• Title/Summary/Keyword: drying degree

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Quality Change of Cinnamon Extract Prepared with Various Drying Methods (건조 방법에 따른 계피 Extract의 품질 변화)

  • 김나미;김동희
    • The Korean Journal of Food And Nutrition
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    • v.13 no.2
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    • pp.152-157
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    • 2000
  • In order to select the optimum drying method for the production of cinnamon extract, water extract and 70% ethanol extract of cinnamon were prepared. And then several drying method of oven drying, vacuum evaporation, spray drying and freeze drying were performed. Content of cinnamic acid, cinnamic aldehyde, eugenol, tannin and free sugar, and antioxidant activity, degree of browning, pH, color value, turbity and solubility were compared. In water extract, contents of cinnamic acid, cinnamic aldehyde, eugenol were 29.45mg/100g, 94.86mg/100g, 120.75mg/100g and decreased to 4.76%∼44.21%, 5.30%∼48.05%, 3.66%∼21.83% by oven dyring, vaccum drying, spray drying respectively, but freeze drying showed a little decrease of those components. In 70% ethanol extract, effectual components decreased to 76.05%∼88.38% and 26.86%∼78.76% by freeze drying and vacuum evaporation respectively. Antioxidant activity decreased by drying and decreasing rate in 70% ethanol extract was lower than water extract. Degree of browning increased as the drying temperature increased. Tannin and free sugars were little affected by drying temperature. Solubility decreased in oven drying and 70% ethanol extract. Overall data suggested that optimum drying methods of cinnamon extract were freeze drying in case of water extract and freeze drying and vaccum drying in case of 70% ethanol extract.

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Comparative Evaluation of Physicochemical Properties of Pine Needle Powders Prepared by Different Drying Methods

  • Chung, Ha-Sook;Lee, Jun Ho
    • Preventive Nutrition and Food Science
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    • v.20 no.2
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    • pp.143-147
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    • 2015
  • Systematic study of how different drying methods, namely hot-air drying, vacuum-drying, and freeze-drying, affect color, browning index, degree of rehydration, water solubility, and vitamin C content is critical for utilizing pine needle powders (PNP) as a novel ingredient in functional foods. Samples prepared by vacuum-drying showed a significantly higher $L^*$-value, whereas higher $a^*$- and $b^*$-values were detected in the hot-air dried samples (P<0.05). The browning index was significantly higher in samples prepared by vacuum-drying compared to samples prepared by freeze-drying (P<0.05). Freeze-dried PNP exhibited a significantly higher degree of rehydration than hot-air dried samples (P<0.05). Water solubilities of freeze-dried and hot-air dried samples were significantly higher than that of vacuum-dried sample (P<0.05). Vitamin C was less destroyed during freeze-drying compared to hot-air or vacuum-drying (P<0.05). Freeze-dried samples displayed a clear porous structure and appeared to have a bigger space, whereas hot-air dried samples showed lower porosity than vacuum and freeze-dried samples.

Effect of Polyphenol Oxidase Activity and Total Phenolic Content on Browning and Quality of Dried-Persimmon According to Maturity Degree of Astringent Persimmon

  • Jung, Kyung-Mi;Song, In-Gyu;Kim, Se-Jong;Lee, Sang-Han
    • Current Research on Agriculture and Life Sciences
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    • v.33 no.2
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    • pp.65-68
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    • 2015
  • Hunter's color value "a" in dried-persimmon of table and full ripe fruit was higher than that in unripe fruit. In case of soluble solid content, full ripe fruit was $50^{\circ}Brix$, the highest degree, while unripe fruit was $40^{\circ}Brix$, the lowest degree. PPO activation of unripe fruit was 4.7, which was higher than table-ripe fruit (0.7) and full ripe (1.0). Polyphenol oxidase activation remained even while drying, but there was no difference in PPO activation degree as drying period increased. Total phenol content of unripe fruit was 101.4, which was higher than table-ripe fruit (57.5) and full ripe fruit (67.4). Total phenol content level increased as drying period increased, which was based on fresh weight. Hardness of unripe and table ripe fruit continued to decrease until three weeks during softening. After that, hardness was high and it started drying. However, in full ripe fruit, hardness increased after two weeks and softening was fast during the drying period, and its weight reduction rate was lower than that of unripe and table ripe fruit.

Quality Properties of Semi-dried Persimmons with Various Drying Methods and Ripeness Degree (다양한 건조방법과 감의 성숙도에 따른 반건시 품질특성)

  • 정경미;송인규;조두현;추연대
    • Food Science and Preservation
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    • v.11 no.2
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    • pp.189-194
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    • 2004
  • This experiment was carried out to compare the quality of semi-dried persimmon according to various drying methods and ripeness degree of persimmons. Most of persimmons were dried naturally there were much opportunities of contamination by impurities, microorganism and discoloration. There were need for developing various drying methods and knowing proper mature degree of persimmons in order to enhance the quality of semi-dried persimmons. Drying time of semi-dried persimmons by hot-air, far infrared ray and dehumid drying could be shorten approximately 11∼12 days, comparing with natural drying. And the loss ratio of natural drying and artifical drying were 7.0% and 0.0%. The moisture content of natural drying and dehumid drying were simillar and the hardness were very low in comparing other drying methods. Average pannel scores in semi-dried persimmons after drying showed that dehumid drying and natural drying were excellent in total prefernce ; 3.9 and 3.4, respectively. Unriped persimmons showed lower moisture content, color values and higher hardness than riped and overriped persimmons. The total preference of riped and overriped fruit were superior than unriped fruit.

Influence of Drying Methods on Measurement of Hydration Degree of Hydraulic Inorganic Materials: 1) Ordinary Portland cement paste and mortar (수경성 무기재료의 수화도 측정에 대한 건조방법의 영향: 1) 보통 포틀랜드 시멘트 페이스트 및 모르타르)

  • Lee, Hyo Kyoung;Kim, Hyeong-Ki
    • Resources Recycling
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    • v.27 no.1
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    • pp.92-105
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    • 2018
  • The present study was carried out to find a suitable drying method for measuring non-evaporable water contents of various hydraulic inorganic materials. In Part 1 of the paper, the case Ordinary Portland cement is discussed. Various drying methods including vacuum and oven drying, and an ignition, were used for the OPC paste and mortar having different w/c. The sole vacuum drying under room temperature led a fluctuation on measurement of hydration degree, while the sole oven drying also yielded unwanted hydration promotion at the early age. A combination of the vacuum and oven drying was considered as a suitable drying method for the OPC case.

Comparative Study on Unsaturated Characteristic Curves of Boeun Granite Weathered Soil during Drying and Wetting Paths (건조 및 습윤과정에서 보은 화강암 풍화토의 불포화특성곡선 비교)

  • Song, Young-Suk
    • Journal of the Korean Geotechnical Society
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    • v.32 no.7
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    • pp.15-24
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    • 2016
  • To investigate the unsaturated characteristics of the Boeun granite weathered soil, matric suction and volumetric water content were measured in both drying and wetting paths using Automated Soil-Water Characteristics Curve Apparatus. Based on the measured results, Soil-Water Characteristics Curve was estimated by van Genuchten (1980) model. The relationship between effective degree of saturation and matric suction showed the non-linear curve with S-shape and the hysteresis phenomenon occurred during drying and wetting paths. Suction Stress Characteristics Curve was estimated by the Lu and Likos (2006) model. The suction stress in drying path was constantly maintained and that in wetting path tended to increase when the effective degree of saturation was low. But the suction stress in drying path was larger than that in wetting path at the same degree of saturation when the effective degree of saturation became larger. Meanwhile, Hydraulic Conductivity Function was evaluated by the van Genuchten (1980) model which is one of the parameter estimation methods. The unsaturated hydraulic conductivity decreased with increasing the matric suction, and the decreasing velocity regarding to the matric suction in drying path was larger than that in wetting path.

Effects of Drying Condition and Binding Agent on the Quality Characteristics of Ground Dried-Pork Meat Products

  • Choi, Yun-Sang;Ku, Su-Kyung;Park, Jong-Dae;Kim, Hee-Ju;Jang, Aera;Kim, Young-Boong
    • Food Science of Animal Resources
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    • v.35 no.5
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    • pp.597-603
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    • 2015
  • The purpose of this study was to investigate the influence of processing conditions (temperature and time) and binding agent types (glutinous rice flour, potato starch, bean flour, and acorn flour) on the physicochemical and sensory characteristics of ground dried-pork meat product. For this purpose, ground dried-pork meat product was produced by adding several binding agents at different drying temperatures and times. The drying time affected moisture content and water activity in all drying temperature. However, under the similar drying conditions, the extent of drying varied depending on the type of binding agents. The results of sensory evaluation for texture degree and overall acceptability indicated the following: overall, higher drying temperatures and longer drying time heightened the degree of texture, and the overall acceptability varied depending on binding agent type. Physicochemical and sensory characteristics were analyzed to determine any possible correlation. The results revealed a high correlation between moisture content, water activity, shear forces, and sensory evaluation (p<0.01). However, there was no correlation with respect to overall acceptability.

Comparison of the Degree of Bacterial Removal by Hand Hygiene Products

  • Hwang, Young Sun
    • Journal of dental hygiene science
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    • v.22 no.1
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    • pp.51-56
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    • 2022
  • Background: The coronavirus disease (COVID-19) pandemic increased awareness regarding the importance of hand hygiene in infection prevention. Although social distancing and vaccination are the strongest ways to prevent infection, personal hand hygiene is the most basic and easiest way to maintain public health. However, in addition to hand washing using running water, sanitizing tissues, and disinfection products are convenient for hand hygiene, especially outdoors. Therefore, it is necessary to improve the appropriateness of individual hand hygiene methods. In this study, we investigated the degree of hand hygiene offered by various hygiene products and hand drying methods for maintaining hand hygiene. Methods: An LED UV light kit was used for fluorescent observation of hand contamination. Bacteria from the hands were cultured to compare the degree of hand hygiene offered by various hygiene products. Bacteria were cultured in a hand-shaped medium dish to identify areas vulnerable to hand hygiene. Moreover, the degree of hand hygiene was observed according to the drying method using bacterial cultures. Results: We confirmed that hand washing under running water with antibacterial soap, sanitizing with alcohol gel disinfectant, and wiping with antibacterial wet wipes was effective for hand hygiene compared to washing under running water alone. However, for all hygiene products, a large number of bacteria were detected on the fingertips. We verified that natural drying, rather than rubbing, is effective in maintaining hand hygiene. Conclusion: These results suggest that hand hygiene products and drying methods are critical in hand hygiene management. Therefore, these results provide a basis for determining whether an individual's hand hygiene management method is appropriate.

A study on intelligent fish-drying process control system

  • Nakamura, Makoto;Shiragami, Teizoh;Sakai, Yoshiro
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.132-137
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    • 1993
  • In this paper, a fish drying process control system is proposed, which predicts the proper change with time in weight of the material fish and the drying conditions in advance, based on the performance of skilled worker. In order to implement a human expertise into an automated fish drying process control system, an experimental analysis is made and a model for the process is built. The proposed system divided into two procedures: The procedure before drying and the one during drying. The procedure before drying is for the prediction of necessary drying time. To estimate the necessary drying time, first, the proper change in weight for the product is obtained by using fuzzy reasoning. The condition part of the production rule consists of the factors of fish body and the expected degree of dryness. Kext, the necessary drying time is obtained by regression models. The variables employed in the models are the factors, inferred change in weight and drying conditions. The model for the procedure during drying is also proposed for more accurate estimation, which is described by a system of linear-differential equations.

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Neutral Sizing of Linerboard Using Fast Cure Type AKD (급속경화형 AKD를 이용한 라이너지의 중성 사이징)

  • Lee Hak-Lae;Seo Man-Seok;Shin Jong-Ho;Youn Hye-Jung
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.38 no.1 s.113
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    • pp.1-8
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    • 2006
  • To overcome troubles in strength and process of linerboard caused by raw materials, a neutral sizing which is usual in fine paper making can be considered. A new sizing agent is necessary to show good performance in a system with high conductivity and COD. In this study, fast cure type AKD was examined as a new sizing agent and compared with conventional AKD. The effects of fixing agent addition and drying condition were also investigated. Fast cure type AKD which has a higher cationicity showed better sizing degree than conventional AKD in spite of low addition level and no curing treatment. And when fixing agent of sufficient amount was added, sizing degree was improved for both AKDs. High cationicity is a crucial factor for neutral sizing of linerboard for obtaining fast and stable sizing degree. Drying with temperature over $100^{\circ}$ was desirable for developing sizing degree.