• Title/Summary/Keyword: Physicochemical changes

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Manufacture of Processed Foods and its Quality Characteristics from Kumquats, a Citrus Variety Produced in Cheju (금감 가공식품(加工食品)의 제조(製造)와 품질특성(品質特性))

  • Koh, Jeong-San;Kim, Chan-Shick;Ko, Myung-Soo;Yang, Young-Tack
    • Korean Journal of Food Science and Technology
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    • v.25 no.1
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    • pp.33-38
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    • 1993
  • In order to utilize Kumquats as a processed products, a Citrus varieties produced in Cheju island, physicochemical properties of Kumquats, sensory evaluation of frozen Kumquats, sensory evaluation and texture parameter of Kumquats processed foods were investigated. Fruit size, weight, peel ratio, peel thickness, and Brix/acid ratio of Youngpa Kumquats cultivated in green house were 29.5 mm, 16.10g, 4.63 mm and 20.0 respectively, and it was suitable for as raw-eating and processing materials. Kumquats juice consisted of 58.27% citric acid, 32.49% malic acid, 9.14% tartaric acid and 0.08% maleic acid of total organic acids. Organic acid contents of Kumquats juice was very different from Citrus unshiu juice in malic acid content. Sensory evaluation on frozen Kumquats stored at $-18^{\circ}C$ for 6 month was good for appearance, taste and texture as summer commodity. Vitamin C content of frozen Kumquats was 74.94 mg/100g, and its content was decreased slightly during fronzen storage. Hardness on Kumquats jam was lowered from 1,294 to 355 g-force as the ratio of Kumquats juice content was increased, but the changes of other texture parameter were not so large. Kumquats jam contained $40{\sim}60%$ orange juice was evaluated as superior to orange jam for panelists.

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Physicochemical Characteristics of Garlic (Allium sativum L.) on the High Temperature and Pressure Treatment (고온고압처리에 따른 마늘(Allium sativum L.)의 이화학적 특성)

  • Kwon, Oh-Chan;Woo, Koan-Sik;Kim, Tae-Myoung;Kim, Dae-Joong;Hong, Jin-Tae;Jeong, Heon-Sang
    • Korean Journal of Food Science and Technology
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    • v.38 no.3
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    • pp.331-336
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    • 2006
  • Effects of high temperature and pressure treatment on garlic (Allium sativum L.) treated at 110, 120, 130, 140, and $150^{\circ}C$ for 1, 2, 3, 4, and 5 hr were evaluated by investigating changes in antioxidant activities, and total polyphenol, total flavonoid, and 5-hydroxymethyl-2-furaldehyde (5-HMF) contents of garlic juice. Antioxidant activities, and total polyphenol, total flavonoid, and 5-HMF contents increased with increasing treated temperature and time. $IC_{50}$ (1.952 mg/g) was achieved at $150^{\circ}C$ for 4 hr, 50 times higher than untreated garlics. Highest total polyphenol content was 18.155 mg/g at $140^{\circ}C$ and 2 hr, seven times higher than untreated garlics. Highest total flavonoid content was $532.73\;{\mu}g/g$ at $150^{\circ}C$ and 1 hr, sixteen times higher than untreated garlics. 5-HMF content was highest (7,765.9 ppm) at $150^{\circ}C$ and 2 hr. Correlation coefficients among antioxidant activities, and total polyphenol, total flavonoid, and 5-HMF contents were very high (p<0.01).

Effects of Undaria pinnatifida on the Physicochemical Properties of Egg (미역첨가 사료가 계란의 이화학적 성질에 미치는 영향)

  • Jo, Kil-Suk
    • Food Science and Preservation
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    • v.12 no.2
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    • pp.117-122
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    • 2005
  • This study was performed to investigate the effects of Undaria pinnatifida on the hysicochemical properties in egg from laying hens fed with $5\%,\;10\%$and $15\%$ supplementation, respectively. The increased amount of Undaria pinnatifida resulted in the decreased weight of egg, expecially in white ones. Darkness, greenness, and blueness of egg yolk and white were increased with the addition of Undanria pinnatifida, and such color changes were predominantly observed in egg york. Among the analyzed minerals, the contents of Ca, Fe and K were increased to $286.6\;mg\%$, $72\;mg\%$ and $430.6\;mg\%$, respectively. But amount of p was reduced to $134.2\;mg\%$. Total cholesterol contents were not significantly changed. Major fatty acids were palmitic, oleic and linoleic acid The contents of omega-3, omega-6 and essential fatty acids were increased to $2.5\%,\;17.6\%$, and $18.4\%$, respectively.

Improvement of Cooking Properties by Milling and Blending in Rice Cultivar Goami2 (도정 및 품종혼합에 의한 고아미2호의 취반특성)

  • Chun Areum;Song Jin;Hong Ha-Cheol;Son Jong-Rok
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.spc1
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    • pp.88-93
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    • 2005
  • The functional vice (Oryza sativa L.) has been highly regarded recently, in the change of rice maykets in the world. Goami2 (GA), one of the functional rice varieties, was developed from high-quality rice, Ilpumbyeo (IP). From the previous study, GA has been proved its beneficial effect on the improvement of metabolic control and body weight reduction especially in obesity, We could certain that GA was very difficult to be gelatinized due to the micro lump shown in the Scanning electron micrographs (SEM) photos. To improve its cooking quality, we investigated the changes of physicochemical properties, which were differentiated by the conditions of milling and blending. As GA was milled every $2\%$ until eliminating $12\%$, the nitrogen content was decreased linearly. But the decreasing rate of nitrogen content of GA during milling process was relatively lower than that of IP. Thus, we assumed that GA has relatively high nitrogen in inner starch of grain. The degree of milling had no effect on the gelatinization of cooked GA, but affected lightness and whiteness linearly, which were ranged in normal values when the rice was milled more than $10\%$ in weight. So we could concluded that the milling process was not proper to improve cooking quality of GA. And we could suggested that GA was needed to soak into water at least one hour before cooking by it water absorption rate at normal temperature$(21^{\circ}C)$ and sensory evaluation. From the texture analysis, cooked GA had higher hardness than other varieties. Therefore, we blended GA with IP, Baekjinju(BJ) and Hwasunchalbyeo(HS), then subjected to sensory evaluation. All evaluation items including the sensory preference were the highest scores for the rice blended with glutinous rice varieties, BJ and HS.

Comparison of quality property between fresh cooked rice and re-heated cooked rice

  • Sim, EunYeong;Woo, Koan Sik;Kim, Mijung;Park, Hye-Young;Oh, Sea Kwan;Lee, Chunki
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.287-287
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    • 2017
  • The objective of this study was to evaluate difference of quality properties of between fresh cooked rice and re-heated cooked rice after retrogradation. Nine rice varieties raised by NICS were compared the properties of physicochemical, texture, sensory evaluation, toyo glossiness value, pasting properties. Among nine rice cultivars, the changes of weight and length-width ratio of after soaking as well as cooking showed how water absorbed in each rice granule. The amount of water absorption after soaking was highest in Wolback (semi-waxy), Hiami and lowest in Samgwang, Seonpum, Ilpum. After cooking, the amount of water absorption was high in Dasan 1 and Andabyeo, however low in Ilpum. In the length-width ratio after soaking, Wolback (semi-waxy cultivar) and Anda (indica cultivar) increase their volume relatively as their shape are while others increased more in length than width. Among cooked rice, the highest value of length-width ratio shows in Anda, Dasan1, Hiami and Seonpum, the Wolbak was similar to that of non-glutinous rice. After cooking, the others stored at $10^{\circ}C$ for 16 hours for retrogradation (imitated at convenience store). Then re-heated using by microwave. Pasting properties were considerably affected by storage temperature and periods of rice. The setback showed in the following order: Wolback (-92.25 RVU, the lowest retrogradation) < Seonpum (-35.20) < Chindle (-22.08) < Jungsanggold (-21.98). Toyo glossiness value of cooked rice showed in the following order: Chindle (82.40) > Samgwang (79.43) > Hiami (79.23). Sensory evaluation of re-heated rice of Jungsanggold, Samgwang, and Chindle were 78.97, 78.36, and 77.35, respectively. Hardness, elasticity, and toughness of re-heated rice ware increased compared to cooked rice, whereas cohesiveness was decreased. Hardness and elasticity is higher in Seonpum, Dasan1 and Hiami, toughness is higher in Jungsanggold, Samgwang and Wolbak. Cohesiveness of Jungsanggold and wolbak showed higher than others.

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Effects of Various Additives for Spoilage Prevention on Brewers grain and Soymilk by-product (여러 가지 첨가제가 맥주박과 베지밀박의 부패방지에 미치는 영향)

  • Lee, H.J.;Kim, H.S.;Jeon, B.S.;Kim, S.W.;Ki, K.S.;Cho, K.K.;Cho, J.S.;Lee, H.G.;Choi, Y.J.
    • Journal of the Korea Organic Resources Recycling Association
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    • v.10 no.3
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    • pp.74-84
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    • 2002
  • This experiment was carried out to evaluate supplemental effects of various preservatives to preserve the Brewers grain and Soymilk from decay and degeneration. The NaCl, organic acid(Ca-propionate), microbial fermenter(H/MF inoculant), and methionine hydroxy analogue(MHA) were used as additives in order to compare preservability of brewers grain and soymilk by-product during 20 days at July to August. Most treatments were appeared rapid decay and degeneration as soften and covered with molds on surface from the early days of experiment. However, MHA treatments showed any change until 20 days of storage. In terms of pH and $NH_3-N$ contents, only MHA treatment showed a stable and low value. The other treatments including Control showed high values as time flowed or unstable states. In conclusion, when high moisture agricultural by-product was treated by over 5% of MHA, there was no significant physicochemical changes in long term preservation over 20 days at summer season.

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Effect of the Beet Addition on the Quality of American Preferred Kimchi during Fermentation (비트 첨가가 미국인 선호 김치의 숙성 중 품질에 미치는 영향)

  • Yang, Yu-Jin;Han, Ji-Sook
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.4
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    • pp.538-543
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    • 2005
  • To improve the Quality of American preferred kimchi (APK), the APK added different ratios of beets were prepared and the Qualities of those kimchi were investigated by measuring the changes of physicochemical, microbiological and sensory characteristics during fermentation at $5^{\circ}C$. The pH of APK added beet (APKB) decreased as the amount of beet increased while total acidity gradually increased. The reducing sugar content was the highest in APKB added $3\%$ beet at early stage of fermentation. The number of Lactobacillus sp. and Leuconostoc sp. were the highest in $3\%$ beet added group during fermentation. In a texture experiment, the hardness of Korean standard kimchi used as control group showed rapidly decrease while the hardness of APKB were decreased slowly as fermentation proceeded. In Hunter's color values of APKB, lightness and redness increased as the amount of beet increased while yellowness decreased. Sensory scores of overall acceptance, taste, texture and appearance evaluated by Americans as sensory panels were the highest in APKB added $1\%$ beet. Americans also preferred fresh kimchi to optimum ripened kimchi. Therefore it was suggested that the American preferred kimchi added $1\%$ beet was the best group among American preferred kimchi groups.

Physicochemical Changes of Woody Charcoals Prepared by Different Carbonizing Temperature (탄화온도가 목탄의 물리·화학적 특성에 미치는 영향)

  • Jo, Tae-Su;Choi, Joon-Weon;Lee, Oh-Kyu
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.3
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    • pp.53-60
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    • 2007
  • Carbon content, properties of micro-pore, and chemical properties of the charcoal prepared from wood powder, wood fiber, and bark of Abies sibirica Ledeb at different temperatures were investigated. The yield of charcoal decreased with increasing the carbonization temperature. The yield of bark charcoal was higher than those of wood and wood fiber charcoal. The content ratio of carbon atom in the charcoal increased with increasing the carbonization temperature, whereas those of hydrogen and oxygen atom were decreased. Ash content of bark charcoal was also higher than those of wood and wood fiber charcoal. The specific surface area of wood and wood fiber charcoal was greater than that of bark charcoal. In all charcoal, the specific surface area and the volume of micro-pore were highest when the carbonization temperature was $600^{\circ}C$, however they tended to decrease when the temperature was reached to $800^{\circ}C$. For the functionality test of chemical groups on the charcoal surface, adsorption test have performed against acidic (HCl) and basic chemicals (NaOH, $Na_2CO_3$, and $NaHCO_3$). As carbonization temperature increased, adsorption amount of HCl increased, while adsorption amounts of NaOH, $Na_2CO_3$, and $NaHCO_3$ were decreased. The charcoal prepared at higher temperature showed basic properties, while the charcoals manufactured at lower temperature presented acidic properties. Therefore, it was considered that the carbonization temperature affected the pH of charcoal.

Changes in Physicochemical Properties of Korean Rice Cake Subjected to Microwave-Drying (마이크로파 건조 방법에 따른 흰떡의 이화학적 특성변화)

  • Im, Ji-Soon;Park, Kwang-Jang;Kum, Jun-Seok
    • Korean Journal of Food Science and Technology
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    • v.31 no.3
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    • pp.631-637
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    • 1999
  • An investigation was carried out to study the effects of aging time, storage temperature, and drying type on the physical, chemical and sensory properties of Korean rice cake. Water content and cooking properties were significantly influenced by aging time and storage temperature. However, aging time did not affect the soup turbidity. Difference in water content was noticeable by drying type. The microwave treated rice cake (MW) showed a higher water content than the other ones. The lightness (L-value) was not affected by the aging time and drying type. Rice cake storaged at 4oC showed the highest L-value. The textural properties of rice cake were influenced by the all sources of variables. There was a significant difference in hardness between microwave and hot air treated rice cake (MWH), and microwave and vacuum treated rice cake (MWV). In the sensory properties, mean intensities of all attributes except chewiness were significantly different among drying types. The MWV showed a higher acceptability than the MW and the MWH. Scanning electron photomicrographs revealed that the MWV has more porous structure. The MWV was the most desirable one as determined by the physical, chemical and sensory evaluation.

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Effect of Corona Discharge on the Changes in Quality and Pasteurization of Ginseng Powder (코로나방전 처리 인삼분말의 살균효과 및 품질변화)

  • Kim, Kyung-Tack;Kim, Sung-Soo;Ha, Sang-Do
    • Korean Journal of Food Science and Technology
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    • v.35 no.6
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    • pp.1237-1243
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    • 2003
  • As a newly emerging pasteurization method for improving the shelf-life of powdered ginseng, the corona discharge generated at high voltage conditions was examined for its effects on microbial pasteurization, physicochemical characterization, and sensory evaluation. The pasteurizing effects of corona discharge on total bacteria, yeast, molds, and coliforms increased with increasing voltage. However, corona discharge treatment of 5 kv/cm did not show significant effects of pasteurization on the yeast, molds, and coliforms. Treatment with 20 kv/cm reduced about 95% of the total bacteria $(6.14{\pm}0.04{\rightarrow}\;4.59{\pm}0.04$) and coliforms ($2.43{\pm}0.05{\rightarrow}\;1.00{\pm}0.05$) and 99% of the yeast and molds ($4.65{\pm}0.06{\rightarrow}\;2.73{\pm}0.06$). The proximate analysis, minerals, free sugars, crude saponin, and colors of the control ginseng and the ginseng treated with 20 kv/cm were not significantly different at p<0.05. Corona discharge of up to 20 kv/cm did not affect the proximate analysis, minerals, free sugars, crude saponin, and colors of the powdered ginseng. Sensory evaluation scores on color, flavor, taste and overall acceptability between the control ginseng and ginseng treated with 20 kv/cm corona discharge were not significantly different at p<0.05 level. Consequently, corona discharge treatment is thought to be a good alternative pasteurization method for improving the shelf-life of powdered ginseng due to its effective pasteurization, maintenance of nutrients and good sensory characteristics.