• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.531-536
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• 2004

Synthesis conditions were optimized using response surface methodology for producing structured lipids (SL) by interesterification of DHA-enriched algae oil derived from microalgae, Schizochytrium sp. and corn oil. Reaction was performed fer 24 hr at $55^{\circ}C$ catalyzed by immobilized lipase from Rhizomucor miehei (RM IM) in shaking water bath. Major fatty acids of SL were palmitic (21.70 mol%), oleic (20.20 mol%), and linoleic (27.34 mol%) acids, and DHA (15.06 mol%). To separate newly synthesized SL-triglycerides (TG) species, HPLC with evaporative light scatting detector (ELSD) was used. Production conditions were optimized using central composite design with reaction temperature $(35-75^{\circ}C,\;X_1)$, reaction time $(2-42\;hr,\;X_2)$, and enzyme concentration $(2-14%,\;X_3)$ as variables. When variables were $70.28^{\circ}C\;(X_1),\;28.74\;hr\;(X_2),\;and\;11.30%\;(X_3)$, maximum content of selected three peaks of synthesized SL-TG species was predicted as 6.97 area%.

• Journal of the Korean Dietetic Association
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• v.4 no.2
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• pp.160-167
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• 1998

Current status of nutrient fortification in processed food in Korea were presented by analyzing the information shown on food labels. The obtained information was assessed by the regulations on food fortification in both Korea and other countries including Codex. The most current regulations were gathered from internet. The results are summarized as follows. 1. Major nutrients fortified were calcium, Vit C, Vit B complex, iron and fiber. The forfified foods were not limitted to certain food group with more frequent fortification in snackfoods, cereal, ramyun, retort pouch foods, milk, and youguart. The descriptive terms of nutrition label for the fortification were various including high, supplemented, added, source, fortified, and abundance though the difference among these terms were not distinct. 2. Current regulation on nutrition label requires to give the content of the fortified nutrient and % RDA. However not all of food items carry above information. Also some ingredients such as chitosan, DHA, taurine, $\omega$-3 fatty acid, chondrichin, bifidus were supplemented mainly to the snack foods which FDA(USA) does not allow to be fortified. 3. The nutrient most frequently fortified was calcium and general practice of fortification appears to follow the regulation in Korea. Presently the regulation itself is not well described, this nutient fortification can cause toxic effect. Since calcium was supplemented to wide range of food group consumers who are not conscious of the safe upper limit may intake the fortified food up to the level of 2g/day. 4. For the effective fortification in Korea, the regulation on fortification should be reformed in accordance with the international guideline Codex and the regulations in other countries especially in America and Japan.

• Korean Journal of Food Science and Technology
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• v.25 no.3
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• pp.288-294
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• 1993

Solubilities of urea-crystallized tuna oil methyl esters in supercritical carbon dioxide were determined by a flow through extraction reactor. Experimental results obtained under a quasi-equlibrium condition showed that at 150 bar, solubilities of the esters in supercritical $CO_2$ were 0.075, 0.028 and 0.006(w/w) at $40^{\circ}C,\;60^{\circ}C\;and\;80^{\circ}C$, respectively. In the pressure and temperature ranges $(100{\sim}200bar\;and\;40{\sim}80^{\circ}C)$, the solubility increased with the density of $CO_2$. However, selectivity of supercritical carbon dioxide on the extracted compounds was much better at low density than at high density. Supercritical fractionation with a temperature gradient $(50{\sim}75^{\circ}C)$ resulted in concentrates of EPA and DHA in purities of 12% and 85%, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.3
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• pp.182-186
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• 2013

In this study, we examined the chemical properties and microbial community characteristics in 25 controlled horticultural soils (CHS) sampled from Gyeongnam Province by fatty acid methyl ester (FAME) method. The electrical conductivity of watermelon CHS was significantly (p < 0.05) higher than those of red pepper CHS, pumpkin CHS, and strawberry CHS. The amounts of total FAMEs, total bacteria, gram-negative bacteria, gram-positive bacteria, and fungi were significantly (p < 0.05) higher in red pepper CHS than those in strawberry CHS and pumpkin CHS. In addition, higher (p < 0.05) ratios of cy19:0 to $18:1{\omega}7c$ were detected in tomato CHS than those in watermelon CHS, pumpkin CHS, and red pepper CHS. This implied that microbial communities of tomato CHS were stressed more than other species of cultivation soils. Actinomycetes community in red pepper CHS was significantly (p < 0.05) higher than those in tomato CHS, strawberry CHS, and watermelon CHS. Differences in soil microbial community composition were highly associated with cultivated crop species which might result from the management inputs such as fertilizer, herbicide, and irrigation.

• Journal of Life Science
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• v.27 no.10
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• pp.1152-1160
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• 2017

A unicellular green alga was axenically isolated from a tidal pool on Ulleung-do, Korea. Morphological, molecular, and biochemical analyses revealed that the isolate belonged to Auxenochlorella protothecoides. The current study is the first record of this species in Korea. The microalgal strain was named as A. protothecoides MM0011 and its growth, lipid and pigment compositions, and biomass properties were investigated. The strain is able to thrive in a wide range of temperatures ($5{\sim}35^{\circ}C$) and to withstand up to 1.5 M NaCl. The results of GC/MS analysis showed that the isolate was rich in nutritionally important polyunsaturated fatty acids (PUFAs). Its major fatty acids were linoleic acid (27.6%) and ${\alpha}-linolenic$ acid (39.6%). Thus, this indigenous microalga has potential as an alternative source of ${\omega}3$ and ${\omega}6$ PUFAs, which currently come from fish and plant oils. Also, the HPLC analysis revealed that the value-added antioxidant, lutein, was biosynthesized as the accessory pigments by the microalga. A proximate analysis showed that the volatile matter content was 85.6% and an ultimate analysis indicated that the gross calorific value was $20.3MJ\;kg^{-1}$. Since 40.5% of total nitrogen and 27.9% of total phosphorus were removed from the medium, respectively, it also has potential as a feedstock for biofuel applications which could be coupled to wastewater treatment. In addition, the biomass may also serve as an excellent animal feed because of its high protein content (51.4%). Therefore, A. protothecoides MM0011 shows promise for application in production of microalgae-based biochemicals and as a biomass feedstock.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.418-427
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• 2003

Conjugated linoleic acid (CLA) is the mixture of positional and geometric isomers of linoleic acid (LA, C18:2 $\omega$6), which is found abundantly in dairy products and meats. This study was peformed to investigate the anticarcinogenic effect of CLA in MCF-7 breast cancer cells. MCF-7 cell were treated with LA and CLA at the various concentrations of 15, 30, 60, 120 UM each. After incubation for 48 and 72 hours, cell proliferation, fatty acids incorporation into cell, peroxidation and activities of antioxidant enzymes were measured. Postaglandin E$_2$ (PGE$_2$) and thromboxane $A_2$ (TXA$_2$) were measured for the eicosanoids metabolism. There was no cell growth differences in both of LA and CLA treated MCF-7 cells at 48 hr incubation. Compared to LA, cell growth was decreased by CLA treatment according to increasing concentration at longer incubation times, respectively (p<0.05). Both of LA and CLA was incorporated into the cellular lipids 22~54% higher than in control but LA incorporation was not so linear as CLA according to concentration. Arachidonic acid (C20:4, $\omega$6) was synthesized after treatment of LA but did not in CLA, respectively. The lipid peroxide concentration in LA 120 $\mu$M group increased as 1.7 times as that in CLA 120 $\mu$M treated. The activities of antioxidant enzymes such as glutathione peroxidase and glutathione reductase were increased by the supplementation with CLA 120 $\mu$M at 72 hr incubation (p<0.001) compared to LA, otherwise activity of superoxide dismutase was not different in both. PGE$_2$ and TXA$_2$ levels were lower in condition of CLA treatments according to lower levels of arachidonic acids than those in LA treated group, respectively. Overall, the dietary CLA might change the MCF-7 cell growth by the changes of cell composition, production of lipid peroxide, activities of antioxidant enzymes and eicosanoid synthesis compared to dietary LA.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.61-70
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• 2020

A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5℃. However, its optimal growth temperatures range from 15℃ to 25℃, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1621-1629
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• 2019

Objective: The objective of this study was to evaluate the physicochemical, sensory and taste characteristics of commercial, frozen, dry, and wet aged Hanwoo sirloin. Methods: Grade 2 sirloin from 6 Hanwoo steers (about 30 months old) were obtained after 5 days postmortem. Samples were assigned to four groups which were commercial beef (CON, control group), frozen beef (Hanwoo frozen, HF; 40 days in $-18^{\circ}C$ freezer), wet-aged beef (Hanwoo wet-aging, HW; 21 days), and dry-aged beef (Hanwoo dry-aging, HD; 40 days). HW and HD were stored in a $80%{\pm}5%$ relative humidity cooler at $1^{\circ}C$. Results: The HF group showed a significantly higher cooking loss and expressible drip with significantly higher pH compared to other groups. In addition, protein and fat contents in the HD group were higher than those in other groups (p<0.05). The shear forces in the HW and HD groups were significantly lower than those in the CON group. The HD group had significantly higher omega-3 and polyunsaturated fatty acids compared with other groups. Glutamic acid levels in the HD group were significantly higher compared with those in other groups. Electronic tongue analysis revealed that sourness of the HD group was lower than that of other groups, whereas the HD group showed significantly higher umami, richness, and saltiness compared to other groups (p<0.05). Sensory test results revealed that the HW group had significantly higher tenderness, while the HD group had significantly higher chewiness, juiciness, and overall acceptability scores. Conclusion: These results suggest that both wet- and dry-aging treatments can effectively improve sensory characteristics, and dry-aging was much more useful to enhance umami tastes and meat quality of 2 grade Hanwoo sirloins.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.6
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• pp.1348-1359
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• 2013

Kwamaegi is made from the flesh of Pacific saury, Cololabis Saira, which is traditional Korean seafood. It is well-recognized as a valuable health food containing EPA(eicosapentaenoic acid) and DHA(docosahexaenoic acid) to be known ${\omega}$-3 fatty acid. This study was conducted to obtain basic data which can be applied to process of canned Kwamaegi using tomato paste sauce. Commercial Kwamaegi was cut into $2{\times}3cm$ lengths, filled 90 g into can (301-3), added with 60 g water and then precooked for 10 min. at $100^{\circ}C$. After precooking, water was drained. The precooked Kwamaegi was packed into the can, and added with 60 g of tomato paste sauce(tomato paste 42%, gum guar 1.0%, salt 2.0%, starch syrup 2.0%, cooking wine 1%, water 52%). The cans were seamed using a vacuum seamer, and then sterilized for various Fo values (Fo 8~12 min.) in a steam system retort at $121^{\circ}C$. pH, VBN, amino-N, total amino acid, free amino acid, color value (L, a, b), texture profile, TBA value, mineral, sensory evaluation and viable bacterial count of the canned Kwamaegi using tomato paste sauce produced at various sterilization condition(Fo 8~12 min.) were measured. There was no remarkable difference between sterilization conditions and sensual characteristics. The results showed that the product sterilized at Fo 8 min. was the most desirable because this condition is the most economical and tasty.

• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.278-289
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• 2021

The rapid aging of society has led to a surge in cognitive dysfunction in the elderly. As there is limited evidence for the development of dementia in medicine, a shift in focus on prevention strategies using bioactive compounds in food is required. This systematic review evaluated the effects of various bioactive compounds on age-associated cognitive decline. The literature was searched for terms related to bioactive compounds in cognitive decline and article selection was limited to clinical randomized controlled trials for a single bioactive compound. We identified 21 studies that evaluated the strength of the evidence. ω-3 fatty acids and vitamin B presented a strong evidence level, whereas vitamin D and E, anserine/carnosine, and chromium were defined as having moderate levels of evidence. ω-3 fatty acids relieved cognitive decline and reduced amyloid β-related protein accumulation. Vitamin B decreased homocysteine levels, which is accompanied by alleviation of cognitive function. In conclusion, ω-3 and vitamin B have the potential to improve age-associated cognitive decline.