• Title/Summary/Keyword: Metabolic Enzymes

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Shalf Life Enhancement of Minimally Processed Fruits and Vegetables

  • Kim, Dong-Man
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 1993.12a
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    • pp.6-9
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    • 1993
  • According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. Thus. to prevent these undesirable changes , val'ious techniques such as controlled atmosphere (CA) storage, modified atmosphere OIA) storage, including vacuum packaging have been receiving considerable attention, Although milch research has been done to find optimal conditions for whole intact frui ts and vegetables, only limi ted information is avai lable on fresh cut. and other minimally processed products. 81 iced frui ts exhibi t increas~d ethylene production and respiration compal'ed to whole f, 'uits during distribution in response to tissue damage. As a result, accelerated senescence and enzymatic browning OCCUI', Recent l'esearch on minimally processed fl'uits and vegetables has mainly focused on methods to inhibit browning, due to ban on use of sulfur dioxide, In order to retard or prevent these physiological changes, val'ious al ternatives, reducing agents. acidulants, chelating agents and inol'ganic sal ts have been evaluated for use on fresh cut fl'ui ts. Al though some agents were effective replacement for sulfur dioxide. consum$\textregistered$I'S demandless use of chemical on such products. Shel~ life of minimally processed products has been extended by inhibition of metabolic reactions associated with loss of quality and by inhibition of aerobic spoilage caused by wide variety of microorganisms. Appl ication of ~I.-\ packaging, including vacuum packaging, retards the rate of respiration, prevents growth of aerobic spoilage organisms, inhibits oxidation and color deterioration. Tissue softening is another major problem in minimally processed products because enzymes re 1 a ted to ce 11 wa 11 degrada t i on are not inactivated. Various treatments have been investigated for retardation of the softening of sliced products. Some studies have concentrated on the application of an active packaging system with ~I, l. packaging and calcium infi 1 tration as possible measures to retain firmness of processed products. In my opinion, one important step for production of minimally processed frui ts wi th favorabl e color of cut surface and firm texture is the selection of better cultivar. As the view, changing tendency of fresh color by apple cultivars and relationship between the tendency and PPO activity will be discussed in the seminar. In addition to the topic, research result on quality enhancement of fresh apple slices by heat shock treatment will be introduced.

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Anti-obesity Effects of African Mango (Irvingia gabonesis, IGOB 131TM) Extract in Leptin-deficient Obese Mice (유전성 비만 마우스에 대한 아프리칸 망고 추출물의 항비만 효과)

  • Lee, Minhee;Nam, Da-Eun;Kim, Ok Kyung;Shim, Tae Jin;Kim, Ji Hoon;Lee, Jeongmin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.10
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    • pp.1477-1483
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    • 2014
  • This study investigated the anti-obesity effects of African mango (Irvingia gabonesis, IGOB $131^{TM}$) extract in leptin-deficient obese mice. Experimental groups were treated with two different doses of IGOB $131^{TM}$ (1% and 2% in each AIN93G supplement) for 8 weeks. Treatment of obese mice with both low and high dose of IGOB $131^{TM}$ significantly reduced body weight gain by 10.9% and 13.3%, respectively, compared to control obese mice. Subcutaneous adipose tissue weight of mice was significantly reduced by 18% by low-dose and 23% by high-dose supplementation. This result was supported by micro-CT analysis around the abdominal regions of mice, indicating that the adipose tissue area and volume were significantly reduced by treatment with IGOB $131^{TM}$. Serum levels of triglycerides in the low- and high-dose groups were reduced by 36.5% and 43.8%, respectively, upon treatment with IGOB $131^{TM}$, whereas total cholesterol levels were reduced by 31.8% and 35.4%. Interestingly, the serum LDL level decreased upon treatment with IGOB $131^{TM}$ while the serum level of HDL dramatically increased upon high-dose treatment with IGOB $131^{TM}$, resulting in a significant reduction in the LDL to HDL ratio of 59.2%. These results were supported by the expression levels of enzymes and proteins related to lipid metabolism assessed by real-time PCR. There was a significant increase of in adiponectin expression as well as significant decreases in the expression of FAS, LPL, and lipid regulatory transcription factors such as PPAR-${\gamma}$, C/EBP, and SREBP upon both low- and high-dose IGOB $131^{TM}$ treatment. However, there was no statistical difference between low- and high-dose treatments. These results suggest that IGOB $131^{TM}$ is able to regulate the serum lipid profiles by reducing triglyceride and increasing HDL levels as well as regulate expression of lipid metabolic factors, resulting in reduction of a weight gain in leptin-deficient obese mice.

Studies of vindoline metabolism in Catharanthus roseus cell cultures using deuterium-labeled tabersonine (Catharanthus roseus 세포 배양액에 deuterium이 치환된 tabersonine을 사용한 vindoline 생합성 경로 연구)

  • Lee, Soo;Lee, Hyang-Yeol
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.1
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    • pp.71-80
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    • 2012
  • Vinca alkaloids produced from Catharanthus roseus are one of the most important natural product drugs in treatments of human cancers. These anticancer drugs are derived from coupling of the two monomeric indole alkaloids, catharanthine and vindoline. In order to investigate vindoline biosynthesis, tabersonine-$CD_3$ 1a is synthesized to use as a deuterium labeled precursor, which is distinguished clearly from the natural counterpart. We show that these deuterium labeled tabersonine 1a are successfully incorporated into the vindoline biosynthetic pathway to yield three deuterated vindoline intermediates. 16-Hydroxytabersonine-$CD_3$ (m/z 356) 2a, 16-Methoxytabersonine-$CD_3$ (m/z 370) 3a, 16-Methoxy-2,3-dihydro-3-hydroxytabersonine-$CD_3$ (m/z 388) 4a are produced from the cell suspension culture measured by UPLC/MS at 5 and 13 days after feeding tabersonine. The conversion rates from 1a to 2a and 2a to 3a are fast, whereas that from 3a to 4a is much slower. This indicates that the rate determining step among the first three vindoline biosynthesis is the last step. As a result of the slow conversion rate from 3a to 4a, the accumulation level of 16-Methoxytabersonine-$CD_3$ 3a is significantly increased up to 13 days. The accumulation ratio among 2a, 3a and 4a is 1, 2 and 0.1 at 5 days. However, the peaks of desacetoxyvindoline-$CD_3$ 5a, deacetylvindoline-$CD_3$ 6a and vindoline-$CD_3$ 7a are not found from the cell extracts even after 13 days of incubation which may indicate no presence of their corresponding enzymes.

Dietary Effect of Silk Protein on Ceramide Synthesis and the Expression of Ceramide Metabolic Enzymes in the Epidermis of NC/Nga Mice (실크단백질의 식이 공급이 아토피 피부염 동물 모델 NC/Nga Mice 피부의 세라마이드 함량 및 관련인자 발현에 미치는 영향)

  • Park, Kyung-Ho;Choi, Young-Sim;Kim, Hyun-Ae;Lee, Kwang-Gill;Yeo, Joo-Hong;Jung, Do-Hyun;Kim, Sung-Han;Cho, Yun-Hi
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.36 no.5
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    • pp.554-562
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    • 2007
  • Ceramide rich intercellular lipid lamellae are thought to be particularly important in maintaining the structural integrity of epidermal barrier. Ceramide is synthesized de novo by serine palmitoyltransferase (SPT) phospholipid intermediates, serine and palmitic acid persist within the stratum corneum. The ceramide which is synthesized is degraded with fatty acid and sphingosine by degradative enzyme ceramidase. The depletion of ceramide in stratum corneum was reported in the atopic dermatitis. As an effort to search for the dietary source for improving the level of ceramide in epidermis, the dietary effects of various-typed silk protein were compared. Seventy male NC/Nga mice, an animal model of atopic dermatitis, were divided into seven groups: group CA as an atopic control with control diet, group S: 1% crude sericin diet, group F: 1% crude fibroin diet, group PS : peptide pattern of sericin(Mw 5000), group PF: peptide pattern of fibroin (Mw 1500), group AS: manufactured the same as amino acid profile of sericin and group AF: manufactured the same as amino acid profile of fibroin. Ten male BALB/c mice were served as group C (control group) control diet. All mice were fed on diet and water ad libitum for 10 weeks. Dry skin condition was established in group CA as ceramide content was decreased. Despite a marked decrease of mRNA and prorein expression of SPT, enzyme do novo synthesis, ceramide content of group S was dramatically increased by inhibiting the mRNA and protein expression of degradative enzyme ceramidase. However, dietary supplementation of crude silk fibroin protein (group F) and in other groups that were supplemented with either amino acid or peptide type of sericin or fibroin did not increase the level of ceramide. Together, our data demonstrate that dietary supplementation of crude sericin is more effective at improving ceramide level in epidemis of NC/Nga mice.

The Effects of Saengshik on the Hepatotoxicity of Mouse Induced by Carbon Tetrachloride (사염화탄소에 의해 유발된 생쥐의 간독성에 생식이 미치는 영향)

  • Kim, Dong-Heui;Deung, Young-Kun;Lee, Young-Mi;Yoon, Yang-Suk;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.37 no.1
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    • pp.11-21
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    • 2007
  • Saengshik which is food not to apply heat is expected to have good effect on the body because metabolic enzymes are preserved in it. In fact, despite of enlargement of saengshik market, the researches on the effect of saengshik are insufficient. So, the aim of this study was to investigate the protective effect of saengshik against $CCl_4-inducing$ hepatotoxicity in ICR mice. As the result of serum biochemical parameters, AST (SGOT) and ALT (SGPT) were significantly decreased at the experimental group treated with saengshik and $CCl_4$ as compared with experimental group 1 treated with $CCl_4$ only (p<0.01). ALP was significantly higher at experimental group 2 compared with control and experimental group 1 (p<0.01). In histological study, experimental group 1 treated with $CCl_4$ only showed severe necrosis all over the liver at the gross observation, and showed severe perivenular necrosis and individual hepatocytic degeneration. However experimental group 2 was not nearly different from control group in appearance and showed mild perivenular necrosis and dominant sever neutrophil infiltration surrounding central veins. The result of this study showed the protective effect against $CCl_4-inducing$ hepatotoxicity and suggest the possibility of the functional health food. However, further studies about the effect of saengshik may be needed.

Hepatoprotective Effects of Semisulcospira libertine Hydrolysate on Alcohol-induced Fatty Liver in Mice (알코올성 지방간 유발 마우스에서 다슬기 유래 가수분해물의 간 보호 효과)

  • Song, Eun Jin;Cho, Kyoung Hwan;Choo, Ho Jin;Yang, Eun Young;Jung, Yoon Kyoung;Seo, Min Gyun;Kim, Jong Cheol;Kang, Eun Ju;Ryu, Gi Hyung;Park, Beom Yong;Hah, Young-Sool
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.318-325
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    • 2017
  • Alcoholic steatosis is a fundamental metabolic disorder and may precede the onset of more severe forms of alcoholic liver disease. In this study, we isolated enzymatichydrolysate from Semisulcospira libertine by alcalase hydrolysis and investigated the protective effect of Semisulcospira libertine hydrolysate on liver injury induced by alcohol in the mouse model of chronic and binge ethanol feeding (NIAAA). In an in vitro study, the hydrolysate protects HepG2 cells from ethanol toxicity. Liver damage was assessed by histopathological examination, as well as by quantitating activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP). After the administration of S. libertina hydrolysate, fat accumulation and infiltration of inflammatory cells in liver tissues were significantly decreased in the NIAAA mouse model. The elevated levels of serum AST, ALT, and ALP activities, along with the lipid contents of a damaged liver, were recovered in experimental mice administrated with S. libertina hydrolysate, suggesting its role in blood enzyme activation and lipid content restoration within damaged liver tissues. Moreover, treatment with S. libertine hydrolysate reduced the expression rate of cyclooxygenase (COX-2), interleukin $(IL)-1{\beta}$, and IL-6, which accelerate inflammation and induces tissue damage. All data showed that S. libertine hydrolysate has a preventive role against alcohol-induced liver damages by improving the activities of blood enzymes and modulating the expression of inflammation factor, suggesting S. libertine hydrolysate could be a commercially potential material for the restoration of hepatotoxicity.