scholarly journals Physicochemical Properties of Chitosan Extracted from Pleurotus ostreatus and Improvement of its Antibacterial Activity by Gamma Radiation

2020 ◽  
Vol 37 (2) ◽  
pp. 52-55
Author(s):  
Md Tanvir Kabir ◽  
Md Shahinur Kabir ◽  
Abdul Bathen Miah ◽  
Md Azadul Kabir Sarker ◽  
Md Kamruzzaman Pramanik

This study was carried out to determine the physicochemical characteristics such as intrinsic viscosity (IV), molecular weight (MW), water binding capacity (WBC), and fat binding capacity (FBC) of chitosan extracted Pleurotus ostreatus fruit body. Antibacterial activity of the gamma irradiated chitosan was also determined. The intrinsic viscosity, MW, WBC and FBC of the produced chitosan were 769.69 ml/g, 1.8×105 Da, 408% and 234%, respectively. The fungal chitosan was subjected to different doses (viz., 5, 10, 20, 30 and 40 kGy) of radiation from 60Co gamma source to observe the effect of gamma radiation on its antibacterial activity. After irradiation, antibacterial activity was evaluated and compared with that of non-irradiated chitosan. Non-irradiated chitosan showed moderate antibacterial activity against Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 6538, Escherichia coli ATCC 35150, and Salmonella enteritidis ATCC 13076 whereas chitosan samples treated with 5, 10 and 20 kGy gamma irradiation separately have shown enhanced antibacterial activity than that of non-irradiated chitosan against the above-mentioned bacteria. However, higher doses of gamma irradiation (30 kGy and 40 kGy) caused a gradual decline of the antibacterial activity. Bangladesh J Microbiol, Volume 37 Number 2 December 2020, pp 52-55

LWT ◽  
2014 ◽  
Vol 57 (2) ◽  
pp. 556-561 ◽  
Author(s):  
Gholamreza Kavoosi ◽  
Aytak Rahmatollahi ◽  
Seyed Mohammad Mahdi Dadfar ◽  
Amin Mohammadi Purfard

2020 ◽  
Vol 45 (5) ◽  
Author(s):  
N.M. Gaila ◽  
M. Buba ◽  
A. Ahmed

The functional properties are the intrinsic physicochemical characteristics which affect the behavior of ingredient in food systems during processing, manufacturing, storage and preparation etc. Such functional properties include water and oil binding, emulsification capacities, swelling ability and viscosity. This work is aimed at evaluating the swelling Ability and water binding capacities of Spinous Amarantus (alayahon daji) (AA) Senna accedentalis (tasba) (TB), Phyllantus niruri (mace mai goyo) (MC), Hibiscus sabdrariffa (yakuwan daji) (YD) and Leptadenia hastate (yadiya) (YE) which are commonly consumed in our localities with little or no knowledge about their nutritional properties. AOAC method of analysis as outlined by Adabowale was adopted for the analysis with little modifications. All the samples analyzed showed significant water swelling ability with AA and YD showing the highest values of 1.5±0.06 v/g while TB shows the lowest value of 0.5±0.05 v/g. There was a significant difference (p <0.05) in the WBC values (%) obtained for the different plants analyzed. The results revealed that crude AA has the highest value of 12.48±0.82 and YD has the lowest value of 5.50±0.09. Insoluble dietary fiber (IDF) was also extracted from the samples and evaluated for water binding capacity. The Insoluble dietary fibre (IDF) showed WBC values. The highest values 1.54±0.08g/g and lowest 0.94±0.00g/g were obtained MC and YE respectively. All the crude samples showed significant water binding capacity (WBC) than their respective insoluble dietary fiber (IDF). This is as a result of the structural and chemical composition of the crude samples. However, the research has revealed that both the crude and the IDF samples analyzed has therapeutic potentials.


2021 ◽  
Vol 22 (8) ◽  
Author(s):  
Nur Rohmah Lufti A'yuni ◽  
Yustinus Marsono ◽  
Djagal Wiseso Marseno ◽  
Priyanto Triwitono

Abstract. A’yuni NRL, Marsono Y, Marseno DW, Triwitoyo P. 2021. Composition, structure, and physicochemical characteristics of pigeon pea (Cajanus cajan) starches from Indonesia. Biodiversitas 22: 3430-3439. Information on the characteristics of pigeon pea (Cajanus cajan (L.) Millsp.) starch would provide a scientific basis for developing its application. However, data about characteristics of pigeon pea starch, especially from the Southeast Asia region, has been limited. This study determined the composition, structure, and physicochemical characteristics of pigeon pea starches from three different Indonesian regions, i.e., Bali, Yogyakarta, and West Nusa Tenggara (NTB). We also investigated the potential application of Indonesian pigeon pea starches. Pigeon pea starch was extracted using a wet method, and then pigeon pea starch was characterized. The yield of pigeon pea starches ranged from 29.83-31.68%. Pigeon pea starches showed a significant difference (P<0.05) in amylose content (54.74-58.51%), relative crystallinity (24.20-28.97%), water-binding capacity (0.70-0.76 g/g), oil binding capacity (0.55-0.58 g/g), swelling power (13.19-14.52 g/g), and solubility (9.48-11.15%). The pasting properties (except for final viscosity) and thermal properties (except for onset temperature and gelatinization enthalpy) differed significantly. Granules of pigeon pea starch were oval to elliptical, with a mean granule diameter of 18.41-19.98 µm. According to X-ray diffraction patterns, pigeon pea starches showed CA type, contained orthorhombic and hexagonal crystals. Pigeon pea starches also showed the same FTIR spectra. The results revealed that the differences in pigeon pea growing locations affect pigeon pea starch's composition and physicochemical properties. The highest amylose content and lowest relative crystallinity were found in Yogyakarta pigeon pea starch. In the future, our findings could be used to develop pigeon pea starch for various food applications.


Food Research ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 1226-1233
Author(s):  
R.H.B. Setiarto ◽  
H.D. Kusumaningrum ◽  
B.S.L. Jenie ◽  
T. Khusniati ◽  
N. Widhyastuti ◽  
...  

This study investigated the effects of annealing, autoclaving-cooling and heat moisture treatment on the microstructure and physicochemical characteristics of taro starch. The taro starch was treated by the annealing process (24 hrs, 50oC), the heat moisture treatment (HMT) (moisture 25%, 3 hrs, 110oC), and the autoclaving (15 mins, 121oC) - cooling (24 hrs, 4oC) with 1 and 2 cycles. The results show that the autoclaving-cooling 2 cycles (AC-2C) changed the microstructure of taro starch into a very compact and dense structure because of formed double helix bound that cannot be hydrolyzed by pancreatic enzymes so it can be converted became resistant starch as the prebiotic source. Pasting properties analysis showed that AC-2C improved shear stress resistance, heat resistance and low retrogradation modified taro starch (MTS). The AC-2C treatment increased water binding capacity (73.84%), solubility (44.58%), and swelling power (16.71%) of MTS. The water-binding capacity had a positive correlation with solubility and swelling power. The AC-2C treatment increased amylose content (27.40%) and decreased reducing sugar level (6.36%) of MTS, so it can encourage the formation of resistant starch to improve the prebiotic properties of taro starch. Modified taro starch AC-2C is the best compared to HMT and annealing based on microstructure and physicochemical characteristics.


Author(s):  
S. Abirami ◽  
Emilin Renitta R ◽  
Antony V. Samrot ◽  
M. Sakthikavitha ◽  
P. Revathi ◽  
...  

In this study, shells of sea crab and fungus Aspergillus niger were subjected for chitosan extraction which has been done following demineralization, deproteination and deacetylation. Chitosan yield from crab shell and fungi was 37.5% and 39.3% respectively and water binding capacity was 58.44% and 60.21% respectively. The extracted chitosan was characterized using Fourier transform infrared spectroscopy (FTIR) and subjected for antibacterial activity against Urinary tract infection (UTI) pathogens – Klebsiella pneumoniae, Proteus mirabilis and E. coli. Chitosan of crab shell showed better antibacterial activity than fungal derived chitosan. Chitosan gel was prepared using the extracted chitosan where it was also showing good antibacterial activity.


2020 ◽  
Vol 2 (1) ◽  
pp. 14

Chitosan was extracted from the chitin of crab shells. The process of deacetylation removes acetyl groups from the molecular chain of chitin. The yield of chitosan was 37.5%, moisture content was 64.32%, water binding capacity was 58.44%. This study concluded that the FT-IR, NMR method is one of the best methods of determination of deacetylation. The crab shell extracted chitosan had significantly inhibited the pathogenic Escherichia coli, Proteus sp., and Klebsiella sp., isolated from UTI infected patients.


2018 ◽  
pp. 37-40
Author(s):  
Phuong Thao Tien Nguyen ◽  
Anh Hung Tran ◽  
Van Tam Le ◽  
Huu Thao Phung ◽  
Phan Quynh Anh Nguyen

Objective: To evaluate the effect of gamma sterilization and its effect on microscopic structure of deeply frozen dog skull. Subjects and methods: 50 pairs of dog skull fragments have the same size,which were taken symmetrically through the midline of the skull, were divided into two lots. Evident lot consisting of 50 pieces are just deeply frozen, not irradicated. Experimental lot which was composed of 50 pieces were deeply frozen and exposed to 25kGy of gamma radiation. Afterwards, to evaluate the effect of gamma sterilization and compare the alter of bone matrix between lot groups. Results: After gamma irradiation, all dog skull fragments were negative with bacteriological examination. In microscopic scale, no difference was found between the two lots and there was no structural change in the irradiated fragments of all dog skull. Conclusion: Gamma irradiation with 25 kGy: (i) It has the ability to kill bacteria completely in the type of bacteria commonly infected tissue. (ii) It does not alter the structure of dog skull in microstructures. Key words: dog skull, gamma, sterilize


Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 401
Author(s):  
Ignacio A. Jessop ◽  
Yasmín P. Pérez ◽  
Andrea Jachura ◽  
Hipólito Nuñez ◽  
Cesar Saldías ◽  
...  

In the search for new materials to fight against antibiotic-resistant bacteria, a hybrid composite from metallic copper nanoparticles (CuNPs) and a novel cationic π-conjugated polyelectrolyte (CPE) were designed, synthesized, and characterized. The CuNPs were prepared by chemical reduction in the presence of CPE, which acts as a stabilizing agent. Spectroscopic analysis and electron microscopy showed the distinctive band of the metallic CuNP surface plasmon and their random distribution on the CPE laminar surface, respectively. Theoretical calculations on CuNP/CPE deposits suggest that the interaction between both materials occurs through polyelectrolyte side chains, with a small contribution of its backbone electron density. The CuNP/CPE composite showed antibacterial activity against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative (Escherichia coli and Salmonella enteritidis) bacteria, mainly attributed to the CuNPs’ effect and, to a lesser extent, to the cationic CPE.


2021 ◽  
Vol 11 (10) ◽  
pp. 4675
Author(s):  
Youssef Elamine ◽  
Hamada Imtara ◽  
Maria Graça Miguel ◽  
Ofélia Anjos ◽  
Letícia M. Estevinho ◽  
...  

The emergence of multidrug-resistant bacteria has prompted the development of alternative therapies, including the use of natural products with antibacterial properties. The antibacterial properties of Zantaz honey produced in the Moroccan Atlas Mountains against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus was evaluated and analyzed using chemometric tools. Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) against S. aureus were the lowest (112.5 ± 54.5 mg/mL), revealing that this species was most sensitive to Zantaz honey. P. aeruginosa showed an intermediate sensitivity (MIC= 118.75 ± 51.9 mg/mL), while E. coli was the most resistant to treatment (MIC = 175 ± 61.2 mg/mL). Content of monosaccharides, certain minerals, and phenolic compounds correlated with antibacterial activity (p < 0.05). Principal component analysis of physicochemical characteristics and antibacterial activity indicated that the parameters most associated with antibacterial activity were color, acidity, and content of melanoidins, fructose, epicatechin, methyl syringate, 4-coumaric acid, and 3-coumaric acid.


LWT ◽  
2021 ◽  
pp. 111879
Author(s):  
Chih-Yao Hou ◽  
Yu-Ching Lai ◽  
Chun-Ping Hsiao ◽  
Song-Yue Chen ◽  
Chih-Tung Liu ◽  
...  

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