• Food Science and Preservation
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• v.15 no.6
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• pp.909-914
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• 2008

This study investigated microbial populations and the sensory quality of sikhae including globefish (GLS), flounder (FLS), gastropods (GAS) and whelks (WHS) during storage at 4C for 16 d following fermentation at 10C for 4 d. General bacterial numbers increased to 102 in GLS and FLS, and to 1045 in WHS and GAS after the 20 d fermentation/storage period. Lactic acid bacteria increased to 108 log cycle in GLS and FLS after 10 d ripening time, and reached this level in GAS and WHS after 15 d and 20 d, respectively. After 20 days the number of lactic acid bacteria in each of the four samples was 108. There were 104105 yeast cells/g in each of the four samples after 20 d. The number of Leuconostoc increased to over 108 log cycle after 10 d in GLS and FLS, and 15 days in GAS for WHS the increase was to 107 log cycle. The pH values of GLS, FLS, GAS and WHS 4.42, 4.56, 4.31 and pH 4.26, respectively. The Sikhae acidity for all four samples ranged from 1.551.85%. From the sensory evaluation the overall acceptability was in the order of FLS > GLS > GAS > WHS.

• Food Science and Preservation
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• v.14 no.1
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• pp.1-7
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• 2007

This study was conducted to determine if chlorine dioxide ($ClO_{2}$) gas might minimize microbial contamination of fresh produce. After exposing grapes to 20 ppm or 40 ppm of chlorine dioxide gas in a closed container, grapes treated with 20 ppm $ClO_{2}$ were packaged in Ny/PE/L-LDPE pouches, stapes treated with 40 ppm $ClO_{2}$ were placed in an empty corrugated box, and untreated control grapes were placed in a box with a sachet containing $ClO_{2}$ gas adsorbed to silica gel (a silica gel pad). The free volume of the sachet material allowed the release of $ClO_{2}$ gas into the headspace of packages containing fresh grapes. Control fruit not exposed to $ClO_{2}$, was placed in a box and stored at either $25^{\circ}C$ or $0^{\circ}C$. Fruit in Ny/PE/L-LDPE film treated with 20 ppm $ClO_{2}$ lost almost no weight during storage at either $25^{\circ}C$ or $0^{\circ}C$. Such fruit had a lower soluble solid content than did other fruit samples. Titratable acidity tended to fall rapidly during storage at either $25^{\circ}C$ or $0^{\circ}C$. Anthocyanin content of grapes decreased over 21 days at $25^{\circ}C$ but increased over 10 weeks at $0^{\circ}C$. The total microbial count of grapes treated with $ClO_{2}$ gas and silica gel pads were lower than controls at $25^{\circ}C$. Fruit treated with 20 ppm $ClO_{2}$ and packaged in Ny/PE/L-LDPE pouches had lower microbial counts than other fruit samples when stored at $0^{\circ}C$. The silica gel pad did not significantly improve total microbial count (compared to untreated control samples) at $0^{\circ}C$. This result may be attributed to a higher rate of diffusion of $ClO_{2}$ gas at room temperature.

• Food Science and Preservation
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• v.23 no.2
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• pp.259-266
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• 2016

Bitter melon powder (BMP) was used in the preparation of rice nuruk (RN) and makgeolli as one of raw materials. RN containing BMP (BMP-RN) was prepared by adding 0~2.0% (w/w) BMP into rice. Fermentative microbial, and antioxidant characteristics of makgeolli were determined during the fermentation process. pH during fermentation decreased from 4.52 (0% BMP-RN), 4.93 (0.5%), 4.80 (1.0%), and 4.88 (2.0%) on the initial fermentation day (day 0) to 4.15, 4.30, 4.57, and 4.59, respectively, corresponding to increases in acidity from 0.64~0.70% to 1.17~1.28%, respectively. Soluble solid contents increased from an initial 2.2~4.4 g/L (day 0) to 9.0~9.3 g/L, and alcohol level increased up to 13.0% by the end of fermentation (day 7). Soluble phenolic contents increased from 0.92, 1.01, 1.32, and 1.41 mg/mL on day 0, to 1.85, 2.03, 2.24, and 2.48 mg/mL on day 7, respectively, while the levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activities and ferric reducing/antioxidant power (FRAP) assay increased from 46.95~70.04%, 55.33~74.13%, and 0.629~1.243 on day 0, respectively, to 54.98~83.4%, 70.34~92.39%, and 0.964~1.455 on day 7, respectively. Makgeolli made with BMP-RN had higher soluble phenolic contents and antioxidant activity than those of makgeolli made without BMP-RN. These results suggested that BNP-RN made a functional makgeolli.

• Food Science and Preservation
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• v.22 no.4
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• pp.520-527
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• 2015

This study investigated the physiological activities of garlic extracts frozen at -20, -80, and $-196^{\circ}C$. To determine the optimum freezing temperature for maintaining garlic's physiological activity, antioxidant and antibacterial activities were investigated. The antioxidant activities were determined by DPPH radical scavenging ability, SOD-like activity, nitrite-scavenging ability, and reducing power. Total phenolic compounds and flavonoids of garlic extract frozen at $4^{\circ}C$ (control) were measured as $6.91{\pm}0.69{\mu}gGAE/g$ and $0.315{\pm}0.017{\mu}gQE/g$, respectively. Although the content of total phenolic compounds was not affected by the different freezing temperatures, the flavonoids contents of garlic extract frozen at $-20^{\circ}C$ were slightly decreased. The DPPH radical scavenging ability of garlic extracts (2 mg/mL) frozen at $-80^{\circ}C$ was 61%, whereas those frozen at $-20^{\circ}C$ and $-196^{\circ}C$ were 51%. SOD-like activity was slightly increased by freezing. However, the nitrite scavenging ability (18% at pH 3.0) and reducing power (OD700=1.6) were not affected by freezing temperatures. Antimicrobial activities did not show significant differences depending on freezing temperatures. Taken together, the physiological activities of the frozen garlic extracts were not significantly changed by the freezing temperatures; however, the antioxidant and antibacterial effects of the phenolic compounds and flavonoids were maintained at $-80^{\circ}C$. These results suggest that $-80^{\circ}C$ frozen garlic could maintain a higher quality than the conventional freezing method ($-20^{\circ}C$) without loss of physiological activities during the storage.

• Food Science and Preservation
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• v.23 no.4
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• pp.502-509
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• 2016

The seasonal appearance and the chemical composition characteristics of cladode of Opuntia humifusa were investigated in this study. The minor (horizontal) and major (vertical) axes, the width, and weight of O. humifusa cladode were compared for its appearance features. Moisture, crude protein, ash, fat, color, dietary fiber, mineral, and amino acids contents were measured for the comparison of their chemical composition characteristics. The cladode of O. humifusa harvested in summer showed higher values of minor and major axis, width, and weight than those harvested in winter. According to the results of Hunter color index, cladode of O. humifusa harvested in summer showed the highest lightness level (Hunter L value). In the meanwhile, cladode of O. humifusa harvested in spring showed the highest Hunter a (redness) and b (yellowness) values. Cladode of O. humifusa harvested in summer had the lowest crude protein and crude fat contents, while it showed the highest crude ash content. The total contents of moisture and dietary fiber were significantly greater than summer-harvested cladode of O. humifusa followed by spring- and winter-harvested cladode of O. humifusa. The major mineral content of all seasonal cladode of O. humifusa was $Ca^{2+}$. Glutamic acid and aspartic acid were the major amino acids in all seasonal samples. Contrary, the contents of total amino acids and free amino acids were the lowest in summer-harvested cladode of O. humifusa. Taken together, it was concluded that the appearance and chemical quality of cladode of O. humifusa was versatile depending on the harvesting season.

• Food Science and Preservation
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• v.23 no.3
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• pp.378-386
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• 2016

Anti-atherogenic effects in tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$)-stimulated human umbilical vein endothelial cells (HUVEC) are involved in the suppression of oxidative stress, cell adhesion molecules, and pro-inflammatory factors. This study investigated the vascular inflammation inhibitory activity of traditional Doenjang plays a key role in the pathogenesis and progression of atherosclerosis. The protective effects of Korean Deonjang was investigated on the expression of cell adhesion molecules (CAMs) in tumor necrosis factor (TNF)-${\alpha}$-induced human umbilical vascular endothelial cells (HUVECs). Deonjang extracts (20, 50, $100{\mu}g/mL$) decreased the expression of 20 ng/mL TNF-${\alpha}$-induced vascular cell adhesion molecule (VCAM)-1 intracellular adhesion molecule (ICAM)-1 proteins, and their corresponding mRNA levels. Nitric oxides (NO) produced by endothlial nitric oxides synthase (eNOS) dilated blood vessels, which had protective effects against platelet and leukocyte adhesion. While TNF-${\alpha}$-induced suppressed the production of nitric oxide in HUVECs, Doenjang restored NO production in HUVECs. In addition, Deonjang reduced the TNF-${\alpha}$-induced expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 mRNA levels. These results suggested that Doenjang can inhibited the production of cell adhesion molecules and inflammatory mediators, which could be a potential candidate for preventing atherosclerosis.

• Food Science and Preservation
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• v.23 no.3
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• pp.402-412
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• 2016

Generation of biogenic amines (BAs) and physiological activities of Makgeolli, Korean rice wine, were investigated during fermentation under different temperatures (20, 25, and $30^{\circ}C$) and time (3, 5, and 7 days). The pH was 3.96~4.36 during fermentation and the acidity increased proportionally with temperature and time. Alcohol and total phenolic contents peaked on day 5 at 25 by 9.0~9.8% and $3.01{\pm}0.07mg/g$, respectively. The organic acid mostly produced was lactic acid, which increased gradually with temperature and time. Formation of biogenic amines comprised of tryptamine and putrescine was observed during fermentation: 6.91, 11.70, and 15.63 mg/mL of tyramine on day 7 at 20, 25, and $30^{\circ}C$, respectively. Antioxidant activities from DPPH and FRAP assay were high in the order of $25^{\circ}C$>$20^{\circ}C$>$30^{\circ}C$ while that from ABTS assay was high regardless of temperature. Processed at 1 mg/mL and $30^{\circ}C$, the inhibitory effect on ${\alpha}$-amylase was $67.99{\pm}0.11$, $73.64{\pm}0.43$, and $75.51{\pm}0.26%$ on days 3, 5, and 7, respectively, which increased proportionally with temperature and time. Inhibitory activity on lipid accumulation in 3T3-L1 adipocytes was the highest in Makgeolli fermented on day 5 at $25^{\circ}C$. This study shows that fermentation at $25^{\circ}C$ for 5 days yields Makgeolli of the best quality with high bioactivities but no biogenic amines.

• Food Science and Preservation
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• v.22 no.4
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• pp.498-504
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• 2015

The purpose of the present study is to provide preliminary data for turning sweetpotato leaves into dehydrated vegetables. To achieve this goal, we have gone through the process of hot-air drying the leaves of sweetpotato that are usually thrown away and examined the drying speed and rehydration resilience, then made a comparative analysis of the general ingredients, lutein, $\beta$-carotene and chromaticity. The drying speed reached the peak at a temperature of $70^{\circ}C$. As for other general ingredients, there was no significant difference according to temperature. The content of lutein, which is a functional ingredient, was large in Shinmi with $171.59{\mu}g/g$ at a temperature of $40^{\circ}C$; small in Hayanmi with $73.75{\mu}g/g$ at a temperature of $70^{\circ}C$. The content of $\beta$-carotene was large in Shinmi with $379.59{\mu}g/g$ at a temperature of $40^{\circ}C$; small in Hayanmi with $170.78{\mu}g/g$ at a temperature of $70^{\circ}C$. The content of functional materials was the largest at a temperature of $40^{\circ}C$, and decreased in the order of temperatures at $50^{\circ}C$, $60^{\circ}C$, and $70^{\circ}C$. As for rehydration stability, rehydration rate in both Shinmi and Hayanmi was the highest at a temperature of $40^{\circ}C$ with 233.93% and 223.47% respectively. To summarize, the quality of dried sweet potato leaf was more affected by temperature than by drying time, and low temperature drying resulted in better product value.

• Food Science and Preservation
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• v.19 no.1
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• pp.95-103
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• 2012

The objective of this study was to develop models for the predict of the milk properties (fat, protein, SNF, lactose, MUN) of unhomogenized milk using the visible and near-infrared (NIR) spectroscopic technique. A total of 180 milk samples were collected from dairy farms. To determine optimal measurement temperature, the temperatures of the milk samples were kept at three levels ($5^{\circ}C$, $20^{\circ}C$, and $40^{\circ}C$). A spectrophotometer was used to measure the reflectance spectra of the milk samples. Multilinear-regression (MLR) models with stepwise method were developed for the selection of the optimal wavelength. The preprocessing methods were used to minimize the spectroscopic noise, and the partial-least-square (PLS) models were developed to prediction of the milk properties of the unhomogenized milk. The PLS results showed that there was a good correlation between the predicted and measured milk properties of the samples at $40^{\circ}C$ and at 400~2,500 nm. The optimal-wavelength range of fat and protein were 1,600~1,800 nm, and normalization improved the prediction performance. The SNF and lactose were optimized at 1,600~1,900 nm, and the MUN at 600~800 nm. The best preprocessing method for SNF, lactose, and MUN turned out to be smoothing, MSC, and second derivative. The Correlation coefficients between the predicted and measured fat, protein, SNF, lactose, and MUN were 0.98, 0.90, 0.82, 0.75, and 0.61, respectively. The study results indicate that the models can be used to assess milk quality.

• Food Science and Preservation
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• v.17 no.1
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• pp.1-8
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• 2010

We investigated the effect of freezing on changes in the chemical components of semi-dried red pepper (SDRP). We used storage temperatures of $0^{\circ}C,\;-10^{\circ}C,\;-20^{\circ}C,\;and\;-70^{\circ}C$. After 30 days of storage, capsaicin content had decreased by 40% at $0^{\circ}C$ and by 21% at $-20^{\circ}C$. Initial vitamin C content was 1,358.02 mg%. Compared with control, the $0^{\circ}C$ storage group showed a significant decrease in vitamin C content but no such decrease was noted in the $-20^{\circ}C$ and $-70^{\circ}C$ storage groups after 30 days. ASTA values were not influenced by storage temperature or period, in agreement with previous results. We concluded that storage was effective at temperatures of less than $-20^{\circ}C$. Next, both dried red pepper (DRP) and SDRP were stored at $-20^{\circ}C$ for 12 months. DRP had the lower level of capsaicinoids (55.01 mg%) owing to the long drying time. After 12 months, SDRP capsaicinoid had decreased by 30-33%, compared with a decrease of 54% in DRP. Initial vitamin C contents were 721.48 and 955.25 mg% in DRP and SDRP, respectively, and, after 12 months, vitamin C loss in the SDRP group (37%) was less than that in fresh red pepper (FRP) samples (45%). Initial $\beta$-carotene content was greatest in the FRP group (259.82 mg%), and that of DRP decreased by 20% after 12 months. The color a/b value of SDRP (1.40) was greater than that of DRP (1.00).