• Journal of the East Asian Society of Dietary Life
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• v.21 no.5
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• pp.723-730
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• 2011

Soybean oil used to fry French fries, chicken nuggets, and donuts was exposed to high temperature at $180^{\circ}C$ for 72 h. The effects of frying foods on the thermooxidative stability of soybean oil were evaluated by determining the contents of free fatty acids, peroxides, total polar compounds, and conjugated dienoic acids, and by analyzing dielectric constant, refractive index, iodine value, smoke point, and fatty acid composition. The contents of free fatty acids, total polar compounds, conjugated dienoic acids, dielectric constant, and refractive index increased, whereas iodine value, smoke point, and U/S ratio of fatty acids composition decreased with frying time. All samples of frying oils after 72 h presented free fatty acid contents of below 2.0% and total polar compounds of below 25%, which were within the legal limits. However, peroxide values of frying oils were not directly correlated with frying time. The type of fried food affected the thermooxidative stability of the frying oils, with chicken nuggets being more stable in thermooxidation than French fries and donust. Among physiochemical indicators of frying oil quality, a rapid method including dielectric constant and refractive index can be used in quantity food production.

• The Korean Journal of Physiology and Pharmacology
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• v.23 no.5
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• pp.403-409
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• 2019

Free fatty acid (FFA) intake regulates blood pressure and vascular reactivity but its direct effect on contractility of systemic arteries is not well understood. We investigated the effects of saturated fatty acid (SFA, palmitic acid), polyunsaturated fatty acid (PUFA, linoleic acid), and monounsaturated fatty acid (MUFA, oleic acid) on the contractility of isolated mesenteric (MA) and deep femoral arteries (DFA) of Sprague-Dawley rats. Isolated MA and DFA were mounted on a dual wire myograph and phenylephrine (PhE, $1-10{\mu}M$) concentration-dependent contraction was obtained with or without FFAs. Incubation with $100{\mu}M$ of palmitic acid significantly increased PhE-induced contraction in both arteries. In MA, treatment with $100{\mu}M$ of linoleic acid decreased $1{\mu}M$ PhE-induced contraction while increasing the response to higher PhE concentrations. In DFA, linoleic acid slightly decreased PhE-induced contraction while $200{\mu}M$ oleic acid significantly decreased it. In MA, oleic acid reduced contraction at low PhE concentration (1 and $2{\mu}M$) while increasing it at $10{\mu}M$ PhE. Perplexingly, depolarization by 40 mM KCl-induced contraction of MA was commonly enhanced by the three fatty acids. The 40 mM KCl-contraction of DFA was also augmented by linoleic and oleic acids while not affected by palmitic acid. SFA persistently increased alpha-adrenergic contraction of systemic arteries whereas PUFA and MUFA attenuated PhE-induced contraction of skeletal arteries. PUFA and MUFA concentration-dependent dual effects on MA suggest differential mechanisms depending on the types of arteries. Further studies are needed to elucidate underlying mechanisms of the various effects of FFA on systemic arteries.

• Food Science of Animal Resources
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• v.40 no.3
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• pp.461-473
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• 2020

The goal of this study was to evaluate the influence of various supplementary feeds on the chemical composition and production of bioactive substances in Protaetia brevitarsis larvae. The primary feed-oak-fermented sawdust-was supplemented with a variety of substances, including aloe, apple, banana, sweet persimmon (S. persimmon) and sweet pumpkin (S. pumpkin). Crude protein and fat content were the highest in the control and S. pumpkin group, respectively. Supplementary feeds increased the content of unsaturated fatty acids, except in the group receiving S. pumpkin, in which oleic acid was the most abundant (58.2%-64.5%). Free essential amino acids in larvae receiving supplementary aloe were higher compared with the control group except for Lys and His. Polyphenol and flavonoid contents and the antioxidant activities of ABTS and DPPH were higher in all treated groups compared with the control group. Although supplementary feeds led to a decreased crude protein content in the treated larvae when compared with the control group, these treatments generally improved the levels of unsaturated fatty acids and antioxidative activity. Therefore, we suggest that among the supplementary foods tested, aloe is a better resource for P. brevitarsis based on crude protein content, free amino acids and other bioactive compounds such as unsaturated fatty acids and antioxidants.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.573-580
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• 2010

The study investigated the effect of diets supplemented with different levels (0 and 2.5%) of yuza (Citrus junos Sieb ex Tanaka) on the nutritional characteristics of eels (Auguilla japonica). Fish ($9.8{\pm}1.3g$) was fed to apparent satiation twice daily for 8 months. There were no significant differences in proximate composition among the treatment groups, except for the ash and carbohydrate contents (P<0.05). The vitamin C content of eel muscle in the yuza-added group was two-times higher than in non-added groups (P<0.05). Among eight organic acids in eel muscle, lactic acid was predominant, followed by citric acid, oxalic acid, malic acid, and acetic acid. Eels fed a 2.5% yuza diet had the highest lactic acid content in all groups. Six sugars were found in all groups and glucose was the major sugar. Glucose and maltose were the dominant sugars in the yuza-added group. The abundant fatty acids in the yuza-added group were C18:1 n-9, C16:0, and C16:1 n-7, which comprised over 80% of the total fatty acids. The major amino acids in samples were glutamic acid, aspartic acid, lysine, and leucine. There were few differences in the free amino acid compositions among the groups. However, histidine was the predominant amino acid and constituted over 53% of the total free amino acids.

• Journal of the Korean Society of Food Culture
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• v.7 no.4
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• pp.303-307
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• 1992

The lipid compositions of buckwheats produced in Korea were analyzed. The samples used in this experiment were as follows; Kyungbuk rice buckwheat. Kangwon hull buckwheat and Kangwon rice buckwheat. The total lipids were extracted and fractionated to neutral lipids, glycolipids and phospholipids respectively by silicic acid column chromatography (SACC). As a result, neutral lipids content of these three samples were in the range of 82.77-95.65%; glycolipids in 1.97-10.83%; and phospholipids in 2.21-6.40%. The composition of neutral lipids of these three samples showed that triglyceride were in the range of 88.7-92.0%; monoglyceride in 2.3-4.0%; free fatty acid in 3.0-3.7%; diglyceride in 0.7-0.8%.; free sterol in 0-0.7%; and steryl esters in 0-2.2%. The major fatty acids of total lipid, neutral lipid, glycolipids and phospholipids of these three samples were oleic, linoleic and palmitic acids.

• Journal of Microbiology and Biotechnology
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• v.10 no.1
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• pp.99-102
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• 2000

To establish optimal conditions for esterification by Candida cylindracea, lipase reactions were performed simultaneously, separately, or individually in the varying initial rates of $0.014-0.060\mu$mole free fatty acids consumed min-1g-1. The reactants which were conditioned at aw of 0.12 gave the highest initial rate of esterifying $0.060\mu$mole free fatty acids consumed min-1g-1. These results suggest that the esterifying activity of lipase in an organic system depends on the transfer of available water within the reaction system.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.6
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• pp.367-370
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• 2002

Candida cylindracea lipase was immobilized by adsorption on acid washed glass beads. It was observed that protein loading of the support depends on the size of the particle, with smaller particle containing higher amount of protein per unit weight. Initial reaction rate linearly varied up to enzyme concentration of 17.25 U/mL. Amount of free fatty acids produced was linearly proportional up to the enzyme loading of 1650 $\mu$g/g of bead. Achievement of chemical equilibrium took longer time in the case of less protein loading. Degree of hydrolysis was found to decrease in second and third consecutive batch operations on repeated use of immobilized lipase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.467-472
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• 1991

In order to investigate the changes of lipid ingredient and fatty acid content in flint corn by a growth process, total lipids from flint corn(Zea may l.) were extracted, purified and fractionated into three lipid classes (neutral lipid ; NL, glycolipid ; GL, phospolipid ; PL) by silicic acid column chromatography (SACC). Non-polar lipid ingredients and fatty acid contents were determined by thin layer chromatography (TLC) and gas chromatography (GC). And non-polar lipid ingredients were quantitatived by TLC scanner. The crude oil among proximare composition increased 2.74% to 4.43% and NL and PL were fractionated by SACC increased 48.5% to 86.02%, 1.01% to 2.73%, respectively. But GL decreased 50.4% to 11.25%. Neutral lipid ingredients identified monoglyceride, were 1.1~3.7%, 11.9~16.1%, 2.3~4.2%, 16.7~21.5% and 58.5~63.6%, respectively. The major fatty acids of NL were linoleic (48.9~61.0%), oleic(22.3~34.2%), palmitic (10.3~11.7%) acids and stearic, linolenic acids were also detected as minor components. The ratio of total unsaturated fatty acid to total saturated fatty acid presented a higher percentage of 5.87~6.34. The physico-chemical characteristics of flint corn lipids were presented as specific gravity presented 0.920, refractive index 1.468, saponification value 191.2, unsaponificable matter 0.97%, acid value 0.58 and iodine value 124.6, respectively.

• Food Science and Preservation
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• v.14 no.3
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• pp.233-238
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• 2007

To develop a new quality control method for evaluation of Korean instant noodle soups, the chemical characteristics of roasted red pepper powder(RRP), mixed with red pepper seasoning oil, were investigated during storage at $65^{\circ}C$ for 6 weeks. The chemical composition was not significantly changed after 6 weeks of storage(P>0.05). The pH value decreased gradually while the acid value increased during storage. Both the American Spice Trade Association(ASTA) value that indicates redness of red pepper, and the CIE $L^*,\;a^*,\;and\;b^*$ values decreased remarkably during storage. The fatty acids of the RRP oil were mainly linoleic acid(55.1%), oleic acid(24.3%), and palmitic acid(13.9%). The composition of fatty acids was not significantly changed after 6 weeks of storage(P>0.05). In the free fatty acid(FFA) composition of the RRP oil, linoleic acid(32.4%) was the principal component. The total amount of FFA and the amount of each individual FFA increased remarkably during storage. The ratio of free unsaturated fatty acids to free saturated fatty acids increased during storage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.1
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• pp.29-35
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• 1992

Total lipids of Korean black soybean (Glycine man Merr) during soaking in water were extracted, purified and fractionated into three lipid classes, and then lipid contents and their fatty acid compositions were investigated. The lipids of the beans consisted of 89.1% neutral lipids, 1.5% glycolipids and 9.4% phospholipids, and these fractions did not change significantly during the soaking period. The neutral lipid fraction of the beans contained 92.1% triglyceride, 3.0% sterol esters and hydrocarbons, 2.8% diglyceride, 1.5% free fatty acids, 0.3% free sterols and 0.3% monoglyceride, and no significant changes were found in the composition of neutral lipid fraction from the soaked beans. Major components of the glycolipid fraction were esterified steryl glycosides (43.6%), steryl glycosides (26.6%) and digalactosyl diglycerides (14.5%), and these fractions did not change significantly during the soaking period. On the other hand, phosphatidyl choline (41.6%) and phosphatidyl ethanolamine (39.5%) were most abundant components found in the phospholipid fraction, and the contents of phospholipids changed a little during the soaking period. Linoleic acid, oleic acid and palmitic acid were the major fatty acids found in total lipids, neutral lipids, glycolipids and phospholipids. A few changes in the major fatty acid compositions of phospholipids were observed during the soaking period.