Browsing by Autor "Jaeyeong Choi"

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Asymmetric flow field-flow fractionation for the monitoring of red wine colloids and macromolecules throughout the winemaking process
(Frontiers Media, 2025) Daniel E. Osorio-Macías; Raúl Ferrer‐Gallego; Jaeyeong Choi; Björn Bergenståhl
Colloids and macromolecules are the major compounds in wine particulate matter and play an important role in many wine properties that change during the winemaking process. However, methodologies are lacking to characterize and quantify the changes these compounds undergo throughout the process. This work uses asymmetric flow-field fractionation coupled to multiple detectors (AF4–MALS–dRI–UV) to separate, characterize, and quantify colloidal and macromolecular properties. Furthermore it provides useful information on the evolution and dynamics of these colloidal and macromolecular fractions throughout five winemaking stages. The results showed that the (AF4–MALS–dRI–UV) technique allows monitoring changes in specific colloidal and macromolecular properties during the winemaking process. In this study, three populations were separated and classified according to their nature and main properties throughout the winemaking process. It was observed that concentration, c, and specific absorptivity (ɛ) tend to vary more depending on the wine variety and the vinification stage. However, the maturation and aging stages tended to stabilize changes in the early stages. In contrast, properties such as hydrodynamic radius (rH), molar mass (MW) and regularly the apparent density ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="m1"><mml:mrow><mml:mover accent="true"><mml:mi>p</mml:mi><mml:mo>^</mml:mo></mml:mover></mml:mrow></mml:math> ) tend to remain more stable as the winemaking process progresses. The results demonstrated the use of AF4–MALS–dRI–UV as a robust and feasible technique to separate the wine particle matter and to monitor fundamental colloidal and macromolecular properties in a wide variety of samples without the support of additional techniques throughout the winemaking process.
Characterization of non-solvent precipitated starch using asymmetrical flow field-flow fractionation coupled with multiple detectors
(Elsevier BV, 2018) Catalina Fuentes; Hisfazilah Saari; Jaeyeong Choi; Seungho Lee; Malin Sjöö; Marie Wahlgren; Lars Nilsson
Characterization on the impact of different clarifiers on the white wine colloids using Asymmetrical Flow Field-Flow Fractionation
(Elsevier BV, 2022) Daniel E. Osorio-Macías; Hans Bolinsson; Javier A. Linares‐Pastén; Raúl Ferrer‐Gallego; Jaeyeong Choi; J. Mauricio Peñarrieta; Björn Bergenståhl
Clarifiers are substances used during the winemaking process to enhance clarity and stability in the wines. The different clarifiers may alter removal capacities differently. In this study, the removal efficiency of seven common fining agents, divided into three groups (mineral clarifiers, synthetic polymeric clarifiers, and vegetable protein clarifiers), was analyzed with Asymmetrical Flow Field-Flow fractionation (AF4). Besides, the relationship between the removal capacity and different molecular and macromolecular properties has been evaluated. The results showed extensive removal of colloidal and macromolecular matter by the bentonites with potential impact on characteristic properties of the wine. The vegetable clarifiers showed a more profiled reduction, potentially preserving characteristics of the wine. The synthetic polymers showed a more limited removal efficiency but with a high affinity to remove colloidal phenols. The use of AF4-UV-MALS-dRI allowed the characterization of the wines after different clarification treatments, showing to be an analytical technique with a potential impact on the wine industry.
Comparison between conventional and frit-inlet channels in separation of biopolymers by asymmetric flow field-flow fractionation
(Royal Society of Chemistry, 2019) Catalina Fuentes; Jaeyeong Choi; Claudia Zielke; J. Mauricio Peñarrieta; Seungho Lee; Lars Nilsson
Asymmetric flow field-flow fractionation (AF4) is a separation technique in which a focusing/relaxation step is used after the sample is injected onto the separation channel. During the focusing/relaxation step, the sample is focused by two counter-directed flows. This allows sample components to establish a diffusion-dependent equilibrium concentration profile. The focusing step may, in some cases, cause a loss of sample due to adsorption into the accumulation wall (i.e. the membrane) or due to aggregation of the sample. In addition, the increase in sample concentration during the focusing step may prevent complete relaxation and cause overloading effects. In this study, a modified AF4 channel equipped with a frit inlet (FI-AF4) is utilized, where the sample is relaxed hydrodynamically as it enters to the channel through the frit. The main advantage of the FI-AF4 channel is to omit the focusing step. The FI-AF4 channel could also allow higher injection mass than in a conventional channel while still avoiding overloading. The purpose of the present study is to compare two channels (conventional and FI-AF4 channels) in terms of the plate height (H), resolution (Rs) and the mass recovery for analysis of a mixture of glycogen and pullulan. In addition, waxy maize (WM) starch was used to compare the mass overloading of the two channels. The results show that the type of relaxation method (i.e. focusing or hydrodynamic relaxation) had no significant effect on mass recovery. The resolution (Rs), was higher in the conventional AF4 channel than in the FI-AF4 channel for the separation of glycogen and pullulan. The results also show that it was possible to inject a higher mass of WM starch (i.e. twice the mass) onto the FI-AF4 channel, compared to a conventional AF4 channel, without observing an overloading effect.
Fractionation and characterization of starch granules using field-flow fractionation (FFF) and differential scanning calorimetry (DSC)
(Springer Science+Business Media, 2019) Catalina Fuentes; In Byeong Kang; Jangjae Lee; Dongsup Song; Malin Sjöö; Jaeyeong Choi; Seungho Lee; Lars Nilsson
Starch is one of the main carbohydrates in food; it is formed by two polysaccharides: amylose and amylopectin. The granule size of starch varies with different botanical origins and ranges from less than 1 μm to more than 100 μm. Some physicochemical and functional properties vary with the size of the granule, which makes it of great interest to find an efficient and accurate size-based separation method. In this study, the full-feed depletion mode of split-flow thin cell fractionation (FFD-SF) was employed for a size-based fractionation of two types of starch granules (corn and potato) on a large scale. The fractionation efficiency (FE) of fraction-a for corn and potato granules was 98.4 and 99.4%, respectively. The FFD-SF fractions were analyzed using optical microscopy (OM) and gravitational field-flow fractionation (GrFFF). The respective size distribution results were in close agreement for the corn starch fractions, while they were slightly different for the potato starch fractions. The thermal properties of FFD-SF fractions were analyzed, and the results for the potato starch showed that the peak temperature of gelatinization (Tp) slightly decreases as the size of the granules increases. Additionally, the enthalpy of gelatinization (ΔH) increases when the granule size increases and shows negative correlation with the gelatinization range (ΔT).
Fractionation of Nanoparticle Matter in Red Wines Using Asymmetrical Flow Field-Flow Fractionation
(American Chemical Society, 2020) Daniel E. Osorio-Macías; Dongsup Song; Johan Thuvander; Raúl Ferrer‐Gallego; Jaeyeong Choi; J. Mauricio Peñarrieta; Lars Nilsson; Seungho Lee; Björn Bergenståhl
The particle matter of wine is mainly composed of wine colloids and macromolecules. The present work develops a methodology using asymmetrical flow field-flow fractionation coupled with multi-angle light scattering, differential refractive index detector, and ultraviolet detector (AsFlFFF-MALS-dRI-UV) for the fractionation and determination of the molar mass, the hydrodynamic radius, and the apparent densities of the aggregates and macromolecules present in wine samples. The results from a set of six Argentinian high-altitude wines showed two main populations: the first population composed of wine colloids with higher UV-specific absorptivity and the second population composed of polysaccharides, such as arabinogalactans. The conformation results showed that population 1 consists of small and dense particles, while population 2 showed high molar masses and lower densities. The results demonstrated the use of AsFlFFF as a new, effective method for the fractionation and characterization of wine colloids and wine macromolecules in red wines with further potential applications.