• Title, Summary, Keyword: pre-drying

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Effects of Pre-drying Process on the Quality of 'Fuyu' Persimmons (예건 처리 온도에 따른 단감(부유)의 품질 변화 조사)

  • Park, Sung Jin;Cho, Kwang Sik;Kim, Jun Tae
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.21 no.2
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    • pp.79-84
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    • 2015
  • Pre-drying of 'Fuyu' persimmon was performed right after harvesting from a farm. Pre-drying conditions were varied with room temperature (RT) for 1 day to 7 days, low temperature (LT, at $20{\sim}30^{\circ}C$) for 1 day to 4 days, high temperature (HT, at $30{\sim}40^{\circ}C$) for 3 h to 12 h, and ultra-high temperature (UT, at $50{\sim}60^{\circ}C$) for 30 min to 120 min. Weight loss of pre-dried persimmon was increased from 1.62% up to 2.96% with increased pre-drying temperature and time. Pre-drying at RT resulted more significant weight loss of persimmon compared to that of pre-drying at HT. Minimum firmness loss of persimmon stored at $0^{\circ}C$ for 100 days was obtained at the condition of HT for 6 h. Rate of peel blackening was decreased from 31.5% to 16.4% and 10.9% by pre-drying at HT for 6 h and 9 h, respectively.

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Effects of Pre-drying Methods on Onion Bulb Rot During Storage (양파 수확 후 예건 방법이 저장 중 부패에 미치는 영향)

  • 서전규
    • Korean Journal of Food Preservation
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    • v.9 no.3
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    • pp.277-281
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    • 2002
  • To decrease the rot of onion bulb during storage in simple house, later cultivar 'Changnyeungdaego' was dried after harvest on the field, ventilation house and non-ventilation house during 1 to 3days in 1997 and 1998. The maximum air temperature during pre-drying maintained highest in the non-ventilation house and lowest in the field, especially higher than 41.6$^{\circ}C$ at second and third day in 1997 and second day in 1998 on the non-ventilation house. Water content of onion bulbs showed 90.3∼89.5% at harvest and reduced 0.3∼l.8% in 1997, 0.2∼2.6% in 1998 after pre-drying, the rate of reduction was highest on the field and lowest on the ventilation house. Mean of maximum air temperature was 39.2$^{\circ}C$ in 1997 and 37.1$^{\circ}C$ in 1998 and relative humidity was 79.3% and 72.7% in July of 1997 and 1998, 78.2% and 79.1% in August of 1997 and 1998 during storage on the simple house after pre-drying. Rotting ratio of onion bulb showed higher in 1998 than 1997, but rotting appeared earlier 1997 than 1998. Total rotting rate as influenced by place and days of pre-drying was the lowest on the ventilation house, and highest on the non-ventilation. As the days of pre-drying increase, rotting rate of onion bulbs were lower. As above results, 1 or 2days of pre-drying on the ventilation house and 2 or 3days of pre-drying on the field were recommended to decrease the rotting onion bulb during storage.

Effects of Salt Concentration and Drying Time on the Quality Characteristics of Pork Jerky during Dehydration

  • Yang, Han-Sul;Kang, Sung-Won;Joo, Seon-Tea;Choi, Sung-Gil
    • Food Science of Animal Resources
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    • v.32 no.3
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    • pp.285-292
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    • 2012
  • This study was conducted in order to evaluate the effects of brine pre-soaking at different concentrations and drying time on the quality characteristics of pork jerky. The physicochemical properties of pork jerky including final moisture content, water activity ($a_w$), shear force, microstructure, and thiobarbituric acid reactive substance (TBARS) values were investigated. The sensory attributes of pork jerky were evaluated and used as parameters for determining the optimum drying condition. The sliced pork samples were pre-soaked at salt concentrations ranging from 0 to 10% for 3 h and then dried at $70^{\circ}C$ for up to 10 h. The pre-soaked samples in the salt solution showed higher final moisture content than the control sample after drying for 10 h. The final moisture content of pork jerky increased with increasing salt concentrations. On the other hand, the water activity with regards to the pre-soaked samples in a 10% salt solution showed the lowest value for up to 8 h drying. The shear force values of pork jerky decreased with increasing salt concentration while the TBARS values of the samples increased with increasing salt concentrations. Sensory evaluation suggested that the color, flavor, juiciness, and tenderness of the pork jerky samples were improved by pre-soaking in a 2% salt solution and the highest likeability score of pork jerky among the samples were obtained by pre-soaking in a 2% salt solution prior to drying.

Analysis of Flow Characteristics of Forced Ventilated Pre-drying Facility for Mandarin (강제 통풍식 감귤 예건시설의 유동 해석)

  • Kwon, Jin-Kyung;Yun, Hong-Sun;Jeong, Hoon;Lee, Hyun-Dong;Lee, Sung-Hyoun;Moon, Jong-Pil
    • Journal of Biosystems Engineering
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    • v.35 no.6
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    • pp.393-400
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    • 2010
  • Uniform and rapid pre-drying of mandarin is important to improve the storage quality. The aim of this study was to suggest the basic design of forced ventilated pre-drying facility for mandarin by thermal flow analysis using computational fluid dynamics software (FLUENT 6.2). Developed CFD simulation model was verified by comparison with experimental data. Airflows and temperature distributions in the five conceptional designs including existing ordinary temperature storage rooms were analyzed and appropriate basic design was determined. Analysis of the effect of arrangement of windows and exhaust fans on thermal flow in facility was carried out for more detailed design. The results of this investigation showed that the predicted airflow velocity by CFD simulation showed a good agreement with the measured value and optimum design condition for simulated forced ventilated pre-drying facility of mandarin has two exhaust fans and two windows on both sidewalls and cover on loaded mandarin.

Properties of Dandelion Tea by Pre-treatment Process (전처리 방법에 따른 민들레 볶음차의 특성)

  • 오상룡;양진무;허향옥;박준희;강우원;강미정;김광수
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.2
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    • pp.136-141
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    • 2000
  • This study was conducted to analyze the properties of the roasted dandelion tea prepared after various pre-treatments such as pre-drying, steaming and air blast drying. The dandelion tea was prepared by roasting the pre-treated dandelion leaves and its total yield, pH, soluble solid content, turbidity, browning and sensory value were evaluated. Total yield and soluble solid content were the highest in case of air blast drying. Turbidity and browning degree were similar in all the teas regardless of their pre-treatment including pre-drying, steaming or air blast drying. The best palatability in the sensory evaluation was obtained at the steaming condition for 60 sec without pre-drying. Longer air blast drying time resulted in the increase in the a and b values. turbidity, browning degree, total yield and soluble solid content in the air blast dried tea.

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Changes of HwBKP, SwBKP, OCC Handsheets' Drying Behavior and Physical Properties by Refining, Kneading and Wet Pressing (고해, 니딩, 습부압착에 의한 HwBKP, SwBKP, OCC 수초지의 건조 거동 및 물성 변화)

  • Lee, Jin-Ho;Park, Jong-Moon
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.5
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    • pp.17-26
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    • 2011
  • Drying behavior and physical properties of HwBKP, SwBKP, and OCC handsheets depending on kneading, refining and wet pressing were analyzed. The maximum drying shrinkage velocity was newly adopted to verify the effect of mechanical treatment of pulps by evaluating drying behavior according to varying the kneading, refining and wet pressing treatments. Those various treatments were changed to evaluate the relationship between the maximum drying shrinkage velocity and handsheets properties. When the drying shrinkage and the maximum drying velocity increased by refining and wet-pressing, handsheets strength was increased. The maximum drying shrinkage velocity showed higher correlation with physical properties of paper than WRV at different refining loads at SwBKP and mixed pulp. At high wet-web dryness, drying shrinkage, the maximum drying shrinkage velocity and strength properties of handsheet were increased. It meant that drying shrinkage behavior was highly affected by not only fibers' shrinkage but also fiber bonding. Kneading pre-treatment for KOCC and SwBKP effectively modified fiber properties and increasing paper strength and drying shrinkage. The effect of kneading pre-treatment was also confirmed by the maximum drying shrinkage velocity. Strength properties of mixed pulp handsheets were not increased by the kneading pre-treatment, although the maximum drying shrinkage velocity and WRV was increased. It meant that fibers network bonding of HwBKP was limited because of ves sels and ray cells' interference for bonding. Therefore in order to improve paper strengths containing HwBKP by mechanical treatments, interference of vessels and ray cells for fiber bondings should be carefully controlled.

Effect of Pre-Treatment Methods before Cooking on Mineral Retention in Siraegi (Raddish Leaves) (조리전 전처리 방법에 따른 시래기의 무기성분의 변화)

  • 박세원;유양자
    • Korean journal of food and cookery science
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    • v.13 no.5
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    • pp.635-638
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    • 1997
  • Dried raddish leaves were prepared by using three different pre-treatment methods (shady sun-drying, freezing after blanching, and shady sun-drying after blanching). Then, the retention of minerals in dried raddish leaves was determined. It was shown that the retention of most minerals (Na, K, Fe, Ca, Mg) except P was higher when shady sun-drying method was used. The retention of P was shown to be the lowest when freezing after blanching method was used.

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Effect of Pre-soaking in Salt and Sugar Solutions before Air Drying on Quality Characteristics of Dried Apples (염 및 당 침지 처리가 건조 사과의 품질특성에 미치는 영향)

  • So, Seul-Ah;Kim, Jong-Won;Kim, Ah-Na;Park, Chan-Yang;Lee, Kyo-Yeon;Rahman, Muhammad Shafiur;Choi, Sung-Gil
    • The Korean Journal of Food And Nutrition
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    • v.29 no.5
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    • pp.808-817
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    • 2016
  • In this study, we investigated the effects of pre-soaking in salt and sugar solution prior to air drying at $50^{\circ}C$ on the characteristics of dried apples. Pre-soaking solutions included single solutions of salt 2% and sugar 2%; and combined solutions of salt 2%+sugar 2% and salt 2%+sugar 5%, respectively. The effects of pre-soaking condition and drying were evaluated in terms of moisture content (MC), water activity, color, antioxidant activity determined by DPPH radical scavenging activity, shear force, microbial contents, and sensory evaluation of apple slices. The control sample without pre-soaking showed the most rapid drying rate; in addition, the single solutions showed higher MC and water activity after drying time of 120 min, as compared to combined solutions. In all samples, MC and water activity showed high correlation coefficients of 0.91 to 0.97; whereas, shear force was negatively correlated with MC and water activity. The single solution of salt 2% showed decrease in change of color, including L, a, and b values, and the number of aerobic bacteria during drying. In addition, highest antioxidant activity and values of sensory preferences were observed in the dried apple pre-soaked in single solution of salt 2%.

The simulation system for ceramic drying processes (세라믹 건조공정 시뮬레이션 시스템)

  • 금영탁;김준한;오근호
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.11 no.3
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    • pp.120-126
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    • 2001
  • The simulation system for analyzing the ceramic drying process is developed. This system consists of 3 parts: pre-processor, analyzer, and post-processor. The pre-processor creates 3-dimensional ceramics, makes finite-element models, and prepares analyzers input. The analyzer computes temperature, moisture, residual stress, displacement, etc. during the drying process using the information about finite-element model, material property, and boundary condition provided by the pre-processor. In post-processor, the analyzers results are visualized to help designers evaluation of the drying of the ceramic.

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Effect of Pre-treatment Methods on the Quality of Ginger during Storage (전처리 방법이 생강의 저장 중 품질에 미치는 영향)

  • 정태연;정태연;남궁배;이세은
    • Korean Journal of Food Preservation
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    • v.6 no.1
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    • pp.1-6
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    • 1999
  • Fresh gingers, harvested in Seosan, Choongcheongnam-do, were pre-treated by a washing-pasteurizing-drying process, a curing process, and non-treated, respectively. Then they were stored in a lab-scale storage room(12$^{\circ}C$, >92%RH) to investigate the effect of pre-treatment methods on the quality changes during long-term storage. Weight loss of ginger during storage showed ranges in 0.7∼4.3%, and the weight of gingers pre-treated by washing-drying process showed a tendency to change less than those treated by curing. After storage of 130 days, spoilage rates were about 20% in non-treated, 11% in curing treated, and 12% in washing-drying treated ginger,, showing the effect of pre-treatment. The final rate of sprouting was 13∼15% regardless of treatment methods. The firmness of gingers showed a tendency to decrease in stored ginger for the longer period; however, the values were ranged from 1,200 to 1,400 g/$\textrm{cm}^2$, that is hard enough to show a marketable quality. The contents of reducing sugar showed a tendency to increase with the lapse of storage time.

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