scholarly journals Characteristics of Sodium Alginate Extracted from Turbinaria sp. and Sargassum sp.

Author(s):  
Rinta Kusumawati ◽  
Jamal Basmal ◽  
Bagus Sediadi Bandol Utomo

Characterization of sodium alginate extracted from two species of brown seaweed (Turbinaria sp. and Sargassum sp.) has been conducted. The aim of the study was to evaluate physical and chemical properties of the two different types of sodium alginates produced from this extraction process. Extraction was conducted in alkaline solution followed by acid treatment with the following steps: sortation of seaweed, washing, alkaline extraction, bleaching, alginic acid and sodium alginate conversion, dehydration using isopropyl alcohol (IPA), drying, chopping and grinding. Each extraction was conducted in duplicate using approximately 1 kg of the raw materials. The physical and chemical properties of the final products (sodium alginate powders) were analyzed. The results of the analysis were as follows: the yield of alginate powder from Turbinaria sp. was 14.77% having water content of 13.48%; whiteness degree of 23.77%; and viscosity of 133.67 cPs while the yield of sodium alginate powder extracted from Sargassum sp. was 24.56% with water content of 12.69%; whiteness degree of 43.80%; and viscosity of 217.50 cPs. Both alginate powders had better physical characteristics compared to commercial grade alginate which had water content of 16.07%, whiteness degree of 29.37%, and viscosity of 102.67cPs.

2008 ◽  
Vol 59 (11) ◽  
Author(s):  
Cristina Dusescu ◽  
Anca Borcea ◽  
Vasile Matei ◽  
Ion Popa ◽  
Irina Gabriela Radulescu

The present paper studies biodiesel samples preparation by transesterification and compares their physical and chemical properties (biofuels prepared from different raw materials - vegetable oils: sunflower oil, crocus oil and soya bean oil) and the biodegradability degree, as well as the possibilities of the integration of such production unit in industrial diagram of auto fuels production.


Química Nova ◽  
2021 ◽  
Author(s):  
Kamila Ody ◽  
João Jesus ◽  
Carlos Cava ◽  
Anderson Albuquerque ◽  
Ary Maia ◽  
...  

ASSESSMENT OF THE ELECTRONIC STRUCTURE OF THE MONOCLINIC PHASE OF NIOBIUM OXIDE BASED ON THE USE OF DIFFERENT DENSITY FUNCTIONALS. Niobium oxides, Nb2O5, are considered semiconductor materials with very attractive physical and chemical properties for applications in many areas, such as catalysis, sensors, medical, aerospace, etc. Especially, the characterization of Nb2O5-based nanostructures with monoclinic structure has received much attention in recent years. However, despite the great importance of this system, some of its fundamentals properties are still not fully understood. Hence, this work aims to apply the theoretical methodologies through Density Functional Theory (DFT) calculations in periodic models based on the use of different density functionals (like B1WC, B3PW, B3LYP, PBE0, PBESOL0, SOGGAXC, and WC1LYP) to investigate the physical and chemical properties of the monoclinic structure of Nb2O5. The band structures, energy bandgap, density of state, and vibrational properties, as well as order-disorder effects on the monoclinic structure of Nb2O5 are investigated in this study. Our theoretical results show a better agreement with experimental data for the B3LYP functional and hence lead to new perspectives on the deeper physicochemical understanding of the monoclinic Nb2O5. From these computational tools, it is possible to unravel the relations between structure and properties, which may contribute to the future development of new devices and applications based on these materials.


2018 ◽  
Vol 12 (3) ◽  
Author(s):  
O. O. Bondarchuk

Physical and chemical properties of cream multistep modes of ripening and fermentations are investigation and their role in the production of sour-cream butter is studied. The process of ripening of cream was carried out multistep, regimes were selected depending on seasonal changes in the composition of milk fat. For raw materials of the autumn-winter period, for the values of iodine number 29.1–34.5, the first stage of ripening was carried out at a temperature of 8°C for 2 hours, the second stage – at 21°C for 7 hours, the third stage – at 13°C for 10 hours. For raw of spring-summer period, for the values of iodine number 34.5–40.1, the first stage of ripening was carried out at 21°C for 6 hours, the second stage – at 13°C for 4 hours, the third stage – at 8°C for 8 hours. It has been established that individual modes of low-temperature cream preparation, taking into account seasonal changes in the composition of milk fat, make it possible to obtain cream before churning almost with the same indexes of effective viscosity. The content of the crystalline phase of milk fat under both temperature regimes was 38.7–40.1%, which is sufficient to obtain of proper consistency sour-cream butter. The content of diacetyl and volatile organic acids more depend on the level of fermentation of cream than on the technological regimes of ripening and seasonality of raw materials. It has been proved that an increase in the fermentation degree of cream promotes an increase in the acidity of plasma and the content of aroma-producing components in the butter, and, accordingly, affects the degree of the sour taste. It is recommended for the production of cultured butter to begin the cream when the acidity of the plasma reaches 60ºT, which ensures the formation of high sensorial characteristic of the finished product.


Author(s):  
T. Mamilov ◽  
◽  
G.S. Aitkaliyeva ◽  
A.B. Ismailova ◽  
M.A. Yelubay ◽  
...  

This paper presents the results of a study of the physical and chemical properties of samples of vegetable oils (sunflower, rapeseed, olive). It has been shown that the viscosity of oils varies from 41.4 to 61.7 cSt at a temperature of 40 ° C for olive and sunflower oils, respectively. The acid numbers of the oil samples were also determined, it was found that the lowest indicator is characteristic of sunflower oil. Pour points of oils also range from -3 to -16 ° C for olive and sunflower oils, respectively. Using the method of IR spectroscopy, functional groups in the composition of samples of vegetable oils were studied and it was shown that the composition of oils contains carbonyl and hydroxyl functional groups, indicating the presence of carboxylic acids. Based on studies of the physical and chemical properties of vegetable oils, it was found that sunflower, olive and rapeseed oils can serve as raw materials for the synthesis of biofuels based on them, since they contain free fatty acids. To obtain biodiesel fuel based on vegetable oils, it is planned to use the transesterification method in the presence of various catalysts (alkaline, acidic, and complex).


2019 ◽  
Vol 40 (6) ◽  
pp. 2581
Author(s):  
Adriana Cristina Bordignon ◽  
Maria Luiza Rodrigues de Souza ◽  
Eliane Gasparino ◽  
Edson Minoru Yajima ◽  
Jesuí Vergílio Visentainer ◽  
...  

After Nile tilapia skin was preserved using the methods of freezing and dry salting, characteristics of skin gelatin were evaluated with regard to yield, rheological features and physical and chemical properties. Preservation was performed after filleting, at which time skins were either frozen (-18°C) for 7 days or salted (25°C) for 7 days. Although no differences (p > 0.05) were observed with respect to humidity, protein, lipid, ash and calcium levels, gelatin from salted skins had a higher concentration of iron relative to frozen skins. Further, twenty-three fatty acids were detected in salted skins compared with merely three found in skin derived gelatin. Of amino acids found, glycine, alanine, proline and arginine were the most abundant. Hydroxyproline abundance in salted and frozen skin gelatin were 8.76% and 8.71%, respectively. In addition, salted skin gelatins had a greater accumulation of saturated fatty acids and lower rates of monounsaturated fatty acids. Salted skin gelatin had the highest yield (18g × 100g-1), gel strength (200 g) and viscosity (19.02mPas) when compared to the yield (17g × 100g-1), gel strength (12.7g) and viscosity (9.16 mPas) of frozen skins. Results show that gelatin from dry salted skin had the best yield and also had relatively better rheological properties, more iron, and better coloration relative to gelatin obtained from frozen skins of Nile tilapia.


2014 ◽  
Vol 787 ◽  
pp. 123-127 ◽  
Author(s):  
Ya Li Wang ◽  
Su Ping Cui ◽  
Hui Wang ◽  
Shi Jie Dong ◽  
Yan Yao

Based on the physical and chemical properties of carbide slag, the contents of heavy metals in effluent came from carbide slag drying process were studied, and then the composition of exhaust gas emitted from the carbide slag drying process and calcinations process of raw materials prepared with carbide slag was detected, in order to know whether there are harmful or corrosive gases released and the effect of the emissions on the environment and related equipments. The results indicate that the exhaust gases emitted from the calcination process of raw meal prepared with carbide slag is mainly composed of CO2 and water vapor, and is free from harmful gases. However, a lot of water in carbide slag during the pre-heat and decomposition process under high temperature would accelerate the corrosion of equipments. Simultaneously, a small number of heavy metal ions contained in the carbide slag can cause environmental pollution and sulfides would be adverse to the cement calcination process resulting in the crust blockage of kiln.


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