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1.
Food Funct ; 15(2): 663-675, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38108083

RESUMO

The influence of co-oleogelators like lecithin or hydrogenated lecithin together with the addition of dispersed water droplets to modulate the microstructure and thus the physical properties of glyceryl stearate (GS)-corn oil oleogels was investigated by thermal profile, microstructure, hardness, and oil binding capacity (OBC). The addition of ß-carotene (ßC) was also assessed. With lecithin, crystallization and melting temperatures were reduced, resulting in less-ordered crystal networks with a lower hardness and OBC, while with hydrogenated lecithin, the opposite effect was observed. In the presence of water, oleogels became harder but more brittle. Finally, ßC acted as a crystal modifier increasing the hardness and OBC in the presence of lecithin, but decreased these parameters in hydrogenated lecithin-containing and water-filled oleogels. This study provides a better understanding on how the composition of GS-based oleogels can affect their physical properties.


Assuntos
Lecitinas , Compostos Orgânicos , Lecitinas/química , Compostos Orgânicos/química , Cristalização , Glicerídeos , Água/química
2.
Food Res Int ; 173(Pt 2): 113455, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37803781

RESUMO

Water-in-oil-in-water (W1/O/W2) emulsions offer the potential to deliver hydrophilic bioactive compounds into foods, yet their application remains limited due to their instability. Thus, the impact of lipid phase composition and state on the colloidal stability, in vitro lipid digestibility and chlorophyllin (CHL) bioaccessibility of W1/O/W2 emulsions before and after incorporation into whole milk was studied. Medium-chain triglyceride oil (MCT) was used as a liquid lipid phase and MCT with glyceryl stearate (GS) or pure hydrogenated palm oil (HPO) as gelled lipid phases. The lipid phase composition was crucial to forming W1/O/W2 emulsions. MCT or MCT+GS allowed the successful formation of W1/O/W2 emulsions, being more stable upon gastric conditions those formulated with MCT+GS than pure MCT. In contrast, the use of HPO led to phase separation, which was maintained after the gastric conditions. Regarding their lipid digestibility, W1/O/W2 emulsions formulated with MCT or MCT+GS were fully digested, whereas only 40% of the lipid was digested using HPO. In accordance, the CHL bioaccessibility was higher using MCT or MCT+GS than HPO. When co-digested with whole milk, the colloidal stability and lipid digestibility of the W1/O/W2 emulsions with MCT or MCT+GS were not altered, whereas the W1/O/W2 emulsion-HPO showed enhanced colloidal stability and lipid digestibility (57.71 ± 3.06%), due to the surface-active properties of milk protein. The present study provides useful information to develop stable functional foods enriched with hydrophilic bioactive compounds by using W1/O/W2 emulsions.


Assuntos
Clorofilídeos , Emulsões , Glicerídeos , Água
3.
Foods ; 10(7)2021 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-34359454

RESUMO

The present paper investigates the use of multiple light scattering for the monitoring of milk fermentation. The experiments were performed on milk fermented with different starter concentrations (0.05% to 4.5% (w/w) at temperatures from 36 to 44 °C and in the presence of antibiotics at concentrations up to 100 µg/kg. The fermentation was monitored continuously by using a multiple light scattering technique and simultaneously by a pH meter, a rheometer and a texture analyzer. The backscattering signal recorded by multiple light scattering measurements was correlated with the changes in pH, rheological parameters and firmness of the samples along the fermentation. A gelation time of 120 min was obtained when the highest concentration of starter (4.5%, w/w) and incubation temperature of 44 °C were used. These results were confirmed by the pH, rheological and texture monitoring. The analysis of backscattering spectra allowed the detection of the effect of antibiotic on the gel formation even at low concentrations (1.3 µg/kg). Overall, the results highlighted the advantages of using a multiple light scattering technique as quality control tool for online monitoring of milk fermentation.

4.
J Food Sci ; 85(2): 316-323, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31968398

RESUMO

This work proposes a novel approach based on the real-time monitoring of the fining process of apple juices by static multiple light scattering. The change in transmission was used to determine the fining effectiveness of three vegetable proteins, respectively, red lentil, green lentil, and green pea proteins. Further treatment with gelatin-bentonite was used as a control. The modified Gompertz function was applied to fit the transmission signals. According to (1) the rate of flocculation and (2) the rate of sedimentation, the best fining efficiency was achieved by red lentil, which was similar to that of gelatin-bentonite and higher than green lentil and green pea proteins. This ranking was obtained at any dose from 60 to 900 mg per liter of juice. The results suggest the use of red lentil as a potential fining agent for apple juices and highlight the advantages of using static multiple light scattering technique as a quality control tool for studying the kinetics of the fining process. PRACTICAL APPLICATION: The study proposed the use of vegetable proteins as fining agents for apple juices. Their efficiency was ably monitored in real time by static multiple light scattering.


Assuntos
Manipulação de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Malus/química , Proteínas de Vegetais Comestíveis/química , Manipulação de Alimentos/instrumentação , Lens (Planta)/química , Pisum sativum/química
5.
Sci Rep ; 9(1): 7545, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101843

RESUMO

Previous theoretical and data-driven studies on urban mobility uncovered the repeating patterns in individual and collective human behavior. This paper analyzes the travel demand characteristics of mobility networks through studying a coarse-grained representation of individual trips. Building on the idea of reducing the complexity of the mobility network, we investigate the preserved spatial and temporal information in a simplified representations of large-scale origin-destination matrices derived from more than 16 million taxi trip records from New York and Chicago. We reduce the numerous individual flows on the network into four major groups, to uncover latent collective mobility patterns in those cities. The new simplified representation of the origin-destination matrices leads to categorization of trips into distinctive flow types with specific temporal and spatial properties in each city under study. Collocation of the descriptive statistics of flow types within the two cities suggests the generalizability of the proposed approach. We extract an overall displacement metric from each of the major flows to analyze the evolution of their temporal attributes. The new representation of the demand network reveals insightful properties of the mobility system which could not have been identified from the original disaggregated representation.

6.
PLoS One ; 13(3): e0194354, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29543875

RESUMO

The path choice behavior of battery electric vehicle (BEV) drivers is influenced by the lack of public charging stations, limited battery capacity, range anxiety and long battery charging time. This paper investigates the congestion/flow pattern captured by stochastic user equilibrium (SUE) traffic assignment problem in transportation networks with BEVs, where the BEV paths are restricted by their battery capacities. The BEV energy consumption is assumed to be a linear function of path length and path travel time, which addresses both path distance limit problem and road congestion effect. A mathematical programming model is proposed for the path-based SUE traffic assignment where the path cost is the sum of the corresponding link costs and a path specific out-of-energy penalty. We then apply the convergent Lagrangian dual method to transform the original problem into a concave maximization problem and develop a customized gradient projection algorithm to solve it. A column generation procedure is incorporated to generate the path set. Finally, two numerical examples are presented to demonstrate the applicability of the proposed model and the solution algorithm.


Assuntos
Fontes de Energia Elétrica , Meios de Transporte , Algoritmos , Automóveis , Modelos Teóricos
7.
J Agric Food Chem ; 65(27): 5523-5530, 2017 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-28635282

RESUMO

This work describes a new approach based on multiple light scattering to study red wine clarification processes. The whole spectral signal (1933 backscattering points along the length of each sample vial) were fitted by a multivariate kinetic model that was built with a three-step mechanism, implying (1) adsorption of wine colloids to fining agents, (2) aggregation into larger particles, and (3) sedimentation. Each step is characterized by a reaction rate constant. According to the first reaction, the results showed that gelatin was the most efficient fining agent, concerning the main objective, which was the clarification of the wine, and consequently the increase in its limpidity. Such a trend was also discussed in relation to the results achieved by nephelometry, total phenols, ζ-potential, color, sensory, and electronic nose analyses. Also, higher concentrations of the fining agent (from 5 to 30 g/100 L) or higher temperatures (from 10 to 20 °C) sped up the process. Finally, the advantage of using the whole spectral signal vs classical univariate approaches was demonstrated by comparing the uncertainty associated with the rate constants of the proposed kinetic model. Overall, multiple light scattering technique showed a great potential for studying fining processes compared to classical univariate approaches.


Assuntos
Difusão Dinâmica da Luz/métodos , Vinho/análise , Cinética , Nefelometria e Turbidimetria , Temperatura , Vinho/classificação
8.
Food Chem ; 161: 199-207, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-24837941

RESUMO

The objective of this research was to evaluate whether mango peel is a potential source of functional cell wall polymers. To reach this objective, the native pectin polymers (NPP) extracted as alcohol insoluble residue from mango peel, were characterised in terms of uronic acid content, degree of methoxylation, neutral sugar content, and molar mass and compared to citric acid (pH 2.5, 2h at 80°C) extracted polymers, mimicking industrial pectin extraction conditions. Water-solubilised NPP were highly methoxylated having two populations with a Mw of 904 and 83kDa and a degree of methoxylation of 66%. Citric acid extraction with a yield higher than H2SO4 extraction resulted in a very branched pectin with an extremely high DM (83%) and a high molar mass. Comparing the Fourier Transform Infra-Red spectroscopy of extracted and native WSF showed that citric acid remained partially associated to the extracted pectin due to its chelating properties.


Assuntos
Quelantes/química , Mangifera/química , Pectinas/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Parede Celular , Espectrometria de Massas , Polímeros
9.
Appl Opt ; 51(31): 7475-81, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-23128693

RESUMO

Nondiffracting Bessel-Gauss beams are assumed as the superposition of infinite numbers of Gaussian beams whose wave vectors lie on a cone. Based on such a description, different methods are suggested to generate these fields. In this paper, we followed an active scheme to generate these beams. By introducing an axicon-based resonator, we designed the appropriate resonator, studied its resonance modes, and analyzed the beam propagation outside the resonator. Experimentally, we succeeded to obtain Bessel-Gauss beams of the first kind and zero order. We also investigated the changes in effective parameters on the output beam, both theoretically and experimentally.

10.
Appl Opt ; 51(30): 7339-44, 2012 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-23089790

RESUMO

We studied the conditions for generating passive Bessel-Gauss beams by using an axicon. We designed an appropriate Gaussian resonator and extracted a quasi-fundamental Gaussian mode from a pulsed Nd:YAG laser pumped by a Xenon flash lamp and measured its parameters, such as propagation factor, divergence angle, and Rayleigh range. Then we generated passive Bessel-Gauss beams using an axicon and investigated their propagation properties, theoretically and experimentally. For example, for the axicon of 1°, the output energy and the Rayleigh range of the generated Bessel-Gauss beams were measured to be 58 mJ and 229.3 mm, respectively. We compared these properties with our results of the Gaussian mode. Finally, by using axicons with different apex angles, and also by changing the beam spot size on the axicon, we generated Bessel-Gauss beams and studied their properties theoretically and experimentally.

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