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The second brain of humans has been known as the microbiome. The microbiome is a dynamic network composed of commensal bacteria, archaea, viruses, and fungi colonized in the human gastrointestinal tract. They play a vital role in human health by metabolizing components, maturation of the immune system, and taking part in the treatment of various diseases. Two important factors that can affect the gut microbiome's composition and/or function are the food matrix and methods of food processing. Based on scientific research, the consumption of whole grains can make positive changes in the gut microbiota. Seeds contain different microbiota-accessible substrates that can resist digestion in the upper gastrointestinal tract. Seed germination is one of the simplest and newest food processing approaches to improve seeds' bioavailability and overall nutritional value. During germination, the dormant hydrolytic seed's enzymes have been activated and then metabolize the macromolecules. The quality and quantity of bioactive compounds like prebiotics, fiber, phenolic compounds (PC), total free amino acids, and γ-aminobutyric acid (GABA) can increase even up to 4-10 folds in some cases. These components stimulate the survival and growth of healthful bacteria like probiotics and boost their activity. This effect depends on several parameters, e.g., germination environmental conditions. This review aims to provide up-to-date and latest research about promoting bioactive components during seed germination and investigating their impacts on gut microbiota to understand the possible direct and indirect effects of seed germination on the microbiome and human health.
Gut microbiome plays a vital role in human health.Promoting gut beneficial bacteria can treat some human diseases.Beneficial gut bacteria can improve by seed's bioactive compoundsSeed's bioactive compounds can increase during germination.Germination is a low-in-cost process that can make an indirect positive effect on the gut.
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Type 2 diabetes (T2D) is a complex and heterogeneous chronic metabolic disorder disease that is associated with high blood sugar. Because of the side effects of synthetic drugs on T2D patients and their economic burden, interest in plant-derived functional foods like grains with biological activities has developed. Based on scientific reports, whole grains are rich sources of energy, nutrients, and bioactive compounds and are assumed to have beneficial health effects on glucose enzymes regulation or hyperglycemia. Nowadays, different methods have been applied to enhance whole seed healthful properties and anti-diabetic compounds, and germination is one of them. Germination (sprouting) is a cost-effective method for boosting the activity of endogenous seed enzymes and modifying the structure of macromolecules. Some of these macromolecules like bioactive peptides, polyphenols, dietary fiber, and vitamins are related to diabetes management. Determining the best germination condition can help to promote these anti-diabetics properties of compounds. This study presents relevant information about diabetes, the effect of seed germination on releasing bioactive compounds, and optimizing environmental germination conditions to improve the anti-diabetic compounds in seeds for reaching functional food.
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Diabetes Mellitus Tipo 2 , Germinación , Humanos , Germinación/fisiología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Semillas/química , Fibras de la Dieta/análisis , Antioxidantes/análisisRESUMEN
Angiotensin-Converting Enzyme (ACE) is one of the main blood pressure regulators in the renin-angiotensin system leading to hypertension. Hypertension is known as the modern world disease which increases the risk of serious human health problems. Synthetic drugs and some natural compounds could treat this disease by binding to ACE and reducing its activity. Pulses, one of the legumes group, that are the rich in protein sources in the human diet, have several bioactive compounds with ACE inhibitory (ACE I) properties. However, several processes need to break down proteins and improve ACE I activity in foods. Germination and fermentation, known by bioprocessing, could make releasing bioactive peptides and polyphenols and exhibit ACE I and either other health properties such as antimicrobial, antioxidant, anti-diabetic and anticancer activities. Various factors such as kind of selective culture, temperature, time and humidity affect these processes. This review summarizes relevant studies about the effect of pulses' germination and fermentation to produce ACE I activity compounds and also explains about main parameters affecting the health properties of these two bioprocessing to treat hypertension that could lead to the development of their application in pharmaceuticals instead of synthetic drugs.
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Inhibidores de la Enzima Convertidora de Angiotensina , Hipertensión , Presión Sanguínea , Fermentación , Humanos , Hipertensión/tratamiento farmacológico , Péptidos/metabolismo , Peptidil-Dipeptidasa A/metabolismoRESUMEN
Accelerating emergence of antimicrobial resistance among food pathogens and consumers' increasing demands for preservative-free foods are two contemporary challenging aspects within the food industry. Antimicrobial packaging and the use of natural preservatives are promising solutions. In the present study, we used beta-casein-one of the primary self-assembly proteins in milk with a high polymeric film production capability-as a fusion partner for the recombinant expression of E 50-52 antimicrobial peptide in Escherichia coli. The pET21a-BCN-E 50-52 construct was transformed to E. coli BL21 (DE3), and protein expression was induced under optimized conditions. Purified protein obtained from nickel affinity chromatography was refolded under optimized dialysis circumstances and concentrated to 1600 µg/mL fusion protein by ultrafiltration. Antimicrobial activities of recombinant BCN-E 50-52 performed against Escherichia coli, Salmonella typhimurium, Listeria monocytogenes, Staphylococcus aureus, Aspergillus flavus, and Candida albicans. Subsequently, the synergistic effects of BCN-E 50-52 and thymol were assayed. Results of checkerboard tests showed strong synergistic activity between two compounds. Time-kill and growth kinetic studies indicated a sharp reduction of cell viability during the first period of exposure, and SEM (scanning electron microscope) results validated the severe destructive effects of BCN E 50-52 and thymol in combination on bacterial cells.
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Antiinfecciosos/farmacología , Bacteriocinas/farmacología , Caseínas/farmacología , Proteínas Recombinantes de Fusión/farmacología , Timol/farmacología , Secuencia de Aminoácidos , Animales , Antiinfecciosos/metabolismo , Aspergillus flavus/efectos de los fármacos , Aspergillus flavus/crecimiento & desarrollo , Bacteriocinas/biosíntesis , Bacteriocinas/genética , Candida albicans/efectos de los fármacos , Candida albicans/crecimiento & desarrollo , Caseínas/biosíntesis , Caseínas/genética , Bovinos , Clonación Molecular , Combinación de Medicamentos , Sinergismo Farmacológico , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Embalaje de Alimentos/métodos , Expresión Génica , Vectores Genéticos/química , Vectores Genéticos/metabolismo , Humanos , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/crecimiento & desarrollo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/crecimiento & desarrolloRESUMEN
The aim of this study was the evaluation of fermentation by lactic acid bacteria (LAB) contains lactobacillus (L.) casei- casei and L. reuteri on acrylamide formation and physicochemical properties of the Iranian flat bread named, Sangak, and Bread roll. Sangak and Bread roll were made with whole and white wheat flour, respectively. Whole-wheat flour had upper content of protein, sugar, ash, fiber, damaged starch and the activity of amylase than the white wheat flour. After 24 h of fermentation, the pH values of the sourdoughs made from whole-wheat flour (3.00, 2.90) were lower, in compared to sourdoughs prepared from white wheat flour (3.60, 3.58). In addition, in Sangak bread, glucose, and fructose were completely utilized after fermentation, but in bread roll, the reduced sugar levels increased after fermentation and baking that represent microorganisms cannot be activated and utilized sugars. Acrylamide formation was impacted by pH of sourdough and total reducing sugar (r = 0.915, r = 0.885 respectively). Bread roll and Sangak bread were fermented by L. casei- casei contained lowest acrylamide content, in two bread types (219.1, 104.3 µg/kg respectively). As an important result, the acrylamide content of Sangak bread in all cases was lower than in the Bread roll.
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Green terror fish were fed for two months with three types of feed including: control diet (C), diet containing 2% fish oil (O) and diet containing fish oil supplemented with 0.1% Pediococcus acidilactici bacteria (PA). At the end of the feeding period, 50 fish of different groups (n = 3) with an average weight of 4.28 g were transferred to 9 tank. Hypoxia tests were set out by sampling at three times including before hypoxia (BH) initiation, hypoxia stress spot (H) and starting mortality (SM). In fish submitted to the diet containing P. acidilactici bacteria, the immune indices of lysozyme activity (4.08, 4.19 and 4.85 µg/ml)], complement activity (2.65, 2.77 and 2.1 U/ml) and total immunoglobulin (10.05, 10.25 and 9.9 µg/ml) improved in all stages of sampling (BH, H and SM), respectively (p < 0.05). The positive effects of the bacteria application also extends for the stress indicators including: cortisol (0.175, 0.3 and 0.335 µM/ml), glucose (0.9, 1.25 and 0.6 µg/ml) and lactate (2.7, 3 and 3.35) µg/ml and plasma electrolytes consisting of Na(+) (178.5, 175.43 and 175.8 mmol/l) and Cl(-)(123.85, 119.30 and 118.43 mmol/l) in all sampling stages (BH, H and SM), respectively (p < 0.05). Put it all together, P. acidilactici, acting as a probiotic, helps reducing stress symptoms in green terror fish.
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Acuicultura , Cíclidos/fisiología , Dieta/veterinaria , Electrólitos/metabolismo , Inmunidad Innata , Pediococcus/química , Probióticos/farmacología , Alimentación Animal/análisis , Animales , Cíclidos/inmunología , Oxígeno/análisis , Probióticos/administración & dosificación , Estrés FisiológicoRESUMEN
In this study, the effects of fat (0.5 %, 3.2 % and 5.0 %), inulin (0.0 and 1.0 %) and starter culture (0.0 %, 0.5 %, 1.0 % and 1.5 %) on the angiotensin converting enzyme (ACE)-inhibitory activity of probiotic yogurt containing non-viable bacteria were assessed. Proteolytic activities of bacteria were also investigated. Yogurts were prepared either using a sole yogurt commercial culture including Streptococcus thermophilus and Lactobacillus delbrueckii subs. bulgaricus or bifidobacterium animalis BB-12 and Lactobacillus acidophilus La5 in addition to yogurt culture. Relative degrees of proteolysis were found to be considerably higher in yogurt samples than UHT milk as the control. Both regular and probiotic yogurts showed considerable ACE-inhibitory activities. Results showed that degree of proteolysis was not influenced by different fat contents, while was increased by high concentration of starter culture (1.5 % w/w) and reduced by inulin (1 % w/w). ACE-inhibitory activities of yogurt were also negatively affected by the presence of inulin and high levels of fat (5 % w/w). Moreover, yogurt containing probiotic bacteria showed higher inhibitory against ACE in comparison to the yogurt prepared with non-probiotic strains.
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The strain bacterium Dietzia natronolimnaea has propounded as a source for biological production of canthaxanthin. Because of sensitivity of this pigment, examine on its stability is important. In this study, stability of encapsulated canthaxanthin from D. natronolimnaea HS-1 using soluble soybean polysaccharide (SSPS), gum acacia (GA), and maltodextrin (MD) as wall materials was investigated at 4, 25, and 45 °C in light and dark conditions during 4 months of storage. It was shown that the type of walls influenced the size of emulsion droplets; spray dried particles, microencapsulation efficiency (ME), and retention of canthaxanthin in microcapsules. SSPS and MD produced the smallest and the biggest emulsion droplets and spray dried particles, respectively. Microcapsules made with SSPS resulted in better ME and higher stability for canthaxanthin. Samples were degraded in all conditions, especially in light and 45 °C. Degradation of microencapsulated canthaxanthin with SSPS and GA proceeded more slowly than did with MD. Regardless of the type of wall materials, total canthaxanthin contents of the microencapsulated products decreased by an increase in time or temperature. Also, samples exposed to light indicated less stability at 4 and 25 °C when compared to the storage at dark conditions. According to the results of this study, SSPS can be considered as potential wall material for the encapsulation of carotenoids.
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Bread is one of the oldest functional foods which its health effects have been investigated in many studies. The current communication presents a review of published studies in recent years on the topic and looks at possible future trends in the improved nutritional and health qualities which have been applied in the bakery industry, directing it further to the formulation design and production of functional breads. The results show that many beneficial ingredients such as dietary fibers, phenolic antioxidants, marine ingredients, and n-3 fatty acids can be used in the bread industry to increase its functionality and result in healthy products, low in calories, cholesterol and celiac disease. Moreover, the use of psyllium seed, amaranth seed, chestnut flour and prebiotics in gluten-free bread (GFB) baking may be the promising frontier to improve overall appearance, quality, sensory properties, and shelf-life of GFB.
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The by-products from three varieties of dates-Mozafati, Sayer, and Kabkab-were subjected to solid-state fermentation using Aspergillus niger alone or in co-culture with Lactiplantibacillus plantarum or Limosilactobacillus reuteri to enhance their phenolic and flavonoid content, along with antioxidant and antimicrobial activities. Solid-state fermentation, being environmentally friendly and cost-effective, is particularly suitable for agricultural residues. Significant increases (p < 0.05) in total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant power were observed post-fermentation, especially under co-culture conditions. The highest TPC (12.98 ± 0.29 mg GA/g) and TFC (1.83 ± 0.07 mg QE/g) were recorded in the co-culture fermentation of by-products from the Mozafati and Sayer varieties, respectively. HPLC analysis revealed changes in polyphenol profiles post-fermentation, with reductions in gallic and ferulic acids and increases in caffeic acid, p-coumaric acid, rutin, quercetin, and kaempferol. FT-IR analysis confirmed significant alterations in polyphenolic functional groups. Enhanced antimicrobial activity was also observed, with inhibition zones ranging from 8.26 ± 0.06 mm for Kabkab to 17.73 ± 0.09 mm for Mozafati. These results suggest that co-culture solid-state fermentation is a promising strategy for valorizing date by-products, with potential applications in nutraceuticals and/or pharmaceutical products and as valuable additives in the food industry.
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Nondairy fermented probiotic powder was developed based on stabilized wheat germ through mixed fermentation (Lactobacillus acidophilus and Lactobacillus plantarum) and electrospraying process. In the first step, the effect of mixed fermentation on lipase and lipoxygenase activity of wheat germ was investigated. The results showed a significant reduction in the activity of both enzymes (82.72% for lipase and 72% for lipoxygenase), therefore, mixed fermentation effectively stabilizes the wheat germ. In the next step, after the preparation of the solutions for drying process and investigating the physical properties (surface tension, electrical conductivity, and viscosity) of the solutions, the electrosprayability of the samples was evaluated at different conditions and revealed that 18 kV applying voltage, 0.3 flow rate, and 12 cm distance between tip to collector was the best for electrospraying the 20% solution of fermented wheat germ with morphologically most semi-uniform particles. Finally, the viability of the probiotics after drying process and during the storage at 25°C was examined. The number of initial cells counted as 14.48 ± 0.2 log cfu/g and the viability studies showed 0.55 log cfu/g decrease in the number of viable bacteria from initial count as a result of the electrospraying process. Furthermore, 7.86 ± 0.03 log cfu/g in freeze-dried and 9.05 ± 0.45 log cfu/g in electrosprayed samples survived after 70 days of storage.
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Rasburicase is an expensive treatment used to control hyperuricemia caused by tumour lysis syndrome (TLS). In this study, a non-chromatographic method was designed based on nano-oil bodies for convenient and economical purification of the recombinant uricase. For this purpose, two chimaeras were synthesized with a different arrangement of the uricase, caleosin and intein fragments. After confirming the protein expression by measuring the uricase activity at 293 nm, purification was conducted through oil-body construction. The results were resolved on the 12% SDS-PAGE gel. Finally, the stability of the oil bodies was examined against different salts, surfactants, temperatures, and pH values. According to our results, the overexpression of uricase-caleosin chimaera under the T7 promoter in Escherichia coli led to the production of soluble protein, which was successfully purified by artificial oil bodies. The active uricase was subsequently released through the self-splicing of intein. Further investigations highlighted the importance of the free C-terminus of caleosin in constructing artificial oil bodies. Moreover, surfactants and low temperature, in contrast to salts, improved the stability of oil bodies. In conclusion, caleosins are an efficient purification tag reducing the cost of purification compared to conventional chromatography methods.
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Recently, the research and innovation to produce raw materials from microbial processes has gained much attention due to their economic and environmental impacts. Lactic acid is a very important microbial product due to its wide application in the food, pharmaceutical, cosmetic, and chemical industries. In the current study, poly (L-lactic acid) (PLLA) was produced by the ring opening polymerization (ROP) technique of L-lactic acid recovered from whey fermentation, and was used for the production of nanocomposites films reinforced with chitosan nanoparticles (CNPs) (average diameter ca. 100-200 nm). Three different CNPs concentrations, namely 1, 3, and 5% w/w, were tested, and their influence on the physical, mechanical, thermal, antibacterial and structural attributes of PLLA film was assessed. The results showed that the addition of CNPs up to 3% caused a significant improvement in water vapor permeability, appearance, tensile strength and elongation at break. The antibacterial properties of nanocomposites followed a dose-depended pattern as a result of CNPs addition. Therefore, the best inhibitory effects on Escherichia coli and Staphylococcus aureus was made by the addition of 5% of CNPs and lower dosages slightly affected the growth of pathogens or didn't cause any inhibitory effects (in 1% of CNPs). It can be concluded that the incorporation of CNPs into the PLLA matrix allows to improve the structural, thermal, physical, mechanical and antibacterial properties of the polymer, generating promising systems for food packaging and biomedical applications.
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In the present study, canthaxanthin was produced by biofermentation from Dietzia natronolimnaea HS-1 (D. natronolimnaea) and was loaded in phospholipid vesicles prepared with natural component using an easy and low dissipative method. Indeed, glycerosomes, hyalurosomes, and glycerohyalurosomes were prepared by direct hydration of both phosphatidylcholine and the biotechnological canthaxanthin, avoiding the use of organic solvents. Vesicles were sized from 63 nm to 87 nm and highly negatively charged. They entrapped a high number of the biomolecules and were stable on storage. Canthaxanthin-loaded vesicles incubated with fibroblasts did not affect their viability, proving to be highly biocompatible and capable of inhibiting the death of fibroblasts stressed with hydrogen peroxide. They reduced the nitric oxide expression in macrophages treated with lipopolysaccharides. Moreover, they favoured the cell migration in an in vitro lesion model. Results confirmed the health-promoting potential of canthaxanthin in skin cells, which is potentiated by its suitable loading in phospholipid vesicles, thus suggesting the possible use of these natural bioformulations in both skin protection and regeneration, thanks to the potent antioxidant, anti-inflammatory and antiageing effects of canthaxanthin.
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The aim of the current study was to evaluate the possibility of the bacterial growth and substrate metabolism during the fermentation of red grape juice and the mixture of red grape juice and rice flour solution using Lactobacillus plantarum and Lactobacillus casei. In recent years, cereal-based beverages have been used as functional compounds such as antioxidants, dietary fiber, minerals, probiotics, and vitamins in diets. In this research, fermentation of red grape juice (media 1) and 1:1 mixture of red grape juice and rice flour solution (media 2) by two strains of gram positive and homofermentative lactic acid bacteria: L. plantarum and L. casei (individually and mixed) was examined. Fermentation was carried out at 37°C for 48 hr. Microbial population, pH, acidity, sugar, and organic acid metabolism were measured during the fermentation period. Data showed that in media 2 fermented with mixed culture of both L. plantarum and L. casei, acidity and microbial population increased sharply at the initial stages of fermentation, and the most percentage of lactic acid production occurred. Red grape juice fermented with mixture of L. plantarum and L. casei showed the most sugar consumption (p < .05). Results indicated that the use of the mixture of red grape juice and rice flour solution can be a proper substrate for producing lactic acid.
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Canthaxanthin (CX) is an orange-red keto-carotenoid with high antioxidant activity. This functional pigment is sensitive to oxygen, light, pH and heat. In this study, CX was produced by the Dietzia natronolimnaea HS-1 and was encapsulated in Alginate (Alg) and Alg-high methoxyl pectin (HMP) through O/W/O multiple emulsion/external gelation method to developed resistant microparticles among acidic and neutral pHs. Results showed that initial CX concentration had a significant influence on total CX (TCX), surface CX (SCX), microencapsulation efficiency (EE) and particles size. The highest EE% for Alg (60.21⯱â¯0.18) and Alg-HMP (70.60⯱â¯0.68) were obtained with CX initial concentration of 11 and 18⯵g/mg, respectively. Alg microparticles showed smaller size compare to Alg-HMP microcapsules. Presence of CX in microparticles and good antioxidant activity was confirmed by FT-IR spectroscopy and DPPH assay, respectively. CX in vitro release was 66% and 49% in acidic condition and 76% and 50% in neutral condition for Alg and Alg-HMP, respectively. Thus, Alg-HMP-CX18 microparticles were selected to be used in both neutral and acidic foods such as milk and fermented milks products as an antioxidant and a colorant agent.
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Actinomycetales/química , Alginatos/química , Antioxidantes/química , Cantaxantina/química , Portadores de Fármacos/química , Liberación de Fármacos , Pectinas/química , Cápsulas , Alimentos , Concentración de Iones de HidrógenoRESUMEN
BACKGROUND: Riboflavin (vitamin B2) is an essential component of the basic metabolism, and an important nutritional and growth factor in humans, animals, plants and micro-organisms. It has been widely used in the fields of pharmaceuticals, feed and food additives. The industrial production of riboflavin mostly relies on the microbial fermentation. Designing an appropriate fermentation medium is of crucial importance to improve the riboflavin production. METHODS: In this study, sequential methodology combining a screening test of minerals by Plackett-Burman (PB) and an optimization test by Central Composite Design (CCD) was applied to enhance riboflavin production by Bacillus subtilis ATCC 6051 in shake flasks. RESULTS: Initially, one-factor-at-a-time approach was applied to evaluate the effect of different carbon sources. The results showed that fructose was significantly most effective on biomass and riboflavin production. After that, 13 minerals [CaCl2, CuCl, FeCl3, FeSO4, AlCl3, Na3MoO4, Co(NO3)2, NaCl, KH2PO4, K2HPO4, MgSO4, ZnSO4, and MnSO4] were studied with the screening test. The results revealed that concentration of MgSO4, K2HPO4, and FeSO4 had greater influence on riboflavin production (p< 0.05). A CCD with five factors (concentration of fructose, MgSO4, K2HPO4, FeSO4, and yeast extract) at five levels was then used to determine the maximum riboflavin concentration. The optimal concentrations (g/l) of these variables determined by Response Surface Methodology (RSM) were fructose, 38.10; MgSO4, 0.85; K2HPO4, 2.27; FeSO4, 0.02; and yeast extract, 4.37. CONCLUSION: Statistical experimental design offers a practicable approach to the implementation of medium optimization. From an industrial view point, our optimum medium, besides fructose and a small amount of yeast extract, is mainly composed of common and cheap inorganic salts, which are available to the industrial riboflavin production.
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Cellulosic nanocrystals from different origins were made to stabilize the canthaxanthin (CTX) in pickering emulsion. Nanocrystals were obtained by hydrochloric acid hydrolysis. Dynamic light scattering (DLS) demonstrated that the length of solid particles were in the range of 112nm-4000nm. AFM indicated the needle-like shape of the cotton cellulose nanocrystals (CCNs) and bacterial cellulose nanocrystals (BCNs) and also illustrated the thickness of the particles to be 6 and 7nm respectively. The crystallinity of both BCNs and CCNs was higher than the cellulose source they were isolated (CL: 75.4%, CCNs: 86.6; BC: 79.2%, BCNs: 88.5%). Effects of different factors such as temperature, pH and ionic concentration on stability were investigated. The results revealed that an increase in both temperature and pH was accompanied by an improvement in emulsion stability in all tested samples. However, increase in ionic concentration resulted in emulsions with less stability. In all the samples, CCN emulsions had better stability than the BCN emulsions, which was associated to smaller particle size and more coverage ability. Test of stability to light showed that CCN emulsions can preserve CTX better than BCN against the light.
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Cantaxantina/química , Celulosa/química , Fibra de Algodón , Nanopartículas/química , Bacterias/química , Emulsiones , Ácido Clorhídrico/química , Concentración de Iones de Hidrógeno , Hidrólisis , Luz , Nanopartículas/efectos de la radiación , Concentración Osmolar , Tamaño de la Partícula , Temperatura , Agua/químicaRESUMEN
This study investigated the effects of various culture parameters (carbon sources, temperature, initial pH of culture, NaCl concentration, and light) on the growth and canthaxanthin production by Dietzia natronolimnaea HS-1. The results showed that the most effective carbon source for growth and canthaxantin production was glucose, and the best pH and temperature were 7 and 31 degrees C, respectively. In addition, the biomass and canthaxanthin production increased in a medium without NaCl and in the presence of light. Under the optimized conditions, the maximum biomass, total carotenoid, and canthaxanthin production were 6.12 +/- 0.21 g/l, 4.51 +/- 0.20 mg/l, and 4.28 +/- 0.15 mg/l, respectively, in an Erlenmeyer flask system, yet increased to 7.25 g/l, 5.48 mg/l, and 5.29 mg/l, respectively, in a batch fermenter system.
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Actinomycetales/metabolismo , Cantaxantina/biosíntesis , Actinomycetales/crecimiento & desarrollo , Biomasa , Carbono/metabolismo , Medios de Cultivo , Fermentación , Concentración de Iones de Hidrógeno , Luz , Cloruro de Sodio/farmacología , TemperaturaRESUMEN
The effects of glycerol, bacterial cellulose nanocrystal (BCNC) and boric acid concentrations on the mechanical properties of PVA based films, including ultimate tensile strength (UTS), elongation at break (EAB), tensile Young's modulus (TYM), tensile toughness to break (TT), ultimate puncture strength (UPS), puncture deformation (PD), puncture Young's modulus (PYM) and puncture toughness to break (PT), were scrutinized using a response surface methodology-central composite rotatable design (RSM-CCRD). Second-order polynomial models with high R2 values ranging from 0.945 to 0.977 were developed for the studied responses using multiple linear regression analysis. The models showed the maximum UTS (72.84MPa), EAB (293.43%), UPS (4.64MPa) and PD (31.80%) could be achieved at 13.89% glycerol concentration, 5.00% BCNC concentration and a boric acid content of 1.96%. The predicted values for optimum conditions were in good agreement with experimental data. Fourier-transform infrared spectroscopy (FTIR) analysis confirmed the formation of intramolecular and intermolecular hydrogen and ether crosslinkages in PVA and/or BCNC chains when boric acid is applied. Results showed that PVA/BCNC nanocomposite films plasticized with glycerol and crosslinked with boric acid showed appropriate mechanical properties that made them suitable as a disposable packaging film.