Physicochemical properties of various alginate-based raft-forming antacid products: a comparative study

Background: Alginate-based, raft-forming antacid products with reflux suppressant activity are complex formulations expected to achieve effective raft formation and cause elimination or displacement of the acid pocket, which is typically manifested in gastroesophageal reflux disease (GERD).Methods: In the present study, six alginate-based raft-forming products commercially available in the Indian market were compared in terms of their acid neutralization properties, strength, resilience and structural and thermal properties of their rafts. Percent alginate content was also determined.Results: Rafts of products containing calcium-based antacids formed voluminous, porous and floating rafts within seconds of addition to the simulated gastric fluid (SGF) compared with the products that contained aluminium and magnesium-based antacids. Marked differences were not evident in the ANC (acid neutralization capacity) values of the various products. No correlation was observed between ANC and raft-forming capacity or duration of neutralization. Raft structures affected their neutralization profiles. Rafts of porous and absorbent nature could retain their ANC probably due to release of trapped antacids. Further, raft strengths of only two products were above the British Pharmacopoeia specification of not less than 7.5 g. Sodium alginate content was within specifications (85-115%) for three of the six products.Conclusions: Raft-forming formulations with higher alginate content and calcium-based antacids have better physicochemical properties such as ANC, neutralization profiles, raft strength and raft resilience than those with lower alginate content or those containing aluminium or magnesium-based antacids.

The Content, Antioxidant Activity, and Structural Characteristics of Sodium Alginate Extracting from Sargassum polycystum Grew in Vietnam: Effect of Various Extraction Conditions

Introduction: Alginate is a biopolymer commonly in brown algae, high content, diversity in structure and bioactivity. They are applied to other fields such as food, functional food, pharmaceuticals, and heavy industry and extracted from Sargassum, Laminarin, Tubinaria and Sargassum polycystum species commonly grow in the world than another genus. The content, the antioxidant activity, and the physical chemistry properties of alginate extracting from the species did not exhibit in the previous studies. Methods: The study focused on the impact of various extraction conditions (temperature (40 to 90,oC), time (01 to 06, hours), the solvent-to-material ratio (10/1 to 40/1, v/w), solvent pH (8, 9, 10), and numbers of extraction (1, 2, and 3 times) on alginate content and its antioxidant activity, also evaluated sugar compositions, average molecular, viscosity, and 13C-NMR spectrum characteristics of alginate. Results: The results showed that the suitable condition for the extraction of alginate was for 4 hours at 60oC with the ratio of Na2CO3 (pH 9)-to-material (40/1, v/w) and one number of extraction. The highest alginate content was 176.22 mg uronic acid equivalent/g DW, corresponding to antioxidant activity (188.54 mg ascorbic acid equivalent/g DW). Alginate possessed the intrinsic viscosity (271.86, ƞ) and the average molecular weight (78.6, kD). Different sugar compositions of antioxidant alginate were fructose, fucose, mannose, galactose, rhamnose, mannose, and glucose. The 13C-NMR spectrum of antioxidant alginate exhibited chemical shifts of C sites of D-mannuronic (M) and L-guluronic (G), corresponded to C1, C2, C6, and C2, C3, C4, C5, C6, respectively. Conclusion: Alginate is non-toxic, therefore, antioxidant alginate extracting from brown algae Sargassum polycystum grown in Vietnam is a potential in functional food and pharmaceuticals.

Variasi Karakter Anatomis Talus Padina australis Hauck 1887 (Dictyotales, Phaeophycota) di Pantai Karang Tengah Kabupaten Cilacap

ABSTRAK: Karakter anatomi dapat digunakan untuk menentukan produktivitas kandungan alginat rumput laut P. australis Hauck. Penelitian ini bertujuan mengetahui variasi karakter anatomis talus Padina australis Hauck. Pengambilan sampel dengan purposive random sampling di pantai Karang Tengah, Kabupaten Cilacap. Persiapan mikroskopis dengan metode parafin dengan safranin 1% dalam alkohol 70%. Parameter yang diamati meliputi ketebalan epidermis, ukuran sel medula, ketebalan talus, dan ukuran tetra sporangia. Pengamatan struktur anatomi secara deskriptif dengan membandingkan karakter anatomi P. australis Hauck pada garis konsentris. Data karakter anatomi dianalisis dengan Uji-t dengan tingkat kepercayaan 95%. Hasil penelitian menunjukkan bahwa variasi karakter anatomi talus dengan garis konsentris 5 memiliki ketebalan epidermis adaxial dan abaxial masing-masing adalah 20,05 μm dan 12,55 μm, sedangkan pada garis konsentris 7 memiliki ketebalan 28,33 μm dan 18 μm. Ketebalan talus dengan garis konsentris 5 dan 7 masing-masing adalah 99,44 μm, 114,77 μm. Diameter meduler dengan garis konsentris 5 dan 7 masing-masing adalah 37,88 μm, 45,5 μm. Diameter rata-rata tetra sporangia masing-masing dengan garis konsentris 5 dan 7 yaitu 25,66 μm, 35,66 μm. Talus P. australis Hauck berdasarkan garis konsentris 5 dan 7 memiliki perbedaan ukuran pada ketebalan epidermis adaxial, ketebalan epidermis abaxial, ketebalan talus, diameter meduler, dan diameter tetra sporangia. Implikasi penelitian ini sebagai database pada data dasar karakter anatomi P. australis yang dikaitkan denggan produktsi alginat dan data dasar taksonomi. ABSTRACT: Anatomical character data can be used to determine the productivity of P. australis Hauck's seaweed alginate content. Each thallus has a thallus size and the number of varied concentric lines. The aim of the research is to determine the anatomical characteristics of the Padina australis Hauck thallus. Seaweed sampling by purposive random sampling technique in Karang Tengah beach, Cilacap regency. Preparation of microscopic by paraffin method with safranin 1% in 70% alcohol. Parameters observed included thickness of the epidermis, size of a medullary cell, the thickness of thallus, and the size of tetra sporangia. The anatomical character data was analyzed by t-Test with a 95% confidence level. The result of the research showed that the anatomical character of the thallus with concentric line 5 had a thickness of adaxial and abaxial epidermis respectively is 20.05 μm and 12.55 μm, whereas in concentric line 7 had a thickness of 28.33 μm and 18 μm. The thickness of the thallus with concentric lines 5 and 7 respectively is 99.44 μm, 114.77 μm. Medullary diameter with concentric lines 5 and 7 respectively is 37,88 μm, 45,5 μm. The average diameter of tetra sporangia with concentric lines 5 and 7 respectively that is 25,66 μm, 35,66 μm. Thallus of P. australis Hauck based on concentric lines 5 and 7 has differences of sizes on the adaxial epidermal thickness, thickness of the abaxial epidermis, the thickness of the thallus, medullary diameter, and diameter of tetra sporangia. The implications anatomical characters associated with alginate productivity and taxonomic baseline data.

Diffusive Properties of Alginate Biosorbents

Effective diffusion coefficients for different heavy-metal salts: Cu, Cd, Zn, Cr, Pb in calcium alginate beads were determined. Their values depended on the metal type, anion from the metal salt, and the alginate content in the beads. The results of calculations indicate a decrease in the values of De, caused by an increase in the alginate content in the alginate sorbent beads. This is in agreement with the mechanism of the diffusion process taking place in porous carriers. Experimental data were found to be in good agreement with the mathematical model, as indicated by high values of the correlation coefficient.

Diffusion of Cd(II), Pb(II) and Zn(II) on calcium alginate beads

Effective diffusion coefficients (De) for different heavy-metal salts: Cd, Pb, Zn in calcium alginate beads were determined. Their values depend on the metal type, anion from the metal salt, and the alginate content in the beads. The results of calculations indicate a decrease in the values of De, caused by an increase in the alginate content in the alginate sorbent beads. This is in agreement with the mechanism of the diffusion process taking place in porous carriers. Experimental data were found to be in good agreement with the mathematical model, as indicated by high values of the correlation coefficient.