• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.25-30
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• 1991

Chicken liver was enzymatically hydrolyzed with an alkaline protease and determined the optimal conditions of reaction temperature and time, pH and enzyme to substrate ratio(E/S ratio) for possible utilization as a protein supplementary ingredient. The functional properties of hydolysate measured were water and oil absorption capacity, emulsifying activity and viscosity and sensory properties were also evaluated. It was found that hydrolysis at $60^{\circ}C$ and pH 8.0 were most effective and the degree of hydrolysis increased with increasing E/S ratio. A decrease in water and oil absorption capacity and an increase in viscosity were found during hydrolysis. The lowest emulsifying activity and highest water absorption were measured for 1/2 hour-hydrolysate and little difference was found for those treated more than 1 hour. The sensory characteristics of odor showed no significant difference among the chicken liver hydrolysates while the brightness increased and red decreased significantly(p<0.01) as the hydrolysis proceeded.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.3
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• pp.213-217
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• 2001

In order to develop a new separation technology, supercritical fluid extraction process was used to produce high purity pigments and fatty acids from seaweed (Undaria pinnatifida). Supercritical carbon dioxide was used as a solvent and ethanol as an entrainer. The sample was treated by a frozen drier and experiments were conducted with a semi-batch flow system at various operating conditions (pressure range, $10.3\~17.2$ MPa; temperature range, $30\~45^{\circ}C$: particle size, $500\~1,000{\mu}m$ extraction time, 60 min). Characteristics of the recovered pigment (chlorophyll a) and fatty acids were determined by UV-spectrophotometry and gas chromatography, respectively. The highest extraction efficiency for fatty acids and pigments was achieved at 12.4 MPa, $35^{\circ}C$, $500{\mu}m$of seaweed size.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.3
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• pp.425-433
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• 2015

This study investigated changes in physicochemical characteristics by drying and fermentation in order to utilize Actinidia arguta. Moisture content of A. arguta was 85.81%. Major sugar and organic acids were sucrose, succinic acid, and citric acid. A. arguta contained 19 kinds of amino acids, including 8 kinds of essential amino acids such as valine, methionine, isoleucine, leucine, threonine, phenylalanine, tryptophan, and lysine. For total organic acids, sample fermented for 17 h at $50^{\circ}C$ under a relative humidity of 80% showed 29,026.53 mg/100 g total organic acids. For total free sugars, cold-dried sample showed the highest level at 6,560.86 mg/100 g, which decreased to 2,386.73 mg/100 g after blanching. For the ratio of essential amino acids, freeze-dried sample showed a content of 11.66%, which increased 4-fold up to 40.71~55.50% with fermentation. Both GABA and vitamin U were highest after 17 h of fermentation (110.29 mg and 6.78 mg/100 g fresh weight, respectively). A. arguta contains a variety of free amino acids that increase in amount after fermentation and thus is expected to be developed as a functional food and substitute tea.

• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.596-602
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• 1994

To separate and concentrate mucilage from yam(Dioscorea batatas DECNE), yam was dried, microparticulated using impact mill and air-classified at different air classifying wheel speed(ACWS) in classifier. As ACWS increased from 5,000 rpm to 22,500 rpm, the contents of dietary fiber, protein and lipid of air classified microparticles(ACM) increased remarkably. Especially the ACM with ACWS over 15,000 rpm showed 36.41% dietary fiber and 16.66% protein. The dietary fiber and protein components were concentrated to $2.5{\sim}9.0$ times as compared with whole yam powder. Concomitantly the non-fibrous carbohydrate decreased from 88.31% to 16.84. The damaged starch(%), WSI and WAI of ACM of ACWS over 15,000 rpm were $1.5{\sim}3.0$ times higher than those of ACM under ACWS 15,000 rpm. The apparent viscosity of ACM was 0.0800 Pa s over ACWS 15,000 rpm and 0.0080 Pa s under ACWS 15,000 rpm. Judging from viscosity of ACM, the mucilage component of yam was concentrated to 10 times. In conclusion, the optimum process to separate and concentrate the mucilage from yam consisted of the microparticulation to $5{\sim}30{\mu}m$ and the air-classification at ACWS over 15,000 rpm.

• Journal of Life Science
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• v.9 no.1
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• pp.44-49
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• 1999

A study was conducted to investigate the possibility of processing seasoned and semi-dried right-eyed flounder (Pseudopleuronects herzensteini) and to examine its quality during storage at $\pm$$3^{\circ}C$ by analyzing the factors such as moisture content, pH, volatile basic nitrogen (VBN), viable cell count and peroxide value (POV). For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were $20^{\circ}C$ and 4 hrs, respectively, under 50$\pm$5$\%$ of relative humidity and 2 m/sec of air blast speed. The shelf-lives of the products by vacuum-packaging method in nylon/polyethylene/linear low density polyethylene (0.015/0.045/0.040 mm) laminated film bag were 35 and 16 days during storage at $-3^{\circ}C$ and $3^{\circ}C$, respectively.

• Food Science and Preservation
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• v.12 no.1
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• pp.54-61
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• 2005

The absorption characteristics and their physical properties of hot air, vacuum and freeze dried soybean curd powder were investigated. Absorption conditions were at 5, 15, and 25 t with $0.11\~0.93$ water activities. Equilibrium moisture content and the monolayer moisture content determined by prediction models showed highest value in the freeze dried soybean curd powder due to porous structure. Absorption energy decreased with increasing water activity was not affected by drying method. In the comparisons of the isothermal absorption models, Oswin model generally was the best fit model for isothermal adsorption of soybean curd powder.

• Korean Journal of Food Science and Technology
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• v.29 no.5
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• pp.925-931
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• 1997

An attempt was made in this study to investigate the possibility of processing seasoned and semi-dried horse mackerel (Tracharus japonnicus) and to examine its keeping quality, by analyzing the factors such as water content, pH, volatile basic nitrogen, viable cell count, peroxide value, color value and sensory evaluation. For processing of the seasoned and semi-dried product, optimum conditions of drying temperature and drying time were $20^{\circ}C$ and 4 hr, respectively, under $50{\pm}5%$ of relative humidity and 2 m/sec of air blast speed. The shelf-life of the products, vacuum-packaging method in nylon/polyethylene/linear low density polyethylene $(0.015/0.045/0.04\;{\mu}m)$ film bag, was 42 days during storage at $-3{\pm}0.5^{\circ}C$, while that of unpackaged one was only 28 days.

• Food Science and Preservation
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• v.24 no.3
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• pp.361-366
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• 2017

This study investigated quality change of ginseng depending on far-infrared (FIR) drying methods. The ginseng was cut into 2 mm slices and measured moisture content (MC), color, total polyphenol content (TPC), total flavonoid content (TFC) and DPPH radical scavenging activity (DPPH). The color values (L, a, and b) were decreased after far-infrared (FIR) drying. As increase in drying time, color was changed. Considering quality parameters including MC, TPC, TFC, and DPPH, the optimum condition for drying was set at $65^{\circ}C$ for 60 min. Furthermore, we compared color and functional compounds depending on drying process including FIR, freeze-, vacuum, and hot-air drying. The color values of ginseng were decreased when dried using vacuum and hot-air. While the color values of ginseng were increased after freeze drying. Comparison with another drying method, FIR drying presented the highest color difference. FIR and vacuum-dried ginseng indicate higher contents of TPC and TFC than freeze- and hot air-dried ginseng. And hot-air-dried ginseng present the highest DPPH when compared to another drying methods. On the other hand, freeze dried ginseng show the lowest TPC, TFC, and DPPH.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.244-248
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• 1993

The fatty and organic acids, and barbaloin in various parts of aloe species dried at different temperatures were analyzed by GC and HPLC. Seven fatty acids and six organic acids were identified and quantified. In the case of fatty acids, generally, the contents of palmitic and eicosanoic acid were abundants, and compared to the total contents of seven fatty acids, Aloe arborescence variant 1 was abundant, but Aloe saponaria was poor. And six fatty acids were distributed in the aloe species with the exception of linoleic acid. The contents of malic, citric and oxalic acids in the aloe species were higher than those of other acids, and compared to the sum of contents of six organic acids, Aloe saponaria was high, but Aloe arborescence variant 1 was low. Therefore Aloe arborescence variant 1 was abundant in total fatty acids, but poor in total organic acids. The contents of fatty and organic acids in the sample dried at $65^{\circ}C$ and $80^{\circ}C$ air circulation were almost similar. The contents of fatty and organic acids in the freeze-dried samples were lower than in the other dried samples. The contents of barbaloin in Aloe arborescence and A. arborescence variant 1 were higher than those of other various samples, and barbaloin was not detected in Aloe saponaria. As the drying temperature was increased, the contents of barbaloin in the various parts of the Aloe vera decreased.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.341-347
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• 1998

To develop simple and accurate analytical method for freezing time prediction of beef and tylose under various freezing conditions, freezing time (Y) was regressed against the reciprocal $(X_3)$ of difference of initial freezing point and freezing medium temperature, reciprocal $(X_4)$ of surface heat transfer coefficient, the initial temperature $(X_1)$ and thickness $(X_2)$ of samples which should cover most situations arising in frozen food industry. As results of the multiple regression analysis, equations were obtained as follows. $Y_{tylose}=3.45X_1+7642.84X_2+4642.67X_3+2946.89X_4-431.33\;(R^2=0.9568)$ and $Y_{beef}=0.68X_1+7568.98X_2+2430.78X_3+3293.26X_4-299.00\;(R^2=0.9897)$. These equations offered better results than Plank, Nagaoka and Pham's models, shown in satisfactory agreement with models of Cleland & Earle and Hung & Thompson when were compared to previous models, and the accuracy of its was very high as average absolute difference of about 10% in the difference between the fitted and experimental results. Also, thermal diffusivities of beef and tylose were measured as $4.43{\times}10^{-4}m^2/hr$ and $4.39{\times}10^{-4}m^2/hr$ at $6{\sim}7^{\circ}C$, $2.42{\times}10^{-3}m^2/hr$ and $3.32{\times}10^{-3}m^2/hr$ at $-10{\sim}-12^{\circ}C$. Initial freezing points of beef and tylose were $-1.2^{\circ}C\;and\;-0.6^{\circ}C$, respectively. Surface heat transfer coefficients were estimated $20.57\;W/m^2^{\circ}C$ with no-packing, $16.11\;W/m^2^{\circ}C$ with wrap packing and $13.07\;W/m^2^{\circ}C$ with Al-foil packing, and the cooling rate of immersion freezing method was about 10 times faster than that of air blast freezing method.