• Korean Journal of Food Science and Technology
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• v.38 no.3
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• pp.444-447
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• 2006

Yam powders were prepared by freeze, fan, hot-air, and coal-heat drying. The viscosities of their suspensions and supernatants and the viscosity changes with addition of sugar, salt, and citric acid were investigated. Viscosity (43 mPa s) of 7.5% suspension of fan-dried yam powder was lower than that of freeze dried yam (58.1 mPa s), but much higher than that of the conventional, hot-air dried yam (17.2 mP s). Coal-heat dried yam had a viscosity of only 4.5 mPa s. The viscosity was related to the protein denaturation induced by heat and acid. Addition of sugar to yam powder increased the viscosity of the suspension but no changes were evident with salt addition. Viscosities decreased when 0.5% citric acid was added (pH 3.4-3.5).

• Korean Journal of Food Science and Technology
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• v.12 no.4
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• pp.292-298
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• 1980

In order to improve the storage stability of powdered soybean curd, moisture sorption characteristics of the curd stored at specific relative humidity and temperature were investigated. The results obtained are summarized as follows; 1. When the fresh soybean curd (2cm thickness) was dried in a hot air drier at $55^{\circ}C$, it took 18 hrs to reduce its moisture content from 85% to 8.8%, and drying rate was very high during the first 5 hrs. 2. Equilibrum moisture content (E.M.C.) of powdered soybean curd by freeze drying was higher than that of sample by got air drying, but the particle size did not influence E. M. C. 3. The monolayer value of freeze dried powder of high E. M. C was higher than that of the hot air dried(8.30 vs 7.35). 4. The free energy for moisture absorption of freeze dried powder at 11% RH were 1285.1 cal/mole, 1323.5 cal/mole at $15^{\circ}C$ and $30^{\circ}C$, respectively, and the free energy of freeze dried product was lower that of hot air dried product. 5. The moisture sorption rate constant was not affected by particle size, and it showed that the moisture sorption rate decreased as temperature was increased. The rate constant of powder produced by freeze drying were 0.00804 at $15^{\circ}C$ and 0.00696 at $30^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.35 no.6
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• pp.499-512
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• 2022

This study investigated the quality characteristics and antioxidant effects of rice cookies containing different percentage of freeze-dried plum powder (3%, 5%, 6%, and 12%). The density of the dough and the thickness of the rice cookies from the control group and the additive group were not significantly different. The pH value of the dough, its moisture content and spread factor, as well as the Hunter's L and b values of the rice cookies significantly decreased as the amount of dried plum powder added increased. However, the sweetness, hardness, thickness, Hunter's a value, total polyphenol, total flavonoid and anthocyanin contents, DPPH and ABTS free radials scavenging activity, and ferric reducing antioxidant power of the rice cookies significantly increased as the amount of dried plum powder added increased. Overall, the results of this study showed that adding dried plum power enhanced the antioxidant activities and quality characteristics of rice cookies.

• Korean journal of food and cookery science
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• v.17 no.5
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• pp.483-489
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• 2001

The objective of this study was to investigate the effect of ripening on the quality of kimchi or freeze-dried/rehydrated kimchi. Kimchi stored/ripened at 0$\^{C}$ for 120 days was taken at an interval of 10 days and freeze-dried/rehydrated with water. The number of lactic acid bacteria(LAB), shearing force and sensory properties of kimchi ripened (Raw sample) or kimchi ripened/freeze-dried/rehydrated (F/D sample) were observed. The results were as follows: (1) The number of LAB of Raw and F/D samples decreased slightly during ripening for 120 days, while the pH of both samples decreased. The number of LAB in kimchi decreased up to 6∼16% of the original value by freeze-drying. (2) Ripening for 120 days did not affect shearing force of kimchi while freeze-drying increased markedly its shearing force. (3) Although overall acceptability and taste of Raw and F/D samples decreased gradually, the degree of change between two samples was different. The odor of Raw and F/D samples decreased slightly during ripening for 120 days while the degree of change between two samples was similar after 70 days of ripening. Moistness of Raw and F/D samples was maintained relatively stable during ripening. Chewiness of Raw sample decreased during ripening for 120 days while that of F/D sample was not affected by ripening. Color of Raw and F/D sample was changed during ripening while the degree of change between two samples was not significant. It can be concluded that the change of some sensory properties between Raw sample and F/D sample was affected by ripening for 120 days while the change in the number of LAB, pH and shearing force between both samples was not affected markedly by ripening.

• Food Science and Preservation
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• v.16 no.6
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• pp.843-848
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• 2009

Green peppers were dried using maltodextrin and recycled dehydration liquid as dehydrating agents, and the quality of dried green pepper powders was compared with that of freeze-dried and hot air-dried samples in terms of moisture content, color, antioxidant activity, capsaicinoid level, and sensory acceptability. The moisture content of maltodextrin-treatedgreen pepper powder was higher than that of samples prepared using recycled dehydration liquid. The lightness (L) value rose with increasing concentrations of maltodextrin powder or liquid. The antioxidant activities of pepper powders prepared using the molecular press dehydration method were similar to that of alpha-tocopherol, and better than that offreeze-dried or hot air-dried samples. Capsaicinoid levels fell with increasing concentrations of maltodextrin powder and liquid. The sensory evaluation data on green pepper powders prepared using the molecular press dehydration method were better than those obtained when freeze-dried and hot air-dried samples were evaluated. These results indicate that drying of green pepper powders using maltodextrin and recycled dehydration liquid as dehydrating agents is very efficient.

• Journal of Life Science
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• v.18 no.9
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• pp.1271-1277
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• 2008

We investigated to determine the inhibitory effects of solvent extracts from dried onion on growth of cancer cell lines (HT-1080 human fibrosarcoma and HT-29 human colon cancer cells) and $H_{2}O_{2}$-induced oxidative stress. Two different drying methods, low temperature vacuum dryer and freeze dryer, were employed to dry onion. Inhibitory effects of acetone with methylene chloride (A+M) and methanol (MeOH) extracts from onion by two drying methods on the growth of HT-1080 and HT-29 cancer cells increased in a dose dependent manner (p<0.05) and the higher inhibitory effect was shown in onion extracts dried by low temperature vacuum dryer. The treatments of hexane, 85% aq. methanol, butanol and water fractions significantly inhibited the growth of both cancer cells (p<0.05) and onion fractions dried by freeze dryer showed a higher inhibitory effect compared with those dried by low temperature vacuum dryer. In order to determine a protective effect on H2O2-induced oxidative stress, DCHF-DA (dichlorodihydrofluorescin diacetate) assay was conducted. All fractions including crude extracts of dried onion appeared to significantly reduce the levels of intracellular reactive oxygen species (ROS) (p<0.05). Higher antioxidant effect was observed in onions dried by the low temperature vacuum dryer method. These results indicate that the low temperature vacuum dryer is useful to dry and produce onion powder.

• 한국문화재보존과학회:학술대회논문집
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• 2003.09a
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• pp.48-54
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• 2003

• 축산식품과학과 산업
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• v.6 no.2
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• pp.30-33
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• 2017

• 대한치주과학회:학술대회논문집
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• 2004.11a
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• pp.121-122
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• 2004

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.419-421
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• 2003