• Title/Summary/Keyword: optimum acidity

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A Study of Rheology with Cooking Methods of Potato (감자의 조리방법에 따른 물성 변화)

  • 이정숙;황영정
    • Culinary science and hospitality research
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    • v.9 no.2
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    • pp.85-97
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    • 2003
  • This study is an attempt that Rheology changes are occurred by boiling, frying, and boiling potatoes with soy bean sauce. Three different methods are tested for chemical analysis, fine potato starch grain structural change, sensory evaluation. 1) Alkaline number and acidity number are changed (+)2.17 in raw, decreased (+)1.76 by boiling, increased (+)2.38 by frying, and (-)2.22 by boiling with soy bean sauce. 2) Potatoes are completely dissolved into the gelatinization when they are boiled at 10$0^{\circ}C$ for 15minutes(PB III), fried at 18$0^{\circ}C$ for 3 minutes(PF IV), and boiled with soy bean sauce l0$0^{\circ}C$ for 30 minutes(PS III). 3) The pectin content ratio is decreased according to frying (31.78$\mu\textrm{g}$/$m\ell$), boiling(44.20$\mu\textrm{g}$/$m\ell$), boiling soy bean sauce(36.37 $\mu\textrm{g}$/$m\ell$), Hemicellulose content ratio is decreased according to frying(1.19%), boiling(1.17%), boiling soy bean sauce(0.92%). And the contend of cellulose and lignin is still regardless of any cooking method. 4) The sensory evaluation conducted by 30 university students as panelists showed that there are more significant differences among four samples in appearance, flavour, texture. As a result, the optimum cooking condition for potatoes is that potatoes are boiled l0$0^{\circ}C$ for 15minutes, fried at 18$0^{\circ}C$ for 3minutes, and boiled with soy bean sauce at 1$0^{\circ}C$ for 30minutes.

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Dyeing Properties of Cotton and Wool Fabrics with Betel Palm Tree (빈랑에 의한 면, 모직물의 염색성)

  • 배정숙
    • Journal of the Korean Home Economics Association
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    • v.42 no.7
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    • pp.63-72
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    • 2004
  • This study discussed the dyeing of wool and cotton fabrics with Betel Palm Tree White woolen fabrics and cotton fabrics purchased from HATH (Korea Apparel Testing & Research Institute) were used as experimental fabrics. Using dyeing powder extracted from dyeing material, various temperatures, dyeing times, and pH were used in the dyeing process. Al, Cr, Fe, Cu, and Sn were used as mordant and the absorption was compared with different mordanting methods. The optimum condition for pre-mordanting dyeing was dye concentration of 25% (o.w.f) and mordant concentration of 0.5$^{\circ}$∼1%. Woolen fabric showed an increase of absorption and the maximum absorption was achieved at weak acidity. According to the mordanting methods, woolen fabrics and cotton fabrics were treated with various mordanting agents, a mordant rate of 1:100, at 60$^{\circ}C$, for 30 minutes and dyed with a dyeing material concentration of 25% (o.w.f), at a rate of 1:100, at 60$^{\circ}C$ for 60 minutes. The best dyeing effect w3s achieved at the temperature of 60$^{\circ}C$ for cotton and 80$^{\circ}C$ for wool fabrics. The light fastness of cotton and wool fabrics was low and particularly the fastness to perspiration was decreased with Fe mordanting. I concluded that pre-mordanting method was better than post-mordanting method for cotton and woolen fabrics.

Studies on the Metal Cupferrate Complexes-1 Spectrophotometric Determination of Cupferron (Metal Cupferrate Complex에 關한 硏究 (第1報) 分光 光電法에 의한 Cupferron 定量)

  • Si-Joong Kim
    • Journal of the Korean Chemical Society
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    • v.7 no.1
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    • pp.29-33
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    • 1963
  • A new method determining the micro amount of cupferron spectrophotometrically was investigated and was considered on the various factors which affect on the method. The method was as follows; ferric alum solution was added in a suitably acidified solution of cupferron. After the precipitates of Fe(Ⅲ)-cupferrate were formed, they were extracted with chloroform and the absorbancy of the organic phase was measured by spectrophotometer, Beckmann Model B (1cm quartz cell). The stable maximum wavelength was 325 $m{\mu}$ at 3.0 to 5.6 of the optimum pH and it obeyed on Boer's law in the range of 5.76 ${\gamma}/ml$ to 74.80 ${\gamma}/ml$ of cupferron. The maximum wavelength was independent on pH, concentration of cupferron and of ferric alum. The absorbancy at 325 $m{\mu}$ was not affected by $SO_4^{--}$ and Ac, but was varied by $Cl^-$ and $NO_3^-$. Sulfuric acid and acetate buffer are preferred to the acid and buffer solution adjusting the pH. At higher acidity, however, the absorbancy was somewhat lowered because of the decomposition of cupferron, and at too high concentration of ferric alum, it was also decreased because of the difficulty in the extraction. By this method, it was able to determine cupferron quantitatively in the percent error of 1.18.

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Physicochemical Characteristics of Various Peach Cultivars

  • Lee, Jun-Young;Park, Heui-Dong;Park, Sang-Won
    • Preventive Nutrition and Food Science
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    • v.6 no.2
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    • pp.107-111
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    • 2001
  • Physical and chemical characteristics of four white-and one yellow-fleshed peach cultivars were compared at optimum maturity stage. In addition, differences of phenolic composition, polyphenol oxidase (PPO) activities and PPO isozyme patterns in two peach types were also investigated. There are no significant differences in firmness and color values between two peach types, except for "Yumyung", a white-fleshed peach with the highest firmness, and "Hwangdo", a yellow-fleshed peach with the highest yellowness (b)* value. In general, the soluble solid/titratable acidity ratios, ascorbic acid and total phenolic contents were significantly higher for white-fleshed peaches than those for yellow-fleshed peach (p<0.05). Three major phenolic compounds, catechin, neochlorogenic acid and chlorogenic acid, were found in both the white-and yellow-fleshed peaches. Among them, catechin was the predominant phenolic compound in the white-fleshed peaches, followed by neochlorogenic acid, and chlorogenic acid. Meanwhile, neochlorogenic acid was present in the highest level of the yellow-fleshed peach, but levels of two other phenolic compounds were lower. PPO activities of the white-fleshed peaches were generally higher than that of the yellow-fleshed peach, with the one major band and two minor bands, and there were no big differences in PPO isozyme patterns between two different peach cultivars.

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Effect of Addition Soy Flour on Tapioca Non-steamed Fermentation (콩분말 첨가에 따른 타피오카의 무증자 알콜발효에 미치는 영향)

  • 하영득
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.32 no.3
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    • pp.388-392
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    • 2003
  • This study was conducted to examine the effect of soy flour on tapioca non- steamed fermentation. A whole soy flour was higher than roasting soy flour in alcohol content. Alcohol content was increased up to 2% of soy flour, and decreased after adding 3% soy flour. The pH and total acidity were showed no significant differences by adding soy flour, roasted soy flour, water and enzyme. The optimum conditions for alcohol production were 2% (w/w) of soy flour,0.5% (w/w) of enzyme and 250% (v/w) of water at 96 hr. Addition of soy flour increased yield of alcohol.

Quality Characteristics of Kimchi with Added Stevioside-containing Sweetener (스테비오사이드 함유 감미료 첨가 김치의 품질특성)

  • Bae, Hyo Ju;Lee, Ju Youn
    • Journal of the Korean Society of Food Culture
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    • v.28 no.1
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    • pp.99-106
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    • 2013
  • The effects of stevioside-containing sweetener (SCS) on kimchi quality were evaluated by investigating acid production, growth of lactic acid bacteria, sensory properties, and several volatile odor component (VOC)s of SCS-added kimchi. The concentrations of SCS added to kimchi instead of 1% white sugar were 0.165, 0.33, 0.66, and 1.32% (w/w). The pH of kimchi with higher amounts of added SCS generally increased, and the acidity of kimchi with higher amounts of added SCS generally decreased. Addition of higher amounts of SCS generally inhibited the growth of lactic acid bacteria in kimchi. Scores of overall acceptability for 0.33 or 0.66% SCS-added kimchi were significantly higher than those for other samples (p<0.05), whereas those for 1.32% SCS-added kimchi were significantly lower than those for other samples (p<0.05). The optimum concentration of SCS added to kimchi appears to be 0.33%. Among major VOCs identified in kimchi, the concentrations of seven components including ethanol generally decreased with addition of higher amounts of SCS, whereas that of diallyl disulfide was not changed markedly. The major VOCs contributing to desirable sensory properties of kimchi were likely dimethyl disulfide and diallyl sulfide.

Optimization of Curd Yogurt Production Using Saccharified Rice Solution by Response Surface Methodology (쌀당화액을 활용한 호상요구르트 제조의 최적화)

  • Kim, Ok-Sun;Sung, Jung-Min
    • Korean journal of food and cookery science
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    • v.31 no.4
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    • pp.485-496
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    • 2015
  • This study was carried out to establish the optimal conditions for curd yogurt using saccharified rice solution. A central composite design was applied to investigate the effects of pectin (2.8~8.4 g), skim milk (14~70 g) and oligosaccharide (28~84 g) ratio on the physicochemical and sensory characteristics of curd yogurt using saccharified rice solution. pH, total acidity, and color value, were analyzed and sensory evaluation was performed. The pH of curd yogurt decreased with decreasing pectin and oligosaccharide ratio. The addition of pectin had a significant effect on the viscosity while skim milk had a significant effect on the color value (a and b value). The results of sensory evaluation showed that, oligosaccharide and skim milk had significant effects on sweetness and sour taste. Oligosaccharide and skim milk masked the sour taste of curd yogurt. The optimum range of ingredients for curd yogurt using saccharified rice solution was predicted to be 4.27~4.90 g of pectin, 30.80~41.30 g of skim milk, and 28.00~36.10 g of oligosaccharide. Based on the overlapped results of physicochemical and sensory evaluation, the optimal amounts of pectin, skim milk and oligosaccharide were 4.59 g, 36.50 g and 32.05 g, respectively.

Quality Properties of Kochujang Added Defatted Rice Bran Powder During Storage (탈지미강을 첨가한 고추장의 저장 중 품질특성)

  • Jeon, Eun-Raye;Jung, Lan-Hee
    • Korean journal of food and cookery science
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    • v.27 no.4
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    • pp.89-98
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    • 2011
  • The physicochemical and sensory properties of kochujang added defatted rice bran powder were periodically examined during storage at 30$^{\circ}C$ for 45 days. The pH of kochujang added defatted rice bran powder increased gradually according to the added level, whereas pH decreased gradually during storage. But the acidity to be appeared opposite of pH. The L-, a and b-values of samples increased gradually according to the amount of added defatted rice bran powder, whereas they decreased gradually during storage. The salinity of samples decreased gradually according to the amount of added defatted rice bran powder and storage. Amino nitrogen content of kochujang added defatted rice bran powder was higher than that of the control during storage. Electron donating activities of kochujang added defatted rice bran powder increased gradually according to the amount added. As a result of the sensory evaluation, the 3% treatment was superior in color, aroma, and overall preference. The sensory evaluation revealed that adding 3% defatted rice bran powder was optimum for improving kochujang quality.

A Study on Physicochemical Properties of Artificial Substrates and Changes of Plant Growth in Tropical Plant Resources Research Center of Korea National Arboretum (국립수목원 열대온실 내 인공배합토의 물리화학적 특성 및 식물 생육 변화에 관한 연구)

  • Song, Jeong-Hwa;Jin, Hye-Young;Ahn, Tai-Hyeon
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.2
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    • pp.52-62
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    • 2010
  • This study was carried out in the Tropical Plant Resources Research Center of Korea National Arboretum to determine the optimum edaphic environment for the growth of tropical and subtropical plants. The physicochemical properties of artificial substrates and the growth characteristics of tropical and subtropical plants were investigated. Subtropical plants exhibited a high growth rate when cultivated in a substrate of Dry Zone that had physical properties similar to those of arid native soil. Mediterranean plants showed a low growth rate when grown in a substrate of Subtropical Zone that required changes in acidity. The substrate of Tropical Zone had high organic matter and mineral contents and therefore had good physical properties:this substrate has a good environment for the stimulation of the growth of tropical plants. Our results indicate that the chemical properties such as pH and mineral contents of most artificial substrates need to be more urgently improved than their physical properties in order to ensure better growth of tropical and subtropical plants. Initial management strategies for the construction of new tropical greenhouses were formulated, and data from monitoring studies will be continuously gathered and incorporated in the manual to keep it updated.

Optimization of Spray Drying Process for Manufacturing Dried Vinegar using Response surface methodology (분말식초제조를 위한 분무건조공정의 최적화)

  • 황성희;정용진;윤광섭
    • Food Science and Preservation
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    • v.9 no.2
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    • pp.194-199
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    • 2002
  • This study was conducted to develop processing method for vinegar powder from natural vinegar for encapsulation applications. To optimize the spray drying process, experiment was designed by central composition method to find optimal conditions for manufacturing vinegar powder. The acidity, water absorption, solid content and heat stability of vinegar powder were selected as response variables. The optimal concentration of inclusion complex which was made with vinegar and ${\beta}$-cyclodextrin was determined on 30。bx. On increasing the concentration of ${\beta}$-cyclodextrin as a wall material, the quality of the vinegar was decreased. The optimum conditions of spray drying process for manufacturing vinegar powder were 188∼192$^{\circ}C$ and 500∼600 Lh$\^$ -1/ as inlet temperature and flow rate, respectively.