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1.
Int J Biol Macromol ; 265(Pt 1): 130953, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38499124

RESUMO

Geranium (Pelargonium graveolens) is known for being an aromatic plant rich in bioactive compounds with antibacterial properties. In this study, geranium essential oil (GEO) was extracted and encapsulated in ultrafine bean starch fibers produced by electrospinning as an antibacterial agent. GEO revealed a composition rich in volatile compounds, including citronellol, cis-geraniol, ß-linalool, citronellyl formate, and linalool formate. In its free form, GEO exhibited high antibacterial activity against pathogenic bacteria strains (L. monocytogenes, S. aureus, and E. coli). The bean starch fibers, produced with and without the addition of GEO, were uniform and continuous, with an average diameter ranging from 249 to 373 nm. Confocal analysis indicated a uniform distribution of GEO in the fibers, with a loading capacity of 54.0 %, 42.9 %, and 36.5 % for 20 %, 30 %, and 40 % GEO concentrations, respectively. Remarkably, fibers containing 40 % GEO showed a significant reduction in tested bacteria (L. monocytogenes, S. aureus, and E. coli), suggesting promising applications in preventing losses and extending the shelf life of food through active packaging.


Assuntos
Monoterpenos Acíclicos , Geranium , Óleos Voláteis , Pelargonium , Óleos Voláteis/farmacologia , Óleos Voláteis/análise , Staphylococcus aureus , Escherichia coli , Antibacterianos/farmacologia
2.
J Food Sci ; 89(3): 1373-1386, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38343299

RESUMO

Onion is rich in bioactive and volatile compounds with antioxidant activity. However, the pungent odor of volatile compounds (VOCs) released restricts its use. The encapsulation of red onion extract by electrospinning is an alternative to mask this odor and protect its bioactive compounds. The main objective of this study was to encapsulate red onion bulb extract (ROE) in different concentrations into zein nanofibers by electrospinning and evaluate their thermal, antioxidant, and hydrophilicity properties. The major VOC in ROE was 3(2H)-furanone, 2-hexyl-5-methyl. Incorporating ROE into the polymeric solutions increased electrical conductivity and decreased apparent viscosity, rendering nanofibers with a lower average diameter. The loading capacity of ROE on fibers was high, reaching 91.5% (10% ROE). The morphology of the nanofibers was random and continuous; however, it showed beads at the highest ROE concentration (40%). The addition of ROE to the nanofibers increased their hydrophilicity. The nanofibers' antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl, nitric oxide, and hydroxyl radicals ranged from 32.5% to 57.3%. The electrospun nanofibers have the potential to protect and mask VOCs. In addition, they offer a sustainable alternative to the synthetic antioxidants commonly employed in the food and packaging industry due to their antioxidant activities.


Assuntos
Nanofibras , Zeína , Cebolas , Antioxidantes , Interações Hidrofóbicas e Hidrofílicas , Extratos Vegetais
3.
Int J Biol Macromol ; 254(Pt 1): 127617, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37879583

RESUMO

Starches from alternative sources, such as avocado seed, have potential for application in the encapsulation of essential oils. This study aimed to extract starch from avocado seeds and its use as wall material to encapsulate ginger essential oil (GEO), at different concentrations. The fibers were produced by electrospinning and evaluated by morphology, size, infrared spectra, thermogravimetric properties, contact angle, loading capacity, and antibacterial activity. The major compounds in GEO were α-zingiberene, ß-sesquiphellandrene, α-farnesene, and α-curcumene. The starch-GEO fibers presented a higher diameter (∼553 nm) than those without GEO (345 nm). Encapsulation of GEO in starch fibers increased their thermal degradation temperatures from 165.8 °C (free GEO) to 257.6 °C (40 % GEO fibers). The starch-GEO fibers presented characteristic bands of their constituents by infrared spectra. Loading capacity ranged from 44 to 54 %. The fibers showed hydrophilic character, with a contact angle of <90°. Free GEO and the fibers with 50 % of GEO displayed antibacterial activity against Escherichia coli, proving the bioactivity of the starch-GEO fibers and its possible applicability for food packaging. Avocado seed starch showed to be a great wall material for GEO encapsulation.


Assuntos
Óleos Voláteis , Persea , Zingiber officinale , Amido , Óleos Voláteis/farmacologia , Antibacterianos/farmacologia
4.
Int J Biol Macromol ; 253(Pt 1): 126610, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37652330

RESUMO

This study aimed to produce oleogels based on non-germinated and germinated wheat starches with orange essential oil, apply them to replace hydrogenated vegetable fat in bread, and assess the antifungal action. The oleogels were prepared using sunflower oil, wheat starches, beeswax, water, and orange essential oil (OEO). They were evaluated to determine the volatile compounds, oil binding capacity, texture profile, storage stability for 20 days, thermogravimetric analysis, and functional groups. The breads were evaluated by their moisture content, specific volume, texture profile, volatile compounds, and microbiological contamination during 15 days of storage. The oleogels showed high storage stability, were fully intact after 20 days of storage, and had a high oil binding capacity (∼100 %). The oleogels with OEO presented increased adhesiveness and reduced hardness compared to the ones without essential oil. The oleogels with OEO based on germinated wheat starch released a high amount of volatile compounds. Substituting saturated vegetable fat with oleogels in bread formulation resulted in decreased hardness and maintained specific volume. Furthermore, incorporating OEO oleogels in the bread led to reduced growth of total mesophiles and fungi.


Assuntos
Pão , Óleos Voláteis , Pão/análise , Triticum , Verduras , Óleos Voláteis/farmacologia , Amido , Ácidos Graxos/análise
5.
Food Res Int ; 170: 112970, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37316009

RESUMO

Proteins are excellent polymeric materials for encapsulating essential oils (EOs) by electrospinning and electrospraying to protect these compounds and form nanomaterials with active properties. Proteins can encapsulate bioactive molecules by several mechanisms, including surface activity, absorption and stabilization mechanisms, amphiphilic nature, film-forming capacity, foaming, emulsification, and gelation, due to interactions among their functional groups. However, proteins have some limitations in encapsulating EOs by the electrohydrodynamic process. Their properties can be improved by using auxiliary polymers, increasing their charges by adding ionic salts or polyelectrolytes, denaturing their structure by heat, and exposure to specific pH conditions and ionic strength. This review addresses the main proteins used in electrospinning/electrospraying techniques, production methods, their interactions with EOs, bioactive properties, and applications in food matrices. Multivariate analysis associated with bibliometrics of metadata extracted from studies in Web of Science using the keywords electrospinning and essential oil (EO) were used as the search strategy.


Assuntos
Bibliometria , Óleos Voláteis , Alimentos , Temperatura Alta , Análise Multivariada , Polímeros
6.
J Food Sci Technol ; 60(2): 494-503, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36712196

RESUMO

The objective was to evaluate the effect of peppermint essential oil (PEO) on the inhibition of potato sprouting induced by gibberellic acid (GA) during storage. PEO (0.08 and 0.15 mL L-1) was applied in the presence and absence of gibberellic acid (10 mg L-1). The presence of phytopathogens and changes in breaking of dormancy, weight loss, moisture content, and total soluble solids were measured during 28 days. The inhibition of potato sprouting by the PEO occurred at the lowest concentration, even in the presence of GA. Sprout development was inhibited with PEO addition, delaying the dormancy break and reducing weight loss. However, potato sprouting was still inhibited after the removal of the PEO, evidencing its residual efficacy. PEO application at both concentrations had a satisfactory effect on sprout suppression and can be used as a promising eco-friendly approach for inhibiting the sprouting of potato tubers during storage.

7.
Food Res Int ; 162(Pt B): 112111, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36461346

RESUMO

The aim of this work was to encapsulate curcumin at different concentrations in capsules and fibers of native potato starch by electrospraying and electrospinning. The best conditions for the production of capsules and fibers were obtained by varying the polymer concentration and resting time of the polymer solution. The best conditions were used for the encapsulation of curcumin. The curcumin-loaded capsules and fibers had an average diameter of 1373 nm to 1787 nm and 108 nm to 142 nm, respectively, and had a high curcumin loading capacity with values ranging from 79.01 % to 97.09 %. Curcumin encapsulated in starch capsules and fibers showed higher thermal stability at 180 °C for 2 h compared to unencapsulated curcumin. The antioxidant activity of starch fibers containing 1 % of curcumin had the greatest ability to inhibit the ABTS radical (45 % inhibition). These materials are promising for use in food or active packaging.


Assuntos
Curcumina , Solanum tuberosum , Curcumina/farmacologia , Cápsulas , Antioxidantes/farmacologia , Amido , Polímeros
8.
J Sci Food Agric ; 101(13): 5599-5607, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33709436

RESUMO

BACKGROUND: The majority of studies with essential oils in foods focus mainly on improving the shelf life of products; however, the present study goes further and demonstrates not only the effect of essential oil on conservation properties, but also the effect of free and encapsulated orange essential oil (OEO) on the technological, sensorial and digestibility properties of bakery products. RESULTS: OEO was encapsulated into ß-cyclodextrin (ß-CD) by inclusion complex formation (ß-CD/OEO 97.4% of encapsulation efficiency). OEO demonstrated in vitro antifungal activity against Aspergillus flavus (inhibition zone of 11.33 mm on mycelial growth). In situ antifungal activity against A. flavus confirmed that free OEO can effectively delay the fungal growth, unlike encapsulated OEO. Regarding texture profile and starch digestibility: cake with ß-CD/OEO showed lower hardness (31.64 N) and lower starch digestibility (69.10%) than cake with free OEO (44.30 N; 82.10%, respectively) and the addition of OEO (both free and encapsulated) decreased the adhesiveness of the cakes. Cake with free OEO showed a higher intensity of orange aroma, being preferred by 60% of panelists, whereas cake with ß-CD/OEO presented a very slight orange taste and aroma. CONCLUSION: The encapsulation of OEO into ß-CD improved the crumb texture of cakes and promoted a lower starch digestibility in the cakes. On the other hand, the encapsulation process was not effective under the conditions tested (OEO concentration and baking temperatures), compromising the action of the OEO as a natural flavoring and preservative agent. © 2021 Society of Chemical Industry.


Assuntos
Aspergillus flavus/crescimento & desenvolvimento , Aditivos Alimentares/química , Óleos Voláteis/química , Óleos de Plantas/química , Triticum/microbiologia , Antifúngicos/química , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Aspergillus flavus/efeitos dos fármacos , Digestão , Aditivos Alimentares/metabolismo , Aditivos Alimentares/farmacologia , Humanos , Odorantes/análise , Óleos Voláteis/metabolismo , Óleos Voláteis/farmacologia , Óleos de Plantas/metabolismo , Óleos de Plantas/farmacologia , Amido/metabolismo , Paladar , Triticum/metabolismo
9.
Int J Biol Macromol ; 155: 6-13, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32194107

RESUMO

The objective of this study was to generate and characterize physically cross-linked aerogels by using germinated and non-germinated wheat starch, with and without the addition of poly (ethylene oxide) (PEO). Aerogels were produced by gelatinization of starch (10% w/v, in distilled water) at 90 °C, followed by multiple freeze/thaw cycles. For the aerogel produced using starch and PEO, a solution of 6% PEO (0.6 g of PEO/10 mL of distilled water) was added to the dispersion. The thermal properties, infrared spectra, relative crystallinity, morphology, water absorption properties, and texture profile of the aerogels were evaluated. After immersion in water for 24 h, the aerogels exhibited high degradation temperature, water absorption capacity, and physical integrity. Aerogels produced using the germinated wheat starch were much more integrated structurally compared to the aerogels produced using the non-germinated wheat starch. Wheat germination did not have any impact on the textural parameters of the aerogels. However, addition of PEO increased the water absorption capacity and reduced the hardness and cohesion of the resulting aerogels. Due to the high water absorption potential, the aerogel produced in this study can serve as an absorbent matrix in food packaging.


Assuntos
Embalagem de Alimentos , Géis , Sementes/química , Amido/química , Triticum/química , Géis/síntese química , Géis/química , Germinação , Química Verde , Porosidade , Água/química
10.
Braz. arch. biol. technol ; 63: e20190046, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1132244

RESUMO

Abstract This research aims to determine the efficiency of chitosan and xanthan gum films in conservation of croaker fillets kept in refrigeration for 9 days. Proximal composition, loss of mass, color, pH, TVB-N (Total Volatile Bases) and microbiological profile were assessed. The films were prepared with chitosan and xanthan gum in varying mass proportions 100:0, m:m (C100XG0); 60:40, m:m (C60XG40); 50:50, m:m (C50XG50). They presented the respective values for moisture content, water solubility, thickness and water vapor permeability: 24.59%, 19.50%, 0.086 mm and 11.45gm-1.s-1.Pa-1for C100XG0; 24.58%; 20.27%, 0.091 mm and 10.41 gm-1.s-1.Pa-1for C60XG40; 22.11%, 22.06%, 0.089 mm and 10.68 gm-1.s-1.Pa-1 forC50XG50.The films were made in small bags format capable to hold about 20 g of fish fillets. A control sample was prepared in parallel, using polyethylene bags under the same storage conditions. The results showed that the chitosan films combined with xanthan gum had excellent antimicrobial properties, capable of preserving the quality of chilled fish fillets during the studied period, since it inhibited the growth of Staphylococcus coagulase-positive, Salmonella spp and coliforms at 45 ° C. Mass loss of the croaker fillets was not significantly affected by xanthan gum addition to the films. On the other hand, xanthan gum addition affected pH and color parameters of the corvina fillets. It was also verified that the combination of these two polymers promoted the reduction of N-BVT, being the C50XG50 film that presented the best response.


Assuntos
Animais , Xanthomonas/química , Embalagem de Alimentos/métodos , Quitosana/química , Peixes/microbiologia , Conservação de Alimentos/métodos , Polissacarídeos Bacterianos/química , Anti-Infecciosos
11.
Int J Biol Macromol ; 139: 1182-1190, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415859

RESUMO

In this study, a method was developed to encapsulated carvacrol in nanofibers from soluble potato starch. The carvacrol was added in starch solutions at various concentrations (0, 20, 30 and 40% v/v) and electrospun into fibers. The morphology, size distribution, thermal stability, FT-IR spectra, relative crystallinity (RC) and antioxidant of the electrospun fibers were analyzed. For mechanical properties and antimicrobial activities evaluation electrospun nonwovens were obtain. The carvacrol-loaded nanofibers showed homogeneous morphology and average diameters ranging from 73 to 95 nm. The carvacrol encapsulated in the nanofibers had greater thermal stability than the free carvacrol. FT-IR analysis showed interactions between starch and carvacrol. The RC of the nanofibers was approximately 40%. The electrospun nonwovens mechanical properties did not present significant differences (p < 0.05). The 40% carvacrol-loaded nanofibers exhibited higher antioxidant activity with 83.1% of inhibition. The electrospun nonwoven loaded with 30% carvacrol resulted in 89.0% reduction of Listeria monocytogenes, 68.0% for Salmonella Typhimurium, 62.0% for Escherichia coli and 49.0% for Staphylococcus aureus. These electrospun nonwovens sustained antimicrobial activity for at least 30 days against S. aureus. The starch nanofibers are promising materials for application as a vehicle for carvacrol release in antimicrobial and antioxidant food packages.


Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Cimenos/química , Eletricidade , Nanofibras/química , Solanum tuberosum/química , Amido/química , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Fenômenos Mecânicos , Reologia , Solubilidade , Temperatura
12.
Int J Biol Macromol ; 132: 300-307, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30928373

RESUMO

Octenyl succinic anhydride starch (OSA-starch) is often used as an emulsifier to protect bioactive compounds such as essential oils. In this study, rosemary essential oil was encapsulated in OSA-starch capsules via electrospraying an emulsion. Creaming was observed in the emulsions with 40% ethanol (v/v) 2 h after preparation, and phase separation occurred after 4 days. The emulsion with 20% ethanol revealed smaller droplets and lower zeta potential, and remained stable for 7 days. The morphology, loading capacity (LC), and encapsulation efficiency (EE) of the capsules, electrosprayed from the emulsions, were evaluated. The capsules from 20 and 30% aqueous ethanol (v/v) were smooth and spherical in shape with few dimpled. EE values were higher in the emulsions with 20% ethanol (82%-98%) when compared to those with 30% ethanol (89%-96%), except when 30% oil content was used. Fourier-transform infrared spectrometry suggested interaction of essential oil with the wall material. In summary, OSA-starch produced a stable emulsion that was suitable for electrospraying into capsules.


Assuntos
Eletricidade , Óleos Voláteis/química , Amido/química , Anidridos Succínicos/química , Cápsulas
13.
Int J Biol Macromol ; 118(Pt A): 107-115, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-29928909

RESUMO

The ultrafine fibers were produced using a polymeric blend of soy protein isolate (SPI), polyethylene oxide (PEO), and zein at a ratio of 1:1:1 (v/v/v) by electrospinning. The ginger essential oil (GEO) was encapsulated in the ultrafine fibers and the morphology, Fourier-Transform Infrared Spectroscopy (FTIR) analysis, thermal properties and relative crystallinity were evaluated. The antimicrobial activity of ginger essential oil was evaluated against five bacteria (Listeria monocytogenes, Staphylococcus aureus, Escherichia coli 0157:H7, Salmonella typhimurium, and Pseudomonas aeruginosa). Based on the preliminary tests, the concentration of GEO selected to add in the polymer solution was 12% (v/v; GEO/polymer solution). The fiber produced with 12% (v/v) GEO was used for antimicrobial analysis and in situ application (in fresh Minas cheese) against L. monocytogenes by micro-atmosphere. The ultrafine fibers produced, regardless the concentration of the essential oil, presented homogeneous morphology with cylindrical shape without the presence of beads. The application of the active fibers containing 12% GEO showed high potential to be applied in food packaging to reduce microbial contamination.


Assuntos
Microbiologia de Alimentos , Listeria monocytogenes/efeitos dos fármacos , Óleos Voláteis/química , Zingiber officinale/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Contagem de Colônia Microbiana , Escherichia coli/efeitos dos fármacos , Escherichia coli/patogenicidade , Embalagem de Alimentos , Humanos , Listeria monocytogenes/patogenicidade , Óleos Voláteis/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/patogenicidade , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/patogenicidade , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade
14.
J Food Sci ; 82(11): 2598-2605, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29083485

RESUMO

The aim of this study was to produce and characterize inclusion complexes (IC) between ß-cyclodextrin (ß-CD) and orange essential oil (OEO) or eucalyptus essential oil (EEO), and to compare these with their pure compounds and physical mixtures. The samples were evaluated by chemical composition, morphology, thermal stability, and volatile compounds by static headspace-gas chromatography (SH-GC). Comparing the free essential oil and physical mixture with the inclusion complex, of both essential oils (OEO and EEO), it was observed differences occurred in the chemical composition, thermal stability, and morphology. These differences show that there was the formation of the inclusion complex and demonstrate the necessity of the precipitation method used to guarantee the interaction between ß-CD and essential oils. The slow loss of the volatile compounds from both essential oils, when complexed with ß-CD, showed a higher stability when compared with their physical mixtures and free essential oils. Therefore, the results showed that the chemical composition, molecular size, and structure of the essential oils influence the characteristics of the inclusion complexes. The application of the ß-CD in the formation of inclusion complexes with essential oils can expand the potential applications in foods.


Assuntos
Eucalyptus/química , Óleos Voláteis/química , Óleos de Plantas/química , beta-Ciclodextrinas/química , Cromatografia Gasosa , Citrus sinensis/química , Estabilidade de Medicamentos , Aromatizantes/análise , Frutas/química , Temperatura Alta , Compostos Orgânicos Voláteis/análise
15.
Int J Biol Macromol ; 104(Pt A): 874-882, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28652153

RESUMO

The aim of this study was to produce ultrafine fibers from zein incorporated with a complex of eucalyptus essential oil (EEO) and ß-cyclodextrin (ß-CD) with antimicrobial properties by electrospinning technique. The EEO was characterized by chemical composition and antimicrobial tests against three Gram positive and four Gram negative bacteria. The inclusion complex (IC) was prepared with ß-CD and EEO by co-precipitation technique and added at different concentrations in zein polymer solution using aqueous ethanol as solvent. The morphology, thermal properties, functional groups, and antimicrobial activity against L. monocytogenes and S. aureus of the ultrafine fibers were evaluated. The composite membranes containing 24% IC exhibited a greater reduction of growth as compared to the fibers without addition of IC. For L. monocytogenes the growth reduction was 28.5% and for S. aureus it was 24.3%. The electrospun IC-ß-CD/EEO composite membranes are promising for use in antimicrobial applications, such as food packaging.


Assuntos
Eletricidade , Eucalyptus/química , Óleos Voláteis/química , Zeína/química , Zeína/farmacologia , beta-Ciclodextrinas/química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Membranas Artificiais , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
16.
J Agric Food Chem ; 65(13): 2661-2669, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28318254

RESUMO

Phosphorus (P) intake, genotype, and growth environment in soybean cultivation can affect the composition of the soybean. This experiment was conducted in two locations (microregions I and II) using a randomized complete block design, including conventional soybean (BRS Sambaíba) and genetically modified (GM) [Msoy 9144 Roundup Ready (RR)] cultivars and varying doses of phosphorus fertilizer (0, 60, 120, and 240 kg/ha P2O5). Soybeans were evaluated for chemical composition, total phenols, phytic acid content, individual isoflavone content, antioxidant activity, oil quality, fatty acid profile, total carotenoid content, and individual tocopherol contents. Multivariate analysis facilitated reduction in the number of variables with respect to soybean genotype (conventional BRS Sambaíba and GM Msoy 9144 RR), dose of P2O5 fertilizer, and place of cultivation (microregion I and II). BRS Sambaíba had higher concentrations of ß-glucosides, malonylglucosides, glycitein, and genistein than Msoy 9144 RR, which showed a higher concentration of daidzein. The highest concentrations of isoflavones and fatty acids were observed in soybeans treated with 120 and 240 kg/ha P2O5, regardless of the location and cultivar.


Assuntos
Fertilizantes/análise , Glycine max/química , Fosfatos/metabolismo , Compostos Fitoquímicos/química , Óleos de Plantas/química , Plantas Geneticamente Modificadas/química , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Valor Nutritivo , Fosfatos/análise , Compostos Fitoquímicos/metabolismo , Óleos de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plantas Geneticamente Modificadas/metabolismo , Glycine max/genética , Glycine max/crescimento & desenvolvimento , Glycine max/metabolismo , Tocoferóis/análise , Tocoferóis/metabolismo
17.
J Sci Food Agric ; 93(9): 2331-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23423960

RESUMO

BACKGROUND: Few studies on starch modifications using different chemical agents are available in the literature, and no reports were found on the combined effect of oxidation and alkaline treatment of corn starch. Thus this work evaluated the physicochemical, pasting, morphological, cystallinity and thermal properties of chemically modified corn starch, after either the isolated or combined action of alkaline (sodium hydroxide) and oxidative (sodium hypochlorite) treatments. RESULTS: The highest values for the sum of carbonyl and carboxyl and enzymatic hydrolysis occurred in starches submitted to oxidative treatment at high active chlorine concentrations. The alkali treatment in isolation modified the pasting properties, reduced the paste temperature and increased the peak viscosity, breakdown, final viscosity and setback of starches. Starch modified by the action of sodium hypochlorite and hydroxide in combination presented more severe damage on granule surfaces. CONCLUSION: The results show that corn starch modified by the combined action of oxidative and alkaline treatments should be studied more, especially at the concentration limit of sodium hydroxide where gelatinization occurs. Under these conditions the effect of oxidation can be more intense and thus allow the production of starches with different properties and an increase in their industrial applications.


Assuntos
Cáusticos/química , Manipulação de Alimentos , Oxidantes/química , Sementes/química , Amido/química , Zea mays/química , Fenômenos Químicos , Cristalização , Géis , Temperatura Alta , Hidrólise , Microscopia Eletrônica de Varredura , Concentração Osmolar , Oxirredução , Hidróxido de Sódio/química , Hipoclorito de Sódio/química , Amido/ultraestrutura , Suspensões , Temperatura de Transição , Viscosidade
18.
Artigo em Inglês | LILACS | ID: lil-655388

RESUMO

Hypercholesterolemia is a major risk factor for cardiovascular disease. Supplements containing the vitamins niacin (B3) and pyridoxine (B6) can promote the reduction of total cholesterol and an increase in HDL cholesterol. In this study, the effects of diets supplemented with niacin (B3) and pyridoxine (B6) on the hepatic and serum lipid profiles of Wistar rats were assessed. The diets were prepared with combinations of three concentrations of niacin (3, 4 and 5 g/kg) and pyridoxine (6, 12 and 18 mg/kg) and one with neither vitamin. The animals were divided into eleven experimental groups of six animals per group, and nine groups were fed on a standard diet with 7.5% fat and vitamin supplementation. Another group was fed with 7.5% fat without vitamin supplements. A control group received the standard diet (AIN-93M) without modifications (4% fat). The weight gain, food intake, serum and hepatic total cholesterol, serum cholesterol fractions (HDL, LDL, and VLDL), serum and hepatic triacylglycerols and hepatic and fecal lipid contents were measured after 30 days. The diet with the highest concentration of niacin and lowest concentration of pyridoxine had the lowest level of total hepatic cholesterol. Hepatic triacylglycerols were reduced by the highest concentration of niacin (5 g/kg), and this reduction was enhanced by increasing the pyridoxine concentration. The diets supplemented with niacin and pyridoxine reduced the levels of serum total cholesterol, LDL, VLDL, triacylglycerols and hepatic lipids. These effects on the lipid profile varied with the concentrations of the two vitamins and the interactions between them.


Assuntos
Animais , Ratos , Colesterol , HDL-Colesterol , Niacina/uso terapêutico , Piridoxina/uso terapêutico , Ratos Wistar
19.
Ciênc. agrotec., (Impr.) ; 34(5): 1285-1292, Sept.-Oct. 2010. graf, tab
Artigo em Português | LILACS | ID: lil-567345

RESUMO

Neste trabalho, objetivou-se estudar a influência dos processos de secagem estacionário e intermitente e do tempo de armazenamento na qualidade tecnológica de grãos de trigo, cultivar Embrapa 16 colhidos com teor de água de 15 por cento e 19 por cento. Grãos de trigo (Triticum aestivum L) foram produzidos em lavoura comercial da Granja Bretanhas, Cooperativa Arrozeira Extremo Sul, no município de Jaguarão, RS. O experimento foi conduzido em delineamento inteiramente casualizado, utilizando dois teores de água de colheita (15 por cento e 19 por cento), dois processos de secagem (estacionário e intermitente) e quatro tempos de armazenamento. A secagem foi realizada até o teor de água de 13 por cento e os grãos acondicionados em embalagens de algodão, em sistema de armazenamento convencional pelo período de 12 meses. Nos tempos zero, 4, 8 e 12 meses foram realizadas as análises de teor de água, peso hectolitro, cinzas, lipídios, acidez graxa, número de queda e alveografia. Os parâmetros mais efetivos para avaliar o efeito dos processos de secagem de trigo intermitente e estacionário em função do tempo de armazenamento foram peso do hectolitro, lipídios e acidez graxa indicando melhor qualidade tecnológica na secagem realizada em secador intermitente. O trigo, cultivar Embrapa 16, colhido seco na planta apresentou qualidade tecnológica inferior e menor conservabilidade ao armazenamento do que o colhido de forma antecipada e seco em secador intermitente.


The objective of this work was to investigate the influence of stationary and intermittent drying process was well as storage time on the technological quality of wheat, cultivar Embrapa 16 harvested at 15 percent and 19 percent moisture content. Wheat grains (Triticum aestivum L) were produced in a commercial plantation at Granja Bretanhas, Cooperativa Arrozeira Extremo Sul, in Jaguarão, RS. The experiment was carried out in a completely randomized design, using two harvest moisture contents (15 percent and 19 percent), two drying processes (stationary and intermittent) and 4 storage times. Drying was performed up to 13 percent moisture content and the grains were kept in cotton packets, at conventional storage system for 12 months. Moisture content, hectoliter weight, ash, fat, fatty acid, falling number and alveography were evaluated at zero, 4, 8 and 12 months. The results of hectoliter weight, fat, fatty acid, ash and falling number showed effective when evaluated the technological quality of wheat, cultivar Embrapa 16 harvested at 15 percent and 19 percent moisture content. Wheat harvest dry at the plant shows inferior technological quality and less conservability in storage as compared to pre-harvested wheat dried at intermittent dryer.

20.
Ciênc. rural ; 39(1): 25-30, Jan.-Feb. 2009. graf
Artigo em Português | LILACS | ID: lil-502632

RESUMO

O objetivo deste trabalho foi estudar os sistemas umidades de colheita e métodos de secagem em função do período de armazenamento sobre a conservabilidade e qualidade tecnológica de trigo. Grãos de trigo (Triticum aestivum L), cultivar 'Embrapa 16', produzidos na Granja Bretanhas, município de Jaguarão, Rio Grande do Sul (RS), safra agrícola de 1997/1998, foram colhidos secos naturalmente nas próprias plantas (14 por cento de umidade), com 16 e 18 por cento de umidade. As amostras colhidas com umidade de 16 e 18 por cento foram submetidas à secagem artificial pelo método intermitente, com ar a 70°C; estacionário, com ar a 45°C; e estacionário, com ar sem aquecimento. Os grãos secos foram armazenados em sistema convencional, pelo período de 12 meses, com a realização de avaliações a cada quadrimestre. O trigo colhido seco na planta apresentou qualidade tecnológica inferior e menor conservabilidade ao armazenamento em comparação com o trigo colhido com umidade superior a 14 por cento e seco em secador artificial.


The objective of this research was to study the harvest moisture and drying method systems as a function to storage period on the conservability and technological quality of wheat. Grains of wheat (Triticum aestivum L), cultivar 'Embrapa 16', produced in the Granja Bretanhas, in Jaguarão, RS, agricultural harvest of 1997/1998 were harvested dry in the plant (14 percent of moisture), with 16 and 18 percent of moisture. The samples harvested with moisture of 16 and 18 percent were submitted to artificial drying by intermittent method, with air at 70°C, stationary, with air at 45°C; and stationary, at room temperature. The grains were stored in a conventional system, during 12 months, with the realization of evaluations at 4 month intervals. Wheat grains harvested dry shown inferior technological quality and conservability in storage as compared to harvested with moisture above 14 percent and dry at artificial dryer.

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