• Korean Journal of Food Science and Technology
• /
• v.21 no.2
• /
• pp.180-184
• /
• 1989

Clarification of the juice extracted from stored Fuji apples was studied with pectolytic enzyme and pH control, separately and in combinations. In the separated treatment, the clarity of the juice was increased with the treated enzyme amount. The juice adjusted pH to 3.5 with malic acid had the highest clarity in pH range from 3.5 to 5.0, but this juice was not acceptable because of high acidity. In combination of the two treatment, the clarity of the juice treated with the enzyme at pH 4.0 was higher than that of the juice without the enzyme, and the juice with ligh trasmittance of about 92% could be obtained at the pH by addition with one-third amount of enzyme which was used for clarification of the juice extracted from the fresh apples at harvesting season.

• Microbiology and Biotechnology Letters
• /
• v.3 no.1
• /
• pp.41-48
• /
• 1975

The chemical components and quality of Takjoo mash were examined on the product brewed by the case of commercial amylase, Lactobacillus bulgaricus and the yeast. 1. Lactic acid was produced at the range of 917~1,350 mg per 100 ml of the mash brewed using wheat flour, corn flour, rice and pressed barley, while succinic acid was formed at the range of 6~32 mg per 100m1 of the mash. 2. Citric acid was formed at the concentration of 6.5mg per 100m1 of the mash on the use of pressed barley, and malic acid formed at the concentration of 1.7 mg and 1.4 mg per 100m1 of the mash respectively, on the use of wheat flour and corn flour. 3. No remarkable differences between the kind of raw materials and commercial amylases and compared with the mash brewed with Nurook were observed in the components of fusel oil formed in the mash. 4. Seventeen kinds of the amino acids of the mash brewed with commercial amylase, Lactobacillus and the yeast were detected and its content was 31mg per 100ml, which is less than that of the conventional takjoo, but the contents of glycine and alanine which pray as the component of seasoning in takjoo were sufficient.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.32 no.3
• /
• pp.381-387
• /
• 2003

This study was performed to establish the fermentation method of non-steamed brown rice vinegar using starch saccharifing enzyme. During vinegar fermentation, initial pH had increased in the higher concentration of alcohol and acetic acid. Final pH was gradually changed to pH 2.90~3.44 from 3.44~4.06. The higher total acidity of brown rice vinegar resulted from the higher alcohol concentration. The total acidity was slightly dropped after gradually increasing from the starting of fermentation. Initial pH was decreased from 3.67 to 3.16. The total acidity was gradually increased from the first day of fermentation with 1.02, it was 1.54 on the second day after fermentation and there was a tendency to decreased after the highest values with 6.53 fermentation for 12 days. In organic acid composition, oxalic, malic, acetic, citric, and succinic acid were detected. The total free amino acid was decreased to 1,121 mg%. The major amino acids were ${\gamma}$ -aminobutyric acid, $\alpha$-aminoadipic acid and alanine, and ${\gamma}$-aminobutyric acid was the highest (539 mg%). The mineral contents such as P and K was high in sample and followed by Mg, Na, Ca.

• Korean Journal of Food Science and Technology
• /
• v.33 no.2
• /
• pp.264-270
• /
• 2001

In order to improve the quality of traditional kochujang, condiments like garlic and onion were added to kochujang and their effect on microbial characteristics, enzyme activities and taste components were investigated during fermentation. Viable cells of yeasts in the kochujang decreased with the increasing ratio of garlic. However, aerobic and anaerobic bacterial counts did not show any remarkable differences in the garlic or onion added kochujang, they decreased slowly after $6{\sim}10$ weeks of fermentation. The activity of liquefying amylase in kochujang decreased slowly during $2{\sim}10$ weeks of fermentation, but that of saccharifying amylase increased remarkably at $14{\sim}18$ weeks. Amylase activities increased at the late period of fermentation in garlic or onion added kochujang. Protease activities of kochujang were strong in the middle of fermentation, but they decreased by addition of garlic or onion. The major free sugars in kochujang were glucose and fructose, and their contents increased as the ratio of garlic increased. The major organic acids in kochujang were succinic, malic and oxalic acid, and they also decreased by addition of garlic and onion. The contents of total free amino acids and amino nitrogen were the highest in 2% garlic added kochujang. The major free amino acid were glutamic acid, aspartic acid, proline, alanine, leucine, isoleucine and arginine. Serine, glutamic acid, lysine and arginine contents in increased by adding garlic or onion.

• Culinary science and hospitality research
• /
• v.23 no.5
• /
• pp.25-33
• /
• 2017

This study was to investigate the effects of enzyme on quality characteristics and antioxidant activities of wild peach (Prunus persica L.) juice. pH levels and S.S (soluble solid) values in all samples ranged from 3.86 to 4.13 and from 48.0 to $55.0^{\circ}Brix$, respectively. The TA (total acidity) values of control (not treatment enzyme) were higher than those of the others. The highest 'L', 'a' and 'b' values were observed on PWP (preserved wild peach (Prunus persica L.) juice of cellulase/pectinase (1:1, w/w) sample. Glucose (26.65 g/100 g) and fructose (17.42 g/100 g) in PWP product were determined, however sucrose and maltose were not detected. The predominating organic acid components analyzed in PWP sample were tartaric (32.36 g/100 g) and lactc acids (209.34 g/100 g), whereas citric acid, acetic acid and malic acid were not detected. Higher scores for taste, flavor, color and overall acceptance were found for PWP products compared to other samples. The total phenolic content (13.31 mg GAE/mg dry weight) analyzed using Folin-Ciocalteu's reagent, of PWP sample was higher than those of the others and the total flavonoid concentrations were also 10.95 mg CE/mg dry weight. The DPPH radical scavenging and ABTS radical scavenging activities in all samples ranged from 55.16 to 74.29% and from 39.59 to 82.79%, respectively. The antioxidant activities were affected by addition of enzyme. These results indicate that the use of the mixture of cellulase and pectinase could increase the quality, and antioxidant potentials of sugar preserved wild peach (Prunus persica L.) juice by enzymatic treatment.

• Journal of Korean Academy of Nursing
• /
• v.19 no.3
• /
• pp.299-306
• /
• 1989

In order to evaluate the effect of fish oil on lipid drogenase(G6PDH), malic enzyme(ME), glucose-6-phosphatase(G6Pase) activities were measured in liver and adipose tissue of rats fed 13 days supplemented fish oil at the level of 10% (W/W). Two other groups of rats were fed 10% soybean oil or lard to compare with the effect of fish oil. In all groups, activities of hepatic G6PDH and ME were depressed from the beginning of feeding. This effect was greatest (50%) in fish oil group. Hepatic G6Pase was highest in rats fed lard. When the level of fish oil was reduced to half, as total fat content was maintained at the level of 10% by complementary lard, lipogenic enzyme depressing effect of fish oil was as significant as shown in 10% fish oil diet. Hepatic G6PDH was depressed significantly(14%) in rats fed fish oil as low as 2％. On the other hand, changes in adipose tissue G6PDH and ME activities were small. Adipose tissue G6Page activity increased slightly in rats fed with increasing fish oil(above 0.5%). It is suggested that fish oil alter, more markedly than either soybean oil or lard, cellular lipid metabolism by reducing activities of hepatic lipogenic enzymes.

• Journal of Applied Biological Chemistry
• /
• v.42 no.1
• /
• pp.1-6
• /
• 1999

Poly-${\beta}$-hydroxybutyrate (PHB) and enzymes related PHB metabolism have been measured in nitrogen-fixing symbiosis of chickpea and cowpea plants. Bacteroids from chickpea and cowpea contained PHB to 0.8% and 43% of their dry weight, respectively, whereas the free-living cells CC 1192 and I 16 produced $285{\pm}55mg$ and $157{\pm}18mg$ of PHB g (dry weight)$^{-1}$. To further understand why chickpea bacteroids contained little PHB, the enzyme activities of PHB metabolism (3-ketothiolase, acetoacetyl-CoA reductase, PHB depolymerase, and 3-hydroxybutyrate dehydrogenase), the TCA cycle (malate dehydrogenase, citrate synthase, and isocitrate dehydrogenase), and related reactions (malic enzyme, pyruvate dehydrogenase, and glutamate:2-oxoglutarate transaminase) were compared in extracts from chickpea and cowpea bacteroids and the respective free-living bacteria. Significant differences were observed between chickpea and cowpea bacteroids and between the bacteroid and free-living forms of CC 1192, with respect to the capacity for some of these reactions. It is indicated that a greater potential for oxidizing malate to oxaloacetate in chickpea bacteroids could be a factor that favors the utilization of acetyl-CoA in TCA cycle rather than for PHB synthesis.

• Journal of Microbiology and Biotechnology
• /
• v.33 no.4
• /
• pp.485-492
• /
• 2023

Methylorubrum extorquens, a facultative methylotroph, assimilates C₁ compounds and accumulates poly-β-hydroxylbutyrate (PHB) as carbon and energy sources. The ethylmalonyl pathway is central to the carbon metabolism of M. extorquens, and is linked with a serine cycle and a PHB biosynthesis pathway. Understanding the ethylmalonyl pathway is vital in utilizing methylotrophs to produce value-added chemicals. In this study, we determined the crystal structure of the mesaconyl-CoA hydratase from M. extorquens (MeMeaC) that catalyzes the reversible conversion of mesaconyl-CoA to β-methylmalyl-CoA. The crystal structure of MeMeaC revealed that the enzyme belongs to the MaoC-like dehydratase domain superfamily and functions as a trimer. In our current MeMeaC structure, malic acid occupied the substrate binding site, which reveals how MeMeaC recognizes the β-methylmalyl-moiety of its substrate. The active site of the enzyme was further speculated by comparing its structure with those of other MaoC-like hydratases.

• Asian-Australasian Journal of Animal Sciences
• /
• v.17 no.9
• /
• pp.1188-1191
• /
• 2004

Two species of marine catfish, Arius maculatus and Osteogeneiosus militaris, belonging to family Ariidae were analysed electrophoretically for genetic variation in 6 enzymes, alcohol dehydrogenase (ADH), malate dehydrogenase (MDH), lactate dehydrogenase (LDH), glucose dehydrogenase (GDH), malic enzyme (ME) and superoxide dismutase (SOD). Eighteen individuals of each species were studied. Two loci MDH and ADH were polymorphic in both. Average heterozygosity in A. maculatus was 1.46, while it was 2.5 in O. militaris. The allele frequencies were used to estimate Nei's genetic distance (D). The D value was calculated to be 0.6879. Two isozyme loci, ME and SOD, were found to be the most reliable species specific markers. No tissue specific loci were observed for the enzymes studied, the bands being identical in each case. The genetic distance observed between O. militaris and A. maculatus in this study suggests that they would be more appropriately classified as species of the same genus rather than being assigned separate genera.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.10a
• /
• pp.225.2-226
• /
• 2003

본 연구에서는 현미로부터 tocoles 획분을 분리하여 고콜레스테롤 식이를 섭취한 흰쥐의 체내 지질대사에 미치는 영향을 조사하였다. 실험동물은 SD계 숫컷 5주령을 구입하여 정상군, 대조군 (1% cholesterol), rice oil 첨가군, tocoles 첨가군의 4군으로 나누어 AIN-76 diet 조성에 의거하여 식이를 조제하여 4주 동안 섭취시켰다. 실험기간이 끝난 후 복부 대동맥으로부터 채혈하고 각 조직을 적출하여 간, 신장, 비장 및 부고환지방 조직의 무게를 측정하였다. 또한 혈청 lipid profile과 TBARS 함량 및 ALT, AST 및 ALP 활성을 분석하였고 간장중 중성지방, 콜레스테롤 및 TBARS 함량과 G6PDH 및 malic enzyme을 분석하였다. 그 결과 간장 및 부고환지방의 무게가 대조군에서 유의적으로 증가하였으나, tocoles 첨가군은 정상군의 수준으로 감소하였다. 혈청 내의 중성지방과 총 콜레스테롤은 실험군 간에 유의적인 차이는 나타내지 않았으나 감소하는 경향을 보였다. 간장 조직 내 지질함량은 대조군에서 높게 나타났으며, tocoles 군에서 중성지방과 콜레스테롤 및 총 지방의 함량이 유의하게 감소하였다. 지질 과산화물 함량은 혈청과 간장 조직 모두 유의적으로 감소하였다.