• Title/Summary/Keyword: reducing sugars

Search Result 364, Processing Time 0.025 seconds

Microbiological Studies and Biochemical Changes in Fermenting Soybean Curd Residue during Fermentation (비지의 발효과정중 발효미생물 및 성분변화)

  • Lee, Moon-Sook;Kim, Kil-Hwan;Lee, Gui-Ju
    • Korean Journal of Food Science and Technology
    • /
    • v.19 no.6
    • /
    • pp.520-527
    • /
    • 1987
  • This study was attempted to identify microorganisms in fermenting soybean curd residues (SCR). The changes in contents of free amino acids, nucleosides, reducing sugars, and oligosaccharides were also studied. The fermentation of SCR which was by change inoculation was carried out at $55^{\circ}C$ for 48 hrs. pH increased gradually during fermentation and isolated microorganisms were identified as Bacillus subtilis and Bacillus licheniformis. Moisture content decreased from 80.8% to 58.4% at 48 hrs of fermentation and other proximate composition did not show any changes during fermentation. The content of total free amino acids increased rapidly and the number and quantities of each amino acid analyzed also increased during the course of fermentation. Glutamic acid, phenylalaine, lysine and aspartic acid were rapidly liberated during fermentation. As to the changes of nucleotides, 5'-AMP little changed during the first 36 hrs but subsequently decreased to approximately 1/6 after 48 hrs of fermentation. On the other hand, 5'-IMP plus 5'-GMP did not show almost any change during the first 36 hrs but increased about 3.5 times at 48 hrs of fermentation. However, 5'-XMP was not detected. The reducing sugar level showed rapid and steady increase throughout the fermentation and that of stachyose plus raffinose decreased slightly. From these results, a possible way of utilization of fermented SCR was proposed as a substitute for soybean in meju preparation.

  • PDF

Combined effects of salts mixture addition and microwave heating on storage stability of Kakdugi (깍뚜기의 저장성 향상을 위한 순간 열처리 및 혼합염 첨가의 병용효과)

  • Kim, Jong-Koon;Yun, Jung-Won;Lee, Jung-Kun;Kim, Woo-Jung
    • Applied Biological Chemistry
    • /
    • v.34 no.3
    • /
    • pp.225-230
    • /
    • 1991
  • In this study, several combined effect of KCl addition into bring solution, microwave heating of Chinese radish for 3 minutes and addition of two salt mixtures into half fermented Kakdugi were investigated to compare their improving effects of storage stability of Kakdugi, Kakdugi was prepared by salting in 15% NaCl solution for 2 hours and fermented at $25^{\circ}C$ and determined for the changed in pH, total acidity and reducing sugars. It was found from the result that the combined method of salts addition and heating treatment improved the storage stability by 6.4 folds based on pH change where salts mixture of phosphated, Ca EDTA, and Sod. citrate contributed the most effect. Changed in reducing sugar were greatly reduced by salt mixture addition while microwave heating and KCl addition affected little. Storage of Kakdugi at $4^{\circ}C$ after preparation with combined method could extend the storage life more than 8 folds of those Kakdugi stored at $25^{\circ}C$. However total acidity showed higher values for those prepared by combined method and stored at $4^{\circ}C\;or\;25^{\circ}C$.

  • PDF

Changes on the Components of Elaeagnus multiflora Fruits during Maturation (성숙에 따른 뜰보리수(Elaeagnus multiflora) 과실의 성분 변화)

  • Hong Ju-Yeon;Nam Hak-Sik;Kim Nam-Woo;Shin Seung-Ryeul
    • Food Science and Preservation
    • /
    • v.13 no.2
    • /
    • pp.228-233
    • /
    • 2006
  • This study was Carried out to the changes of nutrientd and components for food valuation estimation during maturation of Elaeagnus multiflora fruits. The content of moisture was decreased during maturation, but brix was increased. The content of carbohydrate was increased during maturations but crude protein was decreased. And the content of reducing sugar was increased. The content of free fructose and glucose were high and its content were increased during maturation. Total content of free sugars were 135.66 mg/100 g-fr.wt in mature green fruit, 544.26, 787.83 mg/100 g-fr,wt in mature and over mature fruits, respectively. The Organic acids of Elaeagnus multiflora fruits were acetic, citric lactic, and malic, succinic acids. The content of citric acid was the highest among organic acids. Total content of organic acids were 407.95 mg/100 g-fr,wt in green mature fruits, and were decreased during maturation. The content of reducing vitamin C was 56.98 mg/100 g-fr.wt in mature green fruits and total contents of vitamin C was decreased during maturation. The content of phenol substance was 411.39 mg/100 g-fr.wt in the mature green fruit and was decreased during maturation.

Changes of Functional Compounds in, and Texture Characteristics of, Apples, during Post-Irradiation Storage at Different Temperatures (감마선 조사와 저장온도에 따른 사과의 기능성 성분 및 조직감 변화)

  • Yun, Hye-Jeong;Lim, Sang-Yong;Hur, Jung-Mu;Jeong, Jin-Woo;Yang, Soo-Hyung;Kim, Dong-Ho
    • Food Science and Preservation
    • /
    • v.14 no.3
    • /
    • pp.239-246
    • /
    • 2007
  • The effects of gamma irradiation on the physiochemical and physical characteristics of apples were investigated during post-irradiation storage at $4^{\circ}C\;and\;25^{\circ}C$. The contents of total and reducing sugars were analyzed and the results indicated that apples receiving 1 kGy of gamma irradiation did not show significant differences in sugar contents compared to non-irradiated controls. Important physiological characteristics were evaluated by measurement of total phenolic content and total flavonoid content, reducing power, and radical scavenging ability, and the results indicated that gamma irradiation at a dose of 1 kGy did not affect physiological activities. Changes in physical parameters such as weight loss, strength, cohesiveness and hardness, during post-irradiation storage, were temperature-dependent, whether the apples were irradiated or not The color and sensory acceptance of the apples were not affected by irradiation during cold storage. However, minor deterioration in color quality and sensory acceptance of irradiated apples was noted under ambient temperature storage. We conclude that gamma irradiation(1 kGy) does not affect apple nutritional content stability, functional properties, or physical characteristics, especially upon cold storage after radiation treatment.

Effects of Pasteurization and Storage Temperatures on the Physicochemical Characteristics of Kiwi Juice (참다래 쥬스의 이화학적 특성에 미치는 살균 및 저장온도의 영향)

  • Lee, Jin-Won;Kim, In-Whan;Lee, Kwang-Won;Rhee, Chul
    • Korean Journal of Food Science and Technology
    • /
    • v.35 no.4
    • /
    • pp.628-634
    • /
    • 2003
  • To investigate the effects of storage and pasteurization temperature on the quality of kiwi juice $(13.5^{\circ}Brix)$, the Kiwi juice was pasteurized at 65, 75 and $85^{\circ}C$ for 15 sec. The microbial, physicochemical measurements and sensory evaluations were conducted at the same condition during storage at 4 and $25^{\circ}C$ for 30 days. Most of the vegetative bacteria cells in kiwi juice were destroyed by heat treatment over $65^{\circ}C$, and they did not actively grow in kiwi juice after pasteurization. The D values of bacteria in kiwi juice by tubular type of heating exchange were 4.17, 1.47 and 0.81 sec at 65, 75 and $85^{\circ}C$, respectively. The growth of microorganisms during storage were not detected in the most samples. The amounts of vitamin C decreased as the pasteurization-storage-temperature and storage time increased. While reducing sugar increased as the pasteurization-storage temperature-storage time increased, it decreased rapidly after 20 days of storage. Hunter's color values L, a and b of stored kiwi juice were decreased at all storage conditions, browning reaction rate increased as the pasteurization-storage-temperature was decreased.

Hydration and Cooking Properties of Brown Rice Scratched with a Knife (칼집을 낸 현미의 수화 및 취반 특성)

  • Kim, Jae-Young;Baek, Seung-Hwa
    • Korean Journal of Food Science and Technology
    • /
    • v.44 no.6
    • /
    • pp.722-727
    • /
    • 2012
  • In order to improve the physical properties of brown rice by hydration and cooking, the amount of water absorption, hardness, reducing sugar, and minerals were measured for rice (NR), brown rice (NBR), and scratched brown rice (SBR). The amounts of water absorption were present in the order of NBR<0.07 SBR<0.20 SBR=NR after 210 min. The moisture contents of gelatinization rice were significantly different by degree of milling and scratch. The hardness of gelatinization rice were present in the order of NR<0.20 SBR<0.07 SBR

Determination of Optimal Conditions by Response Surface Methodology and Quality Characteristics of Water Extracts of Phellinus linteus (반응표면분석을 이용한 상황버섯 열수추출액의 최적 추출조건과 품질 특성)

  • Youn, Sun-Joo;Cho, Jun-Gu;Kwoen, Dae-Jun;Choi, Ung-Kyu;Kang, Sun-Chul
    • Applied Biological Chemistry
    • /
    • v.49 no.3
    • /
    • pp.215-220
    • /
    • 2006
  • Response surface methodology was implemented to determine an optimal extraction condition in Phellinus linteus water extract. Extraction was performed on 10 experimental conditions including independent variables such as extraction time $(1{\sim}5\;hrs)$ and water volume over sample (sample : $H_2O$ = 1 : $40{\sim}200$, W/V), color browning, reducing and total sugar, that were based on the significant levels of 10% of central composition design. Color browning, reducing and total sugar contents were found to be more affected when the water volume was increased rather than extraction time. Maximum extraction condition was acquired at extraction time of $3.0{\sim}4.5\;hrs$ and water volume of $40{\sim}58.2\;ml$. Being extracted at the optimal extraction condition two of the free sugars, sucrose (0.126%) and glucose (0.012%), were detected. Total content of the free amino acids was found to be $503.26\;{\mu}g%$. Among them, essential amino acid contents were revealed as 5.4%. One major peak from gel permeation chromatography contained polysaccharide(s) with the molecular weights of 10 KDa.

Comparison of the Quality Characteristics of Commercial Makgeolli Type in South Korea (국내 시판 막걸리의 품질특성 비교)

  • Park, Chan-Woo;Jang, Se-Young;Park, Eun-Ji;Yeo, Soo-Hwan;Kim, Ok-Mi;Jeong, Yong-Jin
    • Food Science and Preservation
    • /
    • v.18 no.6
    • /
    • pp.884-890
    • /
    • 2011
  • In this study, the quality characteristics of eight kinds of non-sterilized commercial makgeolli were investigated. The alcohol contents of five kinds of makgeolli were determined to be as follows: 5.7~5.8%, G $6.7{\pm}0.1%$, D $6.8{\pm}0.2%$, and C $7.5{\pm}0.1%$. As for the titratable acidity, makgeolli C and D showed higher than 0.5%, H showed $0.49{\pm}0.02%$, and the rest showed 0.45% or less. For the pH levels, there were no significant differences among the samples. The reducing-sugar content was approximately 200 mg%, and those of makgeolli A and F were lower by approximately 90 mg%. As for the organic acids, malic acid was detected only in makgeolli A and G while the acetic-acid content was high in makgeolli C and D. Concerning free sugars, fructose and sucrose were not detected, and the glucose content of makgeolli G was shown to be the highest ($335.1{\pm}40.3$ mg%). The maltose contents were similar ($23.5{\pm}1.0{\sim}45.0{\pm}1.1$ mg%), except for makgeolli G, whose maltose content was $73.5{\pm}1.8$ mg%. For the alcoholic ingredients, 0.4~0.5 mg/mL 1-propanol, 2-methyl-1-propanol, and iso-amylalcohol were detected, a suitable table wine standard. Further studies involving the quality analysis of the leavening agents, fermentation conditions, and fermentation types are needed.

Study on Quality Characteristics of Korean Traditional Kukhwaju by Addition of Dried Chrysanthemum indicum L. Extract into Mash (건조된 감국 열수추출물의 첨가 방법에 따른 국화주의 특성 연구)

  • Bang, Byung-Ho;Paik, Jean Kyung;Choi, Jea Young;Jeong, Eun-Ja;Rhee, Moon-Soo;Yi, Dong-Heui
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.44 no.9
    • /
    • pp.1333-1338
    • /
    • 2015
  • This study investigated the effects of addition of Chrysanthemum indicum L. extracts on quality characteristics of Kukhwju during fermentation. Fermented liquors without C. indicum L. were used as the control group. For experimental groups, we added 1, 2, 5, and 10% C. indicum L. extracts and brewed according to the addition method written in Yorok. The pH level during fermentation phase, alcohol concentration, level of reducing sugars, and acidity were measured in each of the experimental groups. After fermentation, we measured total contents of phenols, antioxidant effects, free sugars, organic acids, and chromaticity. During fermentation, no significant difference was observed between the C. indicum L. group and control group. Regarding total phenol contents and antioxidant effects, only the 5% and 10% C. indicum L. groups showed higher contents of phenols than the non-addition group. In general, 5% and 10% C. indicum L. addition groups were positively evaluated. In conclusion, Kukhwaju with 10% C. indicum L. extract showed the best antioxidant effects. In the present study, we obtained different characteristics and determined the optimum addition amount of C. indicum L.

Studies on the Chemical Compositions of Citrus junos in Korea (한국산유자(韓國産柚子)의 화학적성분(化學的成分)에 관(關)한 연구(硏究))

  • Jung, Ji-Heun
    • Applied Biological Chemistry
    • /
    • v.17 no.1
    • /
    • pp.63-80
    • /
    • 1974
  • The chemical components of Citrus junos produced in Korea were divided into two parts; common and special components respectively. In the former the relation between the physiological effects of the plant and its ripening process was observed periodically while the latter was analyzed the ripening fruits for their effective utilization as food. The results are summarized as follows: 1. The analytical result of seasonal change showed that the rind ratio was higher than the flesh ratio and on a regional basis, the rind ratio was higher in the islands than on land areas. 2. In the experiment the moisture was increased until the third period, but afterwards it was made constant. While the content of crude fat, cellulose, ash, total acid and soluble non-nitrogen material were decreased until the third period and the cotent of cellulose and total acid were continuousely redused until the last period. In con trast with the above the content of reducing sugars was increased but the content of crude fat, cellulose, ash, crude protein and soluble non-nitrogen material were increased until last period. 3. The content of vitamin C was richer in the rind than in the flesh, in the Korean species than in the Japanese. 4. Free sugars; xylose, fructose, glucose were richer in the rind than in the flesh. 5. The content of volatile organic acids was richer in the rind than in the flesh. Among them, volatile acids, acetic acid, formic and n-valeric acid were found in the rind and formic acid, acetic acid and propionic acid were deteceed in the flesh. 6. The total content of non-volatile acids was richer in the flesh than in the rind. In the kind of non-volatile acids, citric acid,glutaric acid, malic acid, tartaric acid, oxalic acid, malonic acid, succinic acid and an unknown acid were found in the rind and citric acid, malic acid, succinic acid, oxalic acid, glutaric acid and malonic acid in the flesh. 7. Three kinds of aromatic components: D-limonene, ${\alpha}-pinene$, p-cymene and seven other kinds of unknown aromatic components were detected in neutral essential oils. Among them, D-limonene seemed to be main aromatic component in the fruits. 8. From the above results it is confirmed that both rind and flesh of the ripened fruit could be utilized for food effectively, and unripened fruits are suitable for producing citric acid, ripened fruits are also useful for producing juice.

  • PDF