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Immobilization of Bacillus megaterium in Carrageenan from Maluku Sea and Their Effect on Protease Production

Hamdani Syarif, Nurlatifah Sri, Astriany Dewi, Singgih Marlia W., Ibrahim Slamet W.

Rocznik Ochrona Środowiska

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2020

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Tom 22, cz. 1

60--69

EN

Bacteria immobilized in carrageenan are widely used in industry to facilitate bacterial handling and storage. Carrageenan is derived from seaweed and its nature is influenced by the condition of the origin of the sea where seaweed grows, one of the Indonesia sea territories that has seaweed that contains caraganen with good properties is Maluku. This study was conducted to determine the effect of storage time of bacteria immobilized in Maluku sea’s carrageenan on proteolytic activity, the bacteria used were Bacillus megaterium. Bacterial immobilization of carrageenan was made at concentrations of 1%, 1.5%, and 2%, storage in cold conditions for up to 9 months. Protease activity was tested using Kunitz method by adding casein as a substrate. The optimal concentration of carrageenan for immobilization of Bacillus megaterium was obtained at a concentration of 1.5%. Protease isolated from immobilized Bacillus megaterium showed increased activity value from storage for 4 months (0.0489 Ug-1) to 7 months (0.1372 Ug-1), and decreased activity after being stored for 9 months (0.0501 Ug-1).

2

Mieszanie wolnoobrotowe roztworów karagenu – wpływ na właściwości reologiczne ®

Kabziński Maciej

Postępy Techniki Przetwórstwa Spożywczego

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2019

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nr 1

52--54

PL

Artykuł przedstawia wpływ stężenia hydrokoloidu na kształtowanie się charakteru reologicznego wodnych roztworów karagenu w warunkach mieszania wolnoobrotowego. Badany płyn potraktowano jako modelowy układ spożywczy imitujący rzeczywiste środki spożywcze o konsystencji żelu twardego. Operację mieszania prowadzono w warunkach skokowo zmiennej liczby obrotów mieszadła. Na podstawie danych pomiarowych wyznaczono parametry równania Herschela- Bulkleya: granicę płynięcia, współczynnik konsystencji oraz wskaźnik płynięcia. Przeanalizowano nieliniowość zależności opisanych powyżej parametrów oraz zmieniające się wraz ze stężeniem karagenu efekty zależności naprężenia ścinającego od czasu mieszania.

EN

The article presents the effect of hydrocolloid concentration on the rheological character of aqueous carrageenan solutions under low-speed agitating. The test fluid was treated as a model food system imitating real foodstuffs with the consistency of hard gel. The mixing operation was carried out under the conditions of a rapidly variable stirrer speed. Based on the measurement data, the parameters of the Herschel -Bulkley equation were determined: flow limit, consistency coefficient and flow index. Non-linearities of dependences of the parameters described above were analyzed as well as the effects of shear stress from mixing time changing along with the carrageenan concentration.

3

Synthesis of carrageenan/multi-walled carbon nanotube hybrid hydrogel nanocomposite for adsorption of crystal violet from aqueous solution

Hosseinzadeh H.

Polish Journal of Chemical Technology

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2015

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Vol. 17, nr 2

70--76

EN

A novel polysaccharide-based hydrogel nanocomposite was prepared using grafting of acrylic acid (AA) on to kappa-carrageenan (κC) by incorporating multi-walled carbon nanotube (MCNT). In fact, MCNTs were used as nano-sized reinforcements in the synthesized nanocomposite. Spectroscopy together with morphology proved relatively strong κC-MCNT interaction. Besides, the swelling behavior of the nanocomposite hydrogel was studied. The results showed that in the presence of MCNTs, the equilibrium swelling capacity was decreased. This can be attributed to cross-linking role and hydrophilicity nature of MCNTs. The adsorption performance of hydrogel nanocomposite was also investigated for the removal of crystal violet (CV) as a cationic dye. The effects of some important parameters such as MCNT concentration, pH and contact time on the uptake of CV solution were studied. Equilibrium adsorption isotherm data of the hydrogel exhibited better fit to the Langmuir than to the Freundlich isotherm model. According to this model, the maximum adsorption capacity of κC-based hydrogel nanocomposite was found to be 118 mg . g–1.

4

Characteristics of interactions between some texture properties and composition of carrageenan gels as a result of its defined diversified freezing and thawing treatment

Kozłowicz K.

Advances in Science and Technology. Research Journal

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2013

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Vol. 7, nr 18

13--19

EN

Model samples of carrageenan gels based on water, milk and juice were air-blast frozen and frozen by immersion in glycol and in liquid nitrogen. The gel freezing rate was determined on the basis of the kinetics of freezing. Carrageenan gel samples were characterized by evaluation of its thawing drip loss and hardness determined with compression and penetration tests. Freezing in liquid nitrogen ensured the highest freezing rates. Thawing drip loss of gels significantly depended on the carrageenan content, pH of the solution, freezing method and freezing rate. The resulting relationships are linear functions with high determination coefficients. The results of compression and penetration tests prove the significant effect of the carrageenan content and pH on gel hardness. The higher carrageenan content in a sample, the higher compression force and penetration of the gel. Gel freezing resulted in lower hardness. Freezing conditions had a significant effect on the properties tested. The correlation between compression forces and penetration depending on the carrageenan content and the freezing method was described using regression equations with high determination coefficients. Gels based on milk and juice with 2.2% carrageenan content are recommended for immersion freezing at rates above 5.0 cm·h-1.