Sodium alginate coating of Ginkgo biloba leaves extract containing phenylpropanoids as an ecofriendly preserving agent to maintain the quality of peach fruit.

Plant constituents are of great interest in the food processing industry as potential natural preservative agents for controlling foodborne pathogens. In this study, the 95% EtOH/H2 O extract of Ginkgo biloba leaves was separated using polarity extraction solvents with petroleum ether (PE), ethyl acetate (EA), n-butanol (nB), and water (W) by the principle of similarity and compatibility. Through TLC and NMR analysis of these extracts, it can be concluded that the main component of PE extract were organic acids, for EA extract were flavonoids, for nB extract were phenylpropanoids, and water extract were oligosaccharides. Twelve monomer compounds were separated from the extracts to verify the composition of each extraction stage. Results of morphological and molecular identification revealed that Monilinia fructicola and Rhizopus stolonifer were the main fungi causing peach rot. After evaluating the antifungal activity and peach quality of the four extract/sodium alginate coatings, it was found that the n-butanol extract/sodium alginate coating containing phenylpropanoids had the lowest decay index and the best preservation effect, providing a sustainable alternative to reduce the harm to the environment of synthetic preservatives. PRACTICAL APPLICATION: The abuse of synthetic preservatives poses a threat to the ecological environment and physical health. Therefore, this study developed sodium alginate coating of Ginkgo biloba leaves extract containing phenylpropanoids, which has good effects on the preservation of peaches. The agent is a promising environmentally friendly alternative for synthetic preservatives.

Theoretical and experimental investigation of sodium alginate composite films containing star anise ethanol extract/hydroxypropyl-ß-cyclodextrin inclusion complex.

The aim of this study is to prepare composite films incorporated with star anise ethanol extract (SAEE)/hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex. The effects of sodium alginate concentration on mechanical properties of films are tested. Sodium alginate, SAEE, and SAEE/HP-ß-CD inclusion complex-based composite films are characterized in terms of UV-visible spectroscopy, microstructure characterizations, including transmission electron microscopy, scanning electronic microscopy, Fourier transform infrared, and 1 H NMR analysis, and molecular modeling calculations. With various stoichiometries, the complexes of sodium alginate/SAEE/HP-ß-CD are compared through both theoretical and experimental analyses. Molecular simulations are applied to predict the possible orientations of SAEE inside the HP-ß-CD cavity and the optimal stoichiometry of the complex formation. According to the simulation, the system of sodium alginate/SAEE (or SAEE/HP-ß-CD inclusion complex) in a 3:1 stoichiometry reaches the lowest total energy and achieves a balance in complex system. In addition, the composite films can maintain high-content vitamin C and reduce weight loss rate of fresh-cut Chinese yam. In conclusion, coinciding with the experimental results, the molecular modeling successfully calculates the reasonable molecular structure and molecular behavior of sodium alginate/SAEE/HP-ß-CD inclusion complex. The composite films in this study have the potential to be used for food packaging applications. PRACTICAL APPLICATION: In this paper, we present composite films incorporated with star anise ethanol extract (SAEE)/hydroxypropyl-ß-cyclodextrin (HP-ß-CD) inclusion complex for the use of fresh-cut Chinese yam preservation. The present study demonstrates a successful application of molecular modeling to predict the geometry of the final complex. It can serve as a powerful tool to calculate the energy of association between inclusion complex and sodium alginate molecules.

Physical Properties, Chemical Analysis, and Evaluation of Antimicrobial Response of New Polylactide/Alginate/Copper Composite Materials.

In recent years, due to an expansion of antibiotic-resistant microorganisms, there has been growing interest in biodegradable and antibacterial polymers that can be used in selected biomedical applications. The present work describes the synthesis of antimicrobial polylactide-copper alginate (PLA-ALG-Cu2+) composite fibers and their characterization. The composites were prepared by immersing PLA fibers in aqueous solution of sodium alginate, followed by ionic cross-linking of alginate chains within the polylactide fibers with Cu(II) ions to yield PLA-ALG-Cu2+ composite fibers. The composites, so prepared, were characterized by scanning electron microscopy (SEM), UV/VIS transmittance and attenuated total reflection Fourier-transform infrared spectroscopy ATR-FTIR, and by determination of their specific surface area (SSA), total/average pore volumes (through application of the 5-point Brunauer-Emmett-Teller method (BET)), and ability to block UV radiation (determination of the ultraviolet protection factor (UPF) of samples). The composites were also subjected to in vitro antimicrobial activity evaluation tests against colonies of Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria and antifungal susceptibility tests against Aspergillus niger and Chaetomium globosum fungal mold species. All the results obtained in this work showed that the obtained composites were promising materials to be used as an antimicrobial wound dressing.

Mitigation effect of sodium alginate on acrylamide formation in fried potato chips system based on response surface methodology.

Acrylamide is a known neurotoxin and probable carcinogen in humans. Researchers reported that foods rich in carbohydrates could generate high amounts of acrylamide at high temperatures. In recent years, hydrocolloids are applied to reduce acrylamide in thermally processed foods and the effect has been well proved. The present work was to investigate the effect of sodium alginate as the coating agent on acrylamide formation in fried potato chips by a Box-Behnken design. The optimized processing conditions were: sodium alginate at the concentration of 1.34%, frying time at 4.38 min, and frying temperature at 179 °C. The corresponding inhibition rate of acrylamide was 76.59%. Compared to the control group, the oil absorption of coating chips decreased significantly, whereas the addition of sodium alginate did not affect the quality of potato chips. Scanning electron microscope analysis revealed that coating with sodium alginate could effectively prevent oil uptake, which might contribute to acrylamide mitigation. Overall, sodium alginate significantly mitigated acrylamide formation in fried potato chips. PRACTICAL APPLICATION: Sodium alginate could significantly reduce acrylamide formation in fried potato chips systems. Sodium alginate may therefore be a new mitigation strategy for acrylamide formation in commercial fried foods without prejudice to main quality properties valued by consumers.

Culture of Small Colony Variant of Pseudomonas aeruginosa and Quantitation of its Alginate.

Pseudomonas aeruginosa, an opportunistic Gram-negative bacterial pathogen, can overproduce an exopolysaccharide alginate resulting in a unique phenotype called mucoidy. Alginate is linked to chronic lung infections resulting in poor prognosis in patients with cystic fibrosis (CF). Understanding the pathways that regulate the production of alginate can aid in the development of novel therapeutic strategies targeting the alginate formation. Another disease-related phenotype is the small colony variant (SCV). SCV is due to the slow growth of bacteria and often associated with increased resistance to antimicrobials. In this paper, we first show a method of culturing a genetically defined form of P. aeruginosa SCV due to pyrimidine biosynthesis mutations. Supplementation of nitrogenous bases, uracil or cytosine, returns the normal growth to these mutants, demonstrating the presence of a salvage pathway that scavenges free bases from the environment. Next, we discuss two methods for the measurement of bacterial alginate. The first method relies on the hydrolysis of the polysaccharide to its uronic acid monomer followed by derivatization with a chromogenic reagent, carbazole, while the second method uses an ELISA based on a commercially available, alginate-specific mAb. Both methods require a standard curve for quantitation. We also show that the immunological method is specific for alginate quantification and may be used for the measurement of alginate in the clinical specimens.

Agro food by-products and essential oil constituents curtail virulence and biofilm of Vibrio harveyi.

Vibrio harveyi causes severe loss to the aquaculture industry due to its virulence, which is mediated by Quorum sensing (QS) and biofilm formation. In the current study, we have explored the anti-virulent properties and biofilm disruption ability of luteolin (extracted from coconut shell) and linalool against this important aquaculture pathogen. HPLC analysis of the methanolic extract of coconut shells revealed a single major peak which matched to the standard luteolin which was further elucidated by NMR studies. Further, luteolin and linalool were screened for their ability to inhibit biofilms and various quorum sensing mediated virulence factors of V. harveyi. The Minimum Inhibitory Concentration (MIC) of the two compounds was determined and the sub-inhibitory concentrations of the compounds were able to inhibit biofilm formation. Both the compounds disrupted about 60-70% mature biofilms, which was also visually observed by light microscopy. Both linalool and luteolin exhibited a significant reduction in the production of EPS and alginate in the biofilms matrix of V. harveyi which was confirmed by Scanning Electron Microscopy (SEM). Both compounds inhibited the swarming and swimming motility, the crucial quorum sensing (QS) mediated virulence of V. harveyi. The present study shows the presence of valuable polyphenolic compound like luteolin in coconut shells that are discarded as a waste. From the present study we envisage that luteolin and linalool can serve as potent anti-virulent agents to combat QS mediated infections against aquaculture pathogens.

Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High-Fat Diet.

We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high-fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase-producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high-fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague-Dawley rats (5-wk-old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low-density lipoprotein-cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups.

Effect of irradiated sodium alginate and phosphorus on biomass and artemisinin production in Artemisia annua.

It is now being realized that irradiation products of natural bioactive agents can also be beneficially utilized to impart value addition in agriculture by converting these bioactive agents into more useful form. Polysaccharides, such as sodium alginate, have proven to be wonderful growth promoting substances in their depolymerized form for various plants. Artemisinin has been increasingly popular as an effective and safe alternative therapy against malaria; also proved effective against the highly adaptable malaria parasite, which has already become resistant to many other drugs. The drug artemisinin can be extracted from the leafy tissues of Artemisia annua. Therefore, experiments were conducted with an aim to evaluate artemisinin production and overall plant development though depolymerized sodium alginate application and nutrient supply. In the present study, sodium alginate, irradiated by Co-60 gamma rays together with various phosphorus doses, was used to study their effect on growth, physiological and biochemical processes and production of artemisinin in A. annua. Among various applied doses of phosphorus fertilizer, P40 (40 kg Pha(-1)) together with ISA80 (80 mg L(-1)) significantly improved all the parameters studied. Increase in plant height as well as weight was noted at this treatment. Dry leaf yield, artemisinin concentration in leaves and artemisinin yield was also significantly enhanced by the treatment.

Preparation and characterization of microcapsules of Pterodon pubescens Benth. by using natural polymers

An oleaginous fraction obtained from an alcohol extract of the fruit of Pterodon pubescens Benth. (FHPp) was microencapsulated in polymeric systems. These systems were developed using a complex coacervation method and consisted of alginate/medium-molecular-weight chitosan (F1-MC), alginate/chitosan with greater than 75% deacetylation (F2-MC), and alginate/low-molecular-weight chitosan (F3-MC). These developed systems have the potential to both mask the taste of the extract, and to protect its constituents against possible chemical degradation. The influence of the formulation parameters and process were determined by chemical profiling and measurement of the microencapsulation efficiency of the oleaginous fraction, and by assessment of microcapsule morphology. The obtained formulations were slightly yellow, odorless, and had a pleasant taste. The average diameters of the microcapsules were 0.4679 µm (F2-MC), 0.5885 µm (F3-MC), and 0.9033 µm (F1-MC). The best formulation was F3-MC, with FHPp microencapsulation efficiency of 61.01 ± 2.00% and an in vitro release profile of 75.88 ± 0.45%; the content of vouacapans 3-4 was 99.49 ± 2.80%. The best model to describe the release kinetics for F1-MC and F3-MC was that proposed by Higuchi; however, F2-MC release displayed first-order kinetics; the release mechanism was of the supercase II type for all formulations.

Uma fração oleaginosa obtida do extrato etanólico de frutos de Pterodon pubescens Benth (FHPp) foi microencapsulada em um sistema polimérico. Estes sistemas foram desenvolvidos utilizando o método de coacervação complexa, constituído de alginato/quitosana massa molecular média (F1-MC), alginato/quitosana com desacetilação superior a 75% (F2-MC) e alginato/quitosana de massa molecular baixa (F3-MC). Estes sistemas desenvolvidos têm o potencial tanto de mascarar o sabor do extrato, quanto de protegê-lo de possível degradação química. A influência dos parâmetros de formulação e processo foram determinadas por caracterização química, determinação da eficiência de microencapsulação da fração oleaginosa e por avaliação morfológica da microcápsula. As formulações mostraram-se ligeiramente amareladas, inodoras e com sabor agradável. Os diâmetros médios das microcápsulas foram de 0,4679 µm (F2-MC), 0,5885 µm (F3-MC) e 0,9033 µm (F1-MC). A melhor formulação foi F3-MC, considerando-se que apresentou eficiência de encapsulação de 61,01 ± 2,00%, e perfil de liberação in vitro de 75,88 ± 0,45%; o conteúdo dos vouacapanos 3-4 foi 99,49 ± 2,80%. O melhor modelo para descrever a cinética de liberação foi o modelo proposto por Higuchi para F1-MC e F3-MC, entretanto, para F2-MC foi o modelo de primeira ordem, e o mecanismo de liberação foi do tipo super caso II para todas as formulações.

Method for the determination of lycopene in supplements and raw material by reversed-phase liquid chromatography: single-laboratory validation.

A single-laboratory validation study was conducted for a liquid chromatographic (LC) method for the determination of total and all-trans-lycopene in a variety of dietary supplements and raw materials. Gelatin-based and other water-dispersible beadlets, or tablets, capsules, and softgels containing such product forms, were digested with protease. Alginate formulations and the respective applications were treated with an alkaline sodium EDTA acetate buffer to release lycopene from the matrix. Lycopene and other carotenoids were extracted from the resulting aqueous suspensions with dichloromethane and ethanol. Oily product forms were directly dissolved in dichloromethane and ethanol. The extracts were chromatographed on an isocratic high-performance LC system using a C16 alkylamide modified silica column that provided satisfactory resolution of all-trans-lycopene from its predominant cis-isomers and separated the lycopene isomers from other carotenoids such as alpha- and beta-carotene, cryptoxanthin, lutein, and zeaxanthin. The within-day precision relative standard deviation (RSD) for the determination of total lycopene ranged from 0.9 to 5.7% over concentration ranges of 50-200 g/kg for raw materials and 0.3-24 g/kg for dietary supplements. The intermediate precision RSD (total RSD) ranged from 0.8 to 8.9%. Recoveries obtained for beadlet and tablet material for the different extraction variants ranged from 95.0 to 102.1% at levels of 0.02-20 g/kg for tablets and from 95.0 to 101.1% at levels of 1-200 g/kg for beadlet material.

Quantitative determination of alginic acid in pharmaceutical formulations using capillary electrophoresis.

A capillary electrophoresis (CE) method has been developed and validated for the quantitative determination of alginic acid, which is used as a rafting agent in complex antacid formulations. The method involves a preliminary separation of the alginic acid from the formulation by washing the sample matrix with methanol, diluted HCl and water. This is followed by electrophoresis within a fused silica capillary using borate/boric acid buffer as the electrolyte, and the quantification is performed by a UV detector monitoring at 200 nm, where the intrinsic absorption of alginic acid is measured. An assay precision of better than 3% was achieved in intra- and interday determinations. No interference was found from the matrix of the antacid formulations.

The release of fluoride from two products of alginate impression materials.

The purpose of this study was to determine the fluoride content of two products of alginate and the possible fluoride transfer to the teeth, saliva and blood. The total fluoride content of Zelgan normal-set and Kerr alginate fastset powder was assayed by direct diffusion and diffusion of the ash. The soluble fluoride leaching out in water over 24 hour was also determined. The results show that the fluoride contents of Zelgan and Kerr alginate powders are about 1.9% and 1.5% fluoride, respectively. Of the fluoride present in Zelgan and Kerr approximately 6.5% and 5.8%, respectively, leached out in 400 ml deionized water. The fluoride uptake was estimated in two adjacent enamel layers each approximately 7 micrometers thick, using 10 teeth exposed for 5 minutes and 18 h to the alginate gel (Zelgan). The results of acid etch microsamplings indicate a significant increase in the fluoride concentration of the first enamel layer after both 5 min and 18 h exposure. Fluoride uptake within the second enamel layer was insignificant, however. Fluoride transfer to the oral saliva and to the blood was evident after impression taking.

The quantitative analysis of uronic acid polymers by infrared spectroscopy.

I.r. absorption bands associated with the functional groups of carboxylic acid derivatives are useful for the analysis of alginates and pectins. The ester, amide, and uronate contents of pectins and the uronate content of alginates were determined, respectively, from the ester-carbonyl stretching band (1740 cm- minus 1), the amide I band (1650 cm- minus 1), and the carboxylate antisymmetric stretching band (1607 cm- minus 1) obtained from the spectra of solutions in D2O-phosphate buffer. The results are accurate to within plus or minus 2-4%, are self consistent, and agree well with the few reliable results that are available. The method should be applicable for the determination of carboxylic acid derivatives in other polysaccharides.