Ji-Yeon Chun

Characterization of β-cyclodextrin Self-Aggregates for Eugenol Encapsulation

Abstract The application of β-cyclodextrin(CD)-assisted molecular encapsulation of neutraceutical ingredients, functional food in food products, hydrophobic drugs, and volatile substances helps protect the active ingredients against oxidation, loss of volatile compounds and light-induced decomposition and increases the solubility of hydrophobic medicines. Self-assembly aggregation of CDs has been extensively investigated from the aggregation of native CDs to high-order complex aggregates. The increasing complex order of the aggregates is dependent on some parameters such as pH, temperature, time and concentration. The aim of this study was to investigate the effects of the aggregation behaviour of β-cyclodextrin (CD)-eugenol complexes induced at shaking times on the release characteristic at various relative humidity and storage temperatures. The particle size started to increase after shaking for 8 h at 650 nm, and then, significant aggregation (1,110 nm) was observed after 24 h. The retention rate of eugenol significantly increased according to storage duration under various relative humidity and temperature conditions. Prolonged shaking time enhanced the self-aggregation of β-CD-eugenol complexes resulting in eugenol release behavior due to their effect on the aggregation mechanism, as assessed by TEM observation. The aggregation of β-CD-eugenol complexes could be attributed to the slow release of eugenol owing to the presence of a thick layer of β-CD aggregates.

Formulation Development of Multilayered Fish Oil Emulsion by using Electrostatic Deposition of Charged Biopolymers

Abstract Multilayered fish oil (FO) emulsions were manufactured by using the layer-by-layer electrostatic deposition method to improve the physical or oxidation stability. Trans-cinnamaldehyde (cinnamon oil) was added into the emulsion system because it can mask fishy flavors and functions as an antioxidant. To develop the FO emulsion formulation, the composition of emulsifier and biopolymer for stable FO emulsions was determined by using the modified critical micelle concentration principle. In our study, the selected concentrations of coating materials were 1.25% Tween 20 (primary layer), 0.1% chitosan (secondary layer), and 0.2% low methoxyl pectin (tertiary layer). All FO emulsions were physically stable resulting in small particles below 300 nm with a narrow size distribution. Furthermore, the oxidation stability of multilayered FO emulsions decreased with decreasing number of membrane layers because FO was released from layered emulsions. However, trans-cinnamaldehyde had no antioxidant effect on FO emulsions. These data suggest that although cinnamon oil has no effect on the oxidation stability, the physical and oxidation stability of FO can be improved by using multilayered emulsions containing Tween 20, chitosan, and low methoxyl pectin.

Effect of Novel Quick Freezing Techniques Combined with Different Thawing Processes on Beef Quality

This study investigated the effect of various freezing and thawing techniques on the quality of beef. Meat samples were frozen using natural convection freezing (NF), individual quick freezing (IQF), or cryogenic freezing (CF) techniques, followed by natural convection thawing (NCT) or running water thawing (RT). The meat was frozen until the core temperature reached -12℃ and then stored at -24℃, followed by thawing until the temperature reached 5℃. Quality parameters, such as the pH, water binding properties, CIE color, shear force, and microstructure of the beef were elucidated. Although the freezing and thawing combinations did not cause remarkable changes in the quality parameters, rapid freezing, in the order of CF, IQF, and NF, was found to minimize the quality deterioration. In the case of thawing methods, NCT was better than RT and the meat quality was influence on the thawing temperature rather than the thawing rate. Although the microstructure of the frozen beef exhibited an excessive loss of integrity after the freezing and thawing, it did not cause any remarkable change in the beef quality. Taken together, these results demonstrate that CF and NCT form the best combination for beef processing; however, IQF and NCT may have practical applications in the frozen food industry.

Antimicrobial Effect of α- or β-Cyclodextrin Complexes with Trans-Cinnamaldehyde Against Staphylococcus aureus and Escherichia coli

Molecular inclusion or encapsulation based on cyclodextrin (CD) is the most widely used method in encapsulation technology. α- and β-CD complexes consisting of antibacterial trans-cinnamaldehyde were prepared by the molecular inclusion method. The characteristics of the complex were determined, including examination of their antimicrobial effects after the drying process. The particle sizes of the trans-cinnamaldehyde–CD complexes were observed in the range of 300 to 500 nm after production. Particle sizes of both trans-cinnamaldehyde–CD complexes were slightly increased increasing in a dose-dependent manner of trans-cinnamaldehyde. Although β-CD complexes were larger than α-CD complexes, they possessed a lower polydispersity index with a narrow size distribution. The encapsulation efficiency of trans-cinnamaldehyde–CD complexes was >90% in all formulations. Trans-cinnamaldehyde affected reduction of Staphylococcus aureus and Escherichia coli, with antibacterial activity increasing in a dose-dependent manner of trans-cinnamaldehyde concentration. In addition, β-CD complexes showed more effective antimicrobial effects compared to α-CD complexes.

Influence of High Hydrostatic Pressure on the Capsicum Oleoresin Encapsulated by Globular Protein

We studied herein the effects of high hydrostatic pressure on the physical properties of capsicum oleoresin encapsulated with globular protein, such as whey protein isolates (WPI), soybean protein isolates (SPI), and casein protein (CSP). After pressurization at 0.1, 100, 200, and 300 MPa with various concentrations (0.1, 1, 2, and 5 wt%) of proteins, the particle size, ζ-potential, and interface tension were evaluated. Furthermore, the encapsulation efficiency (EE), release study, and morphology were investigated to study the effects of high hydrostatic pressurization upon emulsion stability. While the pressurized emulsion droplet size of capsicum oleoresin emulsion with the protein decreased, the 0.1 wt% concentration of SPI presented the smallest size at 257.37 nm. The interface tension of all protein emulsions decreased slightly after high-pressure treatment according to the increment of the pressure level. EE (%) of the WPI, SPI, and CSP emulsions increased when the pressure level increased. The lowest EE 48.91% was presented in pressurized WPI emulsion at 0.1 MPa while CSP emulsion at 300 MPa showed the highest EE about 65.76%. Over twelve hours, the core material of the pressurized protein emulsions was released slowly compared to non-pressurized conditions with the WPI and CSP emulsions. At the end of the storage of the WPI and CSP non-pressured emulsions, the remaining amount of encapsulated capsicum oleoresin was only 10% and 40%, respectively, less than emulsions treated under high pressurization. Thus, the high pressurized protein could be a candidate for the encapsulation of the capsicum oleoresin.

Effects of Ethanol Addition on the Efficiency of Subcritical Water Extraction of Proteins and Amino Acids from Porcine Placenta.

In a previous study, hydrolysates of porcine placenta were obtained and the extraction efficiency for proteins and amino acids was compared between sub- and super-critical water extraction systems; optimum efficiency was found to be achieved using subcritical water (170℃, 10 bar). In this study, the effects of adding ethanol to the subcritical water system were investigated. The lowest-molecular-weight extraction product detected weighed 434 Da, and the efficiency of extraction for low-molecular-weight products was increased when either the concentration of ethanol was decreased, or the extraction time was lengthened from 10 min to 30 min. The highest concentration of free amino acids (approximately 8 mM) was observed following 30 min extraction using pure distilled water. The concentration of free amino acids was significantly lower when ethanol was added or a shorter extraction time was used (p<0.05). Color change of the solution following extraction was measured. There were no significant differences in color between lysates produced with different extraction times when using distilled water (p>0.05); however, using different extraction times produced significant differences in color when using 20% or 50% ethanol solution for subcritical extraction (p<0.05). The range of pH for the hydrolysate solutions was 6.4-7.5. In conclusion, the investigated extraction system was successful in the extraction of ≤ 500 Da hydrolysates from porcine placenta, but addition of ethanol did not yield higher production of low-molecular-weight hydrolysates than that achieved by DW alone.

Comparison of Moisture Sorption Isotherms and Quality Characteristics of Freeze-Dried and Boiled-Dried Abalone

Abstract This study investigated the moisture sorption isotherm (MSI) profiles of freeze-dried (FD) and boiled-dried (BD) abalone at 15°C, 25°C, and 35°C, and compared the quality characteristics of the abalone after rehydration. The equilibrium moisture content (EMC) and the calculated monolayer moisture content of FD abalone were higher than those of BD abalone. After rehydration, FD abalone showed a higher yield and a lower shear force than BD abalone. Additionally, the appearance of FD abalone was similar to that of fresh abalone, reflecting a potential application of FD to produce value-added dried abalone.

Effects of binders combined with glucono-δ-lactone on the quality characteristics of pressure-induced cold-set restructured pork

This study investigated the effects of binders and glucono-δ-lactone (GdL) on characteristics of pressure-induced (450MPA for 3min) cold-set restructured pork. Isolated soy protein (SP), wheat flour (WF), and κ-carrageenan (CG) were adopted as binders. The addition of binders improved water-binding properties of restructured pork, and the binders diminished the decrease in water binding properties caused by GdL-induced acidification. Pressure-induced restructured pork prepared with binders showed less harder and more cohesive texture than those of the thermal-treated control (TC). The results indicate that pressure-induced cold-set meat restructuring could be achieved when binders and GdL were used in the formulation.

Effects of NaCl Replacement with Gamma-Aminobutyric acid (GABA) on the Quality Characteristics and Sensorial Properties of Model Meat Products

This study investigated the effects of γ-aminobutylic acid (GABA) on the quality and sensorial properties of both the GABA/NaCl complex and model meat products. GABA/NaCl complex was prepared by spray-drying, and the surface dimensions, morphology, rheology, and saltiness were characterized. For model meat products, pork patties were prepared by replacing NaCl with GABA. For characteristics of the complex, increasing GABA concentration increased the surface dimensions of the complex. However, GABA did not affect the rheological properties of solutions containing the complex. The addition of 2% GABA exhibited significantly higher saltiness than the control (no GABA treatment). In the case of pork patties, sensory testing indicated that the addition of GABA decreased the saltiness intensity. Both the intensity of juiciness and tenderness of patties containing GABA also scored lower than the control, based on the NaCl reduction. These results were consistent with the quality characteristics (cooking loss and texture profile analysis). Nevertheless, overall acceptability of the pork patties showed that up to 1.5%, patties containing GABA did not significantly differ from the control. Consequently, the results indicated that GABA has a potential application in meat products, but also manifested a deterioration of quality by the NaCl reduction, which warrants further exploration.

Effect of Porcine Collagen Peptides on the Rheological and Sensory Properties of Ice Cream.

The effects of low molecular-weight collagen peptides derived from porcine skin were investigated on the physicochemical and sensorial properties of chocolate ice cream. Collagen peptides less than 1 kDa in weight were obtained by sub-critical water hydrolysis at a temperature of 300℃ and a pressure of 80 bar. Ice cream was then prepared with gelatin powder and porcine skin hydrolysate (PSH) stabilizers mixed at seven different ratios (for a total of 0.5 wt%). There was no significant difference in color between the resulting ice cream mixtures. The increase in apparent viscosity and shear thinning of the ice cream was more moderate with PSH added than with gelatin. Moreover, the samples containing more than 0.2 wt% PSH had enhanced melting resistance, while the mixture with 0.2 wt% PSH had the lowest storage modulus at -20℃ and the second highest loss modulus at 10℃, indicating that this combination of hydrocolloids leads to relatively softer and creamier chocolate ice cream. Among the seven types of ice creams tested, the mixture with 0.2 wt% PSH and 0.3 wt% gelatin had the best physicochemical properties. However, in sensory evaluations, the samples containing PSH had lower chocolate flavor scores and higher off-flavor scores than the sample prepared with just 0.5 wt% gelatin due to the strong off-flavor of PSH.