• Journal of Food Hygiene and Safety
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• v.30 no.4
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• pp.359-365
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• 2015

The purpose of this study was to investigate the contents of sugars and ${\alpha}$-amylase and ${\beta}$-amylase activities in 98 specimen with enzyme foods and enzyme-shaped foods (the other processed foods, beverage bases, fermented drinks, liquid teas). The ${\alpha}$-amylase activity in enzyme foods and the other processed foods were ranged 4.9~53,854.6 U/g and 2.9~1,182.7 U/g, respectively, there was a big difference in the same type. The ${\alpha}$-amylase activity of the fermented products (beverage bases, fermented drinks, liquid teas) were ranged 0.1~1.7 U/g. The average of ${\beta}$-amylase activity in enzyme foods, the other processed foods, the fermented products were found 126.0 U/g, 5.6 U/g and 10.5 U/g, respectively, enzyme-shaped foods were a lot lower than enzyme foods. Total contents of sugars were average 22.4 g/100 g in enzyme foods, 14.8 g/100 g in the other processed foods, 46.9 g/100 g in beverage bases, 41.1 g/100 g in fermented drinks, 39.5 g/100 g in liquid teas, total contents of sugars appeared high amount in the fermented products. Correlations between ${\alpha}$-amylase activity and lactose content was statistically significant in enzyme foods (r = 0.644) and it was strong in the other processed foods (r = 0.903). Correlations between ${\beta}$-amylase activity and lactose content was statistically significant in enzyme foods (r = 0.648) and it was strong in the other processed foods (r = 0.757). There was a significant relationship between ${\alpha}$-amylase and ${\beta}$-amylase activities in enzyme foods and the other processed foods (r = 0.869, r = 0.760). That is, it was found that also the proportional relationship established among the ${\alpha}$-amylase activity, ${\beta}$-amylase activity.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.105-105
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• 2022

Unripen mandarin in Jeju Island is known to contain functional ingredients including various flavonoids. This Study was carried out to identify the components of Unripen mandarin extracts and Secondary metabolism by enzyme treatment on Unripen mandarin. We extracted Unripen mandarin using optimal extraction method and selected the most optimal enzyme among commercial enzymes for a Secondary metabolism. As a result, flavonoid components such as Hesperidine and Narirutin, which are known to be contained a lot in unripen mandarin, could be analyzed. However In this extraction method there were no other flavonoid components such as Nobiletin, Tangeretin known to contain in unripen mandarin. However as a result of secondary metabolism a new functional component called Prunin which was not known to be contained in unripen mandarin, was detected as a secondary metabolic product due to enzyme treatment. Through this, it can be confirmed that it would be possible to develop high-value-added products by enzyme treatment on unripen mandarin.

• Food Science of Animal Resources
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• v.18 no.2
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• pp.97-106
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• 1998

Antioxidant enzymes such as catalase (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) are known to inhibit oxidative reactions by incativating compounds responsible for the formation of ree radicals. SOD transforms superoxide radical into hydrogen peroxide which is precursor to active free radicals. CAT reduces hydrogen peroxide to water. GSH-Px reduces hydroperoxides to corresponding alcohols. Antioxidant enzyme activities of muscle are different by animal species age, stress and exercise, muscle type and part, conditions of post mortem, storage and processing which are related to oxidative deterioration I muscle foods as well as oxidative defence in living systems. Antioxidant enzyme systems are enhanced rather than weakened in aging skeletal muscle. Red muscle contains higher antioxidant enzyme activity than white muscle. The antioxidant enzyme activities of poultry are higher in leg than in breast, and those of beef are higher in redder and more unstable muscles. It is clear that the effectiveness of the antioxidant enzyme in muscle foods seems to be influenced by meat processing operations. Both GSH-Px and CAT are inactivated by heat processing NaCl also influence the efficiency of the antioxident enzymes since its presence diminishes their catalyitc activity.

• Nutritional Sciences
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• v.7 no.1
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• pp.35-40
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• 2004

This study was performed to evaluate the effect of iron supplementation on iron-deficiency-related indices, oxidative stress and antioxidative enzyme activity in female marathoners. Fourteen teenage female marathoners participated in the study. Subjects were divided into two groups: mild anemic and control, depending on their hemoglobin (Hb) level. The mild anemic group had significantly lower RBC count and hematocrit (Hct) and Hb levels compared to the control group. The mild anemic group (〈12.5g Hb/dI, n=7) was given iron supplements (60mg Fe/day) for four weeks during the summer training period. RBC count, Hct and Hb levels showed an increasing tendency through iron supplementation, and significant differences in these variables between the anemic and control groups disappeared in the post-period. There was no difference in plasma malondialdehyde (MDA) between the anemic and control groups. However, catalase (CAT) and glutathione peroxidase (GPx) activity were significantly higher in the anemic group. The significant difference in enzyme activity between the groups disappeared in the post-period. In addition, superoxide dismutase activity significantly decreased after iron supplementation. In conclusion, antioxidative enzyme activity was up-regulated in an anemic condition and mild iron supplementation decreased the antioxidant enzyme activity of female marathoners while improving their anemic condition.

• Food Science of Animal Resources
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• v.30 no.1
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• pp.36-41
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• 2010

The Hen's egg is widely used in many processed foods as an ingredient and is one of the most prevalent food allergens in children. To detect egg proteins in processed foods, we developed a competitive indirect enzyme-linked immunosorbent assay (ciELISA) using an anti-ovomucoid (OM) antibody, which was produced by immunization of rabbits with OM, the most heat-stable component of the egg proteins. The detection limit of this quantitative assay system was 30 ng/mL. Cross-reactivity of the anti-OM antibody toward OM, ovalbumin, skim milk, casein, whey protein isolate, and isolated soy protein was 100, 0.4, 0.2, 0.04, 0, and 0%, respectively. In the spike test of egg white powder in milk replacer, commercial sausage, and in-house sausage, the assay recoveries ($mean{\pm}SD$) were $129{\pm}13.7%$, $73.9{\pm}12.5%$, and $65.5{\pm}13.6%$, respectively. When egg white in a commercial crab meat analog and sausage was determined by ciELISA, the assay recovery was found to be 108% and 127%, respectively. The combined results of this study indicate that this novel ciELISA for OM detection could be applied for the quantification of hen's egg proteins in processed foods.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.655-658
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• 2008

Although arabinose isomerase (E.C. 5.3.1.4), a commercial enzyme for edible tagatose bioconversion, can be expressed in an Escherichia coli system, this expression system might leave noxious by-products in food. To develop an eligible tagatose bioconversion with food-safe system, we compared the tagatose production activity of immobilized arabinose isomerase expressed in Bacillus subtilis (a host generally recognized as safe) with that of the enzyme expressed in E. coli. A 48% increase in tagatose production (4.3 g tagatose/L at $69.4\;mg/L{\cdot}hr$) was found using the B. subtilis-expressed immobilized enzyme system, compared to the E. coli-expressed enzyme system (2.9 g tagatose/L). The increased productivity with safety of the B. subtilis-expressed arabinose isomerase suggests that it is a more eligible candidate for commercial tagatose production.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.141-147
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• 2012

Biogenic amines have been used as chemical indicators to estimate bacterial spoilage of foods, particularly fish and fish products, cheese, and fermented foods. So far many chromatography methods have been developed to detect biogenic amines in foods. Although these instrumental analyses exhibit good sensitivity, they cannot be used as rapid detection methods due to the chemical treatment of the samples and the time-consuming process involved. For the rapid and simple detection of biogenic amines, enzyme linked immunosorbent assay kits are commercially available. In addition, analytical systems with enzyme-based amperometric biosensor detection have been increasingly developed. The biosensors used to detect the biogenic amines are based on the action of either amine oxidases or amine dehydrogenases that catalyzes the oxidative deamination of biogenic amines to the corresponding aldehydes and ammonia. This review mainly focused on the principle, development, and applications of the detection methods for rapid detection of biogenic amines in foods.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.169-175
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• 2006

Potentiometric biosensor using flow injection analysis system was developed to determine citrate concentration in foods. Biosensor system consisted of sample injector, peristaltic pump, enzyme reactor, carbonate ion selective solid-state electrode, reference electrode, detector, and recorder. Enzyme reactor was prepared with immobilized citrate lyase and oxaloacetate decarboxylase. Carbonate ions produced through enzyme reactions of citrate were potentiometrically detected by ion selective electrode. Optimum conditions for biosensor system were investigated. Interference effect of major sugars and organic acids was less than 5% on citrate biosensor system. Citrate concentrations in fruit juices were determined by biosensor and gas chromatography. No significant difference was observed between two analytical methods. Results indicate citrate biosensor is useful in determining citrate concentration in foods.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.227-233
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• 1996

Tyrosinase is an enzyme which catalyzes an enzymatic browning of some foods and in vivo synthesis of melanin. In order to produce natural and edible inhibitor of the enzyme which is expected to have whitening effect on melanogenesis, a microorganism was selected from fermented foods. It was named as NU-7, and cultured in mushroom (Lentinus edodes, Shiitake) media. Optimal media to produce tyrosinase inhibitor was formulated by varing nitrogen or carbon content. If glucose content was in a range of 3-20% and ammonium sulfate was in a range of 0-0.25%, production of inhibitor was independent of cell mass. Addition of ammonium sulfate as a nitrogen source had little effect on inhibitor production. Production of inhibitor (Y) was proportionally related to shiitake content (X) with a regression equation of Y= -0.96X$^{2}$ + 13.07X + 14.43 (R = 0.96). These results indicate that shiitake and glucose are necessary for the production of tyrosinase inhibitor. In the analysis of mycotoxin in culture broth, aflatoxin was not detected, suggesting that it would be probably edible.

• Korean journal of food and cookery science
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• v.31 no.1
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• pp.18-25
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• 2015

This study investigated the baking properties of sorghum with the addition of xylanase or Pentopan, which is a baking additive containing xylanase. The control bread was made with a 30% substitution for wheat flour and the optimum level of enzyme addition was 0.75 mg/g flour for Pentopan and 5 mg/g flour for xylanase. The water binding capacity of wheat flour increased with the addition of sorghum, but decreased with the addition of either xylanase or Pentopan. The resistance of dough increased while extensibility decreased with the addition of sorghum; however, resistance decreased while extensibility increased with the addition of the enzyme. Specific volume of bread decreased significantly with the addition of sorghum. However, the specific volume was significantly recovered with the addition of enzyme. Crumb firmness was higher in the sorghum-added sample, but crumb firmness of the bread decreased with the addition of the enzyme. The crumb firmness of bread with added xylanase decreased significantly in 24 hours. These results demonstrated that adding sorghum with either xylanase or Pentopan that included xylanase increased specific volume and decreased crumb firmness whereas sorghum decreased the quality of fermented bread when added to wheat flour. The firmness rate of fermented bread particularly decreased with the addition of pure xylanase.