• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.654-660
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• 1998

In preparing PSZT powder by hydrothermal synthesis, effects of reaction temperature, concentration of raw materials and mineralizer on crystallinity, particle size distribution, and dielectric constant were investigated. By varying the concentration of mineralizer and the ratio of Pb to Sr or Zr to Ti, crystalline PSZT powder, having the mean particle size of $0.3{\sim}15{\mu}m$, was prepared by hydrothermal synthesis in the temperature range of $120{\sim}200^{\circ}C$ for a 2h reaction. PSZT ceramics, having dielectric constant of 1000~3000, were prepared at $1150^{\circ}C$ for a 2h sintering reaction of the PSZT powders. Experimental results showed that the weight mean particle size of $0.5{\mu}m$ was obtained when the concentration of KOH in the solution was 10 wt % and the ratio of Pb to Sr was 0.95/0.05, that of Zr to Ti was 0.52/0.48. It also showed that the ceramics of dielectric constant of 2900 were prepared through sintering of this PSZT powder. Size of PSZT particles became smaller with its narrow distribution as the concentration of KOH increased up to 10 wt %. However, it came to be larger at this concentration and above. By adding small amount of Sr that would not affect that crystallinity of particles we can improve dielectric property of sintered materials. Addition of Zr may shift the major crystal phase of synthetic PSZT powder from tetragonal to rhombohedral phase.

• Food Engineering Progress
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• v.13 no.2
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• pp.92-98
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• 2009

An investigation was carried out to study the effects of extraction, heat treatment, and storage temperature on functional ingredients of onion. Extracts of onion paste and freeze dried onion were prepared by treatments with several solvents including hot water, methanol, and ethanol, and then contents of functional ingredients such as total phenol, flavonoid, quercetin, and thiosulfinate were determined. The highest levels of functional ingredients were observed in samples extracted using water at 100$^{\circ}C$ or ethanol. The skin extract contained 60-fold more quercetin than onion paste extract, whereas no thiosulfinate was detected in onion skin extract. Heat treatment of onion extracts at 60, 80, 105, and 121$^{\circ}C$ did not effect on the levels of all functional ingredients tested. During four-week storage, the levels of total phenol, flavonoid, and quercetin were not significantly changed regardless of storage temperature. However, the total thiosulfinate was rapidly reduced as the storage temperature increased.

• Food Engineering Progress
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• v.14 no.1
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• pp.54-59
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• 2010

Instantized thin gruels have been popular to supplement patients who want nutritional, ready-to-eat, and easy-to-use products. In this study, rice-based thin gruels were developed by use of gelatinized rice powder which was manufactured by extrudating rice in a twin-screw extruder. Subsequently, the rice paste from the extruder were dried and ground into fine powder. The gelatinized rice powder was mixed with the powders of various grains, soy beans, nuts, oil seeds, and vegetables to formulate the instantized thin rice gruel with well-balanced nutrients (mixed powder). The mixed powder was granulated to improve reconstitution capability in a fluid bed spray granulator (granulated powder). Lipid and protein contents were higher by 0.9 and 1.9%, respectively, in the granulated powder whereas carbohydrate content was higher by 3.2% in the mixed powder. The calculated dispersibility was 93.7 and 77.0% for the granulated and the mixed powders, respectively. The reconstitution time was 122.3 and 305.3 for the granulated and the mixed powders, respectively. In conclusion, the granulation of the mixed powder improved the dispersibility. This study will be helpful to develop a variety of processed rice products and promote rice process industry.

• Journal of Plant Biotechnology
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• v.48 no.3
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• pp.193-200
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• 2021

Barley (Hordeum vulgare cv. Hangmaeg) sprouts are important microgreens that contain high levels of polyphenols and flavonoids, as well as minerals, vitamin and chlorophyll. Barley sprouts were grown for 9 days and growth was checked every 3 days. In this study, the cultivation efficiency according to the nutrient solution treatment was evaluated by analyzing the length of barley sprouts, fresh weight, chlorophyll, and the yield by growth period. In addition, we tried to increase the industrial applicability of germinated barley through analysis of inorganic component, total polyphenol and total flavonoid content of the extract, and functional substance analysis using HPLC. As a result, the growth rate of the nutrient solution treatment group was faster than that of the control group. When harvested on the 9th day of sowing, the nutrient solution treatment group showed a significant increase in yield compared to the control group. And the barley sprout extract of the nutrient solution treatment group had higher total flavonoid content and luteolin content. Also, the efficiency of water was higher than that of ethanol when extracting phenolics from barley sprouts. Therefore, this study suggests that nutrient input is effective for increasing polyphenol content and increasing production in barley sprout hydroponics.

• Food Engineering Progress
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• v.15 no.4
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• pp.420-425
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• 2011

Addition effects of free fatty acids (FFA), glycerol, monoacylglycerol (MAG), sesamol, and aqueous extracts of sesame seed meal (ASM) on the changes of sesamol and sesamolin were determined in thermally oxidized sesame oil (SO) at 180$^{\circ}C$ for 90 min. Sesamol and sesamolin in SO were analyzed by high performance liquid chromatography (HPLC). As the concentration of FFA and MAG in SO increased up to 10% (w/w), the concentration of sesamol increased significantly by 0.94 and 0.70 mM, respectively (p < 0.05) whereas sesamol in control samples increased by 0.09 mM for 90 min oxidation. Sesamolin in 10% MAG and FFA added SO significantly decreased by 15 and 18%, respectively (p < 0.05) compared to control samples. Sesamolin in SO with addition of 1.5 and 2.5 mM sesamol were not significantly different (p > 0.05). Addition effects of ASM on the changes of sesamol and sesamolin in SO were not constant during thermal treatment. Conversion of sesamol from sesamolin in SO during thermal treatment seemed to be influenced by the presence of FFA and MAG.

• Food Engineering Progress
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• v.13 no.1
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• pp.64-69
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• 2009

From the 25 fresh fruits and vegetable products, 1,250 isolates grown on MRS agar media were screened for the inhibitory activity on the growth of Escherichia coli 0157:H7, Listeria monocytogenes, and Bacillus cereus as well as Lactobacillus plantarum, L. casei, and Lactococcus lactis subsp. lactis. Among them, 607 isolates (49% of total isolates) from 23 different foods produced growth inhibitory activity on the E. coli 0157:H7, L. monocytogenes, or B. cereus. When these isolates were screened for the inhibitory activity on the growth of L. plantarum, L. casei, and Lactococcus lactis subsp., 24 isolates (3% of total isolates) from 7 food samples showed bacteriocin-like activity. These isolates had typical physiological characteristics of lactic acid bacteria, which indicated these isolates were strains of lactic acid bacteria. The inhibitor from 3 out of 24 revealed as nicin. From the RAPD-PCR profiles, 24 strains was classified and it was also indicated that most of the strains isolated from same produce showed similar phylogenetic profile.

• Food Engineering Progress
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• v.14 no.2
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• pp.183-187
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• 2010

Multiple lines of study have shown that Acanthopanax species have anti-oxidant and chemopreventive effect. However, the suitability of Acanthopanax sessilifloru fruit (Ogaza) as a functional food source remains to be investigated. Therefore, we have investigated the effect of Ogaza as an anti-oxidant and anti-inflammatory substance. The phenolic content of Ogaza is 56.1${\pm}$5.2 mg gallic acid equivalents (GAE) per 1 g of Ogaza. The 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging effects of Ogaza extract at 0.25, 0.5, 1, or 2 mg/mL were 34.0, 73.0, 194.3, or 339.7 $\mu g$/mL vitamin C equivalent antioxidnat capacity (VCEAC), respectively. Ogaza extract (1 or 2 mg/mL) inhibited LPS-induced TNF-$\alpha$ production (decrease of 22${\pm}$2% or 19${\pm}$6%, respectively). It also inhibited LPS-induced IL-6 production (decrease of 18${\pm}$2% or 24${\pm}$3%, respectively). In addition, Ogaza extract (0.25, 0.5, 1, or 2 mg/mL) inhibited COX-2 luciferase activity (decrease of 80${\pm}$1%, 83.${\pm}$7%, 96${\pm}$4%, or 98${\pm}$2%, respectively). Overall, these results indicated that Ogaza is promising as a functional food source due to its antioxidant and anti-inflammatory effects.

• Food Engineering Progress
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• v.15 no.3
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• pp.230-234
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• 2011

The objective of this study was to optimize the thermal condition and determine the shelf life of heated Chunbokjang product. The optimum thermal condition of heated Chunbok-jang product was determined by sensory test, and heat penetration curve was obtained by Thermal Microprocessor. Sterilization time was a 21~23 min until $F_0$ value reached 9 min, depending upon the number of abalone. As solid content was reduced and temperature of sterilization was increased, the thermal death time was decreased. The score of sensory test indicated that there was no significant difference in flavor of heated Chunbok-jang product made at different sterilization temperatures (110, 121.1, 125, and $130^{\circ}C$). Heated Chunbok-jang product, however, sterilized at $125^{\circ}C$ showed the highest score in texture and taste values. Salinity and pH were not changed during seven month storages, but texture became firmer, and any microorganism had not been detected from the heated chunbok-jang product during these periods. As a result of storage experiment, the shelf-life of heated Chunbok-jang product was 3-month at room temperature.

• Food Engineering Progress
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• v.15 no.4
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• pp.370-375
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• 2011

In this study the polymerase chain reaction (PCR) combined with denaturing gradient gel electrophoresis (DGGE) was evaluated as a method permitting the rapid detection of pathogens in fresh originally grown vegetables. A universal primer (341GCf/534r) was selected for its ability to amplify the V3 region of 16S-rRNA genes in their target pathogens (Salmonella typhimurium, Pseudomonas fluorescens, Bacillus cereus, Listeria monoytogenes, Staphyloocus aureus, E. coli). The 194 bp fragments in PCR were successfully duplicated as expected. The amplified fragments of the same size from six different pathogens also showed good separation upon DGGE. The detection limit of PCR-DGGE for six pathogens in fresh-cut lettuces were over $10^{5}$ CFU/g when sampled by stomaching. However, when the sampling method was changed from stomaching to shaking, the detection limit of six pathogens in organic vegetables was shown to increase by over $10^{1}$ CFU/g, but only those of B. cereus were over $10^{3}$ CFU/g. Therefore, PCR-DGGE was shown to be a reliable method for the detection of pathogens in fresh-cut vegetables.

• Food Engineering Progress
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• v.15 no.4
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• pp.398-403
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• 2011

A dielectric barrier discharge plasma (DBDP) treatment system was fabricated and the optimum operating conditions for the plasma generation were determined in order to explore the potential of cold plasma as a non-thermal proessing technology. The microbial inactivation performance of the system was also evaluated against Staphyloocus aureus. The system consisted of power supply, transformer, electrode assembly and sample treatment plate. The input power was 220 V single phase AC and amplified to 10.0-50.0 kV on a transformer. A pulsed sine wave of frequency 10.0-50.0 kHz was introduced to the electrode embedded in ceramic as a dielectric barrier material in order to generate plasma at atmospheric pressure. Higher currents and consequently greater power were required for the plasma generation as the frequencies increased. A homogeneous and stable plasma was generated at currents of 1.0-2.0, and frequencies of 32.0-35.3 kHz. The optimum electrode-gaps for the plasma generation were 1.85 mm without loaded samples. More power was consumed as the electrode-gaps increased. The practically optimum electrode- gap was, however, 2.65 mm when samples were treated on slide-glasses for microbial inactivation. The maximum temperature increase after 10 min treatment was less than 20$^{\circ}C$, indicating no microbial inactivation effect by heat and thereby insuring a non-thermal method. The DBDP inactivation effect against Staphyloocus aureus increased linearly with treatment time up to 5 min, but plateaued afterward. More than 5 log reduction was achieved by 10 min treatment at 1.25 A.