching, followed by in-home bleaching and at last the control group and the greater the concentration of bleach is less shear strength. So it is suggested to perform the bleaching treatment after orthodontic treatment.

Oil extraction from rice bran using conventional and bio-based solvents

Rice bran is the outer layer of the rice grain, rich in essential nutrients and bioactive compounds. It is a valuable by-product used for various purposes, including the extraction of rice bran oil (RBO) known for its health benefits. This study focused on extracting oil from the nutritious rice bran using both conventional solvent (n-hexane) and bio-based solvent (isopropanol) for comparison under diverse conditions. The RBO yields were analysed at different temperatures of 40oC, 50oC, and 60oC, with bran-to-solvent ratios of 1:3, 1:5, and 1:7, and extraction times of 2, 4, and 6 hours. The highest yields achieved were 12.4% for n-hexane at 60oC, 1:7 ratio, and 6 hours, and 9.76% for isopropanol at 60oC, 1:7 ratio, and 4 hours. The extracted oil underwent comprehensive physical analysis, including density, acid value, free fatty acid, and iodine value test. The physical analysis revealed density values of 0.867 g/mL for n-hexane and 0.866 g/mL for isopropanol. Acid values were 21.48 mg KOH/g (n-hexane) and 26.90 mg KOH/g (isopropanol). Free fatty acid percentages were 10.74% (n-hexane) and 13.45% (isopropanol). Iodine values were 65.48 mg (n-hexane) and 60.40 mg (isopropanol). The collected data were analysed using response surface methodology (RSM) to optimize the extraction condition, predicting the highest yield at 60oC, with a bran-to-oil ratio of 1:5 parts solvent, and an extraction time of 6 hours. Statistical analysis confirmed the significance of the optimization model (p < 0.05). Overall, this study provided valuable insights, advancing more efficient and effective RBO production methods. Keywords: rice bran; extraction; n-hexane; iso-propanol

Production of Biodiesel Without Catalyst Separation with Palm Oil Interesterification Process Using Essential Oil Biocatalyst

The transesterification is a method commonly used in the production of biodiesel. Therefore, this study aimed to investigate interesterification reaction of palm oil with methyl acetate using essential oil biocatalyst, specifically focusing on eugenol and cajuput oil. The operating parameters were: 250 g of palm oil, a molar ratio of palm oil:methyl acetate of 1:6, a reaction temperature of 60ºC, a stirring speed of 300 rpm, a biocatalyst of 0.75 wt. % in relation to oil, and reaction times of 15, 30, 45, 60, and 75 min. The palm oil, methyl acetate and biocatalyst reacted in a three-necked flask as a reactor under operating conditions. Additionally, simulations were performed using ChemDraw Professional 15.0 to analyze the molecular behavior of the reacting compounds.

Over-Time Stability Evaluation of Fluorinated Self-Assembled Monolayer on Commercial Indium Tin Oxide Electrode on PET Substrate

Motivation: Self-Assembled Monolayer (SAM) modified electrode has a key role in electrochemical biosensor applications to achieve desired sensing properties such as selective interaction with target protein and anti-fouling properties of non-specific protein. However, the degradation of SAM layer on the electrode can cause the electrochemical response to drift over time. This causes adversary effect on the designed biosensor such as limited shelf life and inconsistent electrochemical signal reading between electrodes. For that matter, it is important to understand the signal drift behaviour and ultimately obtain a SAM-modified electrode with good stability over time. In this study, we observed the signal drift of SAM-modified indium tin oxide electrode on PET substrate (ITO-PET). Three-electrode electrochemical impedance spectroscopy (EIS) measurement was carried to evaluate the electrochemical properties of the ITO-PET substrate over time. Materials and Methods: Commercial ITO-PET (Adafruit, NY, USA) was used as electrode and was modified using Perfluoro-octyltriethoxysilane (Sigma Aldrich, St. Louis, MO, USA) self-assembled monolayer. The ITO-PET substrate was modified by using room temperature RCA-1 silanization process as shown in Figure 1. The modified electrode was rinsed in ethanol and DI water and stored in dark condition with temperature of 5oC. The Electrochemical Impedance Spectroscopy measurements were carried by using Solartron SI1260 impedance analyser tandem with SI1287 potentiostat. with saturated KCl Ag/AgCl (RRPEAGCL2, Pine Research, NC, USA) electrode and Pt wire counter electrode (MW-1032; BASi, West Lafayette, IN, USA). Potassium Ferricyanide (K3Fe(CN)6) (Fischer Scientific, Fair Lawn, NJ, USA) with concentration of 10 mM in 1x PBS was used as redox probe. The EIS run was set at 0.31 Vdc and 10 mV Vac amplitude with frequency ranging from 0.1 – 10000 Hz. Results: We observed significant increase charge transfer resistance (Rct)increase of SAM-ITO sample (4498 ± 460 Ω.cm2) compared to the bare ITO sample (1348 ± 68 Ω.cm2). The signal also maintains its consistency after one week of storage in enclosed dry and dark environment at 5oC with 3% change in average Rct value (133 Ω.cm2). Ongoing work in this study includes the electrochemical signal evaluation of the ITO-SAM electrode exposed to protein such as casein and BSA. Figure 1

Non-Isothermal Operation of Membrane Electrode Assembly-Based CO2 Electrolyzer for Enhanced Energy Efficiency

The utilization of membrane electrode assemblies (MEA) in carbon dioxide (CO2) electrochemical conversion showcases the promising potential for stable and scalable industrial applications in fuel production, attributed to efficient gas diffusion and minimized system resistance. The electrochemical performance of MEA-based CO2 electrolyzers relies on the chemical reactivity and product selectivity optimization which is dependent on three factors: CO2 mass transport, charge transport, and ionic transport. Elevating the overall system temperature benefits the performance of the oxygen evolution reaction (OER) at the anode. Furthermore, the elevated temperature enables higher conductivity of anion exchange membranes (AEM), thereby further diminishing cell voltage. However, the downside emerges as CO2 solubility decreases at higher temperatures, fostering a scenario where the catalytic reaction leans toward hydrogen evolution, thereby undermining product selectivity.Herein, we propose an innovative approach involving thermal management for separate temperature control for the anode and cathode, forming a non-isothermal MEA by maintaining an elevated anodic temperature while cooling the cathode. This approach simultaneously addresses the need for a high-temperature anode and a low-temperature cathode. This study exhibits a temperature gradient of approximately 20°C between the anodic and cathodic planes achieved through efficient thermal modulation of water cooling and heating within the electrode plates.We showcase the benefit of non-isothermal operation with an Ag-based cathode and IrO2-based anode using 1 M KOH as the anolyte for CO2 conversion into CO. The non-isothermal condition, i.e., maintaining an anodic temperature of 80°C and a cathode temperature of 60oC, demonstrated a 65% enhancement in CO partial current density (j co), 195.6 mA cm-2, compared to the isothermal 80°C condition, 118.6 mA cm-2. The optimal performance across all temperature regimes is found to be the non-isothermal condition with anode temperature at 60°C and cathode temperature at 40 oC, yielding a j co of 243.5 mA cm-2 at 3.25 V, marking a 13.3% improvement over the isothermal 60°C condition (j co = 214.9 mA cm-2). The increase in the j co can be attributed to the lower temperature at the cathode (40 oC for the non-isothermal condition vs. 60oC for the isothermal ccondition) resulting in higher CO faradaic efficiency.The CO faradaic efficiency remained above 80% (cell potential < 2.7V) for the non-isothermal 60°C condition, whereas it dropped below 80% throughout the entire region cell potential range for the isothermal 60°C condition. This study presents a novel non-isothermal operation for advanced thermal management for MEA-based CO2 electrolyzers for simultaneous enhancement in anode activity as well as cathode selectivity. We believe this thermal management strategy is promising for engineering high-performing MEA-based CO2 electrolyzers at industrial scales.

Effect of Using Alkoxy - Silane (ethoxy silane) Coupling Agent to Enhance the Mechanical Properties of Bio-Composites

This research work investigated the effect of alkoxy silane (ethoxy silane) on the mechanical properties of polyethylene/ dried powdered pine apple peels composite. The pine apple peels was washed in distilled water, sun dried for about eight hours and later oven dried at a temperature of 60oC for about three hours. The dried pine apple peels was pulverized and sieved using a mechanical sieve arranged in descending order of fineness. The alkoxy-silane (ethoxy-silane) coupling agent (2%) was first hydrolyzed in ethanol to deliver the alkoxy functional silane to the interior of the pineapple peels and ion-free water at room temperature for 6 hours. This was followed by addition of the dried powdered pineapple peels into the hydrolyzed coupling agent solution in a reactor at a temperature of about 80 ◦C for 20 minutes. The formed product was oven dried at 110 ◦C for 3 hours and pulverized using a locally made grinding machine and sieved using a set of sieves arranged in descending order of fineness in accordance with BS1377:1990 standard as was reported by Rajan et al., (2007) to obtain pineapple peels coated with the coupling agent (150mμ). The recycled polyethylene waste was washed using distilled water, sun-dried and shredded in a shredding machine. The pineapple peels powder coated with alkoxy silane and the shredded recycled polyethylene waste were blended using a two-roll rheo-mixer at 50°C and a rotor speed of 60 rpm. The percentage of the powdered pineapple peels coated with coupling agent in the recycled polyethylene matrix was varied from 10% to 40% to produce four different compositions. A hydraulic pressing machine was used to compress the produced composites for about ten minutes applying a pressure of about 25 tons at 130°C. The produced composite samples were allowed to cool to room temperature under sustained pressure before being removed from the hydraulic press for various mechanical tests. The impact tests were performed according to ASTM D256 standard using Impact testing machine model EXT94064/6705CE, 300 J. Flexural test was performed using Universal Testing Machine model TUE-C-100, according to ASTM D790. The hardness tests were performed according to ASTM D785 standard using Rockwell Scale K hardness testing machine. The results showed that maximum flexural strength of 10.8MPa and 384Hv were recorded at 40wt.% reinforcement. The developed composite can be used applications where moderate strength will be required.

The effect of temperature, pressure, and grind size on Total Dissolved Solids (TDS) and extraction yield of semi-automatic espresso machines

The number of coffee shops in Indonesia has grown from 1,083 stalls in 2016 to over 2,937 booths in 2019, representing a threefold growth. Coffee shop establishments must provide two essential kinds of equipment: espresso machines, which use pressure, and filter machines, which employ infusion. The issue lies in the exorbitant cost and immense power requirements of semi-automatic and automated espresso machines, which necessitate the use of a manual espresso machine for commercial operations. The equipment can generate satisfactory espresso but encounters several challenges; specifically, the espresso generated is characterized by inconsistency, constantly varying in quality. This might arise due to the erratic nature of the manufacturing process. The two objectives of this study are: (1) to design an economically efficient semi-automatic espresso machine capable of producing products that meet the international quality standards set by the Specialty Coffee Association (SCA standard) and (2) to investigate the impact of critical factors such as pressure, temperature, and grind size, on the consistent quality of the resulting coffee (measured by Total Dissolved Solids (TDS) and extraction yield (EXT)). The research employs the Research and Development (RD) methodology. The research findings indicate that the optimal levels of Total Dissolved Solids (TDS) and extraction yield (EXT) may be attained by using a pressure setting of 8 bars, a temperature of 90ºC, and a grind size of 3.2 on the scale. The technique for optimizing the response resulted in Total Dissolved Solids (TDS) levels of 10.03% and extraction yield (EXT) values of 19.56%. The results have been deemed acceptable based on the criteria set by the global standards of Specialty Coffee Association (SCA).

Development of a transcutaneous form of desloratadine

Introduction: For people with allergies, it is not always possible to prevent allergens admission to the body. For this reason, it is essential to create a long-acting drug that can prevent an allergic reaction. The very promising option is a transdermal therapeutic system (TTS), with H1 blockers. The aim of the study: To create a technology for the production of desloratadine-based TTS, suitable for routine use with prolonged drug releasing. Materials and Methods: Polyvinylpyrrolidone K30 (PVP) was used as the main matrix polymer for TTS, and the Kruofilm polymer membrane was used as the adhesive layer. The formation of the polymer membrane was carried out by drying a water-alcohol solution of the components at a temperature of 60ºC. Characterization of the obtained dosage forms was made by spectrophotometry. The resulting micelles size was measured by dynamic light scattering. Results and Discussion: Round shaped TTS (patches) with water-dissolved DL and its micellar form were obtained. The size of micelles with DL was 22.8±5.2 nm. The spectrophotometric method for determining DL has been developed. The containing of DL in the patches ranged from 5 to 25 mg per patch, depending on the manufacturing technology. Conclusion: We have developed TTSs containing DL by a solution and a micellar form. A top adhesive layer has been selected that has moisture resistance, strength and reliable fixation of the matrix with the active substance on the skin. A method for the spectrophotometric determination of DL in solutions and patches was developed and validated.

Pengaruh Suhu dan Lama Pengeringan terhadap Sifat Kimia dan Fungsional Tepung Kecambah Kacang Merah (Phaseolus Vulgaris L.)

Red beans are a source of vegetable protein. One of the processes for handling red beans is germination. Red sprouts can be turned into flour to extend their shelf life and reduce the unpleasant odor that is usually present in legume products. The quality of flour products is greatly influenced by temperature and drying time, because inappropriate conditions can cause microbial growth and undesirable reactions. The main objective of this study was to assess how temperature and drying time affect the chemical and functional properties of red bean sprout flour. Apart from that, this research also aims to identify the optimal temperature and drying time required to produce red bean sprout flour with the desired characteristics. This research used a Randomized Block Design with a factorial pattern. The first factor investigated was the drying temperature, which was divided into three different levels: 50, 60, and 70°C. The next factor considered is drying time which is also categorized into three levels: 14 hours, 16 hours, and 18 hours. The data that was collected underwent analysis through variance. If the treatment had an impact on the observed variables, the analysis proceeded with a Duncan Multiple Range Test. The research results showed that the most effective treatment for producing red bean sprout flour was achieved with a drying temperature of 70oC and a drying time of 16 hours. This treatment produces red bean sprout flour with the following characteristics; water content 5.16% protein content 22.8%, wettability 142.385 seconds, water absorption capacity 211.35%, water solubility index 50.39%, oil absorption capacity 96.584%, and swelling power 388.20%.

Multilevel Categoric-One Factor Optimization Of Cremophor Rh 40 As Surfactant in Cream With Calabash (Crescentia cujete Linn) Leaves Ethanolic Extract

Indonesia's location on the equator is exposed to a high UV index, which triggers various health problems due to ultraviolet radiation, including melanoma. Melanoma is the 5th deadliest cancer that develops from the malignant transformation of melanin in oxidative stress conditions. Therefore, antioxidants are needed. Calabash is a natural exogenous antioxidant with an IC₅₀ value of 80.21 µg/mL (strong activity). Optimal formulations of cream containing calabash are determined by the concentration of ingredients and the selection of comprehensive analytical methods. This research aims to optimize cream preparations of calabash leaves ethanol extract with varying concentrations of Cremophor RH 40 as a surfactant using the multilevel categoric-one factor method. The cream was made with Cremophor RH 40 concentrations of 5%, 10%, and 15%. The cream was made by mixing the water phase (Nipagin, Glycerine, and Aquadest) and the oil phase (Cremophor RH 40, BHT, IPM, Cetostearyl alcohol, and Nipasol) after both phases reached a temperature of 60ºC in mixer speed no 1 for 15 minutes then followed by adding calabash leaves ethanolic extract until a homogeneous cream was formed. The parameters observed were organoleptic, homogeneity, the type of cream, pH, viscosity, dispersibility, and adhesion. The viscosity, dispersibility, and adhesion were chosen as the parameters for the formula optimization. The cream of calabash ethanolic extract was shown as green, homogeneous semi-solid with a soft texture and distinctive aroma, and was an oil-in-water (O/W) type cream. The average pH of 5.6 was suitable for facial skin. The viscosity value increased with increasing surfactant concentration while dispersibility decreased. The results of formula optimization obtained the optimum formula was FIII with a concentration of Cremophor RH 40 of 15% and a desirability value of 0,896.

Effect of expanded perlite aggregates and temperature on the strength and dynamic elastic properties of cement mortar

The residential market consumes nearly half of the world’s concrete production, and it is anticipated that 68 % of the global population will reside in urban areas by 2050. Researchers have focused their efforts on exploring alternative options to natural aggregates in concrete and mortar. In line with the principles of circular economy, construction and demolition waste has been repurposed for the manufacture of cement-based materials. Volcanic products, which are abundant but underutilized, have been identified as an alternative to recycled aggregates. They offer several advantages over natural river aggregates, including reduced weight, enhanced thermal and acoustic insulation, improved fire resistance and pozzolanic characteristics. While there has been a significant amount of research on the use of expanded perlite as a supplementary cementitious material, studies involving the use of expanded perlite aggregates (EPA) in cement-based construction materials are relatively limited. This paper seeks to address this knowledge gap by investigating the use of EPA in cement-based mortar at both room and elevated temperatures. The study examines the impact of varying replacement percentages (10 %, 20 % and 30 % - by volume) of natural sand with EPA having a maximum grain size of 4 mm, and the exposure temperature of mortar prisms at the age of 28 days. Specifically, temperatures of 100ºC, 150ºC and 200ºC were selected for analysis. The impact of these parameters on the flexural and compressive strength of mortar, as well as its dynamic elastic properties, was experimentally determined. The findings indicate that, at room temperature, higher replacement percentages of natural sand by EPA result in decreased flexural and compressive strengths, by as much as 50 % and 30.71 %, respectively. However, the dynamic moduli values for replacement percentages up to 20 % are similar to those of the reference mix. Conversely, when subjected to temperatures up to 200ºC, significant improvements were observed in the flexural strength values, e.g. over 20 % for temperatures of 150°C and 200°C, with only marginal improvements in compressive strength, 3 % ÷ 20 % for temperatures of 150°C and 200°C, compared to values obtained at room temperature.

Isolation and Characterization of Irvingia gabonensis Seed Contents and the Tableting Properties of its Gum Component

This experimental work was designed to isolate, purify and estimate the fatty acids contents of Irvingia gabonensis seeds (IGS) and to evaluate the tableting properties of the gum constituent of the seed in metformin tablet. A known amount of the IGS was crushed and dispersed in purified water at a temperature of 80oC, Ethanol (90 %) was added, filtered and dried at 40oC. The fatty acid components were recovered using petroleum ether, while the gum was further purified with ethanol (90%). The fatty acid contents obtained were analyzed using an Agilent G1701 GC/MSD system. The gum content was evaluated using parameters such as: flow rate, angle of repose, bulk and tapped density and Carr’s index. The gum was granulated with other excipients and metformin powder dried at 40oC. The granules were evaluated as was done for the gum and tablet compression done at 2.0 KN on a single punch tablet machine fitted with 12.5 mm diameter die size. The GC-MS revealed bioactive compounds mainly fatty acids– lauric acid (36.82%), myristic acid (31.52%), benzyl dodecanoate (9.06%) and palmitic acid (4.03%), n-decanoic acid, 1-(hydroxymethyl)-1,2-ethanediyl ester, tetradecanoic acid, 2-hydroxy-1,3-propanediyl ester, etc. The granule size distribution revealed size and compactness in the following order: Acacia gum &gt; IGS-gum &gt; Gelatin, and average granule size for the batches were found to be 500 μm. Evaluation of metformin tablets gave the following results: crushing strength, friability, and disintegration time for B7 and B8 (7.5 and 10 %w/v IGS-gum as binder) as 58 and 68 N, 1.03% and 1.01%, 20.00 and 26.00 min., respectively. B3and B4 (7.5 and 10 %w/v acacia were shown as gum as binder) 44 and 48 N, 1.10 and 1.03%, 20.00 and 23.50 min., respectively. It can be concluded that at 7.5 and 10 %w/v, IGS-gum proved to be a better binder than acacia in metformin tablets formulation. Dhaka Univ. J. Pharm. Sci. 23(1): 53-62, 2024 (June)

WITHDRAWN: High crystallinity nano-biochar synthesized from lotus leaf wastes for uptake of dye molecules from synthetic and real wastewater

This article investigates the potential of lotus leaves-derived nano-biochar in eliminating methyl violet (MV) dye from synthetic and real textile wastewater. The surface of nano-biochar was characterized by TEM, BET, FTIR, XRD, DLS, and FESEM analyses. The BET surface area of nano-biochar was 456.3 m2.g-1, demonstrating an excellent specific surface area. The highest biosorption efficiency and maximum biosorption capacity of MV were 96.3% and 526.3mg/g, respectively, which were obtained at pH 10, equilibrium time of 200min, adsorbent concentration of 0.5g/L, MV ion concentration of 150 ppm, and temperature of 50oC. Also, the mechanism of the biosorpiton process shows that the process is endothermic. Based on R2 and RSME error values, the biosorpion process followed the pseudo-first-order and Langmuir models, indicating that monolayer biosorption of MV molecules on the biochar surface is dominant. Besides, nano-biochar was successfully reused in three steps with high efficiency. The impact of interference ions such as methylene blue, methyl orange, crystal violet, and brilliant blue on MV sorption was investigated and the outcomes revealed that nano-biochar has a remarkable ability to simultaneously eliminate these dye molecules. Additionally, nano-biochar could eliminate COD, BOD5, turbidity, TDS, and EC from a real textile wastewater with high efficiency. Overall, biochar nano-powder, owing to its high reusability, high sorption capacity, easy synthesis, and low-cost, can be considered an ideal option for industrial application.

Utilization of Geothermal Fluid as a Heat Source for Absorption Refrigeration System for Food Preservation – A Case of Bwanda and Gwisho Hotsprings

Zambia has significant geothermal resources with over 86 hotsprings identified. Installation of a 250kW off-grid pilot binary-cycle power plant is currently underway at the Bwanda and Gwisho goethermal site. It is estimated that there is 90,000 herd of cattle in the villages around the pilot power plant. Little milk from these herds of cattle reaches the market due to scarce collection points with cooling facilities. This study assesses the applicability of utilizing exhaust geothermal fluid from a binary-cycle geothermal power plant for powering an absorption refrigeration system (ARS) for storing food, specifically milk. Two absorption systems; Lithium Bromide-water and the ammonia-water ARS are compared. The COPs, energy input and mass flowrates required to produce various cooling loads (40kW – 160kW) are compared. The results show that the exhaust geothermal fluid energy (504kW) is sufficient for powering both ARSs for storing milk to its suitable storage temperature of 4oC. The results also show that the Lithium Bromide-water system is more suitable for this application, because it produces a higher maximum COP (0.76) compared to the ammonia-water system’s maximum COP (0.64), it produces a higher maximum cooling capacity (380kW) compared to the ammonia-water systems maximum capacity (216kW). It requires lower input mass flowrate and pump work at all cooling capacities (40kW – 160kW). Therefore, a Lithium Bromide-water absorption chiller for storing the amounts of milk currently collected in the study area is designed. Optimized design specifications are provided.

Fungal co-culture enabled co-fermentation of food waste for production of endoglucanase enzyme

The primary scenarios of biochemical industries include diverse applications with high demand and the costly manufacturing of microbial cellulolytic enzymes. Using these enzymes to turn cellulosic waste into fuel is one of the prime applications of these enzymes to produce green fuel. Nevertheless, low production and weak functional abilities make these enzymes expensive and technically non-viable. This study presents multifactor bioprocess approaches to enhance cellulolytic enzyme production and efficiency using a low-cost strategy. Co-fermentation of pea pods (PPs) and potato peel (PP) wastes as food wastes has been conducted for solid-state fermentation (SSF) using fungal strain-based co-culture. To set the SSF, the nutrient medium and moisture balance of SSF have been maintained using an extract of PPs and PP waste, which are found to be rich in sugar and starch composition. Starch may function as a natural inducer in the SSF process to alleviate enzyme production in the presence of sugar composition. At 37 oC and pH 5.0, a maximum of 2.4 U/mL FPA (filter paper activity) has been produced at a substrate ratio of 4:04 (PPs:PP) using 50% of the moisture content on day 5 of the harvesting period. Additionally, 24.7 IU/mL of CMCase (carboxymethyl cellulase) in day 8 and 18.8 IU/mL of BGL (β-Glucosidase) in day 7 have been obtained. A temperature of 37 oC was found to be optimal, while a pH range of 5.0–9.0 was noticed to be optimal for maximum CMCase activity. Thus, the study may provide a sustainable approach to valorizing domestic solid food waste for the economic production of hydrolytic enzymes.

Kinetic optimization of angkak – red ginger extraction and its impact on antioxidant activity

A mixture of angkak and red ginger is a Chinese herbal concoction with potential as an antioxidant. This herbal combination can be extracted using the kinetic hot maceration method by optimizing the stirring speed to be more efficient. Previous studies have shown that using 400, 600, and 800 rpm stirring speeds provides the best IC50 and yield. Based on these problems, this research aims to determine the effect of increasing stirring speed on IC50 and % yield in the extraction of angkak and red ginger, as well as prove the benefits of this herbal combination through the IC50 value. The method used is extracting a mixture of angkak and red ginger at kinetic variations of 400, 600, and 800 rpm using a magnetic hotplate stirrer at a temperature of 60ºC for 2 hours; determination of % yield; determining the chromatogram profile using TLC; determination of antioxidant activity using DPPH; as well as data analysis of percentage yield and IC50 using SPSS. Analysis using SPSS shows that the stirring speed significantly affects the % yield, where increasing the moving speed above 400 rpm results in a decrease in the % yield. However, the moving speed does not affect the IC50. The TLC chromatogram profile shows the presence of 6-gingerol compounds in angkak and red and yellow pigment compounds in red ginger, which have potential as antioxidants. The optimization results in this study obtained optimal % yield and IC50 at 400 rpm with average values, respectively, namely 15.933 ± 3.4771% and 103.76 ± 10.032 ppm, and the combination of angkak and red ginger ingredients can work synergistically to increase yield and antioxidant.

Green tea drying in a closed cycle continuous vibro fluidized bed dryer with dehumidified air

There is potential for the development of zeolite as an adsorbent material for drying high-value items. This study aims to compare the green tea drying characteristic utilizing vibro-fluidized bed dryers that operate without dehumidification and with dehumidification. The research was carried out experimentally. The drying chamber was set at temperatures of 50oC, 60oC, and 70oC. In the drying with dehumidification setup, zeolite was placed in a dehumidifier with a weight-to-tea leaf ratio of 1:2.86, 1:3.33, 1:4, and 1:5. The results showed that zeolite's impact on decreasing drying time is effective at a specific temperature, in this case is 60oC. The effect is negligible at low temperatures (50oC), while at high temperatures (70oC) it is minor and drying time is primarily influenced by temperature. Utilizing zeolite for dehumidification can enhance the rate of drying during the falling rate period.

Effectiveness of sulfuric acid and hydrochloric acid catalysts in the esterification of frankincense cinnamic acid with ethanol and methanol

This research aims to compare the effectiveness of sulfuric acid and hydrochloric acid catalysts in the esterification of frankincense cinnamic acid (STYRAX paraleoncomud PERK). Esterification of sulfuric acid catalyst is carried out with ethanol and for hydrochloric acid catalyst with methanol. Esterification was carried out by refluxing a mixture of 1:20 cinnamic acid - ethanol and methanol, with 3 mL of each catalyst at a temperature of 60oC for one hour. The results were rinsed with 3 x 50 mL distilled water and dried with anhydrous sodium sulfate. The results were filtered and verified for functional groups using FTIR and composition analysis using GC – MS. The results of FTIR interpretation show a decrease in absorption intensity (-OH) at 3500 cm-1 as a functional group that reacts compared to the ester results as an indication of the ongoing esterification reaction. The resulting ethyl cinnamate has a high conversion of 84.42%. Methyl cinnamate also has a distinctive ester aroma but is clearer and based on GC-MS, the content of methyl cinnamate is relatively low, namely 34.40%, the remaining cinnamic acid is 37.28%, and various side products of 28.32%. Thus, the catalyst that provides better conversion is sulfuric acid, but it requires further purification by examining the appropriate absorbent and bleaching agent. The brown color of the ester product catalyzed by sulfuric acid is thought to occur due to the oxidation of the cinnamic acid double bond by the catalyst.

Effect of Maltodextrin Concentrations and Drying Temperature on the Physico-chemical Characteristics and Color Measurements of Butterfly Pea Flowers (Clitoria ternatea L) Powder

Butterfly pea flower (Clitoria ternatea L.) is a tropical plant that is rich in bioactive compounds, especially anthocyanins which are useful as natural dyes and antioxidant compounds. The bioactive compounds of butterfly pea flowers are unstable due to environmental influences, especially temperature, oxygen, light and acidity. In order to improve the stability of bioactive compounds, especially anthocyanin compounds in powder form, it is necessary to utilize encapsulation technology using coating materials. The aim of this research was to determine the effect of maltodextrin concentration and drying temperature on the physico-chemical characteristics and color measurements of encapsulated butterfly pea flower extract. The research method used was a factorial design prepared using a randomized block design consisting of 2 factors. Factor I (maltodextrin concentration) consisted of 3 levels, namely (10%, 20%, and 30%) while factor II (drying temperature) consisted of 3 levels (70ºC, 80ºC, and 90ºC), with 3 repetitions. The observation variables are: a) antioxidant activity, b) anthocyanin content, c) water content, d) dissolution time, e) color properties (L*, a*, and b*). Based on general research results, a maltodextrin concentration of 10% and a drying temperature of 70ºC showed the best results based on antioxidant activity rate and the highest anthocyanin content (51.47% and 47.36mg/g), as well as color measurements with the lowest L* value = 52, highest a* value = +2.6, and highest b* = -11.16. Except for powder solubility, a maltodextrin concentration of 30% and a drying temperature of 90ºC resulted in the fastest solubility time (16.67 seconds). For water content, all treatments were still in accordance with spice standards in Indonesia and standards issued by the USDA.

Optimization of cobia fish (Rachycentron canadum) gelatin extraction with response surface methodology

Cobia fish or often called sea cork fish, is a fish that has thick meat which is nutritionally equivalent to salmon meat. Cobia fish is usually sold in the form of fish fillets and the bones becomes solid waste, which has the potential to be a raw material for fish gelatin. Gelatin is a bone and skin collagen hydrolysis product that can be used for food and nonfood industries. The quality of fish gelatin is influenced by the extraction process, such as acid concentration, temperature, and extraction time. This study aims to determine the effect of hydrochloric acid concentration, temperature, extraction time, and the optimal process of making cobia fish bone gelatin using the response surface methodology with the Box Behnken model. The data was processed using Design Expert 11 software. The model suggested by the software was the cubic model. The optimum extraction conditions obtained were using a concentration of 5.53% hydrochloric acid, a temperature of 90oC, and a stirring time of 6.42 mins would produce a yield of 12.38% and gel strength of 229.14 bloom. The verification results by extracting cobia fish gelatin with optimum conditions obtained a yield of 11.22% and gel strength of 227.60 bloom. The proximate analysis of cobia fish gelatin extracted under optimum conditions was found to contain 6.43% water content, 8.27% ash content, 4.65% fat content, 68.47% protein content, and 12.18% carbohydrate by different. Cobia fish gelatin microstructure is in the form of thick strands with a soft sponge.