Showing 9 results for Biopolymer
E. Sharifi , S.a. Jafarpour, S.m.h. Hosseini,
Volume 7, Issue 3 (9-2018)
Abstract
Aims: Considering the unsaturated nature of fatty acids, the use of technologies to control its oxidation rate is essential for use in the food industry. Thereafter, the aim of this study was to investigate the effects of biopolymer concentration and core material percentage on quality characteristics of fish oil nanocapsules containing clove essential oil prepared by complex coacervation technique.
Materials and Methods: In the present experimental research, the effects of 3 independent variables including the total biopolymer percentage (gelatin-gum Arabic; 6, 8, and 10%), oil content (2 to 3%), and the concentration of clove essential oil (0, 2000, and 3000 ppm) on dependent variables such as size and zeta potential of particles, color, surface oil, encapsulation, and nanoencapsulation efficiency were evaluated. The present study was carried out as factorial experiment in a completely randomized design. One-way analysis of variance and Duncan test were used. The data were analyzed by SPSS 16 software.
Findings: The increase in total biopolymer percentage was associated with increasing particle size as it was in the range between 259.19±55.83 and 814.35±253.05 nm, respectively. In terms of color parameters, the yellowness of produced powders was increased by increasing the concentration of fish oil and cloves essential oil, while lightness was decreased by increasing the concentration of the biopolymer. Also, the superficial oil was increased by increasing oil and clove essential oil concentrations in the nanocapsules, and microencapsulation efficiency in different treatments was recorded between 65.1±2.75 in treatment 15 (10% biopolymer and 3% oil) to 98.84±0.78 in treatment 4 (8% biopolymer and 2% oil).
Conclusion: Using complex coacervation technique with gelatin-gum Arabic as a biopolymer can produce nano-sized particles.
Volume 8, Issue 29 (5-2011)
Abstract
Copolymer Polyhydroxyalkanoat (PHAs) is the most well known degradable product of Poly-beta-hydroxybutyrate (PHB). In this research, for producing this kind of polyesters, Azotobacter was separated from soil, and then purified. By changing culture media conditions such as saturated and unsaturated oils( palmitic acid, Olive oil,Castor oil, Sesame oil, Sprout wheat oil ,Almond oil, Sweet almond oil,Coconut oil, Snake oil, Nigella seeds oil ,Myrtles oil ,Walnut oil ,Paraffin, Stearic acid, Oleic acid, Chamomile oil, Glycerin), nitrogen, temperature and air blowing, optimum biopolymer growth condition inside the cell was evaluated. With using quantities and qualities methods like spectrophotometer assay and percentage counted by using gas chromatography (GC), and rate of PHB production were investigated. Result shows that among 10 separated Azotobacter strains, AZ7 was capable to produce 80.793% amount of PHB. Maximum amount of this biopolymer (84.48 %) in 2 % Almond oil as carbon source, 1% yeast extract as nitrogen source, 200 rpm air blowing and 33°C were observed. It seems that AZ7 strain accumulated 80-90% of their cellular dry weight of PHB in different media and in competitive of foreign strain is a native candidate for production of PHB.
Volume 9, Issue 4 (12-2018)
Abstract
Aims: Tissue engineering and replacement of damaged tissue in medical science is very important and more effective than person-to-person transplantation. Therefore, the production of scaffolds from natural and synthetic polymers with desirable properties to reproduce damaged tissues is increasing. The aim of the present study was to investigate the effect of plasma treatment on contact angle or hydrophilicity of poly-lactic glycolic acid nanofibrous scaffolds and cell culture efficiency.
Materials and Methods: In the present experimental research, two types of solvents such as pure chloroform and the choloroform80% and dimethyl formaldehyde20% were used for electrospinning solution. The level of electrospun scaffolds was corrected by plasma technology; then, the African green monkey kidney (VERO) cells were cultured on them. The raw or non-treated electrospun scaffold was compared with that of plasma treated in hydrophilicity and cell culture viewpoints. To compare the hydrophilicity of scaffolds, the contact angle of them was measured.
Findings: The samples treated with plasma show lower contact angle and consequently higher hydrophilicity. C=O and C-O groups increased in the plasma-treated samples in comparison with those of raw samples. Plasma scaffold level correction improved the adhesion, growth, and proliferation of cells compared to non-treated scaffolds.
Conclusion: The contact angle of the plasma-treated samples is significantly reduced. Plasma treatment can increase the hydrophilicity of poly-lactic glycolic acid nanofibrous scaffolds, and cell adhesion and growth on plasma-treated scaffolds is better than cell growth and proliferation on non-treated scaffolds.
Razie Hashemi, Haniyeh Rostamzad, Masoud Sattari,
Volume 13, Issue 2 (6-2024)
Abstract
This study aimed to produce a smart infection warning film based on chitosan and gum arabic containing anthocyanin (0.5, 0.75, and 1 g) as a wound infection warning. Chitosan/gum film was prepared in a ratio of 1:2 with different doses of anthocyanin pigment (0.5, 0.75, and 1 g), and the control sample was considered without anthocyanin. The prepared film was evaluated on Pseudomonas and Mannitol salt agar media. To evaluate the functional properties of the prepared film, the amount of moisture, solubility, thickness, and water absorption of the treatments were measured. The lowest and highest film moisture content were in the control treatment, and the treatment contained 0.75% anthocyanins, respectively. As the percentage of anthocyanin increased, the thickness and solubility of the samples decreased significantly. Regarding the water absorption test, the highest amount was related to the treatment containing 1% anthocyanin, and the lowest amount belonged to the control treatment. To evaluate the effect of chitosan or gum film containing anthocyanin on the culture medium when the bacteria were well grown, chitosan or gum biofilms containing different concentrations of anthocyanin were cut to 1.1 cm and cut into It was placed on the culture medium for 60 minutes, and the color change of the films was checked with a colorimeter. The highest rate of color change of films in culture medium containing Pseudomonas aeruginosa was obtained in the treatment containing 0.5%; however, in the case of Pseudomonas aureus, the highest color change was observed in the treatment containing 1%. Finally, the best film in terms of physical characteristics is the 1% treatment, and in terms of color change in response to the growth of Pseudomonas, it is 0.5%, and for Staphylococcus aureus, it is 1%.
Volume 14, Issue 64 (6-2016)
Abstract
Volume 20, Issue 137 (7-2023)
Abstract
The consumer demand to use natural preservatives in food products instead of synthetic ones and awareness about not using plastic is increasing. In this research, chitosan-potato starch film containing celery seed extract was prepared at different concentration levels (0.5, 2 and 8%) and the physical properties of the film (thickness, moisture content and solubility), mechanical properties and antioxidant activity also determined. Then, the chicken fillet wrapped by the film was kept in the refrigerator for 15 days and the microbial growth and primary and secondary oxidation compounds formation with peroxide value and thiobarbituric acid and sensory evaluation was also monitored during the storage time. The results showed that the total phenol and flavonoid content of celery seed extract was 70.67±7.8 mgGA/g of extract and 62.81±5.65 mg Quercetin/g of extract, respectively. Addition of celery seed extract (2 and 8%) decreased the moisture content and solubility of the film due to the increase of the film hydrophobicity. Also, by adding the celey seed extract, the elongation at break of the film increased, while the tensile strength and elastic modulus decreased. With the increase in the concentration of the celery seed extract in the film, the DPPH free radical inhibition increases from 14.69 to 73.94%. According to the results of microbial and oxidation tests as well as sensory evaluation, coating a chicken fillet with a chitosan-potato starch film containing 8% celery seed extract would increase its shelf life by up to 15 days.
Volume 21, Issue 157 (2-2025)
Abstract
Eggs are one of the superior value natural sources of protein and other nutrients, at the same time, they are vastly perishable. Consumers' concern about egg contamination and transmission of pathogens, especially salmonella, increased the desire to use safe and packaged eggs. The environmental hazards of synthetic polymers as packaging materials have become a global problem, for this reason, their replacement with biodegradable ones has been developed. To overcome some physical and mechanical weaknesses as well as increase bio-polymers performance, they are combined (composite) and/or reinforcing agents and natural agents are used in their fabrication. A variety of plant essential oils and extracts are widely used in active packaging materials. The results of the studies showed that the barrier and functional properties of active biopolymers are improved due to their hydrophobic nature, as well as the antioxidant and antimicrobial properties of polyphenols content of essential oils and extracts. Egg packaging with these active biopolymers preserves internal quality during storage and ultimately extends its shelf life. In this article, an attempt has been made to review the use of plant chemical compounds (phytochemical) in active biopolymers for egg packaging based on polysaccharide, protein and aliphatic polyester
Volume 22, Issue 1 (1-2020)
Abstract
Poultry should be stored in appropriate conditions to prevent its fast spoilage. Using antimicrobial coatings is considered as one of the methods to preserve this product. In this study, Chitosan and Chitosan-Nisin coatings were examined under refrigerated conditions at a temperature of 4°C. The samples were packed in uncoated as the control, Chitosan coating, and Chitosan-Nisin coating groups. The chicken fillets were tested for microbial (total bacterial count, Salmonella count, and staphylococcus aureus coagulase) and physicochemical (pH, color, and texture) features on the first, third, fifth, and seventh days of storage. Based on the results, the Chitosan coating increased the shelf life of fresh chicken under refrigerated conditions by three-days, which demonstrated an inhibitory effect on the overall bacterial growth until the third day. Finally, Chitosan coating demonstrated an antibacterial effect on the Salmonella and positive staphylococcus aureus coagulase until the fifth day. The samples with Chitosan-Nisin were found to be more effective than the Chitosan coated samples. In addition, the Chitosan-Nisin coated samples prevented the growth of total bacteria including Salmonella, and positive staphylococcus aureus coagulase. Further, it increased the shelf life of fresh chicken under refrigerated conditions at the temperature of 4 °C for seven days.
Volume 22, Issue 4 (6-2020)
Abstract
Cold plasma is a novel non-thermal technology for the food and packaging industry. In this study, the effects of argon glow discharge plasma on the mechanical properties, surface topography, chemical composition, film hydrophilicity, film solubility, and barrier properties of the starch films were examined. Plasma treatment improved Tensile Strength (TS) of the starch film. In contrast to TS, elongation at the break of the plasma-treated films remained unchanged. The surface roughness of starch film increased after plasma treatment. An apparent increase in the surface hydrophilicity was observed due to formation of oxygen-containing polar groups. FTIR analysis confirmed the increase in the oxygen containing groups in plasma-treated starch film. However, film surface hydrophilicity caused no significant change in the solubility of films. No significant difference was found in the barrier properties of the starch films. The evaluation of films modifications by glow discharge plasma will contribute to in-package decontamination studies of food products by plasma.
