• Food Science and Preservation
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• v.14 no.6
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• pp.624-632
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• 2007

Changes in proximate composition, amino acid, free sugar, reducing sugar and vitamin contents of Curcuma longa L. (autumn woolgeom in Korean) and Curcuma atomatica Salib (spring woolgeom) were investigated according to picking time. Moisture, crude ash, crude protein and crude lipid were increased and non nitrogen substances was decreased by extending the picking time. Contents and ratio of total amino acid to essential amino acids was increased by extending the picking time. Free amino acid was increased by extending the picking time. Ratio of essential amino acids to total amino acids was decreased. Fructose was gradually increased, and then glucose, sucrose and total free sugars were decreased by extending the picking time. Amino acid and sugar contents of Curcuma longa. L. were higher than those of Curcuma atomatica Salib. In contents of vitamin C and $B_1$, Curcuma longa L. was decreased and Curcuma atomatica Salib was increased by extending the picking time.

• Korean Journal of Plant Resources
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• v.10 no.1
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• pp.1-5
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• 1997

Proximate composition and the contents of free sugar and amino acid of Korean arrowroot were invesigated to develop and produce the high quality processed products. A higher content of moisture, protein, and fiber were found in male arrowroot than in those of female. Among the total free sugars, sucrose was the highest components and fructose and glucose were follwed. In Korean arrowroot, 17 amino acids were determined and proline of male arrowroot and aspartic acid of female arrowroot were found to be the major components. Arginine was abundant in male arrowroot, while aspartic acid was abundant in female arrowroot on the samples of November. Leucine was abundant in male arrowroot and glutamic acid was in female arrowroot in the samples of February. Among the free amino acid of Korean arrowroots, proline was the most plentiful and major components were histidine, alanine and serine.

• Korean Journal of Food Science and Technology
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• v.27 no.5
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• pp.819-825
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• 1995

Two sweet potato CV.(Ipomoea batatas) were examined, i.e. purple flesh sweet potato(PSP) and light yellow flesh sweet potato(LYSP) which varied in degree of sweetness. On a fresh weight basis, nitrogen free extract in cultivars ranged from $25.73{\sim}26.24%$ and PSP contained more crude fat than LYSP. Total amino acids of PSP and LYSP were 5676.57mg% and 4550.86mg%, respectively. Aspartic acid, serine, alanine and valine were the major components in sweet potatoes. Sulfur-containing amino acids are the first limiting amino acid in PSP. The major fatty acids in PSP and LYSP analyzed by GC were palmitic acid, linoleic acid. The content of the saturated fatty acid was less than that of the unsaturated fatty acid. Carbohydrate contents were $75.43{\sim}79.10%$ and neutral sugars contents were $67.22{\sim}64.85%$(dry wt). Two sweet potato CV. contained the most glucose of all neutral sugars. PSP contained 11.88% for uronic acid, 59.42% for starch. Free sugars of PSP(0.82%) was much less than that of LYSP(2.53%). The contents of thiamin, riboflavin and niacin were similar, and the ascorbic acid contents in PSP and LYSP were 63.4mg% and 48.7mg%(dry wt), respectively. Comparing the mineral content in PSP, K was the greatest element in concentration followed by mg, Ca, Na. The total dietary fiber(TDF) value was 13.43% in PSP, 9.79% in LYSP respectively. The ratio of soluble dietary fiber(SDF) content and insoluble dietary fiber(IDF) content to TDF content for PSP were 57.6%, 42.4%, respectively.

• Food Science and Preservation
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• v.15 no.4
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• pp.524-531
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• 2008

To investigate tea prepared from Ixeris dentata root, color, and levels of free sugars, organic acids, cynaroside, total polyphenolics, and free amino acids were investigated using various thermal processing methods. These included natural drying(ND), hot-air drying(HAD, $75^{\circ}C$), hot-air drying after steam(HADS, steaming at $95^{\circ}C$ for 30 min) and roasting after hot-air drying(RHAD, roasting at $140^{\circ}C$ for $2{\sim}3$ min). Total free sugars, organic acids, cynaroside, and free amino acids contents were highest after ND treatment. Total polyphenolics was highest after RHAD processing. The level of cynaroside, a principal component of Ixeris dentata root, was significantly decreased by HADS. The major free sugars were fructose, glucose and sucrose. Succinic acid was prominent among organic acids, and was present at 2.25%(v/v) after ND treatment. The lightness(L), redness(a), and yellowness(b) of all dried Ixeris dentata root powders were best after RHAD treatment, but analysis of the leaching liquids after hot water treatment yielded variable results. Lightness and redness were the highest after RHAD and yellowness was the highest after ND treatment. Overall, the RHAD drying method was found to be superior to other methods, in sensory evaluation tests.

• Korean Journal of Food Science and Technology
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• v.26 no.4
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• pp.471-474
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• 1994

Growing barley leaves with $20{\sim}50cm$ length were analyzed for chemical constituents including moisture, crude fiber, protein, fat, ash, free sugars, free amino acids, chlorophylls, vitamin C and minerals. During the growth of barley leaves, moisture content decreased, while crude fiber gradually increased. Protein, fat and ash contents of barley leaves remained relatively unchanged. Chlorophyll content increased to a maximum value at the leaf length of 20 cm, and then declined. Minerals of barley leaves were abundant in the following order of K>Ca>P>Na>Mg. Vitamin C content, showing the similar trend to chlorophyll, was the highest at the leaf length of 20 cm. Major free sugars present in growing barley leaves were identified as glucose, fructose and sucrose. All the free sugars reached their maximum values at 20 cm and they were reduced thereafter. Total amount of free amino acids varied from 803 mg% at the Barley stage of l0 cm to 1038 mg% at the later stage of 50 cm. Changes in content for each amino acid were variable to some extent.

• Journal of Ecology and Environment
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• v.45 no.3
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• pp.143-151
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• 2021

Background: Plants are able to optimize defense responses induced by various herbivores, which have different feeding strategies. Local and systemic responses within a plant after herbivory are essential to modulate herbivore-specific plant responses. For instance, leaf-chewing herbivores elicit jasmonic acid signaling, which result in the inductions of toxic chemicals in the attacked leaf (tissue-specific responses) and also in the other unattacked parts of the plant (systemic responses). Root herbivory induces toxic metabolites in the attacked root and alters the levels of transcripts and metabolites in the unattacked shoot. However, we have little knowledge of the local and systemic responses against stem-boring herbivores. In this study, we examined the systemic changes in metabolites in the wild tobacco Nicotiana attenuata, when the stem-boring herbivore Trichobaris mucorea attacks. Results: To investigate the systemic responses of T. mucorea attacks, we measured the levels of jasmonic acid (JA), JA-dependent secondary metabolites, soluble sugars, and free amino acids in 7 distinct tissues of N. attenuata: leaf lamina with epidermis (LLE), leaf midrib (LM), stem epidermis (SE), stem pith (SP), stem vascular bundle (SV), root cortex with epidermis (RCE), and root vascular bundle (RV). The levels of JA were increased in all root tissues and in LM by T. mucorea attacks. The levels of chlorogenic acids (CGAs) and nicotine were increased in all stem tissues by T. mucorea. However, CGA was systematically induced in LM, and nicotine was systematically induced in LM and RCE. We further tested the resource allocation by measuring soluble sugars and free amino acids in plant tissues. T. mucorea attacks increased the level of free amino acids in all tissues except in LLE. The levels of soluble sugars were significantly decreased in SE and SP, but increased in RV. Conclusions: The results reveal that plants have local- and systemic-specific responses in response to attack from a stem-boring herbivore. Interestingly, the level of induced secondary metabolites was not consistent with the systemic inductions of JA. Spatiotemporal resolution of plant defense responses against stem herbivory will be required to understand how a plant copes with attack from herbivores from different feeding guilds.

• Preventive Nutrition and Food Science
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• v.15 no.4
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• pp.287-296
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• 2010

This study was designed to investigate the influence of the pH and enantiomer on the antioxidant activity of Maillard reaction mixture solution in model systems. The loss of glucose in MRPs did not show different characteristics for the different amino acid enantiomers; however, the concentration of glucose decreased as the pH levels increased. The enolization of sugars was observed in all MRP samples according to increase of pH levels. In addition, D-amino acids were detected in L-amino acid systems and L-amino acids could also be observed in D-amino acid systems. Formation of the isomer was the highest in the Glc/L-Lys system. The browning development increased as pH levels increased; however, browning development did not show different characteristics based on the use of L- versus D-isomers of the same amino acid. The L- and D-isomers show different absorption values in the UV-Vis spectra, but the absorption patterns display a similar shape. The antioxidant activities of MRPs derived from the Glc/Gly, Glc/L-Asn and Glc/D-Asn systems at pH 7.0 were greater compared to those of pH 4.0 and pH 10.0. The antioxidant activities of MRPs derived from the Glc/L-Lys and Glc/D-Lys systems decreased as the pH increased. In addition, the results show that the MRPs derived from the D-isomers have similar antioxidant activities as those from L-isomer. Therefore, the MRPs have the different antioxidant activities on the basis of the pH level, but not on the basis of different amino acid enantiomers.

• KSBB Journal
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• v.4 no.1
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• pp.40-47
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• 1989

Changes of principal components of crude green tea were determined after 30 min. of heat treatment at 10$0^{\circ}C$, l15$^{\circ}C$, 14$0^{\circ}C$, 16$0^{\circ}C$. Four kinds of free sugars(sucrose, fructose, glucose, raffinose) and an unidentified sugar compound were separated in green tea by using High Performance LiQuid Chromatography (H.P.L.C.). 26-34 peaks were isolated as aroma compounds of green tea by means of Gas Liquid Chromatography(G.L.C). The typical aroma component of green tea such as linalool, furfural, benzyl alcohol and 13 other substances were identified. Contents of most compounds were decreased by heat treatment. Especially contents of free amino acids, free sugars, vitamin C and tannins were decreased remarkably, while those of total nitrogen and soluble nitrogen were hardly changed. The effect of heat treatment on organoleptic quality of tea extracts were examined by sensory evaluation of which result indicated the most favorable tea was produced at 115$^{\circ}C$. The Percentages of loss in contents of total sugars, reducing sugars, vitamin C, free amino acids and tannins at 115$^{\circ}C$ were 17%, 16%, 36%, 12% and 15% respectively, while those were 38%, 53%, 55%, 74% and 23% at 16$0^{\circ}C$.

• The Korean Journal of Food And Nutrition
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• v.13 no.5
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• pp.453-459
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• 2000

In order to promote the utilization of Rubus coreanum as functional food, and its physicochemical properties and volatile flavor were examined. The contents of chemical compounds showed 5.39% of moisture, 17.3% of total sugars, 8.6% of reducing sugars, 4.5% of crude ash, 3.9% of crude fiber, 10.6% of crude protein and 1.7% of crude fat and that of free sugars was 1.52% of sucrose, 3.98% of fructose, 1.24% of glucose. Among organic acid was 10.2% of citric acid, 6.29% of oxalic acid and 1.94% of malic acid. The highest component of free amino acids was 1,260.3mg of aspartic acid, 1,054.3mg of glutamic acid, respectively. And that of minerals was 38,789ppm of K. A total of 52 volatile flavor components (11 alcohols, 13 acids, 20 carbonyls, 5 hydrocabons, 3 esters) were identified in the Rubus coreanum, respectively. The major volatile flavor components of Rubus coreanum were 3.78% of linalool in alcohols, 14.40% of caproic acid in acids, 2.99% of 2-hydroxy-4-methoxyacetophenone in carbonyls, 1.59% of aromadendrene in hydrocabons and 0.43% of methyl palmitate in esters.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.442-446
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• 1985

The changes of nitrogen utilization ratio (NUR), Protein solution ratio (PSR) and free sugar contents during the amino acid soysauce manufacturing process by a low hydrochloric acid, temperature were investigated. On hydrolysis by 6%-HCI (3 liquor rate of defatted soybean weight, 3LR) at $85^{\circ}C$, NUR and PSR were 74.51%, 56.49% at 65 hours. At the same time free sugars were detected glucose, galactose, arabinose, fructose, xylose. on hydrolysis at $95^{\circ}C$, NUR and PSR were 77.72%, 64.04% at 50 hours, and 5 free sugars of the above statement were detected at 5 hours. Remarkable decreases in the levels of free sugars, only glucose were observed after 80 hours of the hydrolysis. On hydrolysis by 12%-HCI(3LR) at $95^{\circ}C$, NUR and IRA were 88.41%, 69.47% at 50 hours, free sugar were nearly disappeared after 20-35hours. On hydrolysis, galactose's disappearence rate was faster than glucose's.