Gye Hwa Shin

Radish powder was prepared using radish and by-products of radish processing by three different drying methods, such as hot air drying, freeze drying, and microwave vacuum drying. The radish powder was characterized by measuring moisture content, color change, particle size, particle shape, and antioxidant activity. The moisture contents of the standard radish powder under the hot air drying, freeze drying, and microwave vacuum drying conditions were 5.15%, 5.22%, and 4.62%, respectively, while the moisture contents of the non-standard radish powder were 5.57%, 5.51%, and 4.85%, respectively. The smallest particle size of the non-standard radish powder was 9.5±0.10 μm observed by the microwave vacuum drying, and the largest particle size of the non-standard radish powder was 12.2±0.08 μm observed by hot air drying. The DPPH and ABTS radical scavenging activities were the highest in the hot-air-dried standard radish powder of 79.0% and 83.4%, respectively, and the lowest in the microwave vacuum-dried non-standard radish powder of 50.0% and 16.7%, respectively. Therefore, when manufacturing radish powder using non-standard radish waste discarded during radish processing, freeze-drying is considered the most suitable drying method because it could minimize color change of the radish powder and show high antioxidant activity.

Radish powder was prepared using radish and by-products of radish processing by three different drying methods, such as hot air drying, freeze drying, and microwave vacuum drying. The radish powder was characterized by measuring moisture content, color change, particle size, particle shape, and antioxidant activity. The moisture contents of the standard radish powder under the hot air drying, freeze drying, and microwave vacuum drying conditions were 5.15%, 5.22%, and 4.62%, respectively, while the moisture contents of the non-standard radish powder were 5.57%, 5.51%, and 4.85%, respectively. The smallest particle size of the non-standard radish powder was 9.5±0.10 μm observed by the microwave vacuum drying, and the largest particle size of the non-standard radish powder was 12.2±0.08 μm observed by hot air drying. The DPPH and ABTS radical scavenging activities were the highest in the hot-air-dried standard radish powder of 79.0% and 83.4%, respectively, and the lowest in the microwave vacuum-dried non-standard radish powder of 50.0% and 16.7%, respectively. Therefore, when manufacturing radish powder using non-standard radish waste discarded during radish processing, freeze-drying is considered the most suitable drying method because it could minimize color change of the radish powder and show high antioxidant activity.

This study explores the enhancement of mechanical properties in cotton yarn-reinforced poly(lactic acid) (PLA) biocomposites, aimed at providing a sustainable alternative to petroleum-based plastics. The primary challenge addressed is the low interfacial shear strength (ISFF) between the hydrophilic cotton yarn and the hydrophobic PLA matrix. To overcome this, cotton yarn surface was chemically modified using silane treatment. Cotton yarns were aligned on a metal frame and treated with hydrolyzed silane solutions at concentrations of 1%, 2%, 3%, and 4% (w/v) for 3 h. Although the tensile stress of the cotton yarn decreased significantly (p < 0.05) with higher silane concentrations, from 520.46 MPa (untreated) to 340.88 MPa (4% silane-treated), the IFSS improved significantly (p < 0.05) from 5.63 MPa to 12.12 MPa. Consequently, the tensile stress of the cotton yarn/PLA biocomposites increased significantly (p < 0.05), from 20.74 MPa (untreated) to 41.58 MPa (4% silane-treated). This is because the increased IFSS achieved through silane treatment allowed the PLA polymer to more firmly connect adjacent cotton fibers, resulting in maximum strength. FTIR and SEM analyses confirmed successful surface modification of the cotton yarn. These findings demonstrate that silane treatment effectively enhances interfacial bonding between cotton yarn and PLA resin, leading to improved mechanical performance of the biocomposites.

Nano-carriers and dried gels were prepared to prevent the inherent flavor of Yuja (Citrus junos Tanaka) from rapidly deteriorating. The properties and stability of volatile components of Yuja dried gels were compared by using colloidal systems (nanoemulsion (NE) and nanostructured lipid carrier (NLC)), coating materials (maltodextrin (MD) and a mixture of MD and β-cyclodextrin (MD/βCD)), and drying processes (spray-drying and freeze-drying). Drying was found to have a significant effect on the particle size, moisture content, color, morphology, and volatile profiles of Yuja dried gels. Meanwhile, the stability of limonene and γ-terpinene, the main volatile components of Yuja oil, was affected by the colloidal system, coating material, and storage temperature. When Yuja oil was encapsulated by an NLC and MD/βCD coating, the degradation of limonene and γ-terpinene of Yuja dried gels was reduced during storage at 4 °C.

As health concerns and regulatory pressures over saturated and trans fats grow, there is a growing need for healthier alternatives to traditional solid fats, such as butter and hydrogenated oils, that are still widely used in the food system. In this study, cellulose particle-based Pickering emulsions (CP-PEs) were prepared from microcrystalline cellulose and ethylcellulose and then foamed to obtain edible oleofoams (CP-EOs) as a solid-fat replacer. The average size of CP-PE droplets without surfactant was 598 ± 69 nm, as confirmed by confocal and transmission electron microscopy. Foaming with citric acid/NaHCO₃ and structuring with ≥6% glyceryl monostearate resulted in CP-EOs with an overrun of 147 ± 4% and volumetric stability for 72 h. Micro-computed tomography showed a uniform microcellular network, while the rheological analysis showed solid-like behavior with a storage modulus higher than butter. Differential scanning calorimetry showed a melting enthalpy similar to unsalted butter (10.1 ± 0.9 J/g). These physicochemical properties demonstrate that CP-EOs can closely mimic the firmness, thermal profile, and mouth-feel of conventional solid fats and may provide a promising solid-fat replacer.