• Title/Summary/Keyword: moisture content change

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Effects of Concentration of ZnO Nanoparticles on Mechanical, Optical, Thermal, and Antimicrobial Properties of Gelatin/ZnO Nanocomposite Films

  • Shankar, Shiv;Teng, Xinnan;Rhim, Jong-Whan
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.20 no.2
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    • pp.41-49
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    • 2014
  • This study illustrates the synthesis of gelatin based zinc oxide nanoparticle (ZnONPs) incorporated nanocomposite films using different concentrations of ZnONPs. The ZnONPs were oval in shape and the size ranged from 100- 200 nm. The nanocomposite films were characterized by UV-visible, FE-SEM, FT-IR, and XRD. The concentrations of ZnONPs greatly influenced the properties of nanocomposite films. The absorption peaks around 360 nm increased with the increasing concentrations of ZnONPs. The surface color of film did not change while transmittance at 280 nm was greatly reduced with increase in the concentration of ZnONPs. FTIR spectra showed the interaction of ZnONPs with gelatin. XRD data demonstrated the crystalline nature of ZnONPs. The thermostability, char content, water contact angle, water vapor permeability, moisture content, and elongation at break of nanocomposite films increased, whereas, tensile strength and modulus decreased with increase in the concentrations of ZnONPs. The gelatin/ZnONPs nanocomposite films showed profound antibacterial activity against both Gram-positive and Gram-negative food-borne pathogenic bacteria. The gelatin/$ZnONP^{1.5}$ nanocomposite film showed the best UV barrier and antimicrobial properties among the tested-films, which indicated a high potential for use as an active food packaging films with environmentally-friendly nature.

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Physicochemical Properties of Bokbunja Jelly Containing Fermented Sea Tangle Saccharina japonica Powder (유산균 발효다시마(Saccharina japonica)를 첨가한 복분자 젤리의 이화학적 품질특성)

  • Choi, Ji-Won;Lee, Yeon-Ji;Moon, Soo-Kyung;Kim, Yong-Tae
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.55 no.4
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    • pp.408-416
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    • 2022
  • This study investigated the physicochemical properties and physiological activities of jelly prepared from gelatin, sugar, bokbunja extract, and different amounts (0, 0.5, 1, 2 and 3%) of fermented sea tangle Saccharina japonica powder (FSP). The jelly moisture, pH, and sugar content slightly increased with increasing the FSP content. Hardness, springiness, gumminess, chewiness, and cohesiveness also increased with increasing FSP concentration. Jelly antioxidant activity did not change significantly with increasing FSP. In contrast, alcohol dehydrogenase and aldehyde dehydrogenase activities in the jellies increased significantly with increasing FSP concentration. β-secretase inhibitory activity in jellies also increased with increasing FSP concentration. Jellies containing 0.5 or 1% FSP achieved the highest overall sensory acceptance scores. Taken together, these data indicate that addition of FSP to jelly appears to improve its quality and physiological activities.

Study on the Preparation of Kochujang with Utilization of Retrogradated Starch food (노화된 전분식품을 이용한 고추장 제조에 관한 연구)

  • 차은정;김경자
    • Korean journal of food and cookery science
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    • v.12 no.4
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    • pp.481-486
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    • 1996
  • This study was compared with conventional kochujang and the preparation of saccharification kochujanf with the utilization of waste cooked rice, rice cake, bread. Saccharification kochuiang tested to estimated the pH, reducing sugar and changes of organic acid conients, sensory evaluation during the aging at 60 days. Moisture content were increased about B-10% nd crude fat contents were decreased about 20-40% during the aging at 60 days. Change of pH value of kochujang reduces gradually from pH 5.0 up to pH 4.7 during the aging. Total reducing sugar contents of saccharification kochujang reached maximum value at 50 days. The Products of organic acids of during aging were acetic acid, lactic acid, malic acid, tartaric acid and citric acid of the chief of source. Sensory evaluation conducted by fifteen students as panelists showed that were at 1% level significant difference 7 samples in color, flavour, apperance.

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Dimensional Change of Acetylated Softwood (아세틸화 침엽수재의 치수변화 특성)

  • Han, Gyu-Seong;Cho, Nam-Seok
    • Journal of the Korean Wood Science and Technology
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    • v.24 no.4
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    • pp.40-46
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    • 1996
  • It is well-known fact that dimensional stability of wood is greatly enhanced by acetylation of wood. This dimensional stability results from bulking of the reacted acetate within the cell wall, which reduces further swelling when the modified woods corne into contact with water or water vapor. The purpose of this research was to determine the water absorption and dimensional stability of the acetylated solid wood in liquid water and in humidity tests. Radiata pine, Siberian larch, and Japanese larch were acetylated. Antiswelling efficiency(ASE) and equilibrium moisture content(EMC) of acetylated wood, at 95% RH and $20^{\circ}C$ after 4weeks, was quite dependent on WPG, but was not dependent on species.

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Quality Characteristics of Sulgidduk Added with Astragalus membranaceus Powder (황기분말 첨가 설기떡의 품질특성)

  • Lee, Se-Hee;Cho, Sung-Hyun
    • Korean journal of food and cookery science
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    • v.29 no.3
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    • pp.233-239
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    • 2013
  • This study was conducted to investigate rheological and sensory characteristics of Sulgidduk added with Astragalus membranaceus powder. The moisture content of the Sulgidduk ranged from 42.03% to 43.38%. The addition of Astragalus membranaceus powder in the Sulgidduk tended to decrease the pH value, but did not change $brix^{\circ}$ values of the samples. the addition of Astragalus membranaceus powder in the Sulgidduk tended to decrease the lightness (L) in Hunter color value, but to increase the redness (a) and yellowness (b). For the textural characteristics, the addition of Astragalus membranaceus powder decreased the hardness and springiness. In sensory evaluation, the addition of 1.5% Astragalus membranaceus powder had the best score in taste and overall preference. Therefore, this results suggest that adding 1.5% Astragalus membranaceus powder could be applied for making Astragalus membranaceus Sulgidduk.

A Study on the Distribution and Time Dependent Change of Wood Temperature by Solar Radiation

  • Xu, Hui Lan;Kang, Wook;Chung, Woo Yang
    • Journal of the Korean Wood Science and Technology
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    • v.37 no.2
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    • pp.141-147
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    • 2009
  • The fluctuation of physical properties in wood or wood composites is an important subject when the materials in building and construction. Sorption and desorption occur in wood when exposed to the open air, and the temperature distribution in wood can fluctuate as a result of changes in environmental temperature, solar radiation, humidity, and wind velocity. In this study, the temperature difference and fluctuation caused by outdoor environment among different wood species were analyzed using a numerical method. The effect on the process of heat transfer in wood caused by environmental factors was investigated using 1-dimensional partial differential equation with real boundary and initial conditions. The experimental data have been used to check the accuracy of programming code. Through analysis, it was found out that density and moisture content have a negative effect on thermal diffusivity of wood.

Preparation of various soy cheese and their physicochemical and sensory characteristics (대두 Cheese의 제조와 그의 일반 성분 및 수응도에 관한 연구)

  • Yang, Kyung-Soon;Yoon, Sun
    • Korean journal of food and cookery science
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    • v.3 no.2
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    • pp.75-80
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    • 1987
  • For the manufacture of soybean cheese, curds were made from soy milk using either lactic starter or CaCl$_2$and ripened for 3 weeks. When papain was added during ripening, the amout of soluble protein increased. The yields of 3 soybean cheese were 76~88%, indicating that considerable loss of soy protein did not occur during the processing. During the period of ripening the change of moisture content was about 1 n. Total acidity of 3 soy cheese increased, demonstrating the production of lactic acid through lactic fermentation. Texture determined by Instron showed that 3 soy cheese had their own characteristic texture profile curve and that the cheese without papain treatment received the highest textural parameters. 3 manufactured soy cheese received 3-4 (good-very good) sensory scores in appearance, flavor and texture. General acceptibility of 3 cheese were evaluated as desirable or very desirable.

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Effects of Rhizome Size and Mulching Materials on Agronomic Characteristics and Yield in Zingiber mioga ROSC. (양하(Zingiber mioga ROSC.) 지하경 크기와 피복재료가 주요형질과 수량에 미치는 영향)

  • 최성규;이종일
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.2
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    • pp.112-116
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    • 1993
  • The experiment was carried out to investigate the influence of rhizome size and mulching materials on some agronomic characters and flower-head yield of Gingiber mioga ROSCOE. The larger the size of rhizome was, the more the number of leaves developed, and the higher the yield was. The most suitable rhizome size for planting was found to be from I2cm to 15cm. Rice straw and polyethylene film mulching materials increased the soil porosity and reduced change of the soil moisture content. The yield of flower-head was highest in the straw-mulching plot, indicating that straw would be the best mulching material for growth and yield of flower-head in Gingiber mioga ROSCE.

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Effects of Storage Temperatures and Heating Methods on the Textural characteristics of Wheat Flour Gels and Loaf Bread (저장 온도 및 가열 방법이 밀가루겔 및 식빵의 조직 특성에 미치는 영향)

  • 고하영;윤계순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.28 no.3
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    • pp.566-571
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    • 1999
  • Effects of storage temperature at 18oC and 5oC for 9 days and heating conditions on textural char acteristics in strong wheat flour gels were investigated using a Instron after microwave (2450MHz, 700W). Heating condition did not affect the texture property in the wheat flour gels, but the frozen storage was very effective to prevent the hardening of the samples. Hardness, adhesiveness, and gumminess in the wheat flour gels decreased in increasing moisture content from 45% to 55%, but there was little change in cohesiveness. The storage at room temperature for 2 hours resulted in increased hardness in the heated wheat flour gels. PE wrap package of the wheat flour gels prevented weight loss by 3~6% and hardening effectively. Sugar, or sugar and shotening resulted in increased hardness in loaf bread. The hardness and weight loss in loaf breads were markedly changed by the heating time with microwave. The most critical time point was around 4 minutes following the heating.

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Chemical Properties of Artificially Buried Wood in an Intertidal Zone during the Deterioration Period

  • SEO, Sujin;KIM, Taekjoon;LEE, Jae-Won
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.6
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    • pp.896-906
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    • 2020
  • Wood deterioration experiments were carried out for 6 months in an intertidal zone of South Korea to monitor the changes in the chemical properties of two types of species, Korean red pine and sawtooth oak. The results of FT-IR spectra and XRD patterns have shown that the chemical properties of the wood did not change significantly during the 6-month burial period. However, the brightness of the surface decreased after burial; the value of the sawtooth oak sample was lower than that of the Korean red pine sample owing to an accumulation of inorganic compounds in cell lumen as observed by ICP analysis. Among the inorganic compounds, sodium and sulfur concentrations increased significantly over the burial period compared with the control. Further, the maximum moisture content decreased from 199% to 136% in the Korean red pine and 62% to 60% for the sawtooth oak. Nevertheless, the major chemical composition of both the wood species did not change significantly during the 6-month burial period, whereas, the crystallinity decreased with an increasing burial period owing to an accumulation of inorganic compounds in the lumen.