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1.
Foods ; 13(13)2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38998507

RESUMO

Modifying starch allows for improvements in its properties to enable improved uses in food matrices, bioplastics, and encapsulating agents. In this research, four varieties of native potato starch were modified by acid treatment, enzymatic treatment, and ethanol precipitation, and their physicochemical, structural, thermal, and techno-functional characteristics were analyzed. According to FT-IR analysis, no influence of the modified starches on the chemical groups was observed, and by scanning electron microscopy (SEM), spherical and oval shapes were observed in the acid and enzymatic treatments, with particle sizes between 27 and 36 µm. In particular, the ethanolic precipitation treatment yielded a different morphology with a particle size between 10.9 and 476.3 nm, resulting in a significant decrease in gelatinization temperature (DSC) and more pronounced crystallites (XRD). On the other hand, the enzymatic treatment showed higher values for z-potential (ζ), and the acid treatment showed lower mass loss (TGA). Acid and ethanolic treatments affected the dough properties compared to native starches. The techno-functional properties showed a decrease in the water absorption index, an increase in the water solubility index, and varied swelling power behaviors. In conclusion, the modification of potato starches through acid, enzymatic, and ethanolic precipitation treatments alters their physicochemical properties, such as swelling capacity, viscosity, and thermal stability. This in turn affects their molecular structure, modifying morphology and the ability to form gels, which expands their applications in the food industry to improve textures, stabilize emulsions, and thicken products. Furthermore, these modifications also open new opportunities for the development of bioplastics by improving the biodegradability and mechanical properties of starch-based plastic materials.

2.
Int J Biol Macromol ; 272(Pt 2): 132907, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38862318

RESUMO

The aim of this study was to develop a star fruit extract (SFE) and incorporate it into aerogels based on native and phosphorylated potato starches. The phosphorylation of starch enhances its properties by incorporating phosphate groups that increase the spaces between starch molecules, resulting in a more resilient, intact aerogel with enhanced water absorption. The bioactive aerogels based on potato starch and 10, 15, and 20 % (w/w) of SFE were characterized by their morphological and thermogravimetric properties, infrared spectra, water absorption capacity, loading capacity, and antioxidant activity. Epicatechin was the major compound present in SFE. The thermal stability of SFE increased when incorporated into phosphorylated starch aerogels at a concentration of 20 %. The water absorption capacity was higher in phosphorylated starch aerogels (reaching 1577 %) than in their native counterparts (reaching 1100 %). Native starch aerogels with 15 and 20 % SFE exhibited higher antioxidant activity against hydroxyl free radicals compared to phosphorylated starch aerogels, achieving 79.9 % and 86.4 % inhibition for the hydroxyl and nitric oxide radicals, respectively. The ideal choice of freeze-dried aerogel depends on the desired effect, either to act as an antioxidant agent by releasing bioactive compounds from SFE or as a water-absorbent agent in food products.


Assuntos
Antioxidantes , Frutas , Géis , Extratos Vegetais , Solanum tuberosum , Amido , Solanum tuberosum/química , Géis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Amido/química , Fosforilação , Antioxidantes/química , Antioxidantes/farmacologia , Frutas/química , Averrhoa/química , Água/química
3.
Carbohydr Polym ; 316: 120975, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37321705

RESUMO

Blends of polylactic acid (PLA) and thermoplastic starch (TS) with and without chemical modification were obtained by melt extrusion and used to obtain non-woven fabrics by melt-blowing for the first time. Different TS were obtained by reactive extrusion from native cassava, oxidized, maleated, and dual modified (oxidized and maleated) starch. The chemical modification of starch decreases the difference in viscosity and favors blending, resulting in more homogeneous morphologies, unlike the blends with unmodified TS, which displayed a visible phase separation with large TS droplets. The dual modified starch showed a synergistic effect to process TS by melt-blowing. Regarding non-woven fabrics, values in diameter (2.5-82.1 µm), thickness (0.4-0.6 mm), and grammage (49.9-103.8 g/m2) were explained due to differences in viscosity of the components, and to the fact that during melt the hot air preferentially stretches and thins the areas without large droplets of TS. Moreover, plasticized starch acts as a flow modifier. The porosity of the fibers increased with the addition of TS. Further studies and optimization of blends with low contents of TS and type starch modification will be necessary to completely understand these systems with very complex behavior to obtain non-woven fabrics with improved properties and application.


Assuntos
Poliésteres , Amido , Amido/química , Poliésteres/química , Têxteis , Viscosidade
4.
Foods ; 12(9)2023 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-37174411

RESUMO

Ethanolic extracts of propolis and bee honey contain substances beneficial to human health. Mixtures of wall materials were compared in spray-drying microencapsulation of ethanolic extracts of propolis and bee honey rich in bioactive compounds. Maltodextrin and tara gum were used to obtain microencapsulates A, and modified native potato starch and tara gum were used for microencapsulates B. High values of phenolic compounds, flavonoids, and antioxidant capacity were obtained in microcapsules A and B, and the results obtained in terms of encapsulation efficiency, yield, hygroscopicity, solubility, moisture, Aw, bulk density, and color were typical of the spray-drying process. On the other hand, spherical and elliptical microparticles of sizes between 7.83 and 53.7 µm with light and medium stability were observed. Thermogravimetric properties were similar in both microencapsulates; total organic carbon, SEM-EDS, and FTIR analyses corroborated the encapsulation. X-ray diffractogram exhibited amorphous structures, and the release kinetics of phenolic compounds presented high values from 8.13 to 12.58 mg GAE/g between 7 and 13 h. Finally, modified potato starch is a better encapsulant than maltodextrin because it has better core protection and controlled release of the encapsulated bioactive compounds.

5.
Int J Biol Macromol ; 222(Pt A): 65-76, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-36108753

RESUMO

The objective of this work was to evaluate the effects of enzymatic hydrolysis on digestibility and morphological and structural properties of hydrothermally pre-treated (HPT) red rice starch. The pre-treatments were performed in autoclave and cooking for the modification of rice grains and native starch. In vitro starch digestibility was performed consecutively and semi-simultaneously using α-amylase and amyloglucosidase. A first-order mathematical model was used to adjust the hydrolysis kinetic data, which made it possible to calculate the surface area, hydrolysis index, and glycemic index of the starch. Scanning electron microscopy images (SEM), Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) were also performed to investigate the characteristics of the post-hydrolysis starch samples. The autoclaved starch HSS-A3, which was subjected to 121 °C/1.08 bar for 10 min, showed the highest in vitro digestibility values (80.08 %). Both starch samples showed increase of particle size and enzymatic digestibility after HPT. FTIR spectra of the starch samples showed that there was no appearance of new functional groups. However, XRD evidenced that HPT changed the intensity of the peaks and the type of crystallinity was changed for autoclaved starch (A3) from type A to Vh, with crystallinity ranging from 21.71 % to 26.42 %. The semi-simultaneous approach showed more advantages due to the highest in vitro digestibility as well as reducing the processing time and use of reagents.


Assuntos
Oryza , Amido , Amido/química , Oryza/química , Hidrólise , Culinária , alfa-Amilases , Digestão
6.
AACE Clin Case Rep ; 8(3): 109-112, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602880

RESUMO

Background/Objective: AKT2 is a serine/threonine kinase that plays a key role in regulating insulin signaling. The phenotype related to the gain-of-function alteration in the AKT2 gene (c.49G>A, p.Glu17Lys) has been described in 5 patients with clinical findings that mimic hyperinsulinemic hypoglycemia but with undetectable levels of insulin and C-peptide. One of the reports highlights the facial dysmorphic features. We report the case of a new patient with the same activating AKT2 alteration leading to autonomous activation of the insulin signaling pathway and dysmorphic features. Moreover, to our knowledge, this is the first report using waxy maize heat-modified starch (WMHMS) in this condition. Case Report: A previously healthy child was evaluated at 6 months of age for episodes of hypoglycemia. The laboratory test results for the critical samples showed hypoketotic hypoglycemia (glucose level, 2.16 mmol/L [38 mg/dL]) with undetectable levels of insulin (<0.2 mU/L) and C-peptide (<0.033 nmol/L [reference range, 0.37-1.47 nmol/L]). Physical examination revealed hypertelorism, prominent proptosis of the eyes, a flat nasal bridge, delayed psychomotor development, and postnatal symmetrical overgrowth. The genetic study of AKT2 showed a pathogenic variant (c.49G>A, p.Glu17Lys). To achieve euglycemia, a diet of regular uncooked cornstarch (UCCS) carbohydrate was started. Subsequently, waxy maize heat-modified starch (WMHMS; Glycosade Vitaflo) was used to increase the fasting period to 4 hours. However, we did not find any advantages in comparison with UCCS. Discussion: The range of phenotypes of this gain-of-function alteration in AKT2 may be broad, including dysmorphic features, although the patients harbor the same pathogenic variant. Conclusion: Regarding the treatment, we observed a similar response with WMHMS compared with UCCS, with no adverse effects.

7.
Heliyon ; 7(4): e06644, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33889774

RESUMO

The current consumer demand for fresh food and the interest in caring for the environment have driven the development of biodegradable film packaging to replace synthetic films to preserve the integrity of food. The objective of this work was to evaluate the effects of starch modifications (oxidized, cross-linked, and dual: oxidized/cross-linked), starch concentration (1 and 2%), and glycerol concentration (5 and 15%) on water vapor permeability (WVP), mechanical properties (tensile strength and elongation), optical, and structural properties of films based on "hawthorn" yam starch. The WVP of the films was 4.4 × 10-10 to 1.5 × 10-9 g/m∗s∗Pa, where the films with oxidized yam starch showed a 58.04% reduction concerning the native starch. The tensile strength of oxidized yam starch films showed a decrease of 17.51% with an increase in glycerol concentration. For the 1% starch concentration, elongation increased by 17.03% when the glycerol concentration was increased from 5 to 15%. Modification of starch, starch concentration, and glycerol have a significant effect on the barrier, mechanical, physical, and structural properties of films made with yam starch, where films made with oxidized yam starches at a concentration of 1% starch and 5% glycerol showed the best responses of the properties evaluated.

8.
Nanomaterials (Basel) ; 11(4)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808246

RESUMO

The food industry has increased its interest in using "consumer-friendly" and natural ingredients to produce food products. In the case of emulsifiers, one of the possibilities is to use biopolymers with emulsification capacity, such as octenyl succinic anhydride modified starch, which can be used in combination with other polysaccharides, such as chitosan and carboxymethylcellulose, in order to improve the capacity to protect bioactive compounds. In this work, multilayer nano-emulsion systems loaded with oregano essential oil were produced by high energy methods and characterized. The process optimization was carried out based on the evaluation of particle size, polydispersity index, and zeta potential. Optimal conditions were achieved for one-layer nano-emulsions resulting in particle size and zeta potential of 180 nm and -42 mV, two layers (after chitosan addition) at 226 nm and 35 mV, and three layers (after carboxymethylcellulose addition) of 265 nm and -1 mV, respectively. The encapsulation efficiency of oregano essential oil within nano-emulsions was 97.1%. Stability was evaluated up to 21 days at 4 and 20 °C. The three layers nano-emulsion demonstrated to be an efficient delivery system of oregano essential oil, making 40% of the initial oregano essential oil available versus 13% obtained for oregano essential oil in oil, after exposure to simulated digestive conditions.

9.
Rev. chil. nutr ; 48(2)abr. 2021.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1388487

RESUMO

RESUMEN Los recubrimientos se definen como productos comestibles que forman una fina capa sobre el alimento y se caracterizan por que constituyen una barrera semipermeable a los gases y al vapor de agua que retrasa el deterioro del alimento, mejoran las propiedades mecánicas, ayudan a mantener la integridad estructural del producto que envuelven, ayudan a retener compuestos volátiles y pueden actuar como vehículo de aditivos alimentarios. Se evaluó el desempeño de los biorecubrimientos sobre el aguacate mediante la determinación de propiedades sensoriales y fisicoquímicas. Los resultados muestran que todas las variables están significativamente influenciadas por la biomolécula empleada "almidón modificado de ñame variedad espino", observando un desempeño favorable en los biorecubrimientos comestibles, por lo cual se confirma la efectividad de utilizar biorecubrimiento comestible a base de almidón modificado de ñame con anhídrido n-octenil succínico (n-OSA) como una alternativa para la conservación del aguacate mínimamente procesado debido a que presentó menor variación de las propiedades fisicoquímicas.


ABSTRACT Coatings are defined as edible products which form a thin layer on food, and are characterized by a semipermeable barrier for gases and water vapor which slow food spoilage, improve mechanical properties, help maintain the structural integrity of product wrapping, retain volatile compounds and can act as a vehicle for food additives. We evaluated the performance of biofilms on avocado through the determination of physico-chemical and sensory properties. The results show that all the variables were significantly influenced by the biomolecule employed "modified yam variety espino starch", noting a favorable performance in edible biofilms, confirming the effectiveness of using edible biorecubation based on modified yam starch with n-octenyl succinic anhydhyded (n-OSA) as an alternative for the preservation of minimally processed avocado because it had less variation in physicochemical properties.

10.
J Dairy Res ; 88(1): 98-104, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33594965

RESUMO

In this research communication we evaluate the impact of the addition of prebiotic components (inulin, polydextrose, and modified starch, 40 g/l) as fat substitutes on the physicochemical characteristics, probiotic survival, and sensory acceptance of probiotic (Lacticaseibacillus casei 01, 108 CFU/ml) Greek yogurts during storage (7 °C, 28 d). All formulations had probiotic counts higher than 107 CFU/ml during storage and simulated gastrointestinal conditions (SGIC). The prebiotic components increased the probiotic survival to the enteric phase of the SGIC, with inulin producing the most pronounced effect. Inulin addition resulted in products with lower pH values and consistency and higher titratable acidity during storage, with negative impact on the sensory acceptance (flavor, texture, and overall impression) at the end of the storage period. Modified starch addition impacted negatively on the acceptance of the products (appearance, flavor, texture, and overall impression). Polydextrose addition resulted in products with lower consistency, but similar sensory acceptance to the full-fat yogurt. It can be concluded that it is possible to prepare potentially synbiotic Greek yogurts by desorption technique using L. casei as probiotic culture and inulin, polydextrose or modified starch as prebiotic components, with the utilization of polydextrose being advisable.


Assuntos
Substitutos da Gordura/análise , Prebióticos/análise , Probióticos/análise , Sensação , Iogurte/análise , Iogurte/microbiologia , Fenômenos Químicos , Comportamento do Consumidor , Glucanos/análise , Inulina/análise , Amido/análise
11.
Food Chem ; 315: 126241, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32014667

RESUMO

Chemical modification with octenyl succinic anhydride (OSA) helps to control the physicochemical and thermal properties of isolated starches. The main objective, herein, was to partially characterize modified starches from Dominico-Harton plantain and FHIA 21 planted in Colombia. The highest degree of substitution was found in FHIA 21 (0.020) starch with 3% OSA and 4-h reaction at room temperature. The grain morphology was not affected, but small changes on the surface were evident. Both modified starches reported absorption bands in the IR at 1566 and 1738 cm-1, proper for these types of starch derivatives. The hexagonal and monoclinic structures of starch were altered through chemical modification. In the bending curves, a drastic decrease in the viscosity of the modified starches was observed with respect to the native one. The gelatinization temperatures of the modified starches were similar to those of the isolated starches.


Assuntos
Plantago/química , Amido/química , Amilose/análise , Colômbia , Microscopia Eletrônica de Varredura , Plantago/crescimento & desenvolvimento , Amido/análogos & derivados , Anidridos Succínicos/química , Viscosidade , Difração de Raios X
12.
J Food Sci Technol ; 55(7): 2436-2445, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30042559

RESUMO

Betalains of pitaya (Stenocereus pruinosus) fruit can be used as natural pigment, but they are susceptible to deterioration by temperature, pH, and presence of sugars. In this work, a refined extract (Er) of betalains was obtained through aqueous two-phase extraction, which reduced significantly sugar and mucilage contents. In order to favor stability, the encapsulation of the refined extract was evaluated, with native potato starch that was modified through phosphorylation or succinylation and reactive extrusion. Starches were evaluated in terms of degree of substitution, Fourier transform infrared spectroscopy, scanning electron microscopy, and viscous behavior. Microcapsules were formed by spray drying and their stability was evaluated at 40 °C for 39 days and by using them as pigmenting agent of yogurt at 4 °C during 32 days. The behavior of modified starches during encapsulation was superior to that of commercial N-Lok® starch. Microcapsules based on modified starches showed better pigmenting potential and higher stability than Er and microcapsules based on N-Lok® starch. The separation of betalains from pitaya fruit may be a good alternative for adding value to this plant genetic resource.

13.
Ultrason Sonochem ; 42: 795-804, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29429733

RESUMO

This work was focused on the correlation between the structural and techno-functional properties of ultrasound treated cassava starch for the preparation of tailor-made starch-based ingredients and derivatives. Furthermore, the effect of treatment time, sample conditioning and ultrasound amplitude was studied. Ultrasonic treatment of cassava starch induced structural disorganization and microstructural changes evidenced mainly in the morphological characteristics of the granules and in their degrees of crystallinity. These structural modifications were supported by ATR-FTIR and SEM and CSLM studies as well as DRX and thermal analysis. The selection of the processing conditions is critical due to the complete gelatinization of the starch was produced with the maximum amplitude tested and without temperature control. Rheological dynamical analysis indicated changes at the molecular level in starch granules due to the ultrasound treated, revealing the paste stability under refrigeration condition. PCA allow to establish the interrelationships between microstructural and techno-functional properties. In summary, different starch derivatives could be obtained by adjusting the ultrasound treatment conditions depending on their potential applications.

14.
Rev. chil. nutr ; 43(3): 284-289, set. 2016. graf, tab
Artigo em Espanhol | LILACS | ID: biblio-830137

RESUMO

Coatings are defined as edible products which form a thin layer on the food, and are characterized by it constitute a semipermeable barrier to gases and water vapor retarding food spoilage, improve the mechanical properties, help maintain the structural integrity of the product wrapping, to retain volatile compounds and can act as a vehicle for food additives. We evaluated the performance of the biofilms on melon through the determination of physico-chemical and sensory properties. The results show that all the variables are significantly influenced by the biomolecule employed "modified starch", noting a favorable performance in the edible biofilms.


Los recubrimientos se definen como productos comestibles que forman una fina capa sobre el alimento y se caracterizan por que constituyen una barrera semipermeable a los gases y al vapor de agua que retrasa el deterioro del alimento, mejoran las propiedades mecánicas, ayudan a mantener la integridad estructural del producto que envuelven, ayudan a retener compuestos volátiles y pueden actuar como vehículo de aditivos alimentarios. Se evaluó el desempeño de los biorecubrimientos sobre el melón mediante la determinación de propiedades sensoriales y fisicoquímicas. Los resultados muestran que todas las variables están significativamente influenciadas por la biomolécula empleada "almidón modificado", observando un desempeño favorable en los biorecubrimientos comestibles.


Assuntos
Amido , Anidridos Succínicos , Cucurbitaceae , Conservação de Alimentos , Tubérculos
15.
Carbohydr Polym ; 144: 149-58, 2016 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-27083804

RESUMO

The objective of this study was to evaluate the use of inulin (IN), a prebiotic carbohydrate without superficial activity, as an encapsulating matrix of lipophilic bioactive compounds. For achieving the encapsulation, IN was associated with biopolymers that present superficial activity: modified starch (HiCap), whey protein isolate (WPI) and gum acacia (GA). Encapsulation was performed through emulsification assisted by ultrasound followed by freeze-drying (FD) process to dry the emulsions. All blends retained geranylgeraniol. GA-IN blend yielded the highest geranylgeraniol retention (96±2wt.%) and entrapment efficiency (94±3wt.%), whilst WPI-IN blend yielded the highest encapsulation efficiency (88±2wt.%). After encapsulation, composition of geranylgeraniol in the annatto seed oil was maintained (23.0±0.5g/100g of oil). Such findings indicate that the method of encapsulation preserved the active compound. All blends were also effective for maintaining the antioxidant activity of the oil through ORAC and DPPH analyses.


Assuntos
Antioxidantes/química , Inulina/química , Óleos de Plantas/química , Prebióticos , Amidinas , Antioxidantes/isolamento & purificação , Compostos de Bifenilo , Bixaceae , Cichorium intybus , Cromanos , Diterpenos/análise , Diterpenos/química , Emulsões , Goma Arábica/química , Capacidade de Absorbância de Radicais de Oxigênio , Tamanho da Partícula , Picratos , Óleos de Plantas/isolamento & purificação , Amido/química , Água/química , Proteínas do Soro do Leite/química , Zea mays
16.
Semina Ci. agr. ; 37(4): 1897-1910, 2016.
Artigo em Inglês | VETINDEX | ID: vti-473225

RESUMO

The market demand for corn starch and cassava continues to increase because of their use in edible applications, their biodegradable nature, and other appealing properties. As a result, there is a need to identify alternative starch sources, for example, the seeds of S. burchelli, with the potential to be modified for use in post-harvest applications. Therefore, this study aimed to develop and characterize edible films based on the starch phosphates of the seeds of S. burchelli, with the specific aim to apply these starches to cherry tomatoes for post-harvest conservation. After extraction, the starch was phosphorylated with sodium tripolyphosphate (STP) in different concentrations and times according to a 2 x 2 factorial design with additional treatment (native starch). After modification, the starch phosphates were selected for the preparation of edible films using glycerol as a plasticizer, in proportions of 5, 10, 15 and 20% for each selected starch. The films were measured for thickness, permeability to water vapor and solubility in water. According to their permeability values, 4 films were selected for application in the coverage of cherry tomatoes. The conservation of cherry tomatoes with and without coverage was studied over 8 evaluation times (up to 21 days) at 10±2 C and 80±5% relative humidity. The weight loss, soluble solids, titratable acidity, maturation index,


Amidos de milho e mandioca estão sendo cada vez mais procurados no mercado devido à sua alta demanda para fins comestíveis, produtos biodegradáveis e outros. Devido a essa demanda, há necessidade da busca de outras fontes amiláceas, por exemplo, de sementes da S. burchelli, e sua modificação para aplicação em pós-colheita. Por esse motivo, o presente trabalho teve por objetivo elaborar e caracterizar filmes comestíveis a base de amidos fosfatados da semente de S. burchelli visando sua aplicação na conservação pós-colheita de tomate cereja. Após a extração, o amido foi fosfatado com tripolifosfato de sódio (TPS) em diferentes concentrações e tempos combinados, de acordo com um planejamento Fatorial 22 com tratamento adicional (amido nativo). Após a modificação, amidos fosfatados foram selecionados para a elaboração dos filmes comestíveis utilizando o glicerol como plastificante, em proporções de 5, 10, 15 e 20% para cada amido selecionado. No caso dos filmes foram medidos a espessura, permeabilidade ao vapor de água e solubilidade em água. De acordo com o valor de sua permeabilidade, quatro filmes foram selecionados para aplicação em cobertura de tomates cereja. A conservação dos tomates cereja com e sem cobertura foram estudados em oito tempos de avaliação até 21 dias a 10±2 C e 80±5% de umidade relativa. A perda de massa, sólidos solúveis, acidez titulável, índice de maturaçã

17.
R. Inst. Adolfo Lutz ; 75: 01-12, 2016. tab, graf
Artigo em Português | VETINDEX | ID: vti-483055

RESUMO

O amido fermentado de mandioca, polvilho azedo, possui ampla aplicação em produtos de panificação, devido à propriedade de expansão, sem fermento e sem glúten, o que alavancou a comercialização dos amidos substituintes modificados por ácido. O polvilho azedo é fermentado e seco ao sol, com a geração de ácidos: acético, butírico, lático e propiônico, enquanto os amidos modificados por ácido não são fermentados. Neste trabalho foi produzido o polvilho azedo, seco ao sol e em estufa e amidos modificados pelos ácidos prevalentes na fermentação, secos em UVC. Todos os amidos foram comparados, quanto aos ácidos orgânicos, dos amidos secos em diferentes condições e apenas fermentados, sem secagem, bem com quanto às características físico-químicas e reológicas. Ficou comprovado que a secagem solar favorece um produto mais ácido e de maior expansão. O maior volume específico foi observado para a amostra fermentada seca ao sol, seguida das modificadas por ácido lático 0,5 % e ácido acético 0,5 % e ácido lático 1 %. A baixa expansão da amostra fermentada e seca em estufa (E) mostrou que apenas a presença dos ácidos orgânicos não é suficiente para expansão e que a radiação UV (artificial ou solar) influencia diretamente nessa característica.(AU)


The fermented cassava starch, polvilho azedo, has wide application in bakery products, due to expansion property without yeast and gluten, which leveraged the marketing of starches modified by acid. The cassava starch is fermented and sun dried, with the generation of acids: acetic, butyric, lactic and propionic, while starches modified by acid are not fermented. In this work was produced cassava starch, dried in the sun and under oven, and modified by the acids of cassava starch fermentation, dried in UVC. All starches were compared, as the organic acids, dry starches in different conditions and only fermented without drying, as well as with the physicochemical and rheological characteristics. It was proven that solar drying favors a more acidic product and expansion property. The higher specific volume was observed for the sample fermented sun dried, followed by modified by 0.5 % lactic acid and 0.5 % acetic acid and lactic acid 1 %. The low expansion of the fermented sample and dried in an oven showed that only organic acids is not sufficient for expansion and that UV radiation (solar or artificial) directly influences this characteristic.(AU)


Assuntos
Manihot/química , Ácidos Orgânicos , Conservação de Alimentos/métodos , Luz Solar , Raios Ultravioleta , Amidos e Féculas , Amido/análise , Amido/química , Tecnologia de Alimentos
18.
Braz. arch. biol. technol ; Braz. arch. biol. technol;59: e16160069, 2016. tab, graf
Artigo em Inglês | LILACS | ID: biblio-951401

RESUMO

ABSTRACT: This paper provides an assessment of the effect of saturation of spelt starch and monostarch phosphate with copper or iron ions on selected physicochemical properties of the resulting modified starches. Native and modified spelt starch samples were analyzed for selected mineral element content using Atomic Absorption Spectroscopy (AAS). Thermodynamic properties were measured using DSC, and pasting properties by RVA. Flow curves of 5% pastes were plotted and described using the Herschel-Bulkley model. The structure recovery ratio was measured. AAS analysis established the presence of iron(II) and copper(II) ions in the samples of modified starches and that potassium and magnesium ions had leached from them. In comparison to unfortified samples, enriching native starch with copper(II) ions decreases value of all temperatures of phase transformation about 1.3-2.7 °C, but in case of monostarch phosphates bigger changes (2.8-3.7 °C) were observed. Fortified native spelt starch with copper(II) ions caused increasing the final viscosity of paste from 362 to 429 mPa·s. However, presence iron(II) ions in samples caused reduced its final viscosity by 170 (spelt starch) and 103 mPa·s (monostarch phosphate). Furthermore, enriching monostarch phosphate contributed to reduce degree of structure recovery of pastes from 70.9% to 66.6% in case of copper(II) ions and to 59.9% in case of iron(II) ions.

19.
Semina ciênc. agrar ; 37(4): 1897-1910, 2016.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1500487

RESUMO

The market demand for corn starch and cassava continues to increase because of their use in edible applications, their biodegradable nature, and other appealing properties. As a result, there is a need to identify alternative starch sources, for example, the seeds of S. burchelli, with the potential to be modified for use in post-harvest applications. Therefore, this study aimed to develop and characterize edible films based on the starch phosphates of the seeds of S. burchelli, with the specific aim to apply these starches to cherry tomatoes for post-harvest conservation. After extraction, the starch was phosphorylated with sodium tripolyphosphate (STP) in different concentrations and times according to a 2 x 2 factorial design with additional treatment (native starch). After modification, the starch phosphates were selected for the preparation of edible films using glycerol as a plasticizer, in proportions of 5, 10, 15 and 20% for each selected starch. The films were measured for thickness, permeability to water vapor and solubility in water. According to their permeability values, 4 films were selected for application in the coverage of cherry tomatoes. The conservation of cherry tomatoes with and without coverage was studied over 8 evaluation times (up to 21 days) at 10±2 C and 80±5% relative humidity. The weight loss, soluble solids, titratable acidity, maturation index,


Amidos de milho e mandioca estão sendo cada vez mais procurados no mercado devido à sua alta demanda para fins comestíveis, produtos biodegradáveis e outros. Devido a essa demanda, há necessidade da busca de outras fontes amiláceas, por exemplo, de sementes da S. burchelli, e sua modificação para aplicação em pós-colheita. Por esse motivo, o presente trabalho teve por objetivo elaborar e caracterizar filmes comestíveis a base de amidos fosfatados da semente de S. burchelli visando sua aplicação na conservação pós-colheita de tomate cereja. Após a extração, o amido foi fosfatado com tripolifosfato de sódio (TPS) em diferentes concentrações e tempos combinados, de acordo com um planejamento Fatorial 22 com tratamento adicional (amido nativo). Após a modificação, amidos fosfatados foram selecionados para a elaboração dos filmes comestíveis utilizando o glicerol como plastificante, em proporções de 5, 10, 15 e 20% para cada amido selecionado. No caso dos filmes foram medidos a espessura, permeabilidade ao vapor de água e solubilidade em água. De acordo com o valor de sua permeabilidade, quatro filmes foram selecionados para aplicação em cobertura de tomates cereja. A conservação dos tomates cereja com e sem cobertura foram estudados em oito tempos de avaliação até 21 dias a 10±2 C e 80±5% de umidade relativa. A perda de massa, sólidos solúveis, acidez titulável, índice de maturaçã

20.
Rev. Inst. Adolfo Lutz (Online) ; 75: 01-12, 2016. tab, graf
Artigo em Português | LILACS, VETINDEX | ID: biblio-1489536

RESUMO

O amido fermentado de mandioca, polvilho azedo, possui ampla aplicação em produtos de panificação, devido à propriedade de expansão, sem fermento e sem glúten, o que alavancou a comercialização dos amidos substituintes modificados por ácido. O polvilho azedo é fermentado e seco ao sol, com a geração de ácidos: acético, butírico, lático e propiônico, enquanto os amidos modificados por ácido não são fermentados. Neste trabalho foi produzido o polvilho azedo, seco ao sol e em estufa e amidos modificados pelos ácidos prevalentes na fermentação, secos em UVC. Todos os amidos foram comparados, quanto aos ácidos orgânicos, dos amidos secos em diferentes condições e apenas fermentados, sem secagem, bem com quanto às características físico-químicas e reológicas. Ficou comprovado que a secagem solar favorece um produto mais ácido e de maior expansão. O maior volume específico foi observado para a amostra fermentada seca ao sol, seguida das modificadas por ácido lático 0,5 % e ácido acético 0,5 % e ácido lático 1 %. A baixa expansão da amostra fermentada e seca em estufa (E) mostrou que apenas a presença dos ácidos orgânicos não é suficiente para expansão e que a radiação UV (artificial ou solar) influencia diretamente nessa característica.


The fermented cassava starch, polvilho azedo, has wide application in bakery products, due to expansion property without yeast and gluten, which leveraged the marketing of starches modified by acid. The cassava starch is fermented and sun dried, with the generation of acids: acetic, butyric, lactic and propionic, while starches modified by acid are not fermented. In this work was produced cassava starch, dried in the sun and under oven, and modified by the acids of cassava starch fermentation, dried in UVC. All starches were compared, as the organic acids, dry starches in different conditions and only fermented without drying, as well as with the physicochemical and rheological characteristics. It was proven that solar drying favors a more acidic product and expansion property. The higher specific volume was observed for the sample fermented sun dried, followed by modified by 0.5 % lactic acid and 0.5 % acetic acid and lactic acid 1 %. The low expansion of the fermented sample and dried in an oven showed that only organic acids is not sufficient for expansion and that UV radiation (solar or artificial) directly influences this characteristic.


Assuntos
Amidos e Féculas , Conservação de Alimentos/métodos , Luz Solar , Manihot/química , Raios Ultravioleta , Ácidos Orgânicos , Amido/análise , Amido/química , Tecnologia de Alimentos
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