Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
Mais filtros








Base de dados
Tipo de estudo
Intervalo de ano de publicação
1.
Nutrients ; 16(7)2024 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-38612951

RESUMO

BACKGROUND: The study investigated the impact of starch degradation products (SDexF) as prebiotics on obesity management in mice and overweight/obese children. METHODS: A total of 48 mice on a normal diet (ND) and 48 on a Western diet (WD) were divided into subgroups with or without 5% SDexF supplementation for 28 weeks. In a human study, 100 overweight/obese children were randomly assigned to prebiotic and control groups, consuming fruit and vegetable mousse with or without 10 g of SDexF for 24 weeks. Stool samples were analyzed for microbiota using 16S rRNA gene sequencing, and short-chain fatty acids (SCFA) and amino acids (AA) were assessed. RESULTS: Results showed SDexF slowed weight gain in female mice on both diets but only temporarily in males. It altered bacterial diversity and specific taxa abundances in mouse feces. In humans, SDexF did not influence weight loss or gut microbiota composition, showing minimal changes in individual taxa. The anti-obesity effect observed in mice with WD-induced obesity was not replicated in children undergoing a weight-loss program. CONCLUSIONS: SDexF exhibited sex-specific effects in mice but did not impact weight loss or microbiota composition in overweight/obese children.


Assuntos
Obesidade Infantil , Solanum tuberosum , Criança , Humanos , Masculino , Feminino , Animais , Camundongos , Dextrinas , Dieta Ocidental , Disbiose , Sobrepeso , RNA Ribossômico 16S/genética , Peso Corporal , Amido/farmacologia , Frutas
2.
Polymers (Basel) ; 16(5)2024 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-38475281

RESUMO

It has long been known that starch as a raw material is of strategic importance for meeting primarily the nutritional needs of people around the world. Year by year, the demand not only for traditional but also for functional food based on starch and its derivatives is growing. Problems with the availability of petrochemical raw materials, as well as environmental problems with the recycling of post-production waste, make non-food industries also increasingly interested in this biopolymer. Its supporters will point out countless advantages such as wide availability, renewability, and biodegradability. Opponents, in turn, will argue that they will not balance the problems with its processing and storage and poor functional properties. Hence, the race to find new methods to improve starch properties towards multifunctionality is still ongoing. For these reasons, in the presented review, referring to the structure and physicochemical properties of starch, attempts were made to highlight not only the current limitations in its processing but also new possibilities. Attention was paid to progress in the non-selective and selective functionalization of starch to obtain materials with the greatest application potential in the food (resistant starch, dextrins, and maltodextrins) and/or in the non-food industries (hydrophobic and oxidized starch).

3.
Carbohydr Polym ; 326: 121633, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38142079

RESUMO

Polysaccharides are among the most abundant bioresources on earth and consequently need to play a pivotal role when addressing existential scientific challenges like climate change and the shift from fossil-based to sustainable biobased materials. The Research Roadmap 2040 of the European Polysaccharide Network of Excellence (EPNOE) provides an expert's view on how future research and development strategies need to evolve to fully exploit the vast potential of polysaccharides as renewable bioresources. It is addressed to academic researchers, companies, as well as policymakers and covers five strategic areas that are of great importance in the context of polysaccharide related research: (I) Materials & Engineering, (II) Food & Nutrition, (III) Biomedical Applications, (IV) Chemistry, Biology & Physics, and (V) Skills & Education. Each section summarizes the state of research, identifies challenges that are currently faced, project achievements and developments that are expected in the upcoming 20 years, and finally provides outlines on how future research activities need to evolve.


Assuntos
Polissacarídeos
4.
Nutrients ; 15(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36839343

RESUMO

In modern societies obesity has become a serious issue which must be urgently addressed. The health implications of neglected obesity are substantial, as not only does it affect individuals' everyday lives, but it also leads to significantly increased mortality due to the development of several disorders such as type-2 diabetes, cardiovascular diseases, cancers, and depression. The objective of this research was to investigate the alterations in selected health markers caused by overweight and obesity in children. The measured parameters were the activity of the fecal enzymes, the concentration of short-chain fatty acids (SCFAs), and the concentration of branched-chain fatty acids (BCFAs). The activity of the fecal enzymes, specifically α-glucosidase, α-galactosidase, ß-glucosidase, ß-galactosidase, and ß-glucuronidase, was determined using spectrophotometry at a wavelength of 400 nm. Furthermore, concentrations of lactic acid, SCFAs (formic, acetic, propionic, butyric, and valeric acids), and BCFAs (isobutyric and isovaleric acids) were determined using the HPLC method. The obtained results reveal that obese children have different fecal enzyme activity and a different profile of fatty acids from children of normal weight. The group of obese children, when compared to children of normal weight, had increased concentrations of BCFAs (p < 0.05) and higher activity of potentially harmful enzymes such as ß-glucosidase and ß-glucuronidase (p < 0.05). In comparison, children of normal weight exhibited significantly increased concentrations of lactic acid and SCFAs (especially formic and butyric acids) (p < 0.05). Furthermore, their α-glucosidase and α-galactosidase activity were higher when compared to the group of obese children (p < 0.05). These results suggest that the prevalence of obesity has a significant impact on metabolites produced in the gastrointestinal tract, which might result in a higher chance of developing serious diseases.


Assuntos
Celulases , Ácidos Graxos Voláteis , Sobrepeso , Obesidade Infantil , Criança , Humanos , alfa-Galactosidase , alfa-Glucosidases , Ácidos Graxos Voláteis/metabolismo , Fezes/enzimologia , Glucuronidase
5.
Nutrients ; 14(10)2022 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-35631299

RESUMO

Preparations of resistant dextrins have become an interesting topic of research due to their properties, which bear resemblance those of prebiotics, e.g., the improvement of metabolic parameters, increased efficiency of the immune system and induction of vitamin production. The aim of this study was to investigate the effects of the resistant dextrin produced from potato starch on the growth dynamics of typical gastrointestinal microbiota and the activity of fecal enzymes in order to assess a possible exhibition of prebiotic properties. In the study, in vitro cultivation of co-cultures of Lactobacillus, Bifidobacterium, E. coli, Enterococcus, Clostridium and Bacteroides spp. was conducted on media enriched with the resistant dextrin. The CFU/mL for each strain was measured in time periods of 24, 48, 72, 96 and 168 h. Furthermore, the activities of α-glucosidase, α-galactosidase, ß-glucosidase, ß-galactosidase and ß-glucuronidase were determined using spectrophotometric methods at a wavelength of 400 nm. The results show that the resistant dextrin can be utilized as a source of carbon for the growth of intestinal bacteria. Moreover, the results revealed that, after 168 h of cultivation, it enhances the viability of probiotic strains of Lactobacillus and Bifidobacterium spp. and decreases the growth of other intestinal strains (Clostridium, Escherichia coli, Enterococcus and Bacteroides), which is demonstrated by a high Prebiotic Index (p < 0.05). Furthermore, there was no significant change in the pH of the cultures; however, the pace of the pH decrease during the cultivation was slower in the case of culture with resistant dextrin. Furthermore, it was revealed that usage of the resistant dextrin as a medium additive noticeably lowered the activities of ß-glucosidase and ß-glucuronidase compared to the control (p < 0.05), whereas the activities of the other fecal enzymes were affected to a lesser degree. The resistant dextrins derived from potato starch are a suitable prebiotic candidate as they promote the growth of beneficial strains of gut bacteria and improve health markers, such as the activity of fecal enzymes. Nevertheless, additional in vivo research is necessary to further assess the suspected health-promoting properties.


Assuntos
Celulases , Solanum tuberosum , Bactérias , Bifidobacterium/metabolismo , Celulases/metabolismo , Celulases/farmacologia , Clostridium , Técnicas de Cocultura , Dextrinas/química , Dextrinas/farmacologia , Enterococcus , Escherichia coli , Glucuronidase/metabolismo , Lactobacillus , Prebióticos , Solanum tuberosum/química , Amido/metabolismo
6.
Molecules ; 26(18)2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34577093

RESUMO

Dietary fiber can be obtained by dextrinization, which occurs while heating starch in the presence of acids. During dextrinization, depolymerization, transglycosylation, and repolymerization occur, leading to structural changes responsible for increasing resistance to starch enzymatic digestion. The conventional dextrinization time can be decreased by using microwave-assisted heating. The main objective of this study was to obtain dietary fiber from acidified potato starch using continuous and discontinuous microwave-assisted heating and to investigate the structure and physicochemical properties of the resulting dextrins. Dextrins were characterized by water solubility, dextrose equivalent, and color parameters (L* a* b*). Total dietary fiber content was measured according to the AOAC 2009.01 method. Structural and morphological changes were determined by means of SEM, XRD, DSC, and GC-MS analyses. Microwave-assisted dextrinization of potato starch led to light yellow to brownish products with increased solubility in water and diminished crystallinity and gelatinization enthalpy. Dextrinization products contained glycosidic linkages and branched residues not present in native starch, indicative of its conversion into dietary fiber. Thus, microwave-assisted heating can induce structural changes in potato starch, originating products with a high level of dietary fiber content.


Assuntos
Fibras na Dieta/análise , Temperatura Alta , Micro-Ondas , Amido/química , Ácidos/química , Configuração de Carboidratos , Cor , Dextrinas/análise , Dextrinas/química , Glucose/análise , Glucose/química , Microscopia Eletrônica de Varredura , Fenômenos Físicos , Solanum tuberosum/química , Solubilidade , Difração de Raios X
7.
Polymers (Basel) ; 13(5)2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33803238

RESUMO

Starch is the second most abundantly available natural polymer in the world, after cellulose. If we add its biodegradability and non-toxicity to the natural environment, it becomes a raw material very attractive for the food and non-food industries. However, in the latter case, mainly due to the high hydrophilicity of starch, it is necessary to carry out many more or less complex operations and processes. One of the fastest growing industries in the last decade is the processing of biodegradable materials for packaging purposes. This is mainly due to awareness of producers and consumers about the dangers of unlimited production and the use of non-degradable petroleum polymers. Therefore, in the present review, an attempt was made to show the possibilities and limitations of using starch as a packaging material. The most important physicochemical features of this biopolymer are discussed, and special attention is paid to more or less environmentally friendly methods of improving its processing properties.

8.
J Sci Food Agric ; 101(10): 4125-4133, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33368353

RESUMO

BACKGROUND: Fruit mousses are products with a relatively low amount of dietary fiber in a single portion, but with additional portions of soluble fiber they may be good alternative to fiber-rich snacks as take-away food. In the present study, the properties of new soluble dextrin fiber (SDexF) from potato starch were assessed to establish whether it could be used to enrich fruit mousses. The properties of SDexF that can affect processing and storage stability of enriched mousses were studied and compared with those of native potato starch and semiproducts (resulting from various drying temperatures). The effect of the addition of SDexF on the pasting properties of mousse was also analyzed. RESULTS: The application of food-grade hydrochloric and citric acids as catalysts in the dextrinization of food-grade potato starch allowed to SDexF to be obtained. Despite the differences in characteristics of the semiproducts, the final SDexF preparations were very similar in the meaning of solubility, dextrose equivalent (DE), retrogradation, and pasting properties. SDexF preparations were characterized by a significantly lower retrogradation tendency, peak viscosity, final viscosity, and gelatinization enthalpy in comparison with both native starch and semiproducts. Soluble dextrin fiber was successfully added to banana-apple mousse. The addition of SDexF to mousse did not cause any undesirable changes to the viscosity of the product, and surprisingly even resulted in mousse with lower viscosity. Turbidity and RVA studies revealed that SDexF was stable and retrogradation processes can be negligible during storage. CONCLUSION: The SDexF obtained from potato starch can be a novel functional substance to increase the dietary fiber content of fruit or fruit and vegetable mousses. © 2020 Society of Chemical Industry.


Assuntos
Dextrinas/química , Aditivos Alimentares/química , Frutas/química , Extratos Vegetais/química , Solanum tuberosum/química , Fibras na Dieta/análise , Manipulação de Alimentos , Solubilidade , Temperatura , Termodinâmica , Viscosidade
9.
Materials (Basel) ; 13(20)2020 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-33050342

RESUMO

The main applications of ionic liquids in chemistry and material research on one of the most important natural polymers-starch-are presented in this review. A brief characterization of ionic liquids and the advantages and disadvantages of using them in the modification and processing of polysaccharides is presented. The latest reports on the use of various ionic liquids as solvents or co-solvents; as media for synthesizing starch derivatives in oxidation, etherification, esterification, and transesterification, with particular emphasis on biocatalyzed reactions; and as plasticizers or compatibilizers in the processing of starch-based polymers have been investigated. The current trends, possibilities, and limitations of using this type of compound for the production of functional starch-based materials are presented.

10.
Int J Biol Macromol ; 163: 251-259, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32615230

RESUMO

Agrofood byproducts may be exploited as a source of biomolecules suitable for developing bioplastic materials. In this work, the feasibility of using starch, oil, and waxes recovered from potato chips byproducts for films production was studied. The recovered potato starch-rich fraction (RPS) contained an amylopectin/amylose ratio of 2.3, gelatinization temperatures varying from 59 to 71 °C, and a gelatinization enthalpy of 12.5 J/g, similarly to a commercial potato starch (CPS). Despite of its spherical and oval granules identical to CPS, RPS had a more amorphous structure and gave rise to low viscous suspensions, contradicting the typical B-type polymorph crystal structure and sluggish dispersions of CPS, respectively. When used for films production, RPS originated transparent films with lower roughness and wettability than CPS-based films, but with higher stretchability. In turn, when combined with RPS and CPS, oil or waxes recovered from frying residues and potato peels, respectively, allowed to develop transparent yellowish RPS- and CPS-based films with increased surface hydrophobicity, mechanical traction resistance, elasticity, and/or plasticity. Therefore, potato chips industry byproducts revealed to have thermoplastic and hydrophobic biomolecules that can be used to efficiently develop biobased plastics with improved surface properties and flexibility, opening an opportunity for their valorization.


Assuntos
Filmes Comestíveis , Óleos de Plantas/química , Solanum tuberosum/química , Amido/química , Ceras/química , Amilopectina/química , Amilose/química , Fenômenos Químicos , Interações Hidrofóbicas e Hidrofílicas , Microscopia de Força Atômica , Tamanho da Partícula , Solubilidade
11.
Carbohydr Polym ; 243: 116499, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32532383

RESUMO

Medium-substituted esters of starch and higher fatty acids, structurally identified in the first part of paper were subjected to further analyses, mainly to check application potential. In order to determine the possibility of using the esters in the packaging industry, the glycerol-plasticized starch esters were extruded on a single screw extruder in the form of a film. The mechanical properties tests consisted of tensile and tear strength. Hydrophobicity, water absorption and oil absorption were checked as the processing and functional properties. Environmental tests, such as phytotoxicity on monocotyledonous and dicotyledonous plants and biodegradability in soil under strictly controlled conditions of the vegetation hall were carried out. Esterification increased the hydrophobicity of the starch and the tensile and tear strength, without losing important environmental features such as biodegradability and non-toxicity. The obtained polymer materials give hope for their use in the production of new ecofriendly and biodegradable packaging.


Assuntos
Óleos de Plantas/química , Embalagem de Produtos , Amido , Interações Hidrofóbicas e Hidrofílicas , Amido/análogos & derivados , Amido/química , Resistência à Tração
12.
Carbohydr Polym ; 214: 124-130, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30925980

RESUMO

Hydrophobic starch derivatives were obtained by biocatalysed esterification with hydrolysates from high oleic vegetable oils. First, the pure rapeseed oil or waste rapeseed oil, was hydrolysed with a Thermomyces lanuginosus lipase in the buffer solution form. Next, purified hydrolysates were used as donors of the acyl group for the esterification of potato starch after being pregelatinised in ionic liquid - 1-buthyl-3-methylimidazolium chloride. The esterification was catalysed by the same fungal lipase but immobilised on a polymer carrier and conducted in the anhydrous ternary reaction system: hydrophilic ionic liquid - non-ionic surfactant - hydrophobic higher fatty acids. The products have been identified and characterised using the following methods: degree of substitution (DS) by volumetric and elemental analysis method, FTIR and NMR spectroscopies, XRD and SEM. The proposed method can lead to the synthesis of more water-resistant starch derivatives as well as provide a possibility for recycling waste oils from the food industry.

13.
Pol J Microbiol ; 67(3): 339-345, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30451451

RESUMO

The growing number of children with overweight and obesity constitutes a major health problem of the modern world and it has been suggested that intestinal microbiota may influence energy intake from food. The objectives of this study were to determine quantity and proportions of dominant genera of Bacteroides, Prevotella (phylum Bacteroidetes ); Clostridium , Lactobacillus (phylum Firmicutes ) and Bifidobacterium (phylum Actinobacteria ) in the intestines and to determine the content of short-chain fatty acids (SCFAs) and branched-chain fatty acids (BCFAs) in the stool of 20 obese children and 20 children with normal body weight. Strains classified as Firmicutes ( Clostridium and Lactobacillus ) predominated in stool microbiota of obese children, while those of Bacteroidetes ( Prevotella and Bacteroides ) were in minority ( p < 0.001). Concentration of SCFAs in the stool of obese children was lower in comparison to the stool of normal weight children ( p = 0.04). However, these differences were significant only in obese children, not in overweight children in comparison with the lean ones. Therefore, in our study obesity was associated with intestinal dysbiosis and a predominance of phylum Firmicutes . Secondly, stool of obese children contained lower amounts of SCFAs.


Assuntos
Bactérias/classificação , Ácidos Graxos Voláteis/análise , Fezes/microbiologia , Microbioma Gastrointestinal , Obesidade/microbiologia , Sobrepeso/microbiologia , Adolescente , Bactérias/isolamento & purificação , Bacteroidetes/isolamento & purificação , Bifidobacterium/isolamento & purificação , Criança , Disbiose , Fezes/química , Feminino , Firmicutes/isolamento & purificação , Humanos , Masculino , RNA Ribossômico 16S/genética
14.
Environ Sci Pollut Res Int ; 24(22): 18444-18457, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28643283

RESUMO

The present study determines the influence of three ionic liquids (ILs) containing cations with diversified structure on the growth and development of spring barley seedlings and common radish leaves. Increasing amounts of 1-butyl-1-methylpyrrolidinium hexafluorophosphate [Pyrrol][PF6], 1-butyl-1-methylpiperidinium hexafluorophosphate [Piper][PF6], and 1-butyl-4-methylpyridinium hexafluorophosphate [Pyrid][PF6] were added to the soil on which both plants were cultivated. The results of this studies showed that the applied ILs were highly toxic for plants, demonstrated by the inhibition of length of plant shoots and roots, decrease of fresh mass, and increase of dry weight content. Common radish turned out to be the plant with higher resistance to the used ILs. The differences in the cation structure did not influence phytotoxity of ILs for spring barley. Furthermore, all ILs led to a decrease of photosynthetic pigments, which was directly followed by decreased primary production in plants. Oxidative stress in plants occurred due to the presence of ILs in the soil, which was demonstrated by the increase of malondialdehyde (MDA) content, changes in the H2O2 level, and antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD). The changes in the chlorophyll contents and the increase of POD activity turned out to be the most significant oxidative stress biomarkers in spring barley and common radish. Both spring barley and radish exposed to ILs accumulated a large amount of fluoride ion.


Assuntos
Hordeum/efeitos dos fármacos , Líquidos Iônicos/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Raphanus/efeitos dos fármacos , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Biomarcadores/metabolismo , Biomassa , Cátions , Clorofila/metabolismo , Hordeum/crescimento & desenvolvimento , Hordeum/metabolismo , Líquidos Iônicos/química , Fotossíntese/efeitos dos fármacos , Raphanus/crescimento & desenvolvimento , Raphanus/metabolismo , Estações do Ano , Poluentes do Solo/química
15.
Plant Foods Hum Nutr ; 71(2): 190-6, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27155867

RESUMO

Unarguably, diet has a significant impact on human intestinal microbiota. The role of prebiotics as substances supporting the maintenance of appropriate body weight and reducing the demand for energy via stimulation of the growth of beneficial microbiota of the gut and formation products such as short-chain fatty acids, is more and more often highlighted. The objective of this study was to evaluate whether dextrins from maize starch resistant to enzymatic digestion stimulate the growth of Bacteroidetes and Actinobacteria strains representing a majority of the population of colon microbiota in lean individuals and limit the growth of Firmicutes bacterial strains representing a majority of the population of colon microbiota in obese individuals. The study was conducted with the use of in vitro method, using isolates from faeces of children characterized by normal weight, overweight and obesity. It was demonstrated that dextrins from maize starch equally efficient stimulate the growth of the isolates derived from normal-weight, overweight and obese children, and therefore may be added to foods as a beneficial component stimulating growth of strains belonging to Actinobacteria and Bacteroidetes for both overweight, obese and normal-weight children.


Assuntos
Actinobacteria/efeitos dos fármacos , Bacteroidetes/efeitos dos fármacos , Dextrinas/farmacologia , Firmicutes/efeitos dos fármacos , Microbiota/efeitos dos fármacos , Zea mays/química , Actinobacteria/crescimento & desenvolvimento , Bacteroidetes/crescimento & desenvolvimento , Criança , Dieta , Ácidos Graxos Voláteis/metabolismo , Fezes/microbiologia , Feminino , Firmicutes/crescimento & desenvolvimento , Trato Gastrointestinal/microbiologia , Humanos , Masculino , Sobrepeso/prevenção & controle , Prebióticos
16.
Acta Biochim Pol ; 63(2): 261-6, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26929930

RESUMO

Currently, there is a search for substances that would be very well tolerated by an organism and which could contribute to the activation of the growth of Bacteroidetes and Actinobacteria strains, with simultaneous inhibition of the growth of Firmicutes. High expectations in this regard are raised with the use of fiber preparations from starch - resistant corn dextrins, branched dextrins, resistant maltodextrins and soluble corn fiber. In this paper, the influence of fiber preparations made from corn starch was evaluated on growth and activity of Bacteroidetes, Actinobacteria and Firmicutes strains isolated from obese children. It was demonstrated that in the stool of obese children Firmicutes strains predominate, while Bacteroidetes and Actinobacteria strains were in the minority. A supplementation of fecal culture with fiber preparations did not cause any significant changes in the number of strains of Bacteroidetes and Firmicutes. Addition of fiber preparations to the fecal samples of obese children increased the amount of short-chain fatty acids, especially acetic (p < 0.01), propionic, butyric (p = 0.05) and lactic acid (p < 0.01).


Assuntos
Actinobacteria/crescimento & desenvolvimento , Bacteroidetes/crescimento & desenvolvimento , Fibras na Dieta/metabolismo , Fezes/microbiologia , Firmicutes/crescimento & desenvolvimento , Actinobacteria/metabolismo , Bacteroidetes/metabolismo , Criança , Fezes/química , Firmicutes/metabolismo , Microbioma Gastrointestinal , Humanos , Obesidade/microbiologia , Zea mays/química
17.
Carbohydr Polym ; 137: 127-138, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26686113

RESUMO

The utilization of starch films, obtained by extrusion of potato starch with urea as plasticizer, for the fertilization of plants has been undertaken. Release rate of urea from the starch films was conducted in water conditions. The molecular weight distribution, surface erosion and weight loss of the starch samples have been determined. The evaluation of efficiency of urea as a fertilizer in the process of release from the starch films was performed under laboratory conditions based on the plant growth test proposed by OECD 208 Guideline and the PN-ISO International Standard using oat and common radish. Although among extruded starch-based films, those that contain the highest amount of fertilizer hold the most promise for a delayed release system, the time of release of fertilizer from obtained films in undertaken study was not satisfactory. All the same, in the present study effort has been made to utilize extruded samples as a fertilizer for agriculture or horticulture purposes. Urea-plasticized starch was successfully used as a fertilizer. Plant growth assessment, including determination of such parameters as fresh and dry matter of plants and their visual evaluation, has proved the stimulating effect of using extruded films on the growth and development of cultivated plants.


Assuntos
Plásticos Biodegradáveis/química , Fertilizantes , Plastificantes/química , Polímeros/química , Amido/química , Ureia/química , Concentração de Íons de Hidrogênio
18.
Carbohydr Polym ; 137: 657-663, 2016 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-26686176

RESUMO

In this study, potato starch was esterified with oleic acid, using 1-butyl-3-methylimidazolium chloride as a reaction medium and an immobilised lipase from Thermomyces lanuginosus as a catalyst. The degree of substitution (DS) of the products was determined by the volumetric method; and the best esterified product (with the highest DS) was determined by an elemental analysis. The effect of the reaction parameters on the DS, such as the time and the temperature, were also studied. The product with the highest DS (0.22) was found in the reaction carried out at 60 °C for 4h. Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analyses confirmed the esterification of the potato starch. Furthermore, the results of X-ray diffraction (XRD) and a scanning electron microscopy (SEM) revealed that the crystallinity and the morphology of the native potato starch was slightly changed during its partial gelatinisation in the ionic liquid, and was completely destroyed as a result of the formation of the esters. The thermal stability of the starch oleate decreased, when compared to the unmodified starch, as was indicated by a thermal gravimetric analysis (TGA).


Assuntos
Líquidos Iônicos/química , Solanum tuberosum/química , Amido/química , Biocatálise , Esterificação , Espectroscopia de Ressonância Magnética , Microscopia Eletrônica de Varredura , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
19.
Acta Biochim Pol ; 62(4): 677-81, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26610307

RESUMO

The objective of the present study was to demonstrate the effect of dietary resistant dextrins, as potential prebiotics, on the intestinal microflora of young rats. Enzyme-resistant dextrin, prepared by heating of potato starch in the presence of hydrochloric (0.1% dsb) and tartaric (40% dsb) acid at 130ºC for 2 h (CA-dextrin). The experiment was performed on 24 Wistar male rats at 3-wk of age, divided by analogues in three experimental groups (control, starch and dextrin). Analyses determined the overall bacterial counts and the counts of Lactobacillus, Bifidobacterium, Bacteroides and Clostridium strains within the feces and cecal contents of rats using fluorescence in situ hybridization method. CA-dextrin had no effect on primary growth indicators (body weight, body weight gain, dietary consumption) or the mass of the small intestine and the cecum, but dextrins caused a reduction in pH and the concentration of ammonia within the cecal contents. That supplementation of diet with resistant dextrins had a positive effect on composition of intestinal microflora in rats. It increased the counts of Bifidobacterium and Lactobacillus strains both in the feces and in the cecum. Moreover, it reduced the counts of Clostridium and Bacteroides strains. These results may suggest that resistant dextrins exerted a prebiotic-like effect in the large intestine.


Assuntos
Ceco/microbiologia , Fezes/microbiologia , Microbiota , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Contagem de Colônia Microbiana , Masculino , Microscopia de Fluorescência , Ratos , Ratos Wistar
20.
Postepy Hig Med Dosw (Online) ; 69: 1031-41, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26400889

RESUMO

The objective of the present study was to compare the prebiotic properties of starch dextrins, that is, resistant dextrins obtained from potato starch in the process of simultaneous thermolysis and chemical modification, which were selected based on previous research. Both prepared dextrins met the definition criterion of dietary fiber and also the basic prebiotic criterion - they were not degraded by the digestive enzymes of the initial sections of the gastrointestinal tract. The growth of probiotic lactobacilli and bifidobacteria, as well as Escherichia coli, Enterococcus, Bacteroides, and Clostridium strains isolated from feces of healthy people, showed that both studied dextrins were utilized as a source of assimilable carbon and energy by the strains. Furthermore, better growth (higher numbers of cells) counts of probiotic bacteria than those of fecal isolates indicated that the studied resistant dextrins showed a selective effect. Both dextrins might be considered as substances with prebiotic properties due to their chemical and physical properties and selectivity towards the studied probiotic bacterial strains.


Assuntos
Dextrinas/química , Dextrinas/farmacologia , Fibras na Dieta/metabolismo , Microbioma Gastrointestinal/fisiologia , Intestinos/microbiologia , Prebióticos , Fezes/microbiologia , Solanum tuberosum/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA