• The Korean Journal of Food And Nutrition
• /
• v.37 no.1
• /
• pp.48-56
• /
• 2024

Effects of glutamic acid (Glu) and monosodium glutamate (MSG) on oxidative stability of oil-in-water (O/W) emulsions with different emulsifier charges during riboflavin (RF) photosensitization were evaluated by analyzing headspace oxygen content and conjugated dienes. Cetyltrimethylammonium bromide (CTAB), Tween 20, and sodium dodecyl sulfate (SDS) were used as cationic, neutral, and anionic emulsifiers, respectively. Glu acted as an antioxidant in CTAB- and Tween-20-stabilized O/W emulsions during RF sensitization, whereas Glu acted as prooxidants in SDS-stabilized O/W emulsions in the dark. However, adding MSG did not have a constant impact on the degree of oxidation in O/W emulsions irrespective of the emulsifier charge. In RF-photosensitized O/W emulsions, the emulsifier charge had a greater influence on antioxidant properties of Glu than on those of MSG.

• Analytical Science and Technology
• /
• v.28 no.6
• /
• pp.436-445
• /
• 2015

Amomi Fructus with anti-oxidative activity was chosen and essential oil was obtained by SDE (simultaneous distillation extraction), and 39 constituents were determined by GC-MS (gas chromatography-mass spectrometry). Major components were camphor, borneol acetate, borneol, D-limonene and camphene. Three solvent extracts such as hexanes, diethyl ether and methylene chloride from Amomi Fructus were obtained. These were analyzed by GC-MS and 4 more constituents were identified in addition to 39 components discovered in essential oil. Five major components such as camphor, borneol acetate, borneol, D-limonene and camphene were also detected, however the relative peak percents of those components were different from those of constituents in essential oil. To estimate the kind and the amount of materials evaporated at certain temperature and conditions from essential oil and solvent extracts, dynamic headspace apparatus was used and materials evaporated and trapped at certain conditions were analyzed by GC-MS. Recovery yield of SDE method from Amomi Fructus was measured by using camphor and standard calibration solution of camphor methanol solution and, the yield was 82.0%. Content of Hg was measured by mercury analyzer and contents of Cd, Pb, Cr, Mn, Co, Ni, Cu and Zn in Amomi Fructus, essential oils and solvent extracts were determined by ICP-MS (Inductively coupled plasma-mass spectrometer). Pb, Cd and Hg were measured in the concentration of 0.72 mg/kg, <0.10 mg/kg and 0.0023 mg/kg, respectively and these were below permission level of purity test. Contents of Mn, Cu and Zn in Amomi Fructus were 213 mg/kg, 8.29 mg/kg and 31.0 mg/kg, respectively and which were relatively higher than other metals such as Cr, Co and Ni. Metals such as Mn (0.65 ~ 9.08 mg/kg), Cu (1.16 ~ 4.40 mg/kg) and Zn (1.10 ~ 3.80 mg/kg) in essential oil and solvent extracts were detected. At this point it is not clear that the metals were cross-contaminated in the course of treating Amomi Fructus or metals were contained in Amomi Fructus. The influence evaluation toward biological model study of these metals in essential oil and solvent extracts will be needed.

• Korean Journal of Food Science and Technology
• /
• v.30 no.2
• /
• pp.313-318
• /
• 1998

Using direct headspace sampling (DHS) method, volatile terpenoid content was measured according to carrot cultured areas and various portions of carrot. In comparison of volatile terpenoid content in xylem and phloem of carrot, every volatile terpenoid was distributed highly in the xylem rather than the phloem of carrot. The carrot was divided into three different sections; upper (crown), middle (midsection), and lower part (tip), and the volatile terpenoids were measured. The content of ${\alpha}-pinene,\;{\beta}-pinene,\;{\beta}-myrcene,\;and\;{\gamma}-terpinene$ tended to be distributed highly in the upper part rather than the lower part, whereas the content of terpinolene and total terpenoids tended to be high in the lower part. In comparison of volatile terpenoid content according to the carrot cultured areas, volatile terpenoid content of carrot cultured in Cheju island was higher than Yangsan and Haenam areas. In case of total terpenoids, the carrot clutivars cultured in Cheju island contained $1.6{\sim}2.3\;times$ higher than those of Yangsan, and $1.5{\sim}2.4\;times$ higher than Haenam. In order to investigate the above results, we sampled out soils from the carrot fields and measured physical and chemical characteristics of the soils. The pH did not show much difference in the three areas. However the organic carbon, total nitrogen, cation exchange capacity, and total exchangeable cation in soil from Cheju were $2.4{\sim}3.0\;times$ higher than Yangsan and $3.9{\sim}7.1\;times$ higher than Haenam. The physical characteristics of the soils was investigated. The soil from Cheju island was found to be loam; Yangsan, sandy loam, and Haenam, clay loam.

• Applied Biological Chemistry
• /
• v.51 no.3
• /
• pp.238-244
• /
• 2008

The essential oil was obtained from the aerial part of Caryopteris incana Miq. by steam distillation, samples were collected by headspace (HS) and solid-phase microextraction (SPME) methods, and the compositions of the essential oil were analyzed by gas chromatography-mass spectrometry (GCMS). The fragrance of the essential oil was fougere and woody. There were sixty-nine constituents in the essential oil: 28 carbohydrates, 22 alcohols, 7 acetates, 7 ketones, 3 aldehydes, and 2 others. Major constituents were 4,6,6-trimethyl [1S-($1{\alpha},2{\beta},5{\alpha}$)]-bicyclo[3.1.1]hept-3-en-2-ol (11.8%), taucadinol (9.4%), myrtenyl acetate (9.2%), pinocarvone (7.0%), 1-hydroxy-1,7-dimethyl-4-isopropyl-2,7-cyclodecadiene (6.3%), ${\delta}$-3-carene (6.2%). By SPME extraction, forty-nine constituents were identified: 22 hydrocarbons, 16 alcohols, 6 acetates, 3 ketones, and 2 ethers. Major constituents of the SPME-extracted sample were ${\delta}$-3-carene (12.6%), (-)-myrtenyl acetate (11.2%), 6,6-dimethyl-2-methylene-bicycol [3.1.1] heptan-3-o1 (10.9%), pinocarvone (9.3%). By HS extraction, ten constituents were identified: 5 hydrocarbons, 2 amines, 1 alcohol, and 2 others. Major constituents of the HS-extracted sample were (Z)-2-fluoro-2-butene (34.9%), ${\delta}$-3-carene (6.9%), 6-(4-chlorophenul)tetrahydro-2-methyl-2H-1,2-oxazine (5.9%). The $IC_{50}$ value (0.011 ${\mu}g/mg$) in MTT assay using HaCaT keratinocyte cell line was lower than those of commercially-selling rosemary and tea tree, suggesting more toxicological studies are needed for commercial use of the essential oil of Caryopteris incana Miq.

• Food Science and Preservation
• /
• v.16 no.6
• /
• pp.817-823
• /
• 2009

We investigated the effects of storage temperature and packaging treatment on the freshness of high-quality 'Fuji' apples to improve consumer confidence in the maintenance of high fruit quality during distribution. A 0.35 mm-deep PET tray form-sealed with a 0.05 mm LDPE film lid was developed and tested with the aim of optimizing gas composition within the package headspace to utilize potential modified atmosphere (MA) storage to maintain the freshness of apples. Weight loss, color difference, firmness, respiration rate, gas concentrations in packages, acidity, solid soluble content, and fruit decay rate were measured during storage at $5^{\circ}C$ and $25^{\circ}C$. The results showed that respiration rate, weight loss, color difference, and firmness were lower and overall quality better during storage at $5^{\circ}C$ compared with $25^{\circ}C$. Also, the fruits packed in the functional tray form showed a low level of quality changes compared with the control (no packaging). The accumulated gasconcentrations in the headspace of the packages decreased from 21% to 12% $O_2$ and increased from 0% to 5% $CO_2$ (v/v) on day 7, and after remained at those levels thereafter. Soluble solid contents and total acidities of the packaged fruits were in the range of $11\;-\;14^{\circ}Brix$ and 0.2 0.3% during storage. Decay rates in the control and packaged fruits were more than 20% and less than 10% at 3 weeks, respectively. Based on the standard acceptable level (less than 10%) of total weight loss, it could be estimated that the shelf life of top-quality fruits packed in functional trays was 3 weeks at $5^{\circ}C$ and 16 weeks at $25^{\circ}C$, whereas the shelf life of the control fruit was 1 week and 12 weeks, respectively. For the top-quality fruit "Fuji" apples, the best results were obtained with a functional tray form for packaging treatment and a storage temperature of $5^{\circ}C$.

• Korean Journal of Environmental Agriculture
• /
• v.20 no.4
• /
• pp.244-251
• /
• 2001

This study was performed to investigate the recovery efficacy of 2-methylisobomeol (2-MIB) and Geosmin, odor contaminants produced by algae, by pretreatment techniques, and also to investigate both adsorption characteristics and removal efficiency to get some information for the effective removal of 2-MIB and Geosmin by batch experiments. In pretreatment experiments, the best recovery efficiency of both odorants at 0.2 and $2\;{\mu}g/L$ in raw water was 30 mL of sampling size, 9 g NaCl for salting out headspace of sampling phase and 40 minutes of adsorption. At the best condition, the recovery efficiency of 2-MIB was 85% at $0.2\;{\mu}g/L$ and 95% at $2\;{\mu}g/L$, whereas the efficiency of Geosmin was lower than that of 2-MIB : 61% at $0.2\;{\mu}g/L$ and 81% at $2\;{\mu}g/L$. In batch experiments, the removal efficiency of the Geosmin and 2-MIB by adsorbents using distilled water were increased in comparison with raw water, the efficiency in raw water was little different by their concentrations. When these results were applied to the Freundrich adsorption isotherm, the K value of 2-MIB for zeolite, coal activated carbon, and coconut activated carbon was 0.671, 1.811, and 1.340, respectively, and the value of Geosmin was 0.6125, 1.771, and 1.5191, respectively. Thus the adsorption efficiency of 2-MIB and Geosmin was in the order of zeolite, coconut activated carbon, coal activated carbon.

• Economic and Environmental Geology
• /
• v.38 no.2 s.171
• /
• pp.165-176
• /
• 2005

Natural gas in deep sediment may occur in three phases based on the physical and chemical conditions. If the concentration of gas in pore water is less than the solubility, gas is dissolved. If the concentration of gas is greater than its solubility (water is saturated or supersaturated with gas), gas occurs as a fee gas below the gas hydrate stability Lone (GHSZ) and is present as solid hydrate within the GHSZ. The knowledge of gas concentration in deep sediment appears critical to determine the phase of natural gases and to understand the formation and distribution of gas hydrate. However, reliable data on gas concentration are usually available only from the upper section of marine sediment by the headspace gas technique, which is widely used for sampling of gases from the sediments. The headspace gas technique represents only a fraction of gases present in situ because sediments release most of the gases during recovery and sampling. The PCS (Pressure Core Sampler) is a downhole tool developed to recover a nominal $1{\cal}m$ long, $4.32{\cal}cm$ diameter core containing $1,465cm^3$ of sediment, pore water and gas at in situ pressure up to 68.9 MPa. During Leg 204, the PCS was deployed at 6 Sites. In situ methane gas concentration and distribution of gas hydrate was measured by using PCS tool. Characteristics of methane concentration and distribution is different from site to site. Distribution of gas hydrate in the study area is closely related to characteristics of in situ gas concentration measured by PCS.

• Journal of Food Hygiene and Safety
• /
• v.28 no.3
• /
• pp.222-226
• /
• 2013

A simple and sensitive analytical method was developed using gas chromatograph with electron capture detector (GC-ECD) and gas chromatograph-mass spectrometer (GC-MS) for determination and identification of chloropicrin. Because of small molecular weight and high volatile properties of chloropicrin, analytical method was developed utilizing headspace extraction and direct injection to the GC. The developed method was validated using hulled rice sample spiked with chloropicrin at different concentration levels, 0.1 and 0.5 mg/kg. Average recoveries of chloropicrin (using each concentration three replicates) ranged 77.7~79.3% with relative standard deviations less than 10% and calibration solutions concentration in the range $0.005{\sim}0.5{\mu}g/mL$, and limit of detection (LOD) and limit of quantification (LOQ) were 0.004 and 0.01 mg/kg, respectively. The result showed that developed analytical methods was successfully applied to detect a small amount of chloropicrin in hulled rice.

• The Korean Journal of Food And Nutrition
• /
• v.25 no.4
• /
• pp.1092-1098
• /
• 2012

Aroma compounds in sun-dried salt according to saltern material and packaging box were extracted by the headspace and were isolated by using GC-MS. These compounds were identified including ketones, heterocyclic compounds and six other compounds. Major aroma compounds in salts were identified as 4-methyl-2-pentanone, 5-methyl-3-hexanone, 4-methyl-3-penten-2-one, 2-hexanol, benzothiazole, 2,4-bis(1,1-dimethylethyl)-phenol, and 1,3,5-tri-tert-butyl benzene. However, we found no significant differences according to the saltern materials in three salts. Salts stored in Chamaceyparis obtusa (Sieb. et Zucc.) had more diverse aroma profiling than those in Pinus densiflora and Paulownia coreana. We consider that it need to research the development of high value added products for new aromatic salt.

• Korean Journal of Food Science and Technology
• /
• v.39 no.1
• /
• pp.99-103
• /
• 2007

In order to evaluate innate flavor during the roasting process, the components responsible for the aroma of unroasted Polygonatum odoratum root and the volatile odor components released during the roasting process were evaluated using the solid phase-microextraction (SPME) headspace method. The raw P. odoratum root contained aldehyde, alcohol, hydrocarbon and acid components, which gave it a grass-like smell. 2-Methylpyrazine was not revealed from the roasted P. odoratum root at $110^{\circ}C$ and $130^{\circ}C$, but was extracted at $150^{\circ}C$. The 2,5-dimethylpyrazine component was the greatest at $130^{\circ}C$. The hexanal component was greater when the root was roasted at $110^{\circ}C$, compared with those at $130^{\circ}C$ and $150^{\circ}C$. The production of 2-acetyl-1-pyrroline component was the greatest when it was roasted at $130^{\circ}C$. Quantitative descriptive analysis of P. odoratum after roasting revealed a high concentration of 2,5-dimethylpyrazine at $130^{\circ}C$ and $150^{\circ}C$, but a low concentration at $110^{\circ}C$. Most of the 2-acetyl-1-pyrroline, which significantly affected its smell, was revealed at $130^{\circ}C$.