scholarly journals Antioxidant and Physicochemical Properties of Hibiscus Sabdariffa Extracts from Two Particle Sizes

2016 ◽  
Vol 5 (2) ◽  
pp. 98 ◽  
Author(s):  
Sandro Cid-Ortega ◽  
José Á. Guerrero-Beltrán
Keyword(s):  
Citric Acid ◽  
Acid Solution ◽  
Physicochemical Properties ◽  
Antioxidant Capacity ◽  
Distilled Water ◽  
Particle Sizes ◽  
Hibiscus Sabdariffa ◽  
Aqueous Extracts ◽  
Citric Acid Solution ◽  
Red Color

<p>The effect of average particle sizes (APS: 0.45 and 1.01 mm), solvent types (ST: distilled water, 2% citric acid solution, and 50% ethanol), and extraction times (ET: 40, 50, and 60 min) on the physicochemical properties, antioxidant capacity, and half maximal effective concentration (EC50) in calyces of Roselle (Hibiscus sabdariffa) was analyzed. The extracts obtained with distilled water and 2% citric acid solution had an intense red color which purities (C) were 78.5 ± 2.3 and 79.8 ± 2.2, respectively. The alcoholic extracts showed a dark red color (C = 75.9 ± 1.8). The alcoholic (820.2 ± 73.7 mg Trolox equivalents (TE)/100 g dry calyces) and acid extracts (773.34 ± 53.0 mg TE/100 g dry calyces) showed higher antioxidant capacity than the aqueous extracts (673.24 ± 116.0 mg TE/100 g dry calyces). The EC50 value was better for the alcoholic extracts, followed by the 2% citric acid extracts and finally by the aqueous extracts (13.4 ± 1.0, 14.9 ± 1.0, and 17.2 ± 1.2 mg of extract, respectively). According to results, the best antioxidant properties were achieved using an APS of 0.45 mm, 50:50% ethanol:water ratio, and ETs of 30 or 45 min.</p>

Effect of Processing on the Soluble Carbohydrate Content of Lentils

1992 ◽  
Vol 55 (4) ◽  
pp. 301-303 ◽  
Author(s):  
CONCEPCIÓN VIDAL-VAL VERDE ◽  
JUANA FRÍAS ◽  
SERAFÍN VAL VERDE
Keyword(s):  
Citric Acid ◽  
Acid Solution ◽  
Sodium Bicarbonate ◽  
Lens Culinaris ◽  
Sodium Bicarbonate Solution ◽  
The Other ◽  
Raw Material ◽  
Soluble Carbohydrate ◽  
Distilled Water ◽  
Citric Acid Solution

Lentils (Lens culinaris), like other legumes, are important both nutritionally and agriculturally. Soaking of lentil drastically reduce the quantities of α-galactosides present in the raw material (45–100% reduction). Analysis of the soaking medium (distilled water, 0.1% citric acid solution, 0.07% sodium bicarbonate solution) showed that these losses could not be explained by leaching alone, since the α-galactosides in the soaking medium amounted to only 1–10% of the recorded losses. Other monosaccharides (fructose and glucose) underwent a conspicuous increase (120 and 280% respectively) after soaking. The results indicate that during the 9 h soaking period the sugars in the lentils underwent a metabolic mobilization reminiscent of the changes taking place during germination. Cooking of the soaked lentils modified the α-galactoside content only slightly. On the other hand fructose, glucose, and sucrose decreased significantly during cooking. Soaking and cooking in water led to removal of a substantial proportion of the flatulence-causing oligosaccharides.

Solubility of Phosphorus in Citric Acid Solution as an Index of Biological Availability

1979 ◽  
Vol 16 (5) ◽  
pp. 290-292 ◽  
Author(s):  
Minoru YOSHIDA ◽  
Michiyuki ISHIKAWA ◽  
Hiroki NAKAJIMA ◽  
Saburo HOTTA
Keyword(s):  
Citric Acid ◽  
Acid Solution ◽  
Biological Availability ◽  
Citric Acid Solution

scholarly journals Kinetic Study in Atmospheric Pressure Organic Acid Leaching: Shrinking Core Model versus Lump Model

Minerals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 613
Author(s):  
Kevin Cleary Wanta ◽  
Widi Astuti ◽  
Indra Perdana ◽  
Himawan Tri Bayu Murti Petrus
Keyword(s):  
Citric Acid ◽  
Acid Solution ◽  
Acid Leaching ◽  
Core Model ◽  
Shrinking Core Model ◽  
Citric Acid Solution ◽  
Lumped Model ◽  
Leaching Process ◽  
Shrinking Core ◽  
Simulation Results

The kinetics study has an essential role in the scale-up process because it illustrates the real phenomena of a process. This study aims to develop a mathematical model that can explain the mechanism of the leaching process of laterite ore using a low concentration of the citric acid solution and evaluate that model using the experimental data. As a raw material, this process used powder-shaped limonite laterite ores with a size of 125–150 µm. The leaching process is carried out using 0.1 M citric acid solution, F:S ratio of 1:20, and a leaching time of 2 h. The temperature parameter was varied at 303, 333, and 358 K. The experimental results showed that the higher the operating temperature, the higher the extracted nickel. The results of this experiment were used to evaluate the shrinking core kinetics model and the lumped model. The simulation results for both models show that the lumped model can provide better simulation results. Quantitatively, the percentage of errors from the shrinking core model is around 3.5 times greater than the percentage of errors from using the lumped model. This result shows that in this leaching process, the process mechanism that occurs involves the reactant diffusion step and the chemical reactions step; those steps run simultaneously.

Dissolution mechanism of various elements from steelmaking slag into citric acid solution

2019 ◽  
Vol 116 (3) ◽  
pp. 321
Author(s):  
Ningning Lv ◽  
Chang Su ◽  
Hui Kong ◽  
Jinxing Yang ◽  
Weiming Liu ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acid Solution ◽  
Mass Balance ◽  
Dissolution Mechanism ◽  
Steelmaking Slag ◽  
Citric Acid Solution ◽  
Initial Concentration ◽  
Predominant Species ◽  
Dissolution Ratio ◽  
The Relationship

To recycle valuable elements from steelmaking slag, their dissolution mechanism into citric acid solution has been investigated. First, the relationship between dissolution ratio of each element and initial concentration of citric acid (ci) was studied. Then, the concentrations of each species in solution were calculated through mass balance. Based on these results, it can been seen that whenci = 0.00104 mol/L, Ca2+, CaCit−, MgCit−, FeH2PO42+and CaHPO4are the predominant species in solution, and Ca5(PO4)3(OH)(s) precipitate can form easily, which may suppress the dissolution of elements. Whenciincreases to 0.0104 mol/L, dissolution ratio of each element increases significantly, except for iron. And the predominant species correspondingly change to Ca2+, Mg2+, CaCit−, MgCit−, H2Cit−, H3Cit and FeH2PO42+.

Sign in / Sign up

Export Citation Format

Share Document