• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.380-384
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• 1999

For the effective utilization of anchovy as a food source, processing conditions of expanded anchovy snack and monolayer moisture content of the products were investigated. Ground anchovy was mixed with 50% of wheat flour, 2.5% of NaCl and 3.0% of onion. The mixture were rolled, cut, dried and finally deep-fried with soybean oil. When 50% of wheat flour was mixed with ground anchovy, expansion rate showed the highest value among the treatments and organoleptic quality of the product was also high. Dried base with 6.4% of moisture content showed the maximum expansion rate and good crispness and brittleness when fried at $200^{\circ}C$. Monolayer moisture content of the expanded products was calculated as 2.77% by BET equation.

• Korean Journal of Food Science and Technology
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• v.28 no.6
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• pp.1146-1150
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• 1996

The purpose of this research was to provide fundamental data required for the process design of conveying, storage and processing of food powders. Potato starch, corn starch, wheat protein, soybean protein, and model food powders prepared by mixing potato starch and wheat protein were selected and their sorption characteristics such as equilibrium moisture content, monolayer moisture content, and sorption enthalpy were determined. Equilibrium moisture content and monolayer moisture content of high starch powders were higher than those of high protein powders, and the equilibrium moisture content decreased with temperature. The determination coefficients of the regression equations to predict the equilibrium moisture content of food powders were from 0.997 to 0.999. Sorption enthalpy experiments indicated that powder of high moisture content showed lower sorption than that of low· moisture content, and the high protein powder showed lower sorption than high starch powder.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.358-364
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• 1995

In order to determine the moisture content level for safe storage of wild vegetables, drying characteristics and water vapor sorption characteristics of four vegetables, i.e., zucchini slice, sweet potato stem, taro stem, and platycodon, were investigated. The drying curves of these vegetables were consisted of three characteristic stages which were the initial settling down period, the constant drying rate period, and the falling drying rate period. And the falling rate period of the vegetables showed 2 or 3 parts of falling rate. All of the falling rate curves of the vegetables showed upwardly convex shape which is known as a characteristic pattern for the drying of fibrous food materials. The critical moisture contents of the vegetables were $8.29{\sim}9.75,\;10.40{\sim}15.08,\;9.51{\sim}14.52\;and\;3.29{\sim}3.56g\;H_2O/g$ dry solids for zucchini slice, sweet potato stem, taro stem, and platycodon, respectively. Activation energy values of drying rate during falling rate period were 2.30, 2.11, 4.97, and 2.80 kcal/mol for zucchini slice, sweet potato stem, taro stem, and platycodon respectively. The BET monolayer moisture contents of the vegetables were $10.05{\sim}13.59,\;9.49{\sim}12.69,\;9.50{\sim}16.48\;and\;5.01{\sim}5.44g\;H_2O/g$ dry solids for zucchini slice, sweet potato stem, taro stem, and platycodon, respectively. And these values were found to be very compatible with the values of the critical moisture content. Consequently, it was found that the moisture of these vegetables should be removed below the BET monolayer moisture content or below the critical moisture content for the long term storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.215-221
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• 1984

To investigate stability for the quality of selected ginseng products, their sorption properties were clarified in red ginseng extract(RGEP), and red ginseng extract powder(RGEP), and red ginseng extract tea(RGET). Simultaneously, the BET monolayer value of each product was determined in order to inquire out the possibility of establishment as a criterion for the optimum moisture content of the ginseng products. Based on the BET monolayer moisture level of spray dried RGEP which ranged from 4.08 to 4.65%, it would be desirable to establish the optimum moisture content of the products at 4.4${\pm}$0.3%. This is 1.3 to 1.9% lower than the criter on, "less than 6.0%". The optimum moisture level for RGET of which monolayer value ranged 0.93 to 1.37% would be 1.2${\pm}$0.17%. In this case, the maximum permissible limit of moisture content could presumably be raised up to 1.37% in place of current criterion, "less than l.2%". From the results of a study on the growth of molds, the optimum moisture content for RGE assumed to be extended up to 40.0${\pm}$1.07 despite 36.0${\pm}$1.0% of the present criterion. On the other hand, a storage study under the maltreated condition, $48{\pm}2^{\circ}C$ 75%RH, was also carried out in order to make it clear whether the BET monolayer values were able to be used as indices for optimum moisture level of the products. In all samples tested adsorption occurred at even higher levels of moisture than the monolayer values. However, since there are many other possible factors affecting the quality of products the optimum moisture content is preferable to be reduced to the monolayer value. As a result, it was proved that the optimum level of moisture for both RGEP and RGET could be established by the monolayer values.

• Food Science and Preservation
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• v.21 no.3
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• pp.334-340
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• 2014

The moisture sorption isotherms of corn powder prepared from corn kernels roasted for 20 min at 160, 180, 200, 220, and $240^{\circ}C$ were determined at $20^{\circ}C$ using the static gravimetric method over the range of water activities ($a_w$) of 0.11~0.90. The moisture sorption isotherms showed a typical sigmoid shape, and the equilibrium moisture content tended to increase with increasing $a_w$, and increased sharply at above 0.75 $a_w$. At above 0.53 $a_w$, the equilibrium moisture content of the roasted corn powder increased with the increase in the roasting temperature. Six mathematical models (Bradley, Caurie, Halsey, Henderson, Kuhn, and Oswin) were used to fit the experimental data. The Oswin, Caurie, Henderson, and Halsey models were found to have suitability for describing the sorption curves, and the Oswin model was the best fit model for all the roasting temperatures. Concerning the monolayer moisture content, the Guggenheim-Anderson-Boer (GAB) equation showed high significance. The monolayer moisture content increased as the roasting temperature was increased, to 0.043 and 0.053 kg $H_2O/kg$ solids in the corn powder roasted at $180^{\circ}C$ and $240^{\circ}C$, respectively. These results suggest that the roasting temperatures of the corn kernels affected the moisture sorption characteristics ($20^{\circ}C$) of the corn powder.

• Food Science and Preservation
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• v.17 no.4
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• pp.513-518
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• 2010

This study was carried out to estimate the moisture sorption characteristics and prediction model of anchovy powders with different particle size as above 80 mesh, 80-60 mesh and 40-60 mesh. The equilibrium moisture content had higher values at lower storage temperatures, and higher water activity. The monolayer moisture content calculated using the GAB equation showed a higher level of significance than that of BET equation. The estimated monolayer moisture content was 0.024-0.052 g $H_2O/g$ dry solid. The absorption enthalpy was calculated with different particle size and various water activities. It showed that the absorption energy was decreased with increasing water activity but no difference was found on particle size increasement. The fitness of the isotherm curve was shown to be in the order of Khun, Halsey, Caurie and Oswin model. The prediction model equations for the moisture content were established by ln(time), water activity, and temperature, respectively. The model equation will be helpful for future work on drying and storage of anchovy powder.

• Journal of the Korean Society of Tobacco Science
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• v.18 no.2
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• pp.150-159
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• 1996

In this study, to obtain the basic data for the optimum moisture control system, moisture adsorption characteristics, adsorption isotherms models for water and surface physical characteristics of burley and flue-cured tobacco were investigated. By the hypothesis' the phenomenon of moisture adsorption of tobacco is the same as the first order reaction, the wetting constant (k) and equilibrium moisture content were obtained. And activation energy, frequency factors were also calculated by applying its data to Arrhenius equation. The Kamei's empirical formula of moisture adsorption isotherms showed the best agreement with the experimental data and its correlation coefficient (r) was 0.997. It can be seen that specific surface area of burley is 157 m2/g, that of flue-cured is 152 m2/g, -△H1 of adsorbed monolayer is 45,972 J/mol, 45,486 J/mol, respectively, and the condensation heat (40,595 J/mol) being caught in adsorbed multilayer is less than that of monolayer.

• Korean Journal of Food Science and Technology
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• v.16 no.4
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• pp.437-442
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• 1984

The color changes and sorption characteristics of dried whole red pepper stored at various relative humidity and temperature were studied. Dried whole red pepper was browned at relative humidity above 67%, and was molded at relative humidity above 84%, and was decolorated at relative humidity below 32%. Therefore, about 50% RH condition was suitable for the preservation of dried whole red pepper and the safe moisture content levels for storge to prevent decolorization were ranging from 15.65% to 19.62% dry basis (DB) with varying temperatures. The moisture contents of monolayer value for the dried whole red pepper were ranging from 7.52% to 9.23% (DB) with varying temperatures. The third order regression equation for the equilibrium moisture content prediction with relative humidity was determined.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.5
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• pp.457-462
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• 2004

Physical properties of soybean curd powder prepared with hot air, vacuum and freeze drying methods were investigated. Adsorption characteristics were studied under various water activities (such as 0.11, 0.33, 0.44, 0.55, 0.66, 0.75, 0.85, and 0.93) at 5℃, and prediction models were developed. Equilibrium moisture and monolayer moisture contents were the highest when freeze dried. due to the porous structure. In this result, Oswin model was the best fit for the isotherm of soybean curd. Sorption enthalpy indicated that high moisture content of powder showed lower sorption than that of low moisture content.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.399-404
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• 1988

The sorption characteristics of garlic powder stored at various relative humidities and storage temperatures were studied. At lower relative humidity below RH 51%, the sorption equilibrium was easily attained, whereas at higher relative humidity above RH 67%, the powders were browned by higher equilibrium moisture content. The powders were browned at relative humidity above 67% at $20^{\circ}C\;and\;35^{\circ}C,\;above\;84%\;at\;5^{\circ}C$, respectively. The moisture contents of monolayer value for the powder were ranged from 5.53%(DB) to 5.92% (DB) with varying temperatures. And the necessity of moistureproof packaging material suggested for the long term storage of the powder because the lower moisture content and storage temperature, the higher driving force of wetting.