• Journal of Biosystems Engineering
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• v.36 no.6
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• pp.453-460
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• 2011

This study was carried out to test a red pepper tedding factors which is needed for design and development of an auto-tedding machine and a performance. According to this test, the results can be summarized as follows: The results of the tedding factors test according to shape of rotary blade, which is the 0.4 to 0.5 mm brush type, was found to be the most appropriate. As a result of tedding ratio which includes brush diameters, driving velocities and rotation velocities, there was generally no significance difference, but the red pepper tedding efficiency was found to be 39.7%. The moisture drying rate of red pepper was found to be 0.9 %w.b./h in prototype auto-tedding machine and 0.4 %w.b./h in traditional practice. The drying time was found to be 3 days in prototype auto-tedding machine and the traditional practice was 6 days. The average variable coefficient of the red pepper moisture content was found to be 16.8% in prototype auto-tedding machine in comparing with the traditional practice of 35.0%. This test showed a difference around two times, and this difference was evaluated to be the reason for irregular drying and different drying times.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.428-439
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• 1992

Drying process in a fixed bed red pepper dryer was modeled and simulated. Drying efficiency describing the effectiveness of energy usage in red pepper drying was defined as a ratio of energy used for moisture evaporation to total energy consumption, and expressed in combination of measurable temperature variables. The efficiency was compared with real evaporative efficiency and tested in the simulated and experimental drying. An overall drying efficiency was derived, and analyzed for various control variables consisting of drying temperature, air recycle ratio and air flow rate. Optimal operation conditions of drying was then searched by Box's complex method by using it as an objective function. Carotenoids retention was simulated and put as a constraint of product quality in the optimization. The optimization results gave that two staged drying operation could improve the ding efficiency compared with single staged drying. As a technique for further energy saving automatic termination of drying appeared feasible by monitoring an exit air temperature from dryer.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.937-946
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• 1996

A Far Infrared Ray (FIR) dryer was designed , constructed and tested for red pepper , lycium chinese, and mushroom (Cortiellus shiitake ) drying , and the results were compared to the heated air dryer at the same condition. In the FIR dryer, three different panel materials , galvanized, copper and stainless steel, were used and no ceramic coating and those with ceramic coating (three panels) were 58% , 56%, 64%, and 88% , respectively. The drying times of lycium chinese and mushroom were shortened in FIR dryer by 6 hrs and 4 hrs compared to the heated air drying, respectively. while to remarkable difference in the drying times was found in the red pepper drying . The quality of products was better in FIR dryer where more red color value for red pepper and lycium chinese and more brightness for mushroom . The drying performance of a FIR dryer was superior in terms of total cost of 80,800 WON /100kg of lycium chinese , reduced by 25% compared to the heated air drying.

• Journal of Biosystems Engineering
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• v.16 no.3
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• pp.248-262
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• 1991

Simulation model was developed to analyze drying process for tray type red pepper dryer and validated by experiments. This model could predict satisfactorily temperatures and moisture contents of red pepper and temperatures of drying air during drying. Optimize algorithm was developed to search control valiables (drying air temperature, air recycle ratio and air flow rate) of red pepper dryer based on a criterion of minimizing energy consumption under the constraint conditions that statisfied carotenoid retension of at least 210mg per 100g dry matter, the moisture content of bottom layer of 15% (d.b) and drying time of less than 35 hours. Step changes in drying air temperature and air recycle ratio were considered in the optimization. In single step in control variables, the difference of the moisture content between top layer and bottom layer was great and more fan power was required. As the drying trays were exchanged when the moisture content of bottom layer reached to 100% (d.b), fifty percent of energy was saved and the difference of moisture content was little. In double step changes in control variables, optimal conditions were found by changing the step when the moisture content of bottom layer reached to 100% (d.b) (about 19.8 hours from starting drying). Optimum air flow rate was $18.1cmm/m^2$. Optimum drying air temperature and air recycle ratio in the first step was $55.8^{\circ}C$ and 0.80, and in the second step $65.6^{\circ}C$ and 0.88, respectively. In triple step changes in control variables, the optimal conditions were found by changing the steps when the moisture content of bottom layer reached to 250% (d.b) and 150% (d.b). Optimal air temperatures were $66.2^{\circ}C$, $58.4^{\circ}C$ and $66.9^{\circ}C$, and optimal air recycle ratios were 0.778, 0.785, 0.862 at each step, respectively. Optimal air flow rate was $18.9cmm/m^2$. The best operating mode was triple step mode considering energy consumption, drying time, fan power, and quality of dried red pepper. When the triple step mode was used to dry the red pepper, the energy consumption was about 16.5%~57.2% less than that of the single step mode and the drying time was 6.6 hours shorter than that of the double step mode.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.9
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• pp.1358-1365
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• 2016

The purpose of this study was to verify the drying characteristics of seasoned red pepper sauce and establish optimal drying conditions for far infrared drying of seasoned red pepper sauce. Seasoned red pepper sauce, which was dried by heated air, was used. One kg of seasoned red pepper was spread at thicknesses of 10 and 20 mm and dried by a far infrared dryer until a final moisture content of $15{\pm}0.5%$. The far infrared dryer conditions were air velocity of 0.6, 0.8 m/s and drying temperatures of 60, 70, and $80^{\circ}C$. The drying models were estimated using a determination coefficient and root mean square error. Drying characteristics were analyzed based on factors such as drying rate, color changes, content of capsaicinoids, and energy consumption. The results can be summarized as follows. The drying rate (that is, drying time) tended to be reduced as temperature and air velocity for drying increased. The Page and Henderson models were suitable for drying of seasoned red pepper sauce by a far infrared dryer. Redness decreased after far infrared drying under all experimental conditions. The color difference was 18.18 under the following conditions: thickness 20 mm, temperature $70^{\circ}C$, and air velocity 0.8 m/s. This value was slightly higher than those under other far infrared drying conditions. The capsaicinoid properties of seasoned red pepper sauce decreased under all far infrared drying conditions. The highest capsaicin (19.91 mg/100 g) and dihydrocapsaicin (12.87 mg/100 g) contents were observed at a thickness of 10 mm, temperature of $80^{\circ}C$, and air velocity of 0.8 m/s. Energy consumption decreased with higher temperature, slower air velocity, and thinner seasoned red pepper sauce.

• Journal of Nutrition and Health
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• v.8 no.4
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• pp.33-37
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• 1975

This investigation was designed to determine the influence of drying methods on the free amino acids and free sugars in red pepper and to study the browning mechanism of brown-colored red pepper. Three different drying methods were employed: 1) Sun-drying at $25{\sim}28^{\circ}C$ for 15 days, 2) Drying in oven at $60^{\circ}C$ for 49 hours, and 3) Drying in oven at $90^{\circ}C$ for 8 hours. Dried and ground peels were used for the analysis of free amino acids and free sugars. The results were as follows; 1. Sixteen kinds of amino acids i.e. asparagine, methionine, and cystine etc. were identified. Total amino acid content of the sun-dried sample was not different from that of the fresh sample, but the samples dried at $60^{\circ}C$ and $90^{\circ}C$ in the oven were decreased to 24.9% and 67.4% respectively. Of amino acids identified, methionine, lysine and aspartic acid were decreased in all treatments. Especially, methionine ana aspartic acid were decreased rapidly to 71.8% and 73.3% , respectively. 2. Three kinds of free sugars i.e. glucose, fructose and sucrose were identified. The total content of free sugars was significantly decreased in each treatment. Among the reducing sugars, glucose was rapidly decreased; 65.9% for the glucose of sample dried at $90^{\circ}C$ in the oven. 3. At the higher drying temperature, the darker red color was found. Brown-color appeared at $90^{\circ}C-drying$ showed appreciable losses in carotenoid content, but the major color seems to be due to the large increase in browning compounds. 4. It was assumed that increased browning compounds of red pepper were due to the Maillard reaction which is a nonenzymatic browning process.

• Food Science and Preservation
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• v.14 no.6
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• pp.591-597
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• 2007

The quality characteristics of semi-dry red pepper (SDRP) (Capsicum annuum L.) were compared with raw and dry red pepper (DRP). Raw red pepper was divided into pieces and the semi-drying treatment involved air-drying at $65^{\circ}C$. The study focused on describing the characteristics of semi-dry red pepper in comparison with dry red pepper. Factors considered were reduced drying period, ASTA color, capsanthin, capsaicinoids, free sugars and vitamin C content. ASTA color, capsanthin, capsaicinoids, free sugars and vitamin C content of SDRP were higher in SDRP than in DRP for 15 g or less water per 100 g. Red pepper powders made using the semi-drying method showed the highest amount of glucose and vitamin C. Capsanthin content in SDRP (151.6155.9 mg/100 g) was significantly higher than for DRP (133.4 mg/100 g). The capsaicinoid content of SDRP was about 13-25% higher than in DRP. The ASTA values (148.7159.3) for SDRP were much higher than for DRP (139.5). The vitamin C and free sugar content of SDRP was 40-76% and 20-40% higher, respectively, than for DRP. and $20{\sim}40%$, respectively, by SDRP compared to DRP.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1999.12a
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• pp.407-413
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• 1999

• Journal of Nutrition and Health
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• v.8 no.4
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• pp.27-32
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• 1975

This investigation was designed to determine the influence of drying methods on the chemical changes in red pepper. Three different drying methods were employed: 1) Sun-drying at $25{\sim}28^{\circ}C$ for 15 days, 2) Drying in oven at $60^{\circ}C$ for 49 hours, and 3) Drying in oven at $90^{\circ}C$ for 8 hours. Dried and ground peels were used for the analysis of carotenoid pigments, capsaicin, and vitamin C. The results were as follows; 1. The total carotenoid content of sun-dried sample was more significantly in creased about 4% than that of the fresh sample, but both samples dried in oven were decreased about 30%. Among carotenoid groups, diol-polyol group was chiefly increased, and both samples dried in oven were decreased in the same trend; $17{\sim}18%$ reduction was found in hydrocarbons and monols and $36{\sim}38%$ was in diol-polyols. 2. In Capsaicin content in red pepper, the sun-dried sample was increased about twice of that of the fresh sample and both samples dried in oven were also tended to increase. 3. High reduction of vitamin C content was found in each treatment; 76% for the sun-dried and 89% for the oven-dried samples, respectively.

• The Korean Journal of Food And Nutrition
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• v.19 no.1
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• pp.53-57
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• 2006

In order to reduce the drying cost and to maintain the natural color of raw red pepper and also to keep the red pepper hygienically, two kinds of Kimchies made of red pepper powder and mashed red pepper were prepared. The difference of quality characteristics between Kimchi made of red pepper powder and mashed red pepper was examined during fermentation at $7^{\circ}C$. Both of two Kimchi showed the same patterns of changes in pH, acidity, total bacteria cell count and total lactic acid bacteria cell count. But Kimchi made of mashed red pepper showed lower sensory scores than red pepper powder in overall acceptability.