• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.51-55
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• 1983

It was investigated under several cultural conditions to produce biomass directly from starch by an strictly aerobic and amylolytic yeast, Sporobolomyces holsaticus FRI Y-5. Its optimal temperature and initial pH of medium for growth were $23^{\circ}C$ and 6.9, respectively. Activation energy, Ea, for growth was calculated to be 17.33 Kcal/mole from the Arrhenius relationship. When each of 13 nitrogen sources was added to the basal medium, $(NH_2)_2CO$ had the best effect, on which concentration of cell after 3 day incubation was 10.6 g/l and cell yield was 0.451. The yeast growth was affected by $MgSO_4,\;K_2SO_4\;and\;ZnSO_4$ as a mineral source and was best on the medium containing all of them. The addition of yeast extract (5g/l) could enhance the production of biomass and cell yield to 77% and 32%, respectively.

• Korean Journal of Food Science and Technology
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• v.19 no.3
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• pp.206-211
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• 1987

In an attempt to improve the quality stability of dried layer (Porphyra yezoensis Ueda), during longterm storage and distribution, a 6 months storage trial at different temperature and packaging condition was conducted. Dried layer samples were prepared by conventional procedure with different washing condition and $5^{\circ}C$ and $30^{\circ}C$ were employed as storage temperature. The moisture sorption isotherm was drawn at $5^{\circ}C$ and $25^{\circ}C$ and BET equation was prepared from the moisture sorption isotherm. The monolayer moisture contents of dried layer were 7.4% at $5^{\circ}C$ and 6.4% at $25^{\circ}C$, respectively. It was also found that the changes in comprehensive quality of dried layer during storage was much less at low temperature and the degree of washing before drying process as far as its moisture contents are lower than monolayer moisture contents. With regard to the packing methods, vaccum packing was superior to air containing packaging for the maintainance of quality during storage.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.352-358
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• 1986

The relationship between weight reduction and rehydration of dehydrofrozen potato was determined. At initial stage of dehydration sliced potato lost moisture rapidly. After drying for 2 hours weight reduction of sliced potato was 56% for Superior var., and 55% for Irish Cobbler. The empirical drying equations were obtained as follows: ${\frac{M-M_e}{M_o-M_e}}={\exp}(-0.4487\;{\theta}^{1.2328})$ and ${\frac{M-M_e}{M_o-M_e}}={\exp}\;(-0.4951\;{\theta}^{1.1949})$ for Irish Cobbler and Superior, respectively, where $M_o$, $M_e$, and M are dry base moisture content(%) of initial, equilibrium and at time ${\theta}$ in hour, respectively. With the decrease of weight above 50%, the rehydration rate decreased sharply and the color index L value also decreased while a and b increased. Lightness of dehydrofrozen potato decreased slightly and rehydration rate remained constant during storage at $-18^{\circ}C$. The sulfite treatment led to increase of L value and decrease of a and b values.

• 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.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.409-414
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• 1985

The gelatinization kinetics of barley starch in dilute system (1% w/v concn.) at the temperature range of $60{\sim}95^{\circ}C$ was investigated. The gelatinization rate was extremely temperature dependent. The gelatinization at the temperature above $90^{\circ}C$ was an one step 1st order reaction throughout the gelatinization time, but that below $85^{\circ}C$ consisted of two stages which showed different reaction rates. The reaction rate of the 1 st stage was greater than that of the 2nd stage. The activation energy of the 1 st stage was 31.93 Kcal/g mole and those of the 2nd stage were 78.49 and 23.41 Kcal/g mole above and below $75^{\circ}C$, respectively.

• Korean Journal of Food Science and Technology
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• v.13 no.4
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• pp.328-333
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• 1981

As a step to investigate energy conservation in canneries, energy consumption pattern and energy usages of various unit operations in a mushroom cannery were examined. The results are as follows; 1. In the mushroom cannery, fuel oil and electricity were used mainly for temperature control of mushroom growing house in winter and various cultivation operation respectively. To grow and process 1 kg of mushroom, thermal energy of 4634 kcal and electrical energy of 0. 116 kwh were consumed. About 80% of all energy was consumed for cultivation. 2. Steam qualities at each respective processing line were $92{\sim}94%$, giving no great differences among lines. 3. As a direct energy in 1 day processing operations of 8 tons of mushroom, thermal energy of $301.5{\times}10^{4}kcal$ and electrical energy of 60.1 kwh were used. The energy intensive operations were blanching (35%) and retorting (38%).

• Applied Biological Chemistry
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• v.28 no.3
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• pp.115-123
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• 1985

The milling characteristics of barley of various moisture content were investigated using Brabender Grain Hardness Tester (GHT) to set up the optimum conditions of dry milling process. The optimum GHT clearance were 1/0-1/10 for-10+12 mesh particles, 0/5-0/15 for-12+18 mesh, and 0/-15 for -18 mesh. The grain hardness of barley kernel increased with moisture content and the grindability, on the other hand, decreased. The consumed electric energy in milling increased with moisture content and showed the maximum value at the moisture content of 14.04%. The optimum conditions of dry milling of barley were 0/-5 GHT clearance and 12.80% moisture content and the consumed electric energy was 92.41Kwh for the production of 1,000kg of -18 mesh particles.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.310-315
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• 1983

The effects of DFP(Dietary Fiber Preparation) extracted from naked barley on the lipid metabolism of rats were investigated. 1. The composition of DFP was determined as cellulose 19.3%, hemicellulose 58.7%, lignin 10.5 % on dry weight basis. 2. DFP had no significant effect on the growth of rats. (p>0.05) 3. DFP had no significant effects on the composition of serum lipid and the lipid content per g of liver in rats, but caused significant decrease in serum and liver cholesterol levels of rats to a certain degree. (p<0.05)

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.156-161
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• 1982

Three plastic film solar dryers covered with different film layer were constructed by modifying farm vinyl house and studied their performance. The collection efficiency and temperature raising of type C which was covered with double layers of transparent PE and black PVC film was most efficient, followed after B covered with double layer of transparent PE film and type A covered with single layer transparent PE film. The inside temperature of type C was average $18^{\circ}C$ higher than ambient temperature and its collection efficiency showed 31.5% with air flow rate of $3.8m^3/min$. The solar energy collection efficiency of type C was increased in proportion to air flow rate up to 60.2% at $11.3m^3/min$. In demonstration drying test of red pepper in type C, drying capacity per unit area was 2.5 times higher than that of conventional solar drying on straw mat and drying time shortened to about half.

• Korean Journal of Food Science and Technology
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• v.19 no.1
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• pp.75-80
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• 1987

In order to prevent browning during drying of garlic flakes, the effect of dipping in phosphate complex solution prior to drying on the development of brown pigment in the flakes were studied. The browning color development during drying of the flakes was greatly dependent on phosphate complex concentration and their dipping time. A reciprocal relationship between browning color formation and reducing sugar content of dried garlic flakes was found. The browning color development during drying of the flakes was effectively impeded by dipping in 0.3% phosphate complex solution for 3 minute. The reduction of pyruvate content during drying of the flakes was greatly influenced by phosphate complex concentration and drying temperature, and a maximum retention was acieved by 3 minute dipping in 0.2-0.3% phosphate complex solution. The dried yield of the flakes dipped in phosphate complex solution was 1.62-1.75% lower than control and it was mainly caused by the dissolution of soluble solids during dipping.