• Journal of Microbiology and Biotechnology
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• v.31 no.4
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• pp.592-600
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• 2021

Probiotics can be processed into a powder, tablet, or capsule form for easy intake. They are exposed to frequent stresses not only during complex processing steps, but also in the human body after intake. For this reason, various coating agents that promote probiotic bacterial stability in the intestinal environment have been developed. Silk fibroin (SF) is a material used in a variety of fields from drug delivery systems to enzyme immobilization and has potential as a coating agent for probiotics. In this study, we investigated this potential by coating probiotic strains with 0.1% or 1% water-soluble calcium (WSC), 1% SF, and 10% trehalose. Under simulated gastrointestinal conditions, cell viability, cell surface hydrophobicity, and cell adhesion to intestinal epithelial cells were then measured. The survival ratio after freeze-drying was highest upon addition of 0.1% WSC. The probiotic bacteria coated with SF showed improved survival by more than 10.0% under simulated gastric conditions and 4.8% under simulated intestinal conditions. Moreover, the cell adhesion to intestinal epithelial cells was elevated by 1.0-36.0%. Our results indicate that SF has positive effects on enhancing the survival and adhesion capacity of bacterial strains under environmental stresses, thus demonstrating its potential as a suitable coating agent to stabilize probiotics throughout processing, packaging, storage and consumption.

• Journal of Microbiology and Biotechnology
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• v.34 no.5
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• pp.1051-1058
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• 2024

This study investigated the impact of inulin (INL) on viability of L. plantarum D-2 (LPD2) by encapsulation through spray drying (SD) and its commercialization potential to alternative of conventional wall material maltodextrin (MD). LPD2, derived from sea tangle (Saccharina japonica) kimchi, is probiotics exhibiting significant attributes like cholesterol reduction, antioxidant properties, and resilience to acidic and bile environments. To enhance storage viability and stability of LPD2, encapsulation was applied by SD technology. The optimum encapsulation condition with MD was 10% MD concentration (MD10) and inlet temperature (96℃). The optimum concentration ratio of MD and INL was 7:3 (INL3) for alternative of MD with similar encapsulation yield and viability of LPD2. Viability of LPD2 with INL3 exhibited almost 8% higher than that with MD10 after 50 days storage at 25℃. Physicochemical characteristics of the encapsulated LPD2 (ELPD2) with MD10 and INL3 had no significant different between flowability and morphology. But, ELPD2 with INL3 had lower water solubility and higher water absorption resulting in extension of viability of LPD2 compared to that with MD10. The comprehensive study results showed that there was no significant difference in the encapsulation yield and physicochemical properties between ELPD2 with MD10 and INL3, except of water solubility index (WSI) and water absorption index (WAI). INL have the potential to substitute of MD as a commercial wall material with prebiotic functionality to enhance the viability of LPD2 by encapsulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.5
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• pp.707-716
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• 2020

Red sea cucumber Stichopus japonicus, was dried using three methods-far-infrared ray, vacuum, and freeze drying and then enzymatically hydrolyzed using nine proteases: Alcalase, Flavourzyme, Kojizyme, Neutrase, Protamex, trypsin, α-chymotrypsin, and papain. In addition, the potential ability of hydrolysates to inhibit lipid accumulation in 3T3-L1 adipocytes was evaluated. The yield of hydrolysates from red sea cucumbers dried using each method was higher than that of the distilled water extract, and protein contents were either similar or higher. The hydrolysates that exhibited inhibitory effects on lipid accumulation, as demonstrated via Oil red O staining, were those obtained by far-infrared ray drying coupled with Alcalase, Flavourzyme, Kojizyme, or Neutrase treatment. In addition to the advantages of far-infrared drying and the characteristics of Flavourzyme, the Flavourzyme hydrolysate of far-infrared-dried red sea cucumber showed the highest inhibitory effect on lipid accumulation. In addition, this hydrolysate significantly decreased the expression of the protein factor fatty acid-binding protein 4, which is related to the late differentiation of 3T3-L1 adipocytes. Taken together, these results suggest that Flavourzyme hydrolysates from farinfrared-dried red sea cucumber may be used as a functional food and/or a pharmaceutical ingredient for the inhibition of lipid accumulation.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.672-681
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• 2009

The aim of this study was to evaluate the antioxidant activities of enzymatic digests from citrus by-products (CBPs) prepared by high speed drying (HSD). HSD needs a short time (60 min) for drying and can be used in a commercial scale. Enzymatic digests were prepared from the CBPs using 6 enzymes such as aminoglucosidase (AMG), celluclast, pectinex, termamyl, ultraflo, and viscozyme. Antioxidant activities of AMG digest from CBPs were evaluated by different in vitro models such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, alkyl, $H_2O_2$ scavenging, metal chelating, lipid peroxidation, and comet assays, and exhibited strong activities. The antioxidant compounds were detected by an high performance liquid chromatography (HPLC) coupled on-line to an 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid ($ABTS^+$) scavenging detection system, and found that hesperidin was the key compound. Therefore, the results obtained in this study suggest that HSD is an effective method to transform wet CBPs into dried form, and CBPs are potential source of natural antioxidant.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.121-128
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• 2022

The aims of this study were to optimize the processing procedure of high-quality semi-alternating temperature dried Israeli carp Cyprinus carpio (SAD-IC) and to investigate the sensory properties of the product. Based on the differences in moisture content of the dorsal and ventral muscles, high quality SAD-IC was prepared by alternating the drying temperature between 4 h at 35℃, and 2 h at 5℃, three times before final drying for 2 h at 35℃. The surface in SAD-IC produced under the optimal alternating-temperature drying process had a markedly superior browning index value and softer texture compared to products produced using constant-temperature drying. SAD-IC produced from dorsal and ventral muscle had significantly superior taste values than the raw material. These results suggest that SAD-IC has the potential to be industrialized.

• Fisheries and Aquatic Sciences
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• v.25 no.7
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• pp.390-402
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• 2022

In this study we investigate physical and chemical characteristics of immature and mature skipjack tuna (Katsuwonus pelamis) roes in fresh and dried forms. Fresh roes were studied for histological structure and also dried by three methods: hot air drying (HD), vacuum drying (VD) and freeze drying (FD). The obtained roe powders were analysed for proximate composition, color value, fatty acid composition, amino acid profile, equivalent umami concentration (EUC) and protein pattern. Unyolked oocytes were more common in immature roes, while fully yolked oocytes were more common in mature roes. All dried tuna roes contained high content of protein and lipid (69.31%-70.55% and 11.14%-16.02%, respectively). The powders obtained by FD provided the highest lightness value (L^*). The main fatty acid found in all roe powders was docosahexaenoic acid (DHA) (23.49%-27.02%). Glutamic acid, leucine, and aspartic acid were the three most abundant amino acids found in the powders (13.58-14.61, 8.06-8.42, and 7.81-8.39 g/100 g of protein, respectively). The mature roe powder obtained from HD provided the highest EUC value (73.09 g monosodium glutamate/100 g of samples). The protein band at molecular weight of 97 kDa (vitelline) represented the major protein. Therefore, dried tuna roe could be a functional ingredient source of protein and lipid rich in DHA and it also has potential to be used as taste enhancer with umami compound.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.12
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• pp.1725-1731
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• 2016

This study was carried out to investigate the effects of steam-drying on antioxidant compounds and antioxidant activity of Alliun hookeri root (AHR). The yield of methanolic extracts, total phenolic content (TPC), browning intensity (280 nm and 420 nm), and organosulfur compound contents (alliin and cycloalliin) in raw and steam-dried AHRs were 10.71~37.40%, $15.53{\sim}36.36{\mu}g/mg$, 0.48~2.09, 0.01~0.25, $1.46{\sim}700.61{\mu}g/mg$, and $1,173.95{\sim}2,182.60{\mu}g/mg$, respectively. Yield, TPC, and browning intensity of AHRs increased by steam-drying, whereas organosulfur compound contents decreased. Of all methanolic extracts from raw and steam-dried AHRs, four-time steam-drying showed the lowest $EC_{50}$ values (0.43, 7.53, 0.34, and 0.48 mg/mL, respectively) for DPPH radical scavenging activity, ABTS radical scavenging activity, SOD-like activity, and reducing power, whereas four-time steam-drying resulted in the highest TPC ($36.36{\mu}g/mg$) and browning intensity (2.09 and 0.25 at 280 and 420 nm, respectively). The antioxidant activities of methanolic extracts from raw and steam-dried AHRs were closely correlated with their TPC, browning intensity, and organosulfur compound content, showing correlation determination coefficient ($R^2$) values higher than 0.82. As a result, four-time steam-drying of AHRs could be useful as potential antioxidant sources.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.5
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• pp.682-689
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• 2014

This study was carried out to discriminate the effects of the ramie leaf according to the drying methods (hot air drying and freeze drying) on antioxidative activity in vitro and antiproliferation in human cancer cells. There were no significant differences in total polyphenol content of ramie leaf ethanol extracts depending on the drying methods, but total flavonoid content was significantly higher in hot air dried ramie leaf (HR) than in freeze dried ramie leaf (FR). The DPPH radical scavenging activity of HR and FR ethanol extracts were found to be 77.74%, and 77.29% in 1000 ppm, respectively. Antioxidative index of HR and FR ethanol extracts measured by Rancimat were lower than those in BHT, BHA, and ascorbic acid, but were higher than that in control. The antiproliferation effect of 80% ethanol extracts of HR and FR on liver cancer cell line (H460), stomach cancer cell line (AGS), and lung cancer cell line (A549) were increased with a dose-dependent manner. The cancer cell growth inhibition activities of HR and FR ethanol extracts at the concentration of $800{\mu}g/mL$ showed greater than 80% on Hep G2 and A549 cell line, and greater than 75% on AGS cell line. These results suggest that HR and FR ethanol extracts possess potential antioxidative effect and antiproliferation in human cancer cells, and those activities of ramie leaf ethanol extracts depending on the drying methods were similar.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1801-1807
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• 2014

Blue mussels (Mytilus edulis) are widely distributed among the world's oceans in various habitats. The purpose of this study was to investigate the effects of freeze-drying on the antioxidant and antigenotoxic activities of blue mussels collected in the Gyeongnam coast area of Korea. Raw (RM) and freeze-dried blue mussel flesh (FRM) were extracted with ethanol, methanol, and water. Antioxidant activities were evaluated on the basis of DPPH radical scavenging activity, oxygen radical absorbance capacity (ORAC), cellular antioxidant capacity (CAC), and antigenotoxic activity (comet assay). Except for the water extract, RM and FRM showed DPPH radical scavenging activities, which increased upon freeze-drying in MeOH extract. The highest ORAC value was observed in water extract of RM and MeOH extract of FRM. CAC was protected against AAPH-induced oxidative stress in HepG2 cells by both RM and FRM extracts. Freeze-drying lowered ORAC value of water extract, whereas it increased CAC activity, suggesting that antioxidant activities varied according to the generated radicals. All extracts from RM and FRM showed antigenotoxic activities by reducing $H_2O_2$-induced DNA damage in human leukocytes. Freeze-drying had no effect on antigenotoxicity of blue mussels. Taken together, these results indicate that blue mussels possess antioxidant and antigenotoxic properties, and freeze-drying might be a useful processing method for blue mussels to retain their maximum physiological potential as a functional food.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.04a
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• pp.13-18
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• 1992

Moisture movement which is controlled by water potential and permeability of concrete is a very important phenomenon which affects the shrinkage of concrete. Thermocouple psychrometer were used to measure the moisture potentials in concrete. Based on the measured moisture potentials, three method have been proposed to calculate hycraulic conductivity and diffusivity. And also the hystresis of sorption isotherm due to drying and wetting cycle has been crawn.