• Title/Summary/Keyword: ascorbic acid (AA)

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Effects of Ultrasound and Ascorbic acid Cotreatment on Browning of Fresh-cut 'Tsugaru' Apples (초음파 및 Ascorbic acid 병용처리가 신선절단 '쓰가루' 사과의 갈변에 미치는 영향)

  • Cho, Jeong-Seok;Jeong, Moon-Cheol;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.19 no.3
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    • pp.323-327
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    • 2012
  • The effects of ultrasound and ascorbic acid cotreatment on the browning inhibition and microbial growth of fresh-cut Tsugaru apples were investigated. The prepared samples were dipped in distilled water (Cont) or 1% (w/v) ascorbic acid solution (AA) and were then ultrasonicated in distilled water (US) or 1% (w/v) ascorbic acid solution (AA+US). The samples were then packed in a 0.04mm polypropylene bag ($20{\times}15$ cm) and were stored at $10^{\circ}C$ for eight days. The AA+US treated samples showed high $L^*$ and low $a^*$, $b^*$ values as well as inactivated PPO activity. The growth of the total aerobic bacteria also inhibited the AA+US treated samples more. The physicochemical properties were not different among all the samples. It was demonstrated in this paper that the ultrasonication treatment with ascorbic acid prevented the enzymatic browning of and microbial growth in fresh-cut Tsugaru apples.

Influence of Acetic Acid Solution on Heat Stability of L-Ascorbic Acid

  • Jang, Keum-Il;Lee, Hyeon-Gyu
    • Food Science and Biotechnology
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    • v.17 no.3
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    • pp.637-641
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    • 2008
  • This study investigated the heat stability of L-ascorbic acid (AA) in acetic acid solution. To analyze the degradation of AA using high performance liquid chromatography (HPLC), AA was measured at a wavelength of 244 nm in acetic acid and 265 nm in distilled water. During the storage of AA in acetic acid or distilled water at $37^{\circ}C$, degradation of AA was slower in acetic acid than in distilled water. On examining various ratios of AA to acetic acid, the stability of AA at $100^{\circ}C$ for 30 min was the highest when the concentration of acetic acid was 10 times higher than the concentration of AA. After acetic acid was added into AA degraded by heating, the AA is stabilized by reheating. Ultimately, these results indicate that degraded AA is reduced by hydrogen ions dissociated from acetic acid, and the rate of reduction of degraded AA in acetic acid solution is improved with heat processing.

Production of Ascorbic acid-2-glucoside from L-Ascorbic acid with Spinach ${\alpha}-Glucosidase$ (시금치종자의 ${\alpha}-glucosidase$에 의한 L-ascorbic acid로부터 ascorbic acid-2-glucoside의 생산)

  • Chung, Ji-Youn;Song, Hee-Sang;Bang, Won-Gi
    • Applied Biological Chemistry
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    • v.47 no.2
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    • pp.187-191
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    • 2004
  • For the production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (ascorbic acid-2-g1ucoside, AA-2G) from ascorbic acid, the usability of spinach seed as the source of ${\alpha}-glucosidase$ having transglucosylation activity was studied. The optimum conditions for the production of AA-2G from ascorbic acid and glucose donor were investigated by using crude extract of Spinachia oleracea L. Woosung, the selected source of enzyme. The production of AA-2G was the highest with 1.053 mM when spinach seeds were grown for 2 days after germination. Maltose was the most effective glucose donor, and the optimum concentration of ascorbic acid and maltose were 175 mM and 225 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 60 units. The most effective buffer was sodium acetate and its optimum concentration was 175 mM. The optimum pH and temperature were 5.0 and $65^{\circ}C$, respectively. Under the optimum condition, 2.14 mM of AA-2G was produced from ascorbic acid after 50 minutes of reaction.

Formation of A L-Ascorbic Acid 2-o-$\alpha$-glucoside during Kimchi Fermentation

  • Jun, Hong-Ki;Bae, Kyung-Mi;Kim, Young-Hee;Cheigh, Hong-Sik
    • Preventive Nutrition and Food Science
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    • v.3 no.3
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    • pp.225-229
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    • 1998
  • Formation of a L-Ascorbic Acid 2-O-$\alpha$-glucoside(AA-2G) is a chemically stable dervative of asocrbate that shows a vitamin C acitivity in vitro as well as in vivo. We studied whether ascorbic acid(AA) and AA-2G are formed in baechu kimchi during fermentation at 4 $^{\circ}C$ or 18$^{\circ}C$. To determine the formation of AA and AA-2G during fermentation of kimchi, wheat flour (as a carbhydrate source) added baechu kimchi (WBK) and control baechu kimchi(CBK) were prepared and fermented at 4 $^{\circ}C$ or 18 $^{\circ}C$. A substance like AA-2G was detected by HPLC from WBK fermented at 18 $^{\circ}C$ for 26 days in fall season and confirmed later to be the AA-2G showing distinctive characteristics of heat stability and resistance to ascrobate oxidase catalase. However, none of the kimchi formed AA-2G when the kimchi were fermented under a different temperature condition such as 4 $^{\circ}C$ instead of 18 $^{\circ}C$ or a different season such as summer instead of fall even if they were fermented at 18 $^{\circ}C$. The pH of kimchi was decreased rapidly during the first 3 days. and then decreased slowly after 4 days when the kimchi were fermented at 18 $^{\circ}C$. However, there were slight changes of pH in both CBK and WBK feremented at 4$^{\circ}C$ for 30 $^{\circ}C$ days. Therefore, the AA-2G -forming activity in kimchi seems to be correlated with the formentation temperature, the microorganisms involved in kimchi fermentation and a suitable glycosyl donor for AA as provided by wheat flour in this study.

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Production of Ascorbic acid-2-Glucoside from Ascorbic acid with Rice ${\alpha}-Glucosidase$ (벼의 ${\alpha}-Glucosidase$에 의한 Ascorbic acid로부터 Ascorbic acid-2-Glucoside의 생산)

  • Kim, Sung-Kyoon;Hwang, Ki-Chul;Bang, Won-Gi
    • Applied Biological Chemistry
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    • v.43 no.1
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    • pp.12-17
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    • 2000
  • For the enzymatic production of $2-O-{\alpha}-D-glucopyranosyl-L-ascorbic$ acid (AA-2G) from ascorbic acid, rice seed was used as the source of ${\alpha}-glucosidase$ having transglucosylation activity. Among six rice varieties, cultivated in Korea, ${\alpha}-glucosidase$ activity of Oryza savita L. cv. Ilpumbyeo was the highest with 125.03 unit/ml and it had maximum specific activity with 8.52 unit/mg protein when rice seeds were grown for 3 days after germination. For the production of AA-2G using crude extract of O. savita L. cv. Ilpumbyeo, maltose was most effective glucose donor. The optimum concentration of maltose and ascorbic acid were 125 mM and 175 mM, respectively. The optimum concentration of ${\alpha}-glucosidase$ was 100 unit. The most effective buffer was 100 mM sodium citrate. The optimum pH and temperature were 5.0 and $60^{\circ}C$, respectively. Under the optimum condition, $108.43\;{\mu}M/unit$ of AA-2G was produced from ascorbic acid after 35 minutes of reaction, which corresponds to 6.2% of conversion ratio based on the amount of ascorbic acid used.

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Identification of L-Ascorbic Acid 2-Ο-$\alpha$-Glucoside, a Stable Form of Ascorbic Acid, in Kimchi

  • JUN, HONG-KI;KYUNG-MI BAE;YOUNG-HEE KIM
    • Journal of Microbiology and Biotechnology
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    • v.8 no.6
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    • pp.710-713
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    • 1998
  • A material with the same high performance liquid chromatography (HPLC) retention profile as authentic ascorbic acid 2-Ο-$\alpha$-glucoside (AA-2G) was detected in kimchi. This material was identified as AA-2G by testing its susceptibility to $\alpha$-glucosidase hydrolysis, the HPLC profile, and through the elementary analysis. Among several strains of bacteria isolated from fermented kimchi, four strains could produce cydodextrin glucanotransferase (CGTase) which catalyzes the transglucosylation reaction of ascorbic acid. By using starch as the glycosyl donor, AA-2G was produced as the major product through this reaction.

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Tissue-Based Amperometric Biosensor for Determination of L-Ascorbic Acid in Organic Media (유기 용매 속에서 L-Ascorbic Acid의 정량을 위한 바이오센서)

  • Kwon, Hyo-Shik;Lee, Cheal-Gyu
    • Analytical Science and Technology
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    • v.7 no.2
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    • pp.149-153
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    • 1994
  • An amperometric sensor for L-ascorbic acid(AA) in methanol media has been made by immobilizing squash-tissues on a graphite rod disk. A detection limit of the electrode was $2{\times}10^{-6}M$ L-ascorbic acid. In comparison with an isolated enzyme based ascorbate oxidase(AO) electrode, the plant-tissue electrode offered high biocatalytic stability and activity and extremely low cost. The electrode has a useful lifetime of 1 week.

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Development of Cosmeceutical Cosmetics Using Enzyme Bio-Conversion System (효소 생전환 시스템을 이용한 기능성 화장품 개발)

  • Lee Ghang Tai;Kwon Ji Youn;Bae Dong Jun;Yu Chang Seon;Lee Myoung Hee;Oh Sei Ryang;Jang Dong Il
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.1 s.49
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    • pp.111-114
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    • 2005
  • This study is about the cosmeceutical products using enzyme induced bio-conversion system. In general, ascorbic acid (AA) has the higher reducing activity and can be used for various purpose in the cosmetics. But it is very unstable in the aqueous system and difficult to maintain its stability in the cosmetics product. 2-O-$\alpha$-D-Glucopyranosyl-L-ascorbic acid (AA2G) is the stabilized form of AA and showed the less whitening activity than AA. In this study, we developed bio-conversion system improving the stability and efficacy of AA2G and AA, respectively. In this system, AA2G (over $80\%$) can be converted to AA and glucose within 30 min. The converted product showed higher anti-tyrosinase activity like AA (AA2G showed no anti tyrosinase activity) and depigmenting activity in the artificial tanning test. From these results, we could conclude this system is a brand new method to increase the activity of AA and maintain its stability.

Production of 2-O--$\alpha$-D-Glucopyranosyl L-Ascorbic Acid by Cyclodextrin Glucanotransferase from Bacillus sp. JK-43 (Bacillus sp. JK-43의 Cyclodextrin Glucanotransferase에 의한 2-O-$\alpha$-D-Glucopyranosyl L-Ascorbic Acid 생산에 관한 연구)

  • 전홍기;배경미;김영희;김성구
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.29 no.1
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    • pp.49-56
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    • 2000
  • The 2-O-$\alpha$-D-glucopyranosyl L-ascorbic acid (AA-2G) which was enzymatically glucosylated with the cyclodextrin glucanotransferase (CGTase) [EC 2.4.1.19] from Bacillus sp. JK-43 has been reported previously. The presnet experiments examined the optimal conditons for the productio of AA-2G from AA and soluble starch, and characterized the properties of the CGTase from Bacillus sp. JK-43. The reaction mixture for the maximal production of AA-2G was followings; 12% total substrate concentration, 1,400 usits/mL of CGTase and a mixing ratio of 2 : 3(g or AA : g of soluble starch). Under this condition, 1.76mM of AA-2G, which corresponded to 2.53% yield based on AA, was produced after incubation for 24hrs at 45$^{\circ}C$ (pH 5.5). The optimum pH and temperature for the CGTase activity were 6.0 and 45$^{\circ}C$, respectively. The enzyme was stable at pH 5.5 to 9.5, and at temperature up to 5$0^{\circ}C$. The thermostability of the enzyme could be enhanced up to 6$0^{\circ}C$ by the addition of 30mM CaCl2.

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Effects of Combined Treatment with High $CO_2$ Concentration and Ascorbic acid on Browning of Fresh-cut 'Fuji' Apples (고농도 $CO_2$와 Ascorbic acid 처리가 신선절단 사과의 갈변에 미치는 영향)

  • Kim, Sun-Young;Cho, Jung-Seok;Jeong, Moon-Cheol;Moon, Kwang-Deog
    • Food Science and Preservation
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    • v.18 no.4
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    • pp.475-480
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    • 2011
  • This papers were studies the effects of high $CO_2$ concentration pretreatment and ascorbic acid on the browning of fresh-cut apples. The prepared samples were dipped in 1% (w/v) ascorbic acid solution (AA). Fresh-cut apples (3 pieces) were packed in polypropylene bags (0.03 mm, $20{\times}15$ cm), and stored at $10^{\circ}C$ for 16 days. AA-treated samples showed higher L value than those of non-treated and control (dipped in water without $CO_2$ pretreatment), while non-treated samples showed higher hardness than AA-treated sample. Total soluble solids, pH, titratable acidity were not affected by high $CO_2$ pretreatment and AA treatment. These result shows high $CO_2$ concentration pretreatment with dipping in 1% ascorbic acid solution (AA) has an effects on controlling enzymatic browning during the storage of fresh-cut 'Fuji' apples.