Effect of Biodegradable Coatings on the Growth of Aspergillus flavus In Vitro, on Maize Grains, and on the Quality of Tortillas during Storage.

The fungus Aspergillus flavus causes serious damage to maize grains and its by-products, such as tortilla. Currently, animal and plant derivatives, such as chitosan and propolis, and plant extract residues, respectively, are employed as alternatives of synthetic fungicides. The objective of this research was to evaluate the efficacy of several formulations based on propolis-chitosan-pine resin extract on the in vitro growth of A. flavus, the growth of maize grain plantlets and the quality of stored tortillas at 4 and 28 °C. The most outstanding formulation was that based on 59.7% chitosan + 20% propolis nanoparticles + 20% pine resin extract nanoparticles; since the in vitro conidia germination of A. flavus did not occur, disease incidence on grains was 25-30% and in tortillas, 0% infection was recorded, along with low aflatoxin production (1.0 ppb). The grain germination and seedling growth were markedly reduced by the nanocoating application. The percentage weight loss and color of tortillas were more affected by this coating compared to the control, and the rollability fell within the scale of non-ruptured at 4 °C and partially ruptured at 28 °C. The next step is to evaluate the toxicity of this formulation.

Phenolic Compound Profile by UPLC-MS/MS and Encapsulation with Chitosan of Spondias mombin L. Fruit Peel Extract from Cerrado Hotspot-Brazil.

Taperebá (Spondias mombin L.) is a native species of the Brazilian Cerrado that has shown important characteristics such as a significant phenolic compound content and biological activities. The present study aimed to characterize the phenolic compound profile and antioxidant activity in taperebá peel extract, as well as microencapsulating the extract with chitosan and evaluating the stability of the microparticles. The evaluation of the profile of phenolic compounds was carried out by UPLC-MS/MS. The in vitro antioxidant activity was evaluated by DPPH and ABTS methods. The microparticles were obtained by spray drying and were submitted to a stability study under different temperatures. In general, the results showed a significant content of polyphenols and antioxidant activity. The results of UPLC-MS/MS demonstrated a significant content of polyphenols in taperebá peel, highlighting the high content of ellagic acid and quercetin compounds. There was significant retention of phenolic compounds when microencapsulated, demonstrating high retention at all evaluated temperatures. This study is the first to microencapsulate the extract of taperebá peel, in addition to identifying and quantifying some compounds in this fruit.

Effects of zein stabilized clove essential oil Pickering emulsion on the structure and properties of chitosan-based edible films.

Clove essential oil (CLO) Pickering emulsions were prepared with zein colloid particles as stabilizer, and the effects of CLO Pickering emulsion incorporation on the structure, mechanical, barrier and antimicrobial properties of chitosan-based edible films were explored. CLO Pickering emulsions with 3% w/v zein and 50% v/v CLO had smaller particle size and more even distribution. Incorporation of CLO Pickering emulsion in the films decreased the water vapor permeability and tensile strength, but the elongation at break firstly increased then decreased with the maximum value of 19.2% when the content of emulsion was 0.4%. Scanning electron microscopy revealed the formation of microstructure-sized holes in the films by the addition of CLO Pickering emulsion. The emulsified oil droplets were uniformly distributed, due to the good compatibility between oil phase and chitosan matrix. The antimicrobial properties of the films were strengthened by CLO Pickering emulsion incorporation and mainly depended on its concentration.

Evaluation of Chitosan-Starch-Based Edible Coating To Improve the Shelf Life of Bod Ljong Cheese.

The objective of this work was to evaluate the effectiveness of antimicrobial edible coatings to improve the quality of Bod ljong cheese throughout 25 days of storage. Coatings were prepared using chitosan, water chestnut starch, and glycerol as a base matrix, together with several combinations of antimicrobial substances: Cornus officinalis fruit extract (COFE), pine needle essential oil (PNEO), and nisin. Application of coating on cheese decreased water loss, lipid oxidation, changes in headspace gas composition, and color. Moreover, the edible coatings with COFE or PNEO had increased antimicrobial activity and did not permit growth of microorganisms. COFE and PNEO are manufactured from food-grade materials so they can be consumed as an integral part of the cheese, which represents a competitive advantage over nonedible coatings.

Maltose-conjugated chitosans induce macroscopic gelation of pectin solutions at neutral pH.

Injectable polymer scaffolds are particularly attractive for guided tissue growth and drug/cell delivery with minimally invasive intervention. In the present work, "all-polymeric" gelling systems based on pectins and water-soluble maltose-conjugated chitosans (CM) have been developed. Maltose-conjugated chitosan has been synthesized at three different molar ratios, as evaluated by FITR analysis and fluorimetric titration. A thorough rheological characterization of the blends and their parent solutions has been performed. Macroscopic gelation has been achieved by mixing the high esterification degree pectins with CM at higher maltose grafted to chitosan contents. Gels form in a few minutes and reach their full strength in less than two hours. These features encourage their further development as scaffold for tissue engineering.

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.

Effect of chitosan nanoparticles and pectin content on mechanical properties and water vapor permeability of banana puree films.

UNLABELLED: Puree prepared from over-ripe peeled bananas was used as raw material for films processing in a laboratory padder. Pectin and glycerol as plasticizer were added in small concentrations and chitosan nanoparticles (88.79 ± 0.42 nm medium size) incorporated at 0.2% (dry weight basis) as reinforcement material. The mechanical properties, water vapor transmission, thermal stability, and scanning electron microscopy of fractured film surfaces were characterized. Both pectin and glycerol demonstrated an important role in promoting elongation and film handability as was expected. The incorporation of nanoparticles promoted noticeable improvement of the mechanical properties and acted in reducing the water vapor permeation rate, by 21% for films processed with pectin and up to 38% for films processed without pectin, when compared to the control (puree films with no pectin and nanoparticles additions). Microscopic observation revealed a denser matrix when nanoparticles are incorporated into the films. PRACTICAL APPLICATION: The development of films from fruit purees head to a new strategy for plastic processing from natural resources. The over-ripe or even waste banana can be adequately prepared for batch films processed with reasonable mechanical and barrier properties, suitable for applications in the food segment. The addition of small fractions of chitosan nanoparticles, form nanocomposites enhancing mechanical and thermal stability broadening potential film applications.

[Preparation and preliminary characterization of chitosan from Catharsius molossus discards].

OBJECTIVE: To study preparation and characterization of chitosan from Catharsius Molossus processing discards and explore the feasibility of utilization of insects residue. METHODS: Preparation technique of chitosan was studied by orthogonal design,and properties were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), etc. RESULTS: Preparation techniques were as follows: demineralizing: soaked for 30 min at 80 degrees C with 1.3 mol/L HCl, then kept for 12 h under room temperature. Deproteinization and delipidation: treated for 6 h at 90 degrees C with 4 mol/L NaOH. Decolorizing: soaked at room temperature with 3% KM-nO4, then treated with 2% oxalic acid at 70 degrees C. Deacetylating:treated for 5 h at 110 degrees C with 14 mol/L NaOH. CONCLUSION: The technique is stable and feasible. The result also preliminarily showes that chitosan from Catharsius Molossus is better than shrimp's. It will be widely applied in biomedical and other industrial areas with such exciting properties.

Chemical composition and antioxidative activity of Echinophora platyloba DC. essential oil, and its interaction with natural antimicrobials against food-borne pathogens and spoilage organisms.

This study was undertaken to determine the chemical composition and antioxidative capacity of Echinophora platyloba DC. essential oil, and its antimicrobial potency against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The essential oil was analyzed by GC and GC-MS; and evaluated for its antioxidative and antimicrobial (singly or in combination with chitosan, nisin, monolaurin, or amphotericin B) activity. Thirty-three components were characterized representing 95.69% of the total oil composition in which thymol, trans-ocimene, carvacrol, and (E)-sesqui-lavandulol were the major constituents. The oil exhibited high scavenging (IC(50): 49.7 ± 2.3 µg/mL) and relative antioxidative activity (RAA%: 85.21 ± 0.4) in 1,1-diphenyl-2-picrylhydrazyl radicals and ß-carotene/linoleic acid bleaching assays, respectively. The oil showed antimicrobial activity against L. monocytogenes, B. cereus, B. subtilis, S. aureus, S. typhimurium, E. coli O157:H7, P. aeruginosa, C. albicans, C. tropicalis, R. Rubra, and R. mucilaginosa. Moreover, R. mucilaginosa and P. aeruginosa were the most susceptible and most resistant organisms, respectively. Regarding the checkerboard data, 47 fractional inhibitory concentration index (FICIs) (≤ 0.5) indicated synergistic, whereas 7 FICIs (>0.5 to 1) indicated additive effect. Consequently, E. platyloba DC. essential oil could be used as a recommended natural antioxidant and antimicrobial substance for food preservation.

Modification of the conformational skin structure by treatment with liposomal formulations and its correlation to the penetration depth of aciclovir.

The stratum corneum (SC), top layer of the epidermis, is comprised mostly of lipids that are responsible for the permeability properties of the SC and which protect the body from external agents. Changes in these skin microconstituents can be understood by instrumental methods such as attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. The present work shows that different types of analyzed skin, dermatomed abdominal porcine skin, pig ear skin, and human heat separated skin, influenced both the shape and the intensity of recorded spectra. The typical FTIR spectral bands of the conformation of the lipid aliphatic chains in the skin samples were altered after treatment with pure DPPC liposomes and chitosan (CS) coated DPPC liposomes, but not with aqueous CS-solution. The conformational change could be the reason for the variable permeability of the skin. This was confirmed by tape stripping on pig ear skin (imitating in vivo studies): the amount of aciclovir penetrating from polymer coated and polymer free liposomes was significantly higher under the skin surface in comparison with the aqueous CS-solution. Moreover, the addition of the polymer to liposomes induced a higher skin penetration than pure liposomes. One explanation might be the CS's stronger adhesion to the skin.

Efeitos da quitosana sobre alguns parâmetros nutricionais e bioquímicos em ratos / Effects of chitosan over some nutritional and biochemical parameters in rats

The recommendation for a larger intake of food fiber has been an important strategy for the control and prevention of obesity and its co-morbidities. Chitosan, an animal fiber, has been related to the reduction of fat uptake by the intestine, serum cholesterol and glucose, as well as appetite inhibition and weight loss. This study evaluated the effects of consuming powdered chitosan on some nutritional and biochemical parameters in adult female rats. Adult female Wistar rats (n=14) were divided in control group (GC): fed a diet based on casein and microcrystaline cellulose (AIN 93 G) for 10 days; and chitosan group(GQ): fed a diet based on casein and powdered chitosan (5%) substituting microcrystalline cellulose for 10 days. No differences were observed I the food intake, evolution of the body weight, liver weight, fat depots in the abdomen and in the carcass. Also, there were no differences in the glucose and total protein serum concentrations or in the lipid profile.The GQ presented smaller stomach and intestine (with contents) weights.However, these findings are insufficient to suggest any effect on saciety since no difference was observed in the food intake between the groups

El aumento de la ingestión de fibra alimentar ha sido una importante estrategia para el control de la obesidad y sus comorbidades. La quitosana,una fibra de origen animal, está siendo responsabilizada por reducir la absorción de grasas a nivel intestinal, disminución del colesterol y la glucosa séricos y también por la inhibición del apetito y reducción del peso corporal. Este estudio evaluó el efecto de la incorporación de quitosana en polvo, en dietade ratas adultas, sobre algunos parâmetros nutricionales y bioquímicos. Ratas Wistar (n=14) fueron divididas en grupo control (GC), raciónAIN-93G, a base de caseína y celulosa microcristalina (5%) y grupo quitosana e (GQ),ración AIN-93G y quitosana en polvo (5%) em substitución de la celulosa micro cristalina, por10 días. No se observaron diferencias en el consumo alimentar ni en la evolución de los pesos corporal o del hígado, de los depósitos de grasa abdominal y de la carcasa, ni tampoco en las concentraciones séricas de glucosa,proteínas totales y perfil lipídico. Sin embargo, el grupo GQ presentó menores pesos de estómago e intestino delgado (con su contenido). No obstante, estos resultados son insuficientes para deducir algún efecto en la saciedade considerando que no se observó diferencia en el consumo de ración de los grupos

O maior consumo de fibra alimentar tem sido uma das importantes estratégias para o controle e prevenção da obesidade e suas co-morbidades. A quitosana, fibra de origem animal, vem sendo relacionada à redução da absorção de gorduras em nível intestinal, do colesterol e glicose séricos e, também, com inibição do apetite e redução de peso corporal. Este estudo avaliou os efeitos do uso de quitosana em pó, na ração de ratas adultas, sobre alguns parâmetros nutricionais e bioquímicos. Ratas Wistar adultas (n=14) foram divididas em grupo controle (GC): ração AIN-93G, à base de caseína e celulose microcristalina (5%) e grupo quitosana (GQ): dieta AIN-93G e quitosana em pó (5%), em substituição à celulose microcristalina, por 10 dias. Não se observaram diferenças no consumo alimentar, na evolução do peso corporal, do fígado, dos depósitos de gordura abdominal e da carcaça, e, nem tampouco nas concentrações séricas de glicose, proteínas totais e no perfil lipídico. O GQ apresentou menor peso do estômago e do intestino delgado (com conteúdo) sendo, entretanto esses resultados, insuficientes para inferir sobre algum efeito na saciedade, tendo em vista que não foi observada diferença no consumo de ração entre os grupos

[Research of chitins to technology of clarification for xiangjuganmaokeli extraction].

OBJECTIVE: To study the procedure of chitosan to technology of clarification for xiangjuganmaokeli extraction and measure its content. METHODS: The best technology was choosed by orthogonal test. Relative density, the total solid, total sugar and the content of acacetin were examined after the nature clearness and chitins clarify. The total sugar was Counte-racted with ether siank, hydrolyzed with the phenol and sulfuric acid and examined in the 490 nm. Acaciin in powdered herb was determined by HPLC method. RESULTS: The chitin clarifies in front and back relative density, the total solid, the total sugar slightly descends, but the acacetin did not show the significant difference. CONCLUSION: Chitins to technology of clarification for xiangjuganmaokeli extraction can attain the clearness result, and the acacetin did not show the significant difference in front and back.

Chemical intervention strategies for substantial suppression of acrylamide formation in fried potato products.

Prototype processes were developed for the substantial suppression of acrylamide formation (40-95% compared to untreated controls) in cut surface fried potato products using potato chips (crisps) as the primary model. The most efficacious procedures employed sequentially both surface preparation and subsequent acrylamide precursor complexation and/or competitive inhibition processing steps. Surface preparation processing involved either various low-temperature (50-75 degrees C) aqueous (5-30 min) or ca. 80% ethanol blanch solutions for various times (1-5 min) combined with aqueous leaching steps (1-10 min) to reduce concentration of acrylamide precursors in the critical frying zone of cut potato surfaces. Acrylamide precursor complexation and/or competitive inhibition processing strategies included immersion exposure of prepared cut potato surfaces to solutions or dispersions of various combinations of either calcium chloride, phytic acid, chitosan, sodium acid pyrophosphate, or N-acetylcysteine.

[Biologically active compounds of edible mushrooms and their beneficial impact on health]. / Zwiazki biologicznie aktywne zawarte w grzybach jadalnych i ich korzystny wplyw na zdrowie.

Edible mushrooms are valuable a source of biologically active compounds. Some are used in the prophylaxis and therapy of such diseases as cancer and cardiovascular disease. Their antitumor mechanism is complex. The biologically active substances in mushrooms decrease DNA damage, reduce carcinogen concentrations and their activation, inhibit the growth of cancer cells by scavenging free radicals, stimulate the immune system, and induce tumor cell apoptosis. The stimulation of the immune system by the biologically active compounds in edible mushrooms protects against cold, flu, infections, well as AIDS by inhibition of viral replication. Mushrooms contain effective substances which decrease the LDL fraction of cholesterol in blood. They also prevent the accumulation of serum triaclyglycerols, thus decreasing the risk of developing cardiovascular disease. The therapeutic properties of mushrooms result from the specific polysaccharides, such as beta-glucans and chitosans, that are present in the fructification of fungi.