• Korean Journal of Food Science and Technology
• /
• v.36 no.2
• /
• pp.299-305
• /
• 2004

Genetically Modified (GM) corn 'Bt11' was developed to promote insect resistance using crylA (b) gene derived from Bacillus thuringiensis. Effects of heat, pressure, and ${\alpha}-amylase$ on DNA fragment degradation in Btll corn were examined through PCR. Whereas DNA fragment degraded completely within 4 min at $150^{\circ}C$ and by autoclave, most remained after oil-frying, boiling, and drying-autoclave. Treatment of ${\alpha}-amylase$ enzyme did not affect DNA fragment degradation. Among 65 corn-processed foods analyzed, 9 were detected as GM corn-containing foods(13.6%).

• Applied Biological Chemistry
• /
• v.43 no.4
• /
• pp.247-252
• /
• 2000

As functionality investigation of Korean traditional soybean fermentation foods, an antihypertensive peptide was separated during Chunggugjang fermentation by Bacillus subtilis CH-1023 and investigated inhibitory effect against angiotensin converting enzyme. After incubation at $20^{\circ}C,\;30^{\circ}C,\;40^{\circ}C,\;50^{\circ}C,\;60^{\circ}C$ for the $0{\sim}72$ hrs, protein content, protease activity and angiotensin converting enzyme inhibitory rate were determined. The protein content and protease activity were increased and reached maximum at 60 hrs fermentation with $40^{\circ}C$ and decreased after the 60 hrs fermentation. The optimum condition for antihypertensive peptide from Chunggugjang was appeared for 60 hrs at $40^{\circ}C$. Crude extract of Chunggugjang was partially purified by Amicon YM-3 membrane filtration and Sephadex G-10, G-25 gel filtration. The purified peptide showed inhibitory rate of 94.3% with 0.5 mg peptide content. The most prominent amino acid composition of the peptide from Chunggugjang was alanine, followed by phenylalanine, histidine.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1159-1163
• /
• 1999

Along with the increasing demands for food irradiation technology in the food industry, a proper detection means for controlling irradiated foods is required. Enzyme powder, which is permitted to be irradiated in Korea, was subjected to a detection trial by ESR spectroscopy. The high correlation coefficients were observed between the absorbed doses ranging from 2.5 to 15.0 kGy and the corresponding ESR signal intensity, such as $R^2$ = 0.9904 in gamma irradiation and $R^2$ = 0.9696 in electron beam. Pre-established threshold values for both non-irradiated control (1.19) and 2.5 kGy-irradiated samples (6.97 in gamma-ray; 7.36 in electron-beam) were successfully applicable to the detection of 30 coded unknown samples of enzyme powder. The calibration curves obtained from the samples irradiated at 2.5 to 15 kGy were expected to be potentially adopted to estimate absorbed doses ranging front 4 to 7 kGy with a quadratic equation.

• Journal of Food Hygiene and Safety
• /
• v.37 no.1
• /
• pp.15-20
• /
• 2022

The purpose of this study was to compare the conventional culture method, enzyme immune method and the PCR method using species-specific primer in the analysis on the Salmonella spp. found in domestically distributed pet foods. For the study, Salmonella spp. were detected from 175 samples. From the conventional culture method and the PCR method, two samples (jerky and corn gluten) were determined as positive. Also, from the enzyme immune method, one sample (corn gluten) was test-positive. The study revealed that application of the PCR method with species-specific primer allows better distinguishment between the species of the strain collected from the samples than the conventional culture method and/or the enzyme immune method.

• Journal of the Korean Society of Food Culture
• /
• v.23 no.4
• /
• pp.514-520
• /
• 2008

This study addresses the development of a soy hamburger patty containing enzyme-treated textured soy protein (TSP) as a meat analogue. In order to reduce the beany flavor and enhance the texture, TSP was treated with 0.3% Flavourzyme for 5, 10, 20, or 30 min. The degree of hydrolysis and the water holding capacity of the TSP increased with increasing hydrolysis time. The oil binding capacity of the TSP also increased with increasing hydrolysis time, approaching the maximal value, 175.82%, at 30 min, whereas that of pork scored with the lowest value of 128.67%. The volume of pork was reduced to 81.5% as the result of heat treatment, whereas that of the TSP increased to 140.57%. The values of 'L', 'b', and '${\Delta}E$' differed significantly (p<0.001) with heat treatment, but the 'a' values did not differ significantly. With regard to texture, the hardness values were highest in the pork hamburger patty (PHP), and were lowest in the soy hamburger patty (SHP) containing untreated TSP. The hardness of the SHP containing TSP treated for 20 min did not differ significantly from that of the PHP. The cohesiveness and gumminess of the SHP treated for 20 min were highest, whereas those treated for 10 min were the lowest. The gumminess of the SHP treated for 20 min did not differ significantly from that of pork. The chewiness of the PHP was the highest, whereas that of the SHP treated for 5 min was the lowest. In our sensory evaluation, PHP evidenced the highest scores, followed by the SHP treated for 30 min, as color, texture, beany flavor, and overall quality all improved as the consequence of increasing enzyme treatment duration. In conclusion, it is believed that SHP has great potential as a substitute for meat, in that the flavor, texture, and beany flavor of SHP did not differ significantly from those of PHP.

• Korean Journal of Food Science and Technology
• /
• v.20 no.1
• /
• pp.79-84
• /
• 1988

${\alpha}$-Galactosidase from Aspergillus niger as a possible enzyme for removal of flatulence factors in soybean foods was produced the highest in 120 hours in either Czapeck-Dox liquid medium or wheat bran solid medium. The most efficient carbon and nitrogen sources in Czapeck-Dox medium were raffinose and sodium nitrate, respectively, whereas the addition of the sources showed negative effects in wheat bran. pH optima for enzyme activity and stability were 4.0-5.0 and 3.5-6.5, respectively, and optimum temperature for stability was $40-50^{\circ}C$. Upon reaction on p-nitrophenyl-${\alpha}$-D-galactoside, Michaelis constant was 0.42 mM and maximum velocity was 152 ${\mu}moles$ substrate/minute/kg solid medium. Mercuric chloride acted as a strong noncompetitive inhibitor and p-chloromercuribenzoate, even in low concentration, acted as a competitive inhibitor. Crude ${\alpha}$-galactosidase hydrolyzed raffinose and stachyose completely, giving spots of monosaccharides only on thin-layer chromatogram.

• Journal of the Korean Applied Science and Technology
• /
• v.36 no.4
• /
• pp.1443-1459
• /
• 2019

Polyglycerol fatty acid ester nonionic surfactants have been used for a long time in foods and have been suggested as an alternative to the safety problems of PEG based nonionic surfactants. The polyglycerol fatty acid ester surfactants are synthesized by combining a hydrophilic polyglycerin and a lipophilic fatty acid. The hydrophilic polyglycerin is polymerized using glycerin, glycidol, epichlorohydrin, etc. The main issues of the polyglycerol polymerization reaction are to increase the content of the polyglycerol in the form of linear rather than branched or cyclic forms and to narrow the distribution of the degree of polymerization. The method of binding a lipophilic fatty acid group to a hydrophilic polyglycerin includes chemical synthesis such as esterification reaction and enzyme synthesis using lipase enzyme. The main issues of polyglycerin fatty acid ester synthesis are to increase the yield and to control the degree of esterification while reducing side reactions.

• Korean Journal of Medicinal Crop Science
• /
• v.28 no.1
• /
• pp.21-28
• /
• 2020

Background: Owing to its high efficiency in lipid and protein production, peanut (Arachis hypogaea L.) is considered one of most important crops world-wide. The kernels of peanuts are undoubtedly the most important product this plant, whereas the skin is almost completely neglected in nutraceutical terms. However, peanut skin contains potentially health-promoting phenolics and dietary fiber, and there is considerable potential for commercial exploitation. In this study, we evaluated the α-glucosidase inhibitory activity of an extract of peanut skin (PS). Methods and Results: The α-glucosidase inhibitory effects of 80% ethanol extracts of peanut (A. hypogaea L. 'Sinpalkwang') skin were evaluated and found to have a half-maximal inhibitory concentration (IC₅₀) value of 1.2 ㎍/㎖. Progress curves for enzyme reactions were recorded spectrophotometrically, and the inhibition kinetics revealed time-dependent inhibition with enzyme isomerization. Furthermore, using ultra-high performance liquid chromatography combined with quadrupole-orbitrap mass spectrometry, we identified 26 compounds in the peanut skin extract, namely, catechin, epicatechin, and 24 proanthocyanidins. Conclusions: The results suggest that peanut skin can be utilized as an effective source of α-glucosidase inhibition in functional foods and nutraceuticals.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.3
• /
• pp.403-409
• /
• 2001

A novel strain of SFO41 producing a large amount of cholesterol oxidase as an extracellular enzyme isolate from Korean salt fermented foods. The strain was identified as Bacillus megaterium based on morphological, cultural and physiological characteristics. Experiments were carried out to optimized the condition of cholesterol oxidase production using B. megaterium SFO41. B. megaterium SFO41 was shown to give the maximum yield of cholesterol oxidase in the medium containing 2.0% glucose, 0.5% yeast extract. 0.03% $MgSO_4{\cdot}7H_2O,\;0.02%\;K_2HPO_4,\;0.2%\;NH_4NO_3$ and 0.2% cholesterol. The optimum culture conditions, temperature, initial pH and agitation speed were $30^{\circ}C$, 7.0 and 150 rpm, respectively. The enzyme production reached a maximum level at 24 hr of cultivation (2.37 U).

• The Journal of Internal Korean Medicine
• /
• v.41 no.1
• /
• pp.14-28
• /
• 2020

Objectives: The aim of this study was to analyze consumer experience with Digestive Enzymes, a digestive enzyme product that includes medicinal herbs (Multi-Zyme^®). The goal was to provide basic data on improvements and marketability of future digestive enzyme products containing medicinal herbs. Methods: Qualitative research was conducted to explore the current participants' experience. In-depth interviews with a semi-structured interview guide were conducted to investigate the experience and perception of the participants. The participants were recruited using snowball sampling and purposive sampling, and a qualitative content analysis method was adopted. Credibility was ensured by adopting a member check, triangulation, and peer debriefing method. Results: In-depth interviews were completed with a total of 8 participants. The collected data were classified into 16 codes and then further divided into the following seven categories: direct buying, indirect buying, effects, questions, recommendations, positive perception, and negative perception. The categories were grouped into three themes: 'Experience of purchasing existing health foods', 'Experience of taking Multi-Zyme', and 'Opinions on selling Multi-Zyme at Korean medicine clinics'. Conclusion: The participants experienced effect of the Multi-Zyme^® and were willing to recommend it around. However, the Korean medicine doctors need to inform consumers about the dose and duration when taking Multi-Zyme^® to prevent abuse. Some consumers may trust Multi-Zyme^® sales from Korean medicine clinics, but some held opinions that those sales were not trustworthy, so promotion and improvement are needed.