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Subcritical water extraction (SWE) is a process for extracting phenolic and flavonoid compounds from the skin of the peanut (Arachishypogea). The phenolic and flavonoid compounds of peanut skin were frequently recovered using a hazardous solvent in a traditional extraction procedure. Subcritical water extraction is one of the methods for overcoming the toxicity of solvents. Therefore, the study's aim was to identify the best extraction conditions for recovering total phenolic compounds (TPC), total flavonoid compounds (TFC), and antioxidant activity from peanut skin. The solubility of TPC and TFC in subcritical water was determined using the Chrastil and Del Valle-Aguilera models. The best conditions were 10.46 MPa pressure, 12.56 mL/min water flowrate, 120 °C temperature, 375.08 mg/100 g TPC, 396.24 mg/100 g TFC, and 87.96% antioxidant activity. The Chrastil model fits the solubility of TPC and TFC in subcritical water effectively since it has the lowest average absolute relative deviation (AARD), which is 2.81% and 4.47%, respectively. The findings demonstrate that a low temperature condition is ideal for increasing TPC and TFC. [ABSTRACT FROM AUTHOR]

This study was conducted to develop a steamed bun with Kappachychus alvarezii composite flour. A total of six formulations were developed, each with a different percentage of red seaweed (1.5%, 3%, 4.5%, 6%, 7.5%, and 9%). The physicochemical properties of the steamed bun, such as specific volume, bulk density, color, texture profile analysis, proximate analysis, and dietary fiber, were assessed. Sensory evaluations involving 50 untrained panelists were also conducted to determine the acceptability of the steamed bun. The results showed that increment of seaweed powder in the formulations increased the hardness (2853.41 ± 31.96 g), chewiness (1775.47 ± 24.83 g), bulk density (0.68 ± 0.05 g cm−3), and water activity (0.95 ± 0.00). Furthermore, the addition of seaweed powder reduced the cohesiveness (0.54 ± 0.01 g), springiness (0.64 ± 0.01 g), and specific volume (1.47 ± 0.10 cm3 g−1). Sensory evaluation results showed that seaweed powder could be utilized up to 6% without a significant effect on overall acceptability. Meanwhile, the addition of 1.5% of seaweed powder to the formulation increased the composition of ash (0.02 ± 0.01%), moisture (39.61 ± 0.29%), crude fat (0.57 ± 0.12%), and crude fiber (1.69 ± 0.11), while the composition of crude protein (11.11 ± 0.09%) and carbohydrate (47.00 ± 0.59%) was reduced. In addition, there was an increase in dietary fiber (5.26 ± 1.13%) and energy content (248.06 ± 3.02 kcal) as compared to the control sample. Therefore, utilization of K. alvarezii could increase the nutritional composition of the steamed bun. [ABSTRACT FROM AUTHOR]

The purpose of this work was to establish the best particle size for recovering high yields of total phenolic compounds (TPC), total anthocyanin compounds(TAC) and total flavonoid compounds (TFC) from roselle (Hibiscus sabdariffa) by applying supercritical carbon dioxide (ScCO2). The extraction rate, diffusivity and solubility of yield in ScCO2 were also studied and calculated utilizing models. Pressure (10 and 30 MPa), temperature (40 and 60 °C), and particle size (250 µm < dp < 355 µm, 355 µm < dp < 425 µm and 425 µm < dp < 500 µm) were employed as variables in this experiment. The greatest recovery was 11.96% yield, 7.16 mg/100 g TAC, 42.93 mg/100 g TPC and 239.36 mg/100 g TFC under the conditions of 30 MPA, 40 °C and 250 µm < dp < 355 µm, respectively. The extraction rate of supercritical carbon dioxide in roselle extraction ranged from 5.19 E−03 to 1.35 E−03 mg/s fitted using the Esquivel model. The diffusivity coefficient of ScCO2 ranged from 2.17E−12 to 3.72E−11 mg/s2, as fitted by a single sphere model. The greatest solubility of global yield, TAC, TPC and TFC in ScCO2 was 1.50 g/L, 0.3 mg/L, 1.69 mg/L and 9.97 mg/L, respectively, with a particle size of 250 µm < dp < 355 µm. The smaller particle size of roselle provides the maximum bioactive compound recovery and solubility. Furthermore, the diffusivity and extraction of ScCO2 are increased by decreasing the particle size. Therefore, a smaller particle size is appropriate for roselle extraction by ScCO2 based on the experimental and modelling data. [ABSTRACT FROM AUTHOR]

Two dimensional (2D) reduced-graphene-oxide/g-C3N4 modified 2D ZnV2O6 heterojunction for enhanced photocatalytic CO2 reduction has been investigated. The catalysts were fabricated using one-pot solvothermal method and were tested in a fixed-bed reactor under visible and UV-light. The ZnV2O6/RGO/g-C3N4 composite catalyst demonstrated excellent photoactivity for CO2 reduction to CO and hydrocarbons under visible light. The maximum CO yield rate of 2802.9 μmol g−1 h−1 was obtained over the composite, which is 7.4 and 1.7 times higher than using g-C3N4 and ZnV2O6, respectively. The improved activity attributing to synergistic effect of 2D layer heterojunction with enhanced charges separation by RGO mediator under visible light. Comparatively, 2 times lower productivity was obtained under UV-light than visible-light due to higher visible-light absorption. The time-dependent kinetic-model was further developed to understand the influence of photocatalytic oxidation and reduction processes on the reaction chemistry. The model is based on Langmuir–Hinshelwood (L–H) mechanism to understand the formation rates of products during photocatalytic CO2 conversion with water vapours. Kinetic reveals surface reaction is a rate limiting step, which depends on the generation of charge carrier with higher light absorption. The findings from the experimental and kinetic-model would be useful to understand photo-catalytic reaction engineering in solar energy applications. [ABSTRACT FROM AUTHOR]

This research aims to optimize a supercritical carbon dioxide extraction assisted by co-solvent ethanol for the recovery of catechin and epicatechin from peanut (Arachis Hypogea) skin. The second objective was to determine the solubility of catechin and epicatechin by semi-empirical models. The operating conditions were: pressure of 10 to 30 MPa; temperature of 313 to 343 K; and ethanol rate of 0.075 to 0.225 mL/min. Response surface methodology (RSM) was applied to determine the optimum condition to recover the catechin and epicatechin. The optimum condition was found to be 21.86 MPa, 332.23 K, and 0.17 mL/min with 752.03 µg/g of catechin and 3399.84 µg/g of epicatechin. Putra model successfully fitted the solubility of catechin and epicatechin in range of 1.21 E-5 g/L and 6.02 E-5 g/L with 3.11% of AARD (%). Application of RSM was succesful to optimize the conditions with high quantity of catechin and epicatechin. [ABSTRACT FROM AUTHOR]