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1.
Foods ; 13(8)2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38672873

RESUMO

Sorbitol derivatives and other additives are commonly used in various products, such as packaging or food packaging, to improve their mechanical, physical, and optical properties. To accurately and precisely evaluate the efficacy of adding sorbitol-type nucleating agents to these articles, their quantitative determination is essential. This study systematically investigated the quantification of sorbitol-type nucleating agents in food packaging made from impact copolymers of polypropylene (PP) and polyethylene (PE) using attenuated total reflectance infrared spectroscopy (ATR-FTIR) together with analysis of principal components (PCA) and machine learning algorithms. The absorption spectra revealed characteristic bands corresponding to the C-O-C bond and hydroxyl groups attached to the cyclohexane ring of the molecular structure of sorbitol, providing crucial information for identifying and quantifying sorbitol derivatives. PCA analysis showed that with the selected FTIR spectrum range and only the first two components, 99.5% of the variance could be explained. The resulting score plot showed a clear pattern distinguishing different concentrations of the nucleating agent, affirming the predictability of concentrations based on an impact copolymer. The study then employed machine learning algorithms (NN, SVR) to establish prediction models, evaluating their quality using metrics such as RMSE, R2, and RMSECV. Hyperparameter optimization was performed, and SVR showed superior performance, achieving near-perfect predictions (R2 = 0.9999) with an RMSE of 0.100 for both calibration and prediction. The chosen SVR model features two hidden layers with 15 neurons each and uses the Adam algorithm, balanced precision, and computational efficiency. The innovative ATR-FTIR coupled SVR model presented a novel and rapid approach to accurately quantify sorbitol-type nucleating agents in polymer production processes for polymer research and in the analysis of nucleating agent derivatives. The analytical performance of this method surpassed traditional methods (PCR, NN).

2.
Food Chem ; 438: 137977, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-37976874

RESUMO

Films based on poly(vinyl alcohol) (PVA) and cationic starch (CS) were combined with different percentages of sorbitol (S; 15.0, 22.5, and 30.0% w v-1) to assess the effect of plasticizer on the films. Spectroscopic analyses confirmed the interaction between them. However, micrographs indicated the formation of sorbitol crystals on the surface of the films, especially at higher sorbitol concentrations. The blends presented low water vapor transmission rate values, reaching (7.703 ± 0.000) g h-1 m-2 (PVA75CS25S15), and low solubility values for the films containing higher CS amounts. The lack of statistical differences in most parameters suggests that no significant gain comes from increasing the amount of sorbitol at percentages higher than 15%. As a coating, the blend PVA75CS25S15 successfully decreased the loss of moisture content in acerolas by 1.15 times (compared to the control), confirming the suitability of this matrix as a fruit coating.


Assuntos
Álcool de Polivinil , Amido , Amido/química , Álcool de Polivinil/química , Plastificantes/química , Análise Espectral , Etanol , Sorbitol
3.
Plant Physiol Biochem ; 194: 461-469, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36508780

RESUMO

Sugar-alcohols are major photosynthates in plants from the Rosaceae family. Expression of the gene encoding aldose-6-phosphate reductase (Ald6PRase), the critical enzyme for glucitol synthesis in rosaceous species, is regulated by physiological and environmental cues. Additionally, Ald6PRase is inhibited by small molecules (hexose-phosphates and inorganic orthophosphate) and oxidizing compounds. This work demonstrates that Ald6PRase from peach leaves is phosphorylated in planta at the N-terminus. We also show in vitro phosphorylation of recombinant Ald6PRase by a partially purified kinase extract from peach leaves containing Ca2+-dependent protein kinases (CDPKs). Moreover, phosphorylation of recombinant Ald6PRase was inhibited by hexose-phosphates, phosphoenolpyruvate and pyrophosphate. We further show that phosphorylation of recombinant Ald6PRase was maximal using recombinant CDPKs. Overall, our results suggest that phosphorylation could fine-tune the activity of Ald6PRase.


Assuntos
Prunus persica , Fosforilação , Prunus persica/metabolismo , Fosfatos/metabolismo , Folhas de Planta/metabolismo , Hexoses/metabolismo
4.
J Sci Food Agric ; 102(13): 6112-6122, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35474219

RESUMO

BACKGROUND: Treatment with low temperatures can be used to quarantine mangoes against fruit-fly infestation. However, mangoes can develop chilling injury (CI) when stored at temperatures below 13 °C. We demonstrated that the immersion in polyol solutions can alleviate CI symptoms in 'Palmer' mangoes stored at 8 °C. These suggest that polyols can be used to reduce CI in mangoes during quarantine at low temperatures. Thus, we investigated the efficacy of applying 0.1% (v/v) glycerol, propylene glycol, or sorbitol to 'Palmer' mangoes subjected to cold treatment (1.0 °C) for 28 days. Mangoes were then ripened at 23 °C for 7 days. RESULTS: Among these polyols, sorbitol was the most effective in alleviating CI for up to 14 days of cold treatment. Mangoes treated with sorbitol showed lower levels of malondialdehyde (MDA) and hydrogen peroxide (H2 O2 ), and reduced polyphenol oxidase (PPO) activity. These fruit also had elevated levels of ascorbate (AsA), especially in the epicarp, and increased superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) activity. CONCLUSION: Sorbitol can reduce the CI, but to an unsatisfying level, and it should be combined with other treatments storage at low temperature. © 2022 Society of Chemical Industry.


Assuntos
Mangifera , Antioxidantes/farmacologia , Temperatura Baixa , Frutas , Quarentena , Sorbitol
5.
Food Chem X ; 12: 100161, 2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-34877526

RESUMO

The proximal composition, amino acid, carbohydrate, and volatile profiles of caferana (Bunchosia glandulifera) seeds flour were here assessed. Seeds were also subjected to the following extraction processes: one with pressurized ethanol (PLE) and two with ethanol + supercritical CO2 mixture at different temperatures and pressures (SC1 and SC2). Extracts were characterized in terms of caffeine, total phenolic, and δ-lactam. The characterization of caferana seed and its extracts is unprecedented in terms of carbohydrate and volatiles profiles, besides the δ-lactam identification/isolation. SC2 extract exhibited a higher caffeine (9.3 mg/g) and δ-lactam (29.4 mg/g) content, whereas the PLE extract contained a higher total phenolic amount (3.0 mgGAE/g). Caferana is regionally associated to protective effects on mental health. Its byproduct (seed) revealed to be a promising source of bioactive compounds, and a potential raw material of nutritive extracts and flours that can be incorporated into pharmaceutical, nutraceutical, cosmetic, and food products.

6.
Polymers (Basel) ; 13(19)2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34641171

RESUMO

The aim of this work was to use glycerol (Gly) and sorbitol (Sor) as plasticizers with oxidized starch potato (OS) to produce biodegradable and environmentally friendly films, and to demonstrate the resulting physicochemical and functional viability without subtracting the organoleptic characteristics of the food. Analyses by water vapor permeability (WVP), attenuated total reflection Fourier transform infrared spectra (ATR-FTIR), scanning electron microscopy (SEM), tensile strength (TS), and transparency (UV) showed that the best film result was with 1.5 g of Gly and 2.0 g of Sor, conferred shine, elasticity 19.42 ± 6.20%, and mechanical support. The starch oxidized to 2.5%, contributing a greater transparency of 0.33 ± 0.12 and solubility of 78.90 ± 0.94%, as well as less permeability to water vapor 6.22 ± 0.38 gmm-2 d-1 kPa-1. The films obtained provide an alternative for use in food due to their organic compounds, excellent visual presentation, and barrier characteristics that maintain their integrity and, therefore, their functionality.

7.
Int J Food Microbiol ; 345: 109129, 2021 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-33711686

RESUMO

The production of pome fruits as pears and apples, as well as their derived industries, is of great economic importance in North Patagonia. The elaboration of fermented beverages as cider or perry has evidenced a substantial diversification during the last years, with the evaluation of different fruit varieties, yeast starters and technological changes. In this work, two cryotolerant yeasts belonging to the species Saccharomyces uvarum were evaluated at laboratory and pilot scale in sterile and no-sterile pear must. One of the strains was originally isolated from apple chicha (strain NPCC1314) and the other from apple cider (strain NPCC1420) in Patagonia. Both physicochemical and sensory features of the fermented products were evaluated. Both strains were able to successfully complete the fermentations, although strain NPCC1420 showed the better kinetic properties including a faster sugar consumption than the strain NPCC1314. Both strains showed excellent implantation capacity, but the fermented products showed different chemical profiles. The perry fermented with the strain NPCC1314 was characterized by better sensory attributes as assessed by trained panelists and a greater acceptance for untrained public than the same fermented with the strain NPCC1420. The two strains were able to consume sorbitol, both in pear must and in agar-plates supplemented with sorbitol as the sole carbon source. This ability is described for the first time in S. uvarum, at least for the two strains evaluated in this work.


Assuntos
Bebidas Alcoólicas/análise , Alimentos Fermentados/microbiologia , Pyrus/microbiologia , Saccharomyces/metabolismo , Argentina , Reatores Biológicos , Chile , Fermentação , Frutas/química , Frutas/microbiologia , Malus/microbiologia , Saccharomyces/isolamento & purificação , Leveduras/classificação , Leveduras/isolamento & purificação
8.
Sci Total Environ ; 769: 144869, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33486179

RESUMO

Amidst the global plastic pollution crisis, bio-based polymers have been proposed as a potential substitute to tackle this issue. Owed to their biodegradability, biopolymers are generally regarded as eco-friendly during the post-consumer (disposal) stage. However, the environmental burden of the many production processes biopolymers and their components undergo better reflect the sustainable nature of these materials. Previous studies evaluating the Life Cycle Assessment (LCA) of starch-based composites have focused on commercially available starches, although other non-conventional starches can also be used to produce biopolymers. To address this knowledge gap, in the present study we evaluated the LCA of starch-Brazil nut fiber biocomposites prepared with starch from three different sources, Andean potato, corn, and sweet potato, and applying two different plasticizers, glycerol and sorbitol. Results indicated that the starch-based biocomposites were less impacting than conventional PLA-Brazil nut fiber and PP-glass fiber composites. The type of starch and plasticizer significantly influenced the environmental load of the production of the composites. The main drivers of these differences were the multiple agricultural practices, such as irrigation and fertilization, and the crop efficiency for starch extraction. Sorbitol was found to be many times more impacting than glycerol in most categories, which is due to the complex processing of sorbitol and high content in biocomposites with similar mechanical properties than glycerol. Additionally, Brazil nut fibers are presented as an eco-friendly and low-burden natural filler due to their easy processing and agricultural waste origin. The limitations, applications, and significance of the results were discussed.


Assuntos
Bertholletia , Solanum tuberosum , Animais , Estágios do Ciclo de Vida , Plastificantes , Amido
9.
Sci. agric. ; 78(supl. 1): e20200271, 2021. graf, tab, ilus
Artigo em Inglês | VETINDEX | ID: vti-765603

RESUMO

Effects of plasticizer types and whey protein concentrate (WPC) as coatings were evaluated on internal quality and shelf life of eggs stored for 42 days. Eggs were coated with WPC at 8 % solution combined with the plasticizers glycerol (GLY), sorbitol (SOR), and propylene glycol (PRO). The eggs were stored at 20 °C. Weight loss, Haugh Unit (HU), albumen and yolk pH, and yolk index (YI) were evaluated weekly from day 0 to 42 days. After, electron microscopy of the eggshell structure was performed. The data was submitted to the analysis of variance and the effects of treatment, storage time, and the interaction between these factors were evaluated. There was significant interaction between factors (treatment and periods) for weight loss (p < 0.0001), HU (p < 0.0001), albumen (p < 0.0001), and yolk pH (p < 0.0001), and YI (p < 0.0001). After 42 days, uncoated eggs showed greater weight loss (5.4 %), compared to WPC+GLY, (3.8 %), WPC+SOR (3.3 %) and WPC+PRO (3.9 %). Similar results were verified for HU at 42 days of storage. Uncoated eggs showed HU of 58.46 (B), while coated eggs showed higher values: WPC+GLY 66.58 (A), WPC+SOR 68.79 (A), and WPC + PRO 71.53 (A). The plasticizers GLY, SOR and PRO, associated with WPC, demonstrated effectiveness in maintaining the quality of eggs throughout the 42 days of storage. However, WPC+SOR showed superiority in preserving quality integrity of eggs. This result can be related to the chemical structure of SOR, making the combination more efficient for storage.(AU)


Assuntos
Leite/química , Leite/fisiologia , Ovos/análise , Plastificantes/análise , Propilenoglicol/análise
10.
Sci. agric ; 782021.
Artigo em Inglês | LILACS-Express | VETINDEX | ID: biblio-1497906

RESUMO

ABSTRACT: Effects of plasticizer types and whey protein concentrate (WPC) as coatings were evaluated on internal quality and shelf life of eggs stored for 42 days. Eggs were coated with WPC at 8 % solution combined with the plasticizers glycerol (GLY), sorbitol (SOR), and propylene glycol (PRO). The eggs were stored at 20 °C. Weight loss, Haugh Unit (HU), albumen and yolk pH, and yolk index (YI) were evaluated weekly from day 0 to 42 days. After, electron microscopy of the eggshell structure was performed. The data was submitted to the analysis of variance and the effects of treatment, storage time, and the interaction between these factors were evaluated. There was significant interaction between factors (treatment and periods) for weight loss (p 0.0001), HU (p 0.0001), albumen (p 0.0001), and yolk pH (p 0.0001), and YI (p 0.0001). After 42 days, uncoated eggs showed greater weight loss (5.4 %), compared to WPC+GLY, (3.8 %), WPC+SOR (3.3 %) and WPC+PRO (3.9 %). Similar results were verified for HU at 42 days of storage. Uncoated eggs showed HU of 58.46 (B), while coated eggs showed higher values: WPC+GLY 66.58 (A), WPC+SOR 68.79 (A), and WPC + PRO 71.53 (A). The plasticizers GLY, SOR and PRO, associated with WPC, demonstrated effectiveness in maintaining the quality of eggs throughout the 42 days of storage. However, WPC+SOR showed superiority in preserving quality integrity of eggs. This result can be related to the chemical structure of SOR, making the combination more efficient for storage.

11.
Sci. agric ; 78(supl. 1): e20200271, 2021. graf, tab, ilus
Artigo em Inglês | VETINDEX | ID: biblio-1498001

RESUMO

Effects of plasticizer types and whey protein concentrate (WPC) as coatings were evaluated on internal quality and shelf life of eggs stored for 42 days. Eggs were coated with WPC at 8 % solution combined with the plasticizers glycerol (GLY), sorbitol (SOR), and propylene glycol (PRO). The eggs were stored at 20 °C. Weight loss, Haugh Unit (HU), albumen and yolk pH, and yolk index (YI) were evaluated weekly from day 0 to 42 days. After, electron microscopy of the eggshell structure was performed. The data was submitted to the analysis of variance and the effects of treatment, storage time, and the interaction between these factors were evaluated. There was significant interaction between factors (treatment and periods) for weight loss (p < 0.0001), HU (p < 0.0001), albumen (p < 0.0001), and yolk pH (p < 0.0001), and YI (p < 0.0001). After 42 days, uncoated eggs showed greater weight loss (5.4 %), compared to WPC+GLY, (3.8 %), WPC+SOR (3.3 %) and WPC+PRO (3.9 %). Similar results were verified for HU at 42 days of storage. Uncoated eggs showed HU of 58.46 (B), while coated eggs showed higher values: WPC+GLY – 66.58 (A), WPC+SOR – 68.79 (A), and WPC + PRO – 71.53 (A). The plasticizers GLY, SOR and PRO, associated with WPC, demonstrated effectiveness in maintaining the quality of eggs throughout the 42 days of storage. However, WPC+SOR showed superiority in preserving quality integrity of eggs. This result can be related to the chemical structure of SOR, making the combination more efficient for storage.


Assuntos
Leite/fisiologia , Leite/química , Ovos/análise , Plastificantes/análise , Propilenoglicol/análise
12.
Food Chem ; 309: 125764, 2020 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-31771916

RESUMO

Coating fruits surface with biodegradable films obtained from starch is an alternative to delay the fruit ripening process. This study aimed to develop a biodegradable film from a polymer blend consisting of natural cassava starch, casein, and gelatin, and using sorbitol as the plasticizer. Among all the prepared biodegradable films (BFs), the one with desirable results in thickness, opacity, solubility, and water vapor transmission rate (WVTR) analyzes was based on a high concentration of starch, and casein, and low concentration of gelatin. Also, this film had the lowest solubility among all of them. Guava fruit coated with this film showed a two-day increase in shelf-life when compared to non-coated guavas. The increase in shelf-life was due to the extremely low water vapor transmission rate of the films, decreasing the fruits' mass loss, and, consequently, retarding their senescence. These results indicate that the biodegradable film is a promising material for fruit coating.


Assuntos
Caseínas/química , Filmes Comestíveis , Gelatina/química , Amido/química , Frutas/química , Permeabilidade , Psidium/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água/química
13.
Magn Reson Chem ; 57(7): 404-411, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30864253

RESUMO

Although the Cu2+ -sorbitol complex [Cu2+ -Sorb] structure in crystalline state has been determined by X rays, it is not known in solution, where most studies of this complex are performed. Therefore, the goal of this work was to obtain information about the structure of this complex in aqueous solution using nuclear magnetic resonance and electron paramagnetic resonance spectroscopies. The magnetic resonance results indicate that the complex is formed at approximately pH 12. In this pH the sorbitol 1 H relaxation times were so short (broad line) that was not possible to use standard nuclear magnetic resonance parameters (nuclear Overhauser effect and spin-spin coupling constants values) to solve the three-dimensional structure. However, valuable structural information about the complex in solution was obtained. The relaxation results indicate that the Cu2+ ions are buried in the structure and not accessible to solvent; the 1 H and 13 C spectra shows strong paramagnetic shift effect indicating short distance between these nuclei and Cu2+ in the structure. No electron paramagnetic resonance signal was observed in pH 12 indicating strong Cu2+ - Cu2+ dipolar interaction, compatible to Cu2+ -Cu2+ distances measured in crystal, from 1.148 to 1.393 Angstroms. The complex self-diffusion coefficient (D) of 1.58 × 10-10  m2 /s value, determined by Diffusion-Ordered Spectroscopy, is compatible to a molecular weight of 3-6 KDa. Therefore, these results corroborate that the [Cu2+ -Sorb] complex is assembled in solution, at pH 12, with several structural parameters compatible to the toroidal hexadecacuprate supramolecular structure determined in solid state.

14.
Bioprocess Biosyst Eng ; 41(2): 185-194, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29052765

RESUMO

Equimolar amounts of lactobionic acid and sorbitol may be obtained in a reaction catalyzed by the enzymes glucose-fructose oxidoreductase and glucono-δ-lactonase, which are found in the periplasm of Zymomonas mobilis. These reactions are generally conducted using immobilized bacterial cells, and the cell treatment and immobilization steps are costly and time-consuming. This study evaluated alternatives to simplify the preparation of calcium alginate-immobilized biocatalyst and its application in different operation modes and types of reactors. It was possible to eliminate cell permeabilization with cetyltrimethylammonium bromide, and the reticulation of Z. mobilis cells with glutaraldehyde sufficed to inhibit the fermentative metabolism of carbohydrates by the bacterium, with accumulation of bioconversion products. When the process was carried out in a mechanically stirred reactor in batch mode, 530 mmol L- 1 of products were obtained in 24 h. The process was also tested in fed-batch mode so as to use of a larger amount of lactose, since it could not be used in the batch because of its low solubility in water. Under this condition, final products concentration reached 745 mmol L- 1 within 42 h. Similar results were obtained for reactions conducted in a pneumatically stirred reactor in batch and fed-batch modes, proving the potential use of this process in several industrial settings.


Assuntos
Alginatos/química , Células Imobilizadas/metabolismo , Sorbitol/metabolismo , Zymomonas/metabolismo , Ácido Glucurônico/química , Ácidos Hexurônicos/química
15.
Toxicon ; 133: 123-126, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28478057

RESUMO

EchiTAb + ICP is a pan-African antivenom used for the treatment of snakebite envenomation in rural sub-Saharan African communities, where the cold chain can be difficult to maintain. To develop a formulation of EchiTAb + ICP that can be distributed and stored without refrigeration, we submitted three different formulations of EchiTAb + ICP: control (i.e. liquid antivenom formulated without stabilizer), liquid antivenom stabilized with sorbitol, and freeze-dried antivenom formulated with sucrose, to an accelerated stability study (i.e. 38 ± 2 °C and 75% relative humidity for 6 months). We analyzed changes in color, residual humidity, reconstitution time (for freeze-dried preparation), pH, osmolality, total protein concentration, antibody monomers content, turbidity, bacterial endotoxins, and pre-clinical neutralizing efficacy of the lethal effect of Echis ocellatus venom at 0, 3 and 6 months. In the control formulation, instability was evidenced by the development of a yellow coloration and an increment in aggregation and turbidity, without change in its neutralizing activity. The sorbitol-stabilized formulation did not develop marked aggregation or turbidity, but instability was evidenced by the development of yellow coloration and a drop in the neutralizing potency. The freeze-dried formulation maintained its neutralizing potency and did not show marked signs of instability, thus indicating that freeze-drying could confer EchiTAb + ICP with improved thermal stability required for distribution and storage at room temperature in sub-Saharan Africa.


Assuntos
Antivenenos/química , Estabilidade de Medicamentos , Sorbitol , Sacarose , África Subsaariana , Animais , Antivenenos/farmacologia , Liofilização , Camundongos , Temperatura , Venenos de Víboras/antagonistas & inibidores
16.
Rev. Assoc. Paul. Cir. Dent ; 71(1): 21-24, Jan.Fev.Mar.2017.
Artigo em Português | LILACS, BBO - Odontologia | ID: biblio-832071

RESUMO

O objetivo da pesquisa foi comparar os efeitos de edulcorantes naturais utilizados como substrato por Streptococcus mutans e Lactobacillus acidophilus, verificando a capacidade desses microrganismos em metabolizar os edulcorantes, favorecendo o crescimento e a produção de ácidos. Para tal estudo, realizou-se um total de 180 leituras para as variáveis crescimento e produção de ácido, e para o processamento dos dados usou-se o pacote estatístico SPSS. Dadas às condições da metodologia, foi possível concluir que a Stevia Rebaudiana Bertoni ofereceu melhores resultados na redução do crescimento bacteriano e na produção de ácidos do que o Sorbitol.


This paper aimed at comparing the effects of natural sweeteners used as a substrate for Streptococcus mutans and Lactobacillus acidophilus, in order to verify the ability of these microorganisms to metabolize sweeteners, promoting the growth and the production of acids. For this study, the variables "growth" and "acid production" were analyzed and the processing data was based on the SPSS statistical package. It was concluded that Stevia rebaudiana Bertoni offered better results in reducing bacterial growth and production of the Sorbitol acids.


Assuntos
Sorbitol , Stevia , Edulcorantes , Crescimento
17.
J Ind Microbiol Biotechnol ; 44(3): 407-411, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28035480

RESUMO

The production of recombinant proteins by Pichia pastoris under AOX1 promoter is usually performed using methanol together with either glycerol or sorbitol as co-substrate. Although both co-substrates have been widely used, comparative studies are scarce. In addition, these comparisons have been performed at different specific growth rate (µ) that it is well known that has an important effect on productivity. Thus, the effect of using these co-substrates on the production of Rhyzopus oryzae lipase (ROL) by P. pastoris was compared in continuous cultures growing at the same µ at either 22 or 30 °C. Results show that using glycerol as co-substrate led to higher volumetric productivities, and lower specific and volumetric methanol consumption rates. Scale-up simulation with 10-10,000 L bioreactor sizes indicated that glycerol produced the highest volumetric productivity of ROL with lower aeration requirements. Therefore, glycerol rises as a better option than sorbitol in ROL production.


Assuntos
Meios de Cultura/química , Glicerol/química , Metanol/química , Pichia/enzimologia , Sorbitol/química , Reatores Biológicos , Proteínas Fúngicas/biossíntese , Microbiologia Industrial , Lipase/biossíntese , Regiões Promotoras Genéticas , Proteínas Recombinantes/biossíntese , Rhizopus/enzimologia , Temperatura
18.
Plant Cell Physiol ; 58(1): 145-155, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011870

RESUMO

Glucitol, also known as sorbitol, is a major photosynthetic product in plants from the Rosaceae family. This sugar alcohol is synthesized from glucose-6-phosphate by the combined activities of aldose-6-phosphate reductase (Ald6PRase) and glucitol-6-phosphatase. In this work we show the purification and characterization of recombinant Ald6PRase from peach leaves. The recombinant enzyme was inhibited by glucose-1-phosphate, fructose-6-phosphate, fructose-1,6-bisphosphate and orthophosphate. Oxidizing agents irreversibly inhibited the enzyme and produced protein precipitation. Enzyme thiolation with oxidized glutathione protected the enzyme from insolubilization caused by diamide, while incubation with NADP+ (one of the substrates) completely prevented enzyme precipitation. Our results suggest that Ald6PRase is finely regulated to control carbon partitioning in peach leaves.


Assuntos
Aldeído Redutase/metabolismo , Folhas de Planta/enzimologia , Proteínas de Plantas/metabolismo , Prunus domestica/enzimologia , Aldeído Redutase/antagonistas & inibidores , Aldeído Redutase/genética , Frutosedifosfatos/metabolismo , Frutosedifosfatos/farmacologia , Frutosefosfatos/metabolismo , Frutosefosfatos/farmacologia , Glucofosfatos/metabolismo , Glucofosfatos/farmacologia , Dissulfeto de Glutationa/metabolismo , Hexosefosfatos/metabolismo , Hexosefosfatos/farmacologia , Immunoblotting , Cinética , Modelos Biológicos , NADP/metabolismo , Oxidantes/metabolismo , Oxidantes/farmacologia , Fosfatos/metabolismo , Fosfatos/farmacologia , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/classificação , Proteínas de Plantas/genética , Prunus domestica/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Compostos de Sulfidrila/metabolismo
19.
Toxicol Lett ; 260: 36-45, 2016 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-27553672

RESUMO

Sorbitol is a polyol used by the food industry as a sweetener. Women are consuming diet and light products containing sorbitol during pregnancy and in the postnatal period to prevent themselves from excessive weight gain and maintain a slim body. Although there is no evidence for the genotoxicity of sorbitol in the perinatal period, this study focused on evaluating the effects of the maternal intake of sorbitol on the biochemical and toxicological parameters of lactating Wistar rat offspring after 14days of mother-to-offspring exposure. A dose-dependent reduction of offspring length was observed. An increase in sorbitol levels determined in the milk was also observed. However, we detected an inverse relationship between the exposition dose in milk fructose and triacylglycerols concentrations. There was an increase in the plasmatic levels of ALT, AST and LDLc and a decrease in proteins, cholesterol and glucose levels in the offspring. Sorbitol exposure caused hepatocyte genotoxicity, including micronuclei induction. Maternal sorbitol intake induced myelotoxicity and myelosuppression in their offspring. The Comet assay of the blood cells detected a dose-dependent genotoxic response within the sorbitol-exposed offspring. According to our results, sorbitol is able to induce important metabolic alterations and genotoxic responses in the exposed offspring.


Assuntos
Transtornos do Crescimento/etiologia , Insuficiência Hepática/etiologia , Lactação , Fenômenos Fisiológicos da Nutrição Materna , Transtornos Mieloproliferativos/etiologia , Adoçantes não Calóricos/efeitos adversos , Sorbitol/efeitos adversos , Animais , Biomarcadores/sangue , Feminino , Frutose/análise , Transtornos do Crescimento/sangue , Transtornos do Crescimento/patologia , Transtornos do Crescimento/fisiopatologia , Células Hep G2 , Insuficiência Hepática/sangue , Insuficiência Hepática/patologia , Insuficiência Hepática/fisiopatologia , Humanos , Fígado/fisiopatologia , Masculino , Leite/química , Testes de Mutagenicidade , Mutagênicos/efeitos adversos , Transtornos Mieloproliferativos/sangue , Transtornos Mieloproliferativos/patologia , Transtornos Mieloproliferativos/fisiopatologia , Adoçantes não Calóricos/administração & dosagem , Adoçantes não Calóricos/análise , Gravidez , Efeitos Tardios da Exposição Pré-Natal/sangue , Efeitos Tardios da Exposição Pré-Natal/etiologia , Efeitos Tardios da Exposição Pré-Natal/patologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Ratos Wistar , Sorbitol/administração & dosagem , Sorbitol/análise , Triglicerídeos/análise
20.
Talanta ; 152: 33-8, 2016 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-26992492

RESUMO

Reference methods for quality control of vaccines usually require treatment of the samples before analysis. These procedures are expensive, time-consuming, unhealthy and require careful manipulation of the sample, making them a potential source of analytical errors. This work proposes a novel method for the quality control of thermostabilizer samples of the yellow fever vaccine employing attenuated total reflectance Fourier transform infrared spectrometry (ATR-FTIR). The main advantage of the proposed method is the possibility of direct determination of the analytes (sodium glutamate and sorbitol) without any pretreatment of the samples. Operational parameters of the FTIR technique, such as the number of accumulated scans and nominal resolution, were evaluated. The best conditions for sodium glutamate were achieved when 64 scans were accumulated using a nominal resolution of 4 cm(-1). The measurements for sodium glutamate were performed at 1347 cm(-1) (baseline correction between 1322 and 1369 cm(-1)). In the case of sorbitol, the measurements were done at 890cm(-1) (baseline correction between 825 and 910 cm(-1)) using a nominal resolution of 2 cm(-1) with 32 accumulated scans. In both cases, the quantitative variable was the band height. Recovery tests were performed in order to evaluate the accuracy of the method and recovery percentages in the range 93-106% were obtained. Also, the methods were compared with reference methods and no statistical differences were observed. The limits of detection and quantification for sodium glutamate were 0.20 and 0.62% (m/v), respectively, whereas for sorbitol they were 1 and 3.3% (m/v), respectively.


Assuntos
Glutamato de Sódio/análise , Sorbitol/análise , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Temperatura , Vacina contra Febre Amarela/química , Limite de Detecção , Controle de Qualidade , Glutamato de Sódio/química , Sorbitol/química , Vacina contra Febre Amarela/normas
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