Food Science and Biotechnology
한국식품과학회 (Korean Society of Food Science and Technology)
- 월간
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- 1226-7708(pISSN)
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- 2092-6456(eISSN)
과학기술표준분류
- 농림수산식품 > 식량작물과학
- 농림수산식품 > 식품과학
Aim & Scope
The Food Science and Biotechnology (Food Sci. Biotechnol.; FSB) was launched in 1992 as the Food Biotechnology and changed to the present name in 1998. It is an international peer-reviewed journal published monthly by the Korean Society of Food Science and Technology (KoSFoST). The FSB journal covers; Food chemistry/food component analysis Food microbiology and biotechnology Food processing and engineering Food hygiene and toxicology Biological activity and nutrition in foods Sensory and consumer science s Consumer perception and sensory evaluation on processed foods are accepted only when they are relevant to the laboratory research work. As a general rule, manuscripts dealing with analysis and efficacy of extracts from natural resources prior to the processing or without any related food processing may not be considered within the scope of the journal. The FSB journal does not deal with only local interest and a lack of significant scientific merit. The main scope of our journal is seeking for human health and wellness through constructive works and new findings in food science and biotechnology field.
http://www.fsnb.or.kr/submission/ KSCI KCI SCOPUS SCI SCIE제18권2호
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Quantitative risk assessments are related to implementing hazard analysis and critical control points (HACCP) by its potential involvement in identifying critical control points (CCPs), validating critical limits at a CCP, enabling rational designs of new processes, and products to meet required level of safety, and evaluating processing operations for verification procedures. The quantitative risk assessment is becoming a standard research tool which provides useful predictions and analyses on microbial risks and, thus, a valuable aid in implementing a HACCP system. This paper provides a review of microbial modeling in quantitative risk assessments, which can be applied to HACCP systems.
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Park, Young-Woo;Lee, Seung-Wook;Choi, Hyung-Kyoon;Yang, SeungOk;Kim, Young-Suk;Chun, Ho-Nam;Chang, Pahn-Shick;Lee, Jae-Hwan 294
Distribution of isoflavones and fatty acids in soymilk fermented with 7 Lactobacilli (L-type), 7 Bifidobacteria (B-type), or 5 Streptococci (S-type) were monitored. Total isoflavones in fermented soymilk ranged from 5.24 to$8.59{\mu}mol/g$ dry basis while those in unfermented soymilk were$8.06{\mu}mol/g$ dry basis. Depending on the types of inoculated microorganisms, fermented soymilk showed different profiles in isoflavones, especially aglycones and$\beta$ -glucosides. Four L-type fermented soymilk had significantly higher aglycone content (33.69-46.21%) and low$\beta$ -glucosides compared to control (p<0.05). All B-type fermented soymilk showed significantly high aglycone levels (p<0.05). Out of 5 Streptococci, 4 strains produced over 82.2% aglycones. Lipid content ranged from 162 to 224 mg/g and linoleic acid was the highest, followed by oleic, linolenic, palmitic, and stearic acids. Average ratio of unsaturated to saturated fatty acids in control, L-, B-, and S-type fermented soymilks was 6.30, 6.09, 6.30, and 5.94, respectively. This study can help to develop a fermented soymilk containing high isoflavone aglycones and low fat content. -
The purpose of this study was to prepare stable water-in-corn oil (W/O) emulsion droplets coated by polyglycerol polyricinoleate (PGPR). W/O emulsions (20 wt% aqueous phase, 80 wt% oil phase containing 8 wt% PGPR) were produced by high pressure homogenization (Emulsions 1), however, appreciable amount of relatively large water droplets (d>
$10{\mu}m$ ) were found. To facilitate droplet disruption, viscosity of each phase was adjusted: (i) increased the viscosity of aqueous phase by adding 0.1 wt% xanthan (Emulsions 2); (ii) decreased the viscosity of oil phase and aqueous phase by heating them separately at$50^{\circ}C$ for 1 hr immediately before emulsification (Emulsions 3). Homogenizing at the elevated temperature clearly led to a smaller water droplet size, whereas xanthan neither improved nor adversely affected on the microstructures of the emulsions. In addition, the Emulsions 3 had good stability to droplet aggregation under shearing stress, thermal processing, and long term storage. -
This study examined variations in postmortem meat quality characteristics and consumer sensory evaluations of different pork quality classes in fresh and cooked meat. Pale, soft, and exudative (PSE) meat had the highest drip loss, lightness, and the lowest
$pH_{24\;hr}$ whereas dark, firm, and dry (DFD) meat showed the opposite results. When the fresh meat was evaluated by consumer panelists, they could only distinguish the PSE class of meat and it scored lowest in overall acceptability. However, the panelists did not consider cooked PSE or DFD pork to be unacceptable overall, indicating that consumers cannot distinguish the quality of cooked pork. -
Antioxidant-rich oils were extracted from different parts of sea buckthorn berry with supercritical
$CO_2$ (SC-$CO_2$ ) and n-hexane. The functional components were analyzed and the extracts were screened for their potential as radical scavengers in 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), 2,2'-azinobis-3-ethylbenzotiazoline-6-sulphonic acid (ABTS), galvinoxyl systems. Minor differences were found in fatty acid composition of oils extracted by the two methods. Seed oil contains the highest content of tocopherols while pulp oil and whole berry oil possessed higher concentration of carotenoids. Whole berry oil, pulp oil, and seed oil extracted by SC-$CO_2$ showed 91.7, 90.9, and 93.5% radical scavenging activity (RSA) at 6 mg/mL towards DPPH and 74.3, 54.3, and 74.8% towards galvanoxyl radical at 10 mg/mL. The hexane-extracted oils showed similar scavenging ability. However, the oils obtained by hexane showed significantly higher RSA (p<0.05) than those obtained by SC-$CO_2$ while whole berry oil has the highest RSA towards ABTS among 3 oil samples. -
The proteins from 15 types of cultivar of hot peppers cultivated in Korea were extracted and its allergenicity was investigated by immunoblotting and enzyme-linked immunosorbent assay (ELISA). The immunoblotting of hot pepper proteins extracts (HPEs) against serum of hot pepper sensitized patients revealed dominant IgE binding to 14, 37, and 40 kDa molecules. The specific levels of IgE to HPEs sample No. 1, 3, and 7 were much higher than the other samples in patients. Also, IgE binding capacity of HPEs were not reduced by thermal processing and digestion in ELISA using human IgE antibody acquired from hot pepper sensitized patients. By means of Western blotting using anti-thaumatin IgY, thaumatin-like protein (TLP) acting as allergen in several plants and fruits was detected in tested hot peppers. This study demonstrates that the antigenic protein in hot peppers are present but are differently contained according to cultivars.
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The prescriptions (DB-1-DB-5) were prepared with the active herbal medicines, Acanthopanax senticosus, Glycyrrhiza uralensis, Polygonatum odoratum, and Cichorium intybus. The most active crude polysaccharide fraction (DB-2-3), which was isolated through the fractionation of hot-water extract from DB-2, was significantly reduced by periodate oxidation (52.7 and 63.7%) on intestinal immune system modulating and anticancer activity. When DB-2-3 was further fractionated by column chromatographies, DB-2-3IIc-2 showed the most potent activities. In addition, DB-2-3IIc stimulated the proliferation of bone marrow cells via Peyer's patch in dose-dependent pattern by oral administration. The metastasis of colon 26-M3.1 lung carcinoma had significantly inhibited in mice fed DB-2-3IIc at 1 mg/mouse (43.8%). DB-2-3IIc-2 mainly contained uronic acid (46.1%) and 42.5% of neutral sugar with a small amount of protein (7.6%), and component sugar analysis also showed that DB-2-3IIc-2 was composed Ara, Gal, and GalA (molar ratio; 0.50:0.63:1.00). It may be suggested that activities of DB-2-3IIc-2 are resulted from pectic polysaccharides containing a polygalacturonan moiety with side chain of neutral sugars, such as Ara and Gal.
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The principal objective of this study was to investigate changes in ice dendrite size during the freezing of tuna, in order to formulate a mathematical model of ice dendrite size. The tuna was frozen via a uni-directional heat transfer. Thermogram analysis allowed us to determine the position of the freezing front versus time, which is referred to as the freezing front rate. The morphology of the ice dendrites was assessed via scanning electron microscopy after freeze-drying, and the retained pore size was measured as ice dendrites. We noted that the mean size of ice dendrites increased with the distance to the cooling plate; however, it decreased with reductions in the cooling rate and the cooling temperature. In addition, shorter durations of the freeze-drying process decreased the freezing front rate, resulting in a larger size of the ice dendrite pores that operate as water vapor sublimation channels. According to our results, we could derive a linear regression as an empirical mathematical model equation between the ice dendrite size and the inverse of the freezing front rate.
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Cho, Won-Il;Cheigh, Chan-Ick;Choi, You-Jung;Jeong, Jeong-Yoon;Choi, Jun-Bong;Lee, Kang-Pyo;Cho, Seok-Cheol;Pyun, Yu-Ryang;Chung, Myong-Soo 336
To confirm the antimicobial mechanism of Torilis japonica, antimicrobial profile was observed on various spore conditions by combining 0.1% (3 mM) torilin with antimicrobial activity and 0.27% water fraction with germinants. A 75% ethanol extract of T. japonica fruit reduced Bacillus subtilis ATCC 6633 spore counts by 3 log cycles and reduced the vegetative cells to undetectable level (by about 6 log cycles) (both in terms of CFU/mL). Further fractionating the ethanol extract into n-hexane and water fractions revealed that the former reduced the spore count by 1 log cycle whereas the latter had no effect. The antimicrobial active compound was isolated and purified from the hexane layer, and identified as torilin ($C_{22}H_{32}O_5$ ). The water fraction of the ethanol layer did not show antimicrobial activity, whereas the antimicrobial effect of 0.1% (3 mM) torilin was significantly enhanced in the presence of the water fraction (0.27%). This result can be explained by synergistic effects of the water fraction containing considerable amounts of germinants such as L-alanine and K+ ions that triggered germination. -
Inhibitory effect of Escherichia coli O157 adhered to Caco-2 cells by the cells of Lactobacillus plantarum K11 and the cell-free culture supernatant (CFCS) and bacteriocin prepared from this strain was investigated. As the cell counts of viable L. plantarum K11 previously adhered to Caco-2 were increased, the rate of adhesion and adherent cell counts of E. coli O157 was lower. However, because the heated L. plantarum K11 rarely have the adhesion ability to Caco-2, the adhesion rate and adherent cell counts of E. coli O157 were high. In addition, the inhibitory effects of E. coli O157 adhesion by the CFCS and bacteriocin of L. plantarum K11 were dose-dependent manner. Therefore, the inhibition of adhesion of E. coli O157 to Caco-2 may result from the antimicrobial substances such as lactic acid and bacteriocin. Moreover the inhibitory activity of adhesion by the heated bacteriocin for 30 min at 100oC was similar to activity of non-treated bacteriocin, but the activity was disappeared by treatment with protease.
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In this research, fatty acid composition and trans fatty acids of 22 selected meat products produced by Turkish companies were analyzed by capillary gas liquid chromatography (GLC). Total fat contents of the meat products ranged from 11.60-42.50%. Salami had the lowest fat content 11.60% and sucuk (soudjuk) the highest 42.50%. Major fatty acids were C
$_{16:0}$ , C$_{18:0}$ , trans C$_{18:1}$ , cis C$_{18:1}$ , and C$_{18:2}$ in the samples. Total unsaturated fatty acid contents have changed from 38.73 to 70.71% of total fatty acids, and sausage had the highest percentage among the samples. The majority of samples contain trans fatty acids and the level ranged from 2.28 to 7.95% of the total fatty acids. The highest amount of total trans fatty acids was determined in kavurma (Cavurmas) (7.95%), and total trans fatty acids of meat products such as pastrami contained more than 5% of the total fatty acids. -
Lipid oxidation and contents of tocopherols and phospholipids (PL) in soy-added fried products during storage in the dark were studied. Flour dough containing soy flour at 0, 10, 20, and 30% on a weight basis was fried in corn oil at
$180^{\circ}C$ for 2.5 min. The fried products were stored at$60^{\circ}C$ for 11 days in the dark. Lipid oxidation of the fried products was evaluated by conjugated dienoic acid (CDA) and p-anisidine values (PAV). Tocopherols and PL were determined by high performance liquid chromatography (HPLC). CDA contents and PAV of the fried products were increased during storage, and addition of soy flour improved lipid oxidative stability of the fried products, which was partly related to increased amount of tocopherols and PL in the soy-added fried products. Tocopherols and PL were degraded during the dark storage of the fried products. Soy flour addition to the dough did not affect the rate of tocopherols degradation during storage of the fried products; however, PL degradation was higher in the soy-added fried products. Residual amounts of$\alpha$ -tocopherol and phosphatidylinositol showed high correlations with the lipid oxidation of the fried products during storage in the dark. -
This research was conducted to determine the effect of far-infrared ray (FIR) irradiation of grape berries as a potential application for manufacturing grape products with a high amount of antioxidant chemicals. Two grape cultivars, the red grape cv. Campbell Early and the white grape cv. Thompson Seedless, produced increased amounts of crude extracts, in the FIR treatments compared to a non-FIR treatment control with same temperature. However, total phenolic concentrations and antioxidant activity in a 'Campbell Early' increased in the extracts following FIR treatment, whereas those of 'Thompson Seedless' did not increase significantly. High performance liquid chromatography (HPLC) analysis indicated that functional components affecting antioxidant activity were significantly increased in the extract of 'Campbell Early' following FIR treatment. Our results indicate that application of FIR treatment in heat process of grapes increases levels of antioxidative phenolic chemicals and it may help to enhance the availability of antioxidative compounds in various grape food products.
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Regional variation in the fatty acid content of shellfish was investigated on 5 species of Korean shellfish including murex shell, ark shell, jack-knife clam, orient hard clam, and little neck clam that were originated from 2 geographically different regions in Korea (Region 1: South coast,
$34-35^{\circ}N$ ,$127-129^{\circ}E$ ; Region 2: West coast,$36-38^{\circ}N$ ,$126-127^{\circ}E$ ). Significant regional difference in total fatty acids content was observed in murex shell and little neck clam (p<0.01), but not in the other species of shellfish. The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids including n-3 and n-6 fatty acids were appreciably higher in murex shell from Region 2 and in little neck clam from Region 1 than the shellfish originated from their counterpart areas (p<0.05). Nevertheless, relative percentages of the fatty acids remained constant within same species regardless of geographic regions or species. Considering the facts of that the fish/shellfish are unique sources of n-3 fatty acids and a little neck clam is the most-consumed shellfish in Korea, n-3 fatty acids intake might vary with the habitat of the shellfish that Koreans consume. -
Lee, Jeon-Geun;Kausar, Tusneem;Chung, Hyung-Wook;Jeong, Il-Yun;Bhatti, Ijaz A.;Kwon, Joong-Ho 374
Three physical methods, photostimulated luminescence (PSL), thermoluminescence (TL), and electron spin resonance (ESR), have been applied to detect the irradiation treatment for the non- and steamed sesame seed samples. PSL successfully screened the irradiated samples from the non-irradiated control by comparing their photon counts (PCs) with the lower (less than 700 count/60 sec) and upper threshold values (higher than 5,000 count/60 sec). TL signals were still detected in all irradiated samples even after steaming, which was reconfirmed with TL ratios [integrated area of$TL_1$ (the first glow)/$TL_2$ (the second glow)] through re-irradiation step. ESR spectrometry showed that radiation-induced cellulose radicals were detected in all the irradiated samples irrespective of steaming treatment. Identification of the irradiated sesame seeds was possible even after steaming by analyzing PSL, TL, and ESR. -
For an accurate risk assessment of furan, a potential human carcinogen, levels must be determined in human blood plasma using a simple and robust assay. In this study, solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) was used to analyze blood plasma levels of furan in 100 healthy individuals who consumed a normal diet. The subjects were 30 to 70 years of age and 51% were women. Ultimately, an analytical method was established for analyzing furan in human blood. The limit of quantification (LOQ) and furan recovery rate in blood were 1.0 ppb and 104%, respectively. Finally, furan was detected in 21 individuals (13 males, 8 females) with levels ranging up to 17.86 ppb (ng furan/g food).
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To isolate lactic acid bacteria having high exopolysaccharides (EPS) production ability, 50 strains were initially isolated from the sourdough. Twenty-one strains formed highly mucoid colonies on the sucrose agar medium, which are indicative of active EPS synthesis. DU-07, DU-10, DU-12, DU-19, and DU-21 produced
$11.51{\pm}0.167$ ,$13.09{\pm}0.193$ ,$12.72{\pm}0.108$ ,$11.61{\pm}0.284$ , and$13.32{\pm}0.094\;g/L$ EPS, respectively, in MRS medium. The isolated strains, DU-10, DU-12, and DU-21, were identified as Enterococcus flavescens, Enterococcus faecium, and Lactobacillus amylovorus, respectively, by using API 50CHL kit and determining partial sequences of their 16S rDNA. Especially, L. amylovorus DU-21 showed the highest production of EPS, as well as the highest inhibitory activities against pathogenic (p<0.05). Interestingly, the L. amylovorus DU-21 seem to be endemic to sourdough fermentations, as they have not been isolated from other environments. -
Effect of Irradiation of Red Radish Seeds on the Seed Viability and Functional Properties of SproutsWaje, Catherine K.;Park, Ju-Hwan;Kim, Gui-Ran;Kim, Yu-Ri;Han, Bum-Soo;Lee, Yeon-Kyung;Moon, Kwang-Deog;Kwon, Joong-Ho 390
Red radish seeds were irradiated at doses up to 8 kGy using electron beam (e-beam) and gamma ray ($\gamma$ -ray). The seed viability and functional properties (carotenoid, chlorophyll, ascorbic acid, and total phenol) of sprouts grown from these irradiated seeds were evaluated. High germination percentage ($\geq$ 97%) was observed in seeds irradiated at$\leq$ 5 kGy, but the yield ratio and sprout length significantly decreased with increased irradiation dose. Irradiation at$\geq$ 6 kGy resulted in curling of the sprout roots. Sprouting enhanced the functional properties of red radish seeds as indicated by the increased carotenoid, chlorophyll, ascorbic acid, and total phenol contents during germination. However, radiation treatment hampered the growth of seeds resulting in underdeveloped sprouts with decreased carotenoid, chlorophyll, ascorbic acid, and total phenol contents. In general, e-beam and$\gamma$ -ray irradiation of red radish seeds showed similar effects on the seed viability and functional properties of sprouts. Postharvest storage reduced the functional quality of sprouts. -
The nucleotide sequence contains 2 open reading frames encoding a 45-amino-acid protein homologous to a transcriptional repressor protein CopG, and a 203-amino-acid protein homologous to a replication protein RepB. Putative countertranscribed RNA, a double-strand origin, and a single-strand origin were also identified. A shuttle vector, pUCL2.1, for various lactic acid bacteria (LAB) was constructed on the basis of the pCL2.1 replicon, into which an erythromycin-resistance gene as a marker and Escherichia coli ColE1 replication origin were inserted. pUCL2.1 was introduced into E. coli, Lc. lactis, Lactobacillus (Lb.) plantarum, Lb. paraplantarum, and Leuconostoc mesenteroides. The recombinant LAB maintained traits of transformed plasmid in the absence of selection pressure over 40 generations. Therefore, pUCL2.1 could be used as an E. coli/LAB shuttle vector, which is an essential to engineer recombinant LAB strains that are useful for food fermentations.
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Changes in Enzyme Activities of Rice with Respect to the Viviparity and the Duration of Lodging TimeThe Japonica cultivar 'Janganbyeo' was cultivated and about half of paddy field was totally lodged at 30 days after heading. Both lodged paddy and unlodged paddy were harvested at intervals. The lodged paddy and brown rice did not show any signs of viviparity until the
$4^{th}$ day of lodging. The activities of$\alpha$ -amylase, diastase, and lipase of lodged paddy and brown rice began to increase on the$2^{nd}$ day of lodging and then increased slowly afterwards. The activities of protease and phytase of lodged paddy and brown rice reached the maximum values on the$2^{nd}$ day and then decreased until the final day of lodging. In contrast, unlodged paddy and brown rice showed relatively small increase in viviparity and in activities of$\alpha$ -amylase, diastase, protease, lipase, and phytase. Especially, activities of diastase and lipase were observed even in unlodged paddy and brown rice. -
In this study, a rapid and efficient concentrating procedure that can be used for detecting viruses in vegetables was developed. The Sabin strain of poliovirus type 1 was used to evaluate the efficiency of virus recovery. The procedure included: (a) elution with 0.25 M threonine-0.3 M NaCl pH 9.5; (b) polyethylene glycol (PEG) 8000 precipitation; (c) chloroform extraction; (d) 2
$^{nd}$ PEG precipitation; (f) RNA extraction; (g) reverse transcription-polymerase chain reaction (RT-PCR) combined with semi-nested PCR. The overall recoveries by elution/concentration were 29.0% from cabbage and 13.7% from lettuce. The whole procedure usually takes 18 hr. The overall detection sensitivity was 100 RT-PCR units of genogroup II norovirus (GII NoV)/25 g cabbage and 100 RT-PCR units of GII NoV/10 g lettuce. The virus detecting method developed in this study should facilitate the detection of low levels of NoV in cabbage and lettuce. -
Effects of chlorophyll and visible light exposure on the volatile formations and headspace oxygen content were studied in lard model systems at
$55^{\circ}C$ . Samples with or without addition of chlorophyll under light underwent photosensization or photooxidation, respectively. Total volatiles (TI) in lard with 5 ppm chlorophyll photosensization were 19 times higher than those in visible light photooxidized samples for 48 hr while TI in lard with chlorophyll in the dark were not significantly different from those in photooxidized samples (p>0.05). Headspace oxygen content in photosensitized lard decreased from 21 to 15% for 48 hr but that in photooxidized lard or that in lard with chlorophyll in the dark did not change significantly (p>0.05), which indicates that lard system used in this study is a photosensitizer-free model system and the presence of chlorophyll accelerated the lipid oxidation only under visible light. Oxidation mechanisms of photooxidation with or without presence of photosensitizers under visible light were not the same based on the difference of oxidized volatile profiles and headspace oxygen depletion. -
Water and 70% ethanol extracts obtained from a sea cucumber (Stichopus japonicus) body wall by heat reflux or pressurized solvent extraction showed 2,2-diphenyl-1-picrylhydrazyl (
$DPPH^{\cdot}$ ) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation ($ABTS^{{\cdot}+}$ ) scavenging activities comparable to those of fruits and vegetables. The highest activities were observed for the water extract from heat reflux extraction. Crude saponins exhibited higher radical scavenging activities than the soluble matters in the extracts. However, they were responsible for only about 3 to 15% of the scavenging activities of the extracts. Total phenolic contents showed a significant correlation with$DPPH^{\cdot}$ scavenging activities, suggesting a significant contribution of phenolic constituents to the antioxidant properties of the extracts. However, total flavonoid contents showed little correlation with the radical scavenging activities. The results suggest that the water or 70% ethanol extract obtained from sea cucumber body wall by simple heat reflux extraction could provide considerable antioxidant benefits. -
Antimicrobial coating on chicken carcasses may reduce the effects of cross-contamination and improve product shelf-life and safety. Thyme oil was mixed at 0.5%(v/v) with a pre-gelatinized pea starch coating solution. The coating solution was spread on chicken breast meat after inoculation with selected spoilage and pathogenic bacteria. After inoculation, the chicken meats were packaged in plastic bags and stored at
$4^{\circ}C$ . During 12 day storage, total aerobic bacteria, lactic acid bacteria, and inoculated organisms were counted at 4 day intervals. Thyme oil treatments reduced the viability of Salmonella as well as the growth of Listeria and Pseudomonas by 2 log CFU/g, and appeared to eliminate inoculated Campylobacter during storage. The addition of thyme oil increased the viscosity of the pre-gelatinized pea starch solution. The results suggested that thyme oil inclusion in an edible starch coating may be a satisfactory delivery system to enhance the safety of processed fresh meat. -
The preventive effect of chewing gum containing maltitol, xylitol, gum base, and sugar on remineralization were investigated. The clinical study consisted of 8 weeks' randomized, double blind, controlled, cross-over clinical trials including 24 healthy adults had chew gum. After each test week, remineralization effect was evaluated by measuring microhardness and scanning electron microscopy (SEM). Microhardness of experimental chewing gum containing maltitol or xylitol was significantly higher than that of sugar gum (p<0.005). Images of SEM showed the remineralization effect of gum containing gum base, maltitol, or xylitol compared with sugar gum. Maltitol and xylitol gums were more effective in remineralization than sugar gum. It was concluded that maltitol and xylitol can be used as sugar substitute to prevent dental caries.
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The final bio-metabolites of lipid peroxidation (LPO) such as 4-hydroxynonenal (4-HNE) and malondialdehyde (MDA) have been suggested to mediate the oxidative stress-linked pathological incidences. Natural phytochemicals such as polyphenolic compounds in green tea have been known in preventing the LPO induced cellular growth inhibition and apoptosis. We investigated that green tea ethanol extracts (GTE) inhibit LPO-induced apoptosis in ECV 304 cells. GTE had time- or dose-dependent anti-apoptotic effects as evidenced by changes in cell morphology, MTT assay, DNA fragmentation, LPO production, and the Western blotting for apoptotic expression. In the 4-HNE-induced apoptosis model, GTE
$10-20{\mu}g/mL$ decreased cell death through decreasing LPO production. GTE protected 4-HNE induced apoptosis, as evidence with down regulation of mitochondrial signaling such as cytochrome C and caspase-3 activity. GTE increased bcl2, survival signaling protein, compared to 4-HNE alone within 6 hr incubation. Since polyphenols in GTE are effective antioxidants in endothelial ECV 304 cells, we suggested that natural polyphenols might be anti-atherosclerotic. -
In this study Bacillus subtilis PTCC 1023 was used for the production of protopectinase using soybean based media. The use of isolated soybean protein (ISP) and soybean flour resulted in similar protopectinase production and growth rates. The effect of medium composition on protopectinase production was studied using central composite design (CCD) methodology. The change in the concentration of ISP (1-7%), glucose (0-10%), and phosphate (0.1-0.3 M) was found to affect the protopectinase activity (response variable) after 24 hr of cultivation. In the range studied, ISP and glucose had a negative effect on the response variable, whereas phosphate had a positive effect. A statistically significant interaction was identified between phosphate and ISP, suggesting that correct optimization of medium formulation in this case can only be obtained using factorial design of experiments. Protopectinase activity exceeding 215 U/mL was obtained in a medium containing 4% ISP, 0.3M phosphate, and no added sugar.
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The antioxidant properties of water extracted polysaccharides (PW), 1%(w/v) NaOH extracted polysaccharides (PN1), and 5%(w/v) NaOH extracted polysaccharides (PN5) were assessed in this paper. PW showed good capability of scavenging
$H_2O_2$ , anti-lipid peroxidation, reduction power, and scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH). The maximum values were all observed at the dose of 1 mg/mL sample. As far as the antioxidant activities of PN1 were concerned, the capability of scavenging superoxide radical, chelating metal, and total antioxidation showed higher than those of PN5. When polysaccharide concentration was 1 mg/mL, the 3 index described above were attached 71.8%, 51.6%, and$446.3{\mu}M$ Trolox equivalent, respectively. With respect to PN5, higher capabilities of scavenging hydroxyl free radicals were obtained while the peak of 84.8% was observed at the concentration of 1.0 mg/mL. Moreover, the concentration-dependent influences were characterized in all cases. -
In comparison to processed wheat flour products, there is no established method for determining the water absorption of rye flour. The aim of this study was to work out a method using the Planetary mixer P 600 for the determination of water absorption (WA) and the rheological properties in rye dough made from rye flours of 4 different types (I-IV). In the correlation analysis showed that WA had positive correlation with ash, beginning of gelatinization,
$125-160{\mu}m$ particles, sedimentation values at 20 and 25 min, bread yield, pH, and total titratable acidity, but had negative correlation with initial viscosity, gelatinization maximum, viscosities on swelling at 25, 28, and$31^{\circ}C$ . The WA determined by the Planetary mixer P 600 agreed well with the experimental baking tests. -
Chung, Jin-Ho;Shin, Heung-Chule;Cho, Jeong-Yong;Kang, Seong-Koo;Lee, Hyoung-Jae;Shin, Soo-Cheol;Park, Keun-Hyung;Moon, Jae-Hak 463
Sixteen antioxidative active compounds isolated from the EtOAc layer of MeOH extracts of kochujang, Korean fermented red pepper paste, were structurally elucidated as fumaric acid, methyl succinate, succinic acid furan-2-yl ester methyl ester (gochujangate, a novel compound), 2-hydroxy-3-phenylpropanoic acid, 3,4-dihydroxybenzoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 6,7-dihydroxy-2H-chromen-2-one (esculetin), caffeic acid, cis-p-coumaric acid, trans-p-coumaric acid, daidzin, genistin, apigenin 7-O-$\beta$ -D-apiofuranosyl($1{\rightarrow}2$ )-$\beta$ -D-glucopyranoside, apigenin 7-O-$\beta$ -Dglucopyranoside, and quercetin 3-O-$\alpha$ -L-rhamnopyranoside by mass spectrometry (MS) and nuclear magnetic resonance (NMR) experiments. These compounds were analyzed for the first time as antioxidants from kochujang. -
Formaldehyde (FA) is a carcinogenic compound present in cigarette smoke. In this study, the amount of formaldehyde was analyzed in 5 kinds of cigarettes and the inhibitory effect of plant volatile extracts on the formation of FA was investigated. After extraction of the cigarette sample, FA was converted into its thiazolidine derivatives by reaction with cysteamine, and then measured using a gas chromatography-nitrogen phosphorus detector (GC-NPD). The concentrations of FA in cigarette smoke were found between 138.24 and
$217.82{\mu}mol/g$ cigarette smoke. Extracts isolated from Welsh onion (Allium cepa L.), garlic (Allium sativum L.), crown daisy (Chrylsanthemum coronarium L.), green pepper (Capsicum annuum L.), and sesame dropwort (Oenanthe javanica DC) were used for analyzing their inhibitory effects on the formation of FA. The inhibitory effects of extracts of Welsh onion, garlic, crown daisy, green pepper, and sesame dropwort on the formation of FA were 64, 47, 38, 47, and 19%, respectively. -
Ultraviolet B (UVB) radiation provokes the generation of reactive oxygen species (ROS) in the cells and skin, which induce oxidative stress in the exposed cells, leading to photoaging and cancer. Using the human keratinocytes HaCaT cell line, we investigated the photoprotective effects of aucubin isolated from Eucommia ulmoides. Pretreatment with aucubin markedly suppressed UVB-induced oxidative stress, which manifests as a decrease in intracellular lipid peroxidation, elevation of catalase activity, and reduced glutathione content. In addition, aucubin significantly reduced expression of matrix metalloproteinase-1 (MMP-1) protein (54%) and mRNA. Taken together, these results suggest that aucubin may offer protection against UVB-induced oxidative stress and may be used as a potential agent in prevention of UVB-induced photoaging.
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The compositional changes of wormwood (Artemisia princeps var. orientalis) essential oils were studied under 4 different storage conditions i.e., being exposed to air at 20 and
$40^{\circ}C$ . Sixty-four volatile compounds consisting of 24 terpene hydrocarbons, 18 alcohols, 11 ketones, 6 esters, 1 aldehyde, 2 hydrocarbons, and 2 oxides were identified on the basis of their mass spectra characteristics and retention indices in original wormwood essential oils. Identified compounds constituted 80.53% of the total peak area. Borneol (12.13%) was the most abundant compound, followed by$\alpha$ -thujone (8.66%), T-cadinol (6.67%), and 1,8-cineole (6.21%) in original wormwood essential oils. Under the condition of$40^{\circ}C$ of temperature with the cap being opened for 3 min everyday respectively during 6 months of storage, the total amount of functional groups in essential oil determined by peak area percent were decreased by 79.45%, at most. The total level of monoterpene hydrocarbons decreased markedly in the aerobic condition and high temperatures. Whereas the total level of esters increased significantly. Wormwood essential oils were stored in experimental conditions, with the changes in the volatile compounds of essential oils being accelerated by high temperatures and contact with the atmosphere. -
Yoon, Ji-Ho;Jung, Dong-Chae;Lee, Eun-Hye;Kang, Yoon-Seok;Lee, Sung-Yong;Park, Sae-Rom;Yeom, Hye-Jung;Ha, Mi-Sun;Park, Sang-Kyu;Lee, Yu-Si;Ha, Sang-Do;Kim, Gun-Hee;Bae, Dong-Ho 488
A protein isolate was prepared from black soybean (Glycine max L. Merrill) that possessed higher antioxidant activity than ordinary white soy protein isolates. The isolate was partially hydrolyzed by alcalase to reduce the allergenicity of black soybean. Alcalase remarkably reduced the molecular mass of the major soybean allergens that have molecular weights of 53, 38, and 24 kDa. Hydrolytic breakdown occurred more effectively in Gly m Bd 30K than in Gly m Bd 60K or Gly m Bd 28K. Alcalase hydrolysis increased the solubility and hydrophobicity of the black soybean protein isolate. The foaming activity and stability of black soybean proteins were highly increased by the partial hydrolysis. -
To improve phenylalanine ammonia lyase (E.C.4.3.1.5-PAL) activity in recombinant Escherichia coli, Some approaches for improving phenylalanine ammonia lyase (PAL) activity in recombinant E. coli were developed following preliminary studies by means of response surface method. The results shown that permeabilization with combination of Triton X-100, cetyl trimethyl ammonium bromide (CTAB), and acetone enriched cellular recombinant PAL activity significantly, which improved over 10-fold as compared with the control (untreat cell), as high as 181.37 U/g. The optimum values for the tested variables were Triton X-100 0.108 g/L, CTAB 0.15 g/L, and acetone 45.2%(v/v). Furthermore, a second-order model equation was suggested and then validated experimentally. It was indicated that addition of surfactants and organic solvents made the cells more permeable and therefore allowed easier access of the substrate to the enzyme and excretion of the product, which increased the rate of transport of L-phenylalanine and trans-cinnamic acids. These improved methods of PAL activity enrichment could serve as a rich enzyme source, especially in the biosynthesis of L-phenylalanine.
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The fibrinolytic enzyme, subtilisin D5, was purified from the culture supernatant of the isolated Bacillus amyloliquefaciens DJ-5. The molecular weight of subtilisin D5 was estimated to be 30 kDa. Subtilisin D5 was optimally active at pH 10.0 and
$45^{\circ}C$ . Subtilisin D5 had high degrading activity for the A$\alpha$ -chain of human fibrinogen and hydrolyzed the$B{\beta}$ -chain slowly, but did not affect the$\gamma$ -chain, indicating that it is an$\alpha$ -fibrinogenase. Subtilisin D5 was completely inhibited by phenylmethylsulfonyl fluoride, indicating that it belongs to the serine protease. The specific activity (F/C, fibrinolytic/caseinolytic activity) of subtilisin D5 was 2.37 and 3.52 times higher than those of subtilisin BPN' and Carlsberg, respectively. Subtilisin D5 exhibited high specificity for Meo-Suc-Arg-Pro-Tyr-pNA (S-2586), a synthetic chromogenic substrate for chymotrypsin. The first 15 amino acid residues of the N-terminal sequence of subtilisin D5 are AQSVPYGISQIKAPA; this sequence is identical to that of subtilisin NAT and subtilisin E. -
Lee, So-Young;Kim, Jin-Hee;Song, Eu-Jin;Kim, Koth-Bong-Woo-Ri;Hong, Yong-Ki;Lim, Sung-Mee;Ahn, Dong-Hyun 506
The antimicrobial activity of water and ethanol extracts from 30 species of algae was measured using the agar diffusion method and minimum inhibitory concentration (MIC) test. In agar diffusion method, the 95% ethanol extracts from 12 of the algae showed growth inhibition against the tested microorganisms. In particular, Ishige okamurai, Ecklonia stolonifera, Sargassum siliquastrum, Sargassum thunbergii, Colpomenia bullosa, and Ecklonia cava had strong antibacterial activities against Gram-positive bacteria at 4 mg/mL. In the results of the MIC test, S. siliquastrum showed the most antimicrobial activity, where its MIC values ranged from 0.005 to 0.0075% against Listeria monocytogenes, Clostridium perfringens, and Basillus subtilis. In the thermal stability test, for the ethanol extracts of I. okamurai, E. cava, S. siliquastrum, S. thunbergii, and C. bullosa, the extracts proved to maintain high antimicrobial activities when they were treated at$121^{\circ}C$ for 15 min. In the pH stability test, the antimicrobial activity of the S. siliquastrum ethanol extract was stable from pH 2 to 10, whereas the activity of the other species ethanol extracts were weakened under pH 10 against several microbes. -
This study was carried out to investigate the changes of yield, total phenolics, saponin content and composition, antimicrobial, and antioxidant activities of various fractions of fine ginseng root (Panax ginseng C.A. Mayer) by maceration method in the order of increasing polarity (hexane, chloroform, ethyl acetate, butanol, and water). Butanol fraction showed the highest total saponin content compare to other fractions. Hexane fraction could harvest significantly high ginsenoside Rg2, Rg1, and Rf (p<0.05). And the contents of ginsenoside Rh1, Rg3, and Rg1 showed relatively higher in the fraction of ethyl acetate than other fractions. The system of hexane-chloroform-ethyl aceate-butanol showed relatively high content of ginsenoside Re, Rd, Rc, Rb3, and Rb1. However, the last fraction of water still remained lots of Rb2 content. The fraction of water was the highest phenolics. The 1,1-diphenyl-2-picryhydrazil, superoxide, and hydroxyl radical scavenging activity of water fraction was higher than the other fractions. In antimicrobial activity, the fraction of hexane showed relatively high antimicrobial activity against Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus, Bacillus cereus, and Escherichia coli. And the fractions of the chloroform and ethyl acetate showed higher antimicrobial activities than the other samples in against P. aeruginosa and S. typhimurium.
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A bacterial strain (Strain N-08) capable of extracellularly producing high level of non-reducing oligosaccharide (NR-OS) isolated from soil. The strain was identified phylogenetically by 16S rDNA sequence analysis and found to be very close to Arthrobacter crystallopoietes. The high production of NR-OS was observed in the basal culture medium containing maltose as a sole carbon source. The NR-OS in culture supernatant was purified by glucoamylase treatment and Dowex-1 (OH.) ion exchange chromatography and its structure was characterized. This oligosaccharide consisted of only glucose. Methylation analysis indicated that this fraction was composed mainly of non-reducing terminal glucopyranoside. Matrixassisted laser-induced/ionization time-of-flight (MALDI-TOF) and electrospray ionization-mass spectrometry (ESI-MS)/MS analyses suggested that this oligosaccharide comprised non-reducing disaccharide unit with 1,1-glucosidic linkage. When this disaccharide was analyzed by
$^1H$ -NMR and$^{13}C$ -NMR, it gave the same signals with$\ alpha$ -D-glucopyranosyl-(1,1)-$\alpha$ -Dglucopyranoside. These results indicated that the NR-OS produced by A. crystallopoietes N-08 was${\alpha}1$ ,${\alpha}1$ -trehalose. This is the first report of the trehalose which can be produced directly from maltose by A. crystallopoietes N-08. -
Quenching mechanisms and kinetics of
$\alpha$ -,$\beta$ -,$\gamma$ -, and$\delta$ -tocopherol in photosensitized oxidation of lard were studied. Lard at 0.03, 0.07, 0.11, and 0.3 M in methylene chloride containing$4.4{\times}10^{-6}\;M$ chlorophyll and 0, 0.1, 0.3, and 0.6 mM$\alpha$ -,$\beta$ -,$\gamma$ -, and$\delta$ -tocopherol were stored under light for 4 hr, respectively. Oxidation was determined by headspace oxygen and peroxide value. Tocopherols prevented the photosensitized oxidation of lard (p<0.05). Steady state kinetic study showed that$\alpha$ -,$\beta$ -,$\gamma$ -, and$\delta$ -tocopherol prevented the photosensitized oxidation of lard by quenching singlet oxygen. Singlet oxygen quenching rates of$\alpha$ -,$\beta$ -,$\gamma$ -, and$\delta$ -tocopherol by headspace oxygen depletion were 1.86, 2.39, 2.47, and$2.11{\times}10^7/M/sec$ , respectively. The quenching rates of$\alpha$ -,$\beta$ -,$\gamma$ -, and$\delta$ -tocopherol by peroxide value were 1.42, 1.11, 0.97, and$0.42{\times}10^7/M/sec$ , respectively. The quenching rates of tocopherols were slightly different depending on the measurements of oxidation. -
Park, Mi-Jung;Choi, Kyu-Duck;Lee, Tae-Seek;Choi, Hye-Sung;Shim, Kil-Bo;Myeong, Jeong-In;Park, Mi-Seon;Shin, Il-Shik 533
Withdrawal time of erythromycin in the cultured black rockfish (Sebastes schlegeli) was investigated to provide regulatory authority and fishery industry with full information needed to secure food safety of the fish treated with erythromycin. Medication was carried out using the experimental diet containing erythromycin of which concentration was 200 mg/kg diet and its daily dose was about 40 mg/kg body weight. The withdrawal time needed to reduce antibiotic contents around 10.0 mg/kg accumulated during 9 days medication below 0.2 mg/kg was identified about 10 days. The antibiotic with 13.7 mg/kg of fish on the$9^{th}$ days of medication was completely depleted after 30 days from stop of medication. -
Evaluation for Efficacies of Commercial Sanitizers and Disinfectants against Bacillus cereus StrainsKim, Il-Jin;Ha, Ji-Hyoung;Kim, Yong-Su;Kim, Hyung-Il;Choi, Hyun-Chul;Jeon, Dea-Hoon;Lee, Young-Ja;Kim, Ae-Jung;Bae, Dong-Ho;Kim, Keun-Sung;Lee, Chan;Ha, Sang-Do 537
Bactericidal efficacies of various sanitizers and disinfectants against 10 Bacillus cereus strains isolated from Korean foods and 8 standard B. cereus strains were investigated. The sanitizing capabilities of ethanol, iodine, chloride, quaternary ammonium, hydrogen peroxide, and peroxide acetic acid were investigated using the EN 1276 method based on quantitative suspension testing. The resistance against sanitizers and disinfectants was higher for wild-type than standard strains, and the bactericidal activities decreased in dirty conditions. Ethanol, chlorine, and iodine at the maximum level allowed under Korean food sanitation laws showed a great effectiveness against B. cereus. Hydrogen peroxide at 1,100 ppm showed the lowest bactericidal activity against B. cereus. These results indicate that the legally allowed maximum concentrations of sanitizers and disinfectants in Korea do not reduce all B. cereus strains by at least$5\;{\log}_{10}\;CFU/mL$ . -
Water and ethanol extracts were prepared from the haesongi mushroom (Hypsizigus marmoreus) to measure functional components. The ability of the extracts to inhibit angiotensin-converting enzyme (ACE) and their hypoglycemic effects were also determined; the latter was measured by
$\alpha$ -amylase and glucosidase inhibition. Extraction yield, protein content, total phenol, and$\beta$ -glucan in the water extracts were 55.86, 17.71, 1.89, and 21.93%, respectively. The respective values for the ethanol extracts were lower than those for water extracts. Both water and ethanol extracts showed dosedependent ACE inhibition, the effect of the former being greater. The water extract inhibited ACE activity by 95.34% at 40 mg/mL. The$IC_{50}$ values of the water extracts were 63.32 and 0.41 mg/mL for$\alpha$ -amylase and glucosidase, respectively. Thus, the water extracts had a greater hypoglycemic effect than the ethanol extracts. From these results, water is a better solvent than ethanol to extract from the haesongi mushroom functional components that show ACE inhibition and have hypoglycemic effects. -
The objective of this study was to investigate Fourier transform infrared (FT-IR) spectrometry and the X-ray diffraction (XRD) characterization of melanoidins formed from glucose and fructose with amino acid enantiomers in the Maillard reaction. Before dialysis, FT-IR spectroscopy of all the samples showed that the characteristic absorption intensities appeared as a broad and intense band of the stretching vibration of the -OH group at 3,400/cm for a high pH. The absorption bands of the melanoidins sharply decreased in intensity after dialysis as compared to those before dialysis. In particular, the absorption bands at 992 and 575/cm disappeared. The XRD confirmed that the crystal structure of the melanoidins disappeared after dialysis and a new crystal structure was formed at 9 and
$28^{\circ}$ ($2{\theta}$ . In particular, broad diffraction peaks were formed in the$10-21^{\circ}$ ($2{\theta}$ ) range for a high pH, while other sharp diffraction peaks disappeared. -
This study investigated the proapoptotic effect of ethanol extracts obtained from dandelion (Taraxacum officinale) flower on human ovarian cancer SK-OV-3 cells. Cells were treated with dandelion flowers ethanol extract (DFE) ranging from 1.5625 to
$100{\mu}g/mL$ for 24 hr. Significant antiproliferative effects of DFE were first observed from at$6.25{\mu}g/mL$ (p<0.05), and this inhibition showed in a dose-dependent manner. When cells were treated with more than$6.25{\mu}g/mL$ DFE, cell-cycle analysis showed that DFE caused an increase in the percentage of sub-G0/G1 cells and arrested at the S and G2/M phase in a dose-dependent manner. Moreover, apoptosis induction by DFE involved p53 activation and bax upregulation as well as downregulation of bcl-2. Our findings indicate that DFE resulted in apoptotic cell death, suggesting that DFE possesses potential anticancer properties. -
Xanthorrhizol, a sesquiterpene isolated from Curcuma xanthorrhiza Roxb., was used to investigate its effect on reducing the saliva and multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus by anti-biofilm and confocal laser scanning microscopy (CLSM) assays. Xanthorrhizol exhibited significant antibiofilm activity in the dose- and time-dependent manners. Exposure to 2 and
$5{\mu}g/mL$ xanthorrhizol for 30 min remained <50% of saliva and multi-species biofilms formed for 24 hr. In addition, exposure to$10{\mu}g/mL$ xanthorrhizol for 30 min reduced 65 and 77% of 24 hr saliva and multi-species oral biofilms, respectively. CLSM results visually demonstrated that xanthorrhizol reduced bacterial viability in the saliva and multi-species oral biofilms. These results suggest that C. xanthorrhiza Roxb. containing xanthorrhizol with strong anti-biofilm activity can be employed as a plant source for oral care functional foods. -
A high performance liquid chromatography (HPLC) method has been developed for determination of 11 ginsenosides in black ginseng (BG, white ginseng that is subjected to 9 cycles of
$95^{\circ}C$ for 3 hr). After eluted by gradient elution of water-acetonitrile without buffer in 70 min, 11 ginsenosides in BG were identified. The proposed method provided good linearity ($R^2$ >0.9995), accuracy (92.2-106.6%), and intra- and interday precision (RSD<2.6%). In addition, ginsenosides compositions in white, red, and black ginsengs were investigated using this method, respectively. Interestingly, in BG, the content of ginsenoside$Rg_3$ which does not existed in white ginseng was 7.51 mg/g, approximately 20 times than that in red ginseng. -
Hong, Hee-Do;Sim, Eun-Mi;Kim, Kyung-Tack;Rho, Jeong-Hae;Rhee, Young-Kyung;Cho, Chang-Won 565
This study was conducted to evaluate the effects of different preparation methods on the recovery and quantification of ginsenosides in raw Korean ginseng (Panax ginseng C.A. Meyer). Eight major ginsenosides ($Rb_1$ ,$Rb_2$ ,$Rb_3$ , Rc, Rd, Re, Rf, and$Rg_1$ ) were analyzed by high performance liquid chromatography (HPLC), after which the recovery and repeatability of the extraction of those ginsenosides using 3 different preparation methods were compared [A. direct extraction (DE) method, hot MeOH extraction/evaporation/direct dissolution; B. solid phase extraction (SPE) method, hot MeOH extraction/evaporation/dissolution/$C_{18}$ cartridge adsorption/MeOH elution; C. liquid-liquid extraction (LLE) method, hot MeOH extraction/evaporation/dissolution/n-BuOH fractionation]. Use of the DE method resulted in a significantly higher recovery of total ginsenosides than other methods and a relatively clear peak resolution. Use of the SPE and LLE methods resulted in clearer peak resolution, but lower ginsenoside recovery than the DE method. The LLE method showed the lowest ginsenoside recovery and repeatability among the 3 methods. Given that the DE method employed only extraction, evaporation, and a dissolution step (avoiding complicate and time consuming purification), this technique may be an effective method for the preparation and quantification of ginsenosides from raw Korean ginseng. -
Choi, Ji-Hye;Kim, Myo-Jeong;Kim, Young-Wan;Lee, Hee-Seob;Park, Jong-Tae;Lee, Byong-Hoon;Park, Kwan-Hwa 570
The debranching enzyme of Nostoc punctiforme (NPDE) is a novel enzyme that catalyzes the hydrolysis of$\alpha$ -1,6-glycosidic linkages in starch, followed by the sequential hydrolysis of$\alpha$ -1,4-glycosidic linkages. The debranching activity of NPDE is highly specific for branched chains with a degree of polymerization (DP)>8. Moreover, the rate of hydrolysis of$\alpha$ -1,4-linkages by NPDE is greatly enhanced for maltooligosaccharides (MOs) with a DP>8. An analysis of reaction mixtures containing various starches revealed the accumulation of maltooctaose (G8) with glucose and maltose. Based on the novel enzymatic properties of NPDE, an MO mixture containing more than 60% G8 with yield of 18 g G8 for 100 g starch was prepared by the reaction of NPDE with soluble starch, followed by ethanol precipitation and gel permeation chromatography (GPC). The yield of the G8-rich mixture was significantly improved by the addition of isoamylase. In summary, a 4-step process for the production of a G8-rich mixture was developed involving the enzymatic hydrolysis of starch by NPDE. -
To reduce the content of undesirable erucic acid in mustard oil (MO), it was enzymatically modified with capric acid using immobilized lipase TL IM to produce structured lipid (SL). After reaction, the content of erucic acid was reduced up to 21.7% under the performed reactions in this study. Meanwhile, unsaturated fatty acids existing at sn-2 position (oleic acid, linoleic acid, and linolenic acid) in MO were not much changed.