• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.176-187
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• 1988

Volatile flavor components in the Chinese quince fruits were trapped by simultaneous steam distillation-extraction method, and these were fractionated into the neutral, the basic, the phenolic and the acidic fraction. In the identification of carboxylic acids, the acidic fraction was methylated with diazomethane. Volatile flavor components in these fractions were analyzed by the high-resolution GC and GC-MS equipped with a fused silica capillary column. The total of one hundred and forty-five compounds from the steam volatile concentrate of the Chinese quince fruits were identified: they were 3 aliphatic hydrocarbons, 1 cyclic hydrocarbon, 4 aromatic hydrocarbons, 9 terpene hydrocarbons, 17 alcohols, 3 terpene alcohols, 6 phenols, 21 aldehydes, 7 ketones, 28 esters, 27 acids, 3 furans, 2 thiazoles, 2 acetals, 3 lactones and 9 miscellaneous ones. The greater part of the components except for carboxylic acids were identified from the neutral fraction. The neutral fraction gave a much higher yield than others and was assumed to be indispensable for the reproduction of the aroma of the Chinese quince fruits in a sensory evaluation. According to the results of the GC-sniff evaluation, 1-hexanal, cis-3-hexenal, trans-2-hexenal, 2-methyl-2-hepten-6-one, 1-hexanol, cis-3-hexenol, trans, trans-2, 4-hexadienal and trans-2-hexenol were considered to be the key compounds of grassy odor. On the other hand, esters seemed to be the main constituents of a fruity aroma in the Chinese quince fruits.

• Animal Bioscience
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• v.35 no.7
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• pp.1069-1079
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• 2022

Objective: The objective of this study was to investigate the effect of 4-month intensive feeding on the meat quality, fatty acid profile, flavor, and growth performance of grazing Hulunbuir sheep (HBS). Methods: The HBS were selected 4-months after birth in a pasture rearing system as the experimental animals (n = 44, female, average body weight 23.8±2.2 kg) then divided equally into pasture-based grazing fattening (PAS) and concentrate-included intensive fattening (CON) groups for another 4-month finishing. When finished fattening, all animals were slaughtered to collect musculus longissimus dorsi subcutaneous adipose tissue and to investigate the influences on meat quality, fatty acid profile, flavor and growth performance. Results: The results showed lambs in CON group got significantly higher live weight, hot carcass weight, and dressing percentage. The CON group had significantly higher value of redness (a^*), lightness (L^*) and water holding capacity (p<0.05), significantly lower value of Warner-Bratzler shear force than the PAS group (p<0.05). The subcutaneous fat from CON group lambs demonstrated a significantly higher content of C18:1 and C18:2 (p<0.05), but lower C14:0 and C16:0, indicating an increased degree of unsaturated fatty acid. The content of 4-methyloctanoic acid, 4-ethyloctanoic acid and 4-methylnonanoic acid had increased 2 to 4 times, representing a more intense odor in the CON group. However, the values were still lower than most sheep breeds reported, indicating the indoor feeding system could not fundamentally deteriorate the excellent meat characteristic of HBS. Conclusion: It was evident that lambs in CON group exhibited a better meat production performance, improved in meat color, texture and healthier fatty acid profile through pasture-weaned concentrate included intensive fattening system, which offers a good alternative regimen for lamb finishing and has a wide prospection in the HBS meat industry.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.143-148
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• 1984

The effects of various nutrients added to soy protein concentrate (SPC)-yogurt on the growth of Lactobacillus acidophilus and the flavor of SPC-yogurt were investigated. Soy milk was prepared from SPC (4.2% as protein) and various nutrients. One hundred ml of the prepared soy milk was given proper heat treatment, inoculated with 2.5ml of 24 hr-old culture, and incubated for 24 hr at $37^{\circ}C$. The growth of L. acidophilus was estimated from viable cell counts, titratable acidity and pH. The growth curve obtained from the experiment suggested that the log phase ended after 6 hr and the stationary phase ended after 30 hr. Glucose and fructose greatly enhanced the acid production by L. acidophilus. The optimum concentration of these two sugars in the media was approximately 3% each. Yeast extract greatly stimulated the acid production by L. acidophilus, and the optimum concentration of this additive was approximately 0.5%. Higher concentration of SPC resulted in slightly higher acidity in soy yogurt.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.51-53
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• 1985

Soy milks prepared from full-fat soy flour, defatted soy flow, soy protein concentrate (SPC) and soy protein isolate (SPI) were fermented with Lactobacillus acidophilus. Effects of lactic fermentation on the flavor and volatile compounds of soy milks were investigated. Sensory evaluation showed that the flavor of soy yogurt beverages was inferior to that of milk yogurt beverage and the flavor of SPI-yogurt beverage was better than that of other soy yogurt beverages. SPI-milk fermented with L. acidophilus was more acceptable than unfermented SPI-milk. Lactic fermentation reduced n-hexanal in SPC-milk and SPI-milk while it increased diacetyl in both soy milks.

• Korean Journal of Food Science and Technology
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• v.18 no.2
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• pp.118-123
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• 1986

Soy milk prepared from soy protein concentrate was fermented with Lactobacillus acidophilus, L. bulgaricus, L. casci, Streptococcus lactis or S. cremoris. Growth and acid production of each organism in soy milk and flavor of soy yogurt beverages were investigated. Volatile compounds in soy milk and soy yogurts were also determined. Among the five organisms tested, L. bulgaricus produced most amount of acid in soy milk while S. cremoris produced least amount of acid in soy mile. Sensory evaluation showed that the flavor of soy yogurt beverages was inferior to that of milk yogurt beverage and the flavor of soy yogurt beverage prepared by L. bulgaricus was better than that of other soy yogurt beverages. Soy milk fermented with L. bulgaricus was more acceptable than unfermented soy milk. Lactic fermentation reduced n-hexanal in soy milk while it produced diacetyl that was not detected in unfermented soy milk.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.3
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• pp.121-128
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• 1989

Volatile compounds were collected by simultaneous distillation extraction and carbon dioxide method, and analyzed by GC and GC-MS. The neutral fraction obtained from the whole steam volatile concentrate 55 kinds of components, phenolic fraction had 4 kinds of components, basic fraction had 13 kinds of components and 10 kinds of components were in acidic fraction. Alcohols, propanols, butanols, octanols, dodecanols etc. and aldehydes, pentanals, hexanal, 2-methyl-1-propanal, heptenal etc. were highly increased after boiled and roasted. And these compounds were contributed to formation of filefish flavor. The molecular ion peak of phenolic fraction was generally appeared in the range 100 to about 160. From the basic fraction, 2-methylpyrazine, 2,5-dimethylpyrazine, 2-ethyl-3,5-di-methylpyrazine and 2-methylpyridine were identified. The contents of basic compounds and furans obtained from the neutral fraction were increased at the higher heating temperature. The flavor of acidic fraction was influenced by the low molecular as isovaleric and valeric acid.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.1
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• pp.44-54
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• 2016

This study compared the physicochemical characteristics, proximate composition, taste compounds, and antioxidant properties of Sikhye prepared with mulberry fruit concentrate. Analysis of the physicochemical characteristics of Sikhye added with mulberry indicated that sugar content and titratable acidity increased significantly with increasing mulberry concentration, whereas pH decreased significantly. The whiteness index (L) was 36.77~51.40, which significantly decreased with increasing mulberry concentrate. The redness index (a) was -0.90~1.97 and highest in Sikhye sample containing 4% mulberry concentrate. The yellow index (b) was 0.03~1.90 and highest in Sikhye sample containing 1% mulberry concentrate. Analysis of the antioxidant properties of Sikhye added with mulberry indicated that total polyphenol content and flavonoid content increased significantly as the amount of mulberry concentrate increased above 1%. Total anthocyanin color also increased significantly with increasing mulberry concentrate. The mulberry Sikhye sample containing 8% extract showed the strongest antioxidant properties based on DPPH radical scavenging activity, reducing power, and FRAP assay. Evaluation of the sensory properties of Sikhye added with mulberry revealed that the most preferred flavor, color, and taste were observed in Sikhye samples containing 2%, 4%, and 8% extract, respectively. However, the highest overall preference was observed in Sikhye sample containing 2% extract, indicating that 2% concentration was most suitable for Sikhye and that flavor and aftertaste were more critical than taste. Analysis of the storage characteristics of Sikhye added with mulberry indicated that total bacteria count increased across all samples with increased storage period. However, total bacteria count in the added mulberry concentration group decreased in comparison to the control group as the amount of added mulberry increased.

• Culinary science and hospitality research
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• v.23 no.7
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• pp.176-182
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• 2017

This study evaluated th physicochemical and sensory characteristics of teriyaki sauce added with bitter melon (Momoridaica charantia L.) roasting powder. Teriyaki sauce containing Momoridaica charantia L. roasting powder at concentration of 0% (control), 2% (RMT2), 4% (RMT4), 6% (RMT6), 8% (RMT8). Color of teriyaki sauce added with Momoridaica charantia L. roasting powder were lower than the control. The pH of the sauce ranged from $4.31{\pm}0.01{\sim}4.87{\pm}0.01$. As the amount of added Momoridaica charantia L. roasting powder was increased, total soluble solid content and viscosity of teriyaki sauce increased. DPPH and ABTS radical scavenging activities of Momoridaica charantia L. added teriyaki sauce increased. The sensory evaluation was performed with scoring test s for color, flavor, taste, bitter taste, and overall acceptability by 50 professional panelists. In sensory evaluation, teriyaki sauce added with 4% Momoridaica charantia L. roasting powder concentrate high score in sensory preference. Based on the results, 4% should be recommended as the optimum level of Momoridaica charantia L. roasting powder concentrate to be added for the preparation of teriyaki sauce.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.226-231
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• 1996

A serum-pulp method was applied to concentrate peach pulp with aroma recovery. The serum portion was concentrated to five-fold at $50{\sim}55^{\circ}C$ and $30{\sim}50$ mmHg with aroma recovery. The concentrated serum, insoluble pulp and aroma fraction were recombined to make a two-fold concentrated peach pulp. The results of GC and GC/MS analysis for volatile compounds and sensory evaluation of concentrated peach pulp indicated that flavor quality was significantly improved by addition of aroma fractions. A 10% aroma recovery appeared to be appropriate for peach pulp.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.88-91
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• 1999

Aroma components of tea processed from Korean chicory roots were isolated and identified. The model system of amino-carbonyl reaction was carried out to study the formation mechanism of aroma compounds of chicory tea during manufacturing process. The concentration extracts from chicory tea and model system were analyzed and identified by gas chromatography(GC) and GC-mass spectrometry. Twenty-nine compounds, including pyrazines, furans, acids, alcohols, pyrroles and lactones were isolated and identified in chicory tea. The main compounds were pyrazines including methyl pyrazine, 2,5-dimethyl pyrazine, 2, 6-dimethyl pyrazine, 2-ethyl-6-methyl pyrazine, 2-ethyl-3-methyl pyrazine, thrimethyl pyrazine, 3-ethyl-2-5-dimenthyl pyrazine, 5-ethyl-2-3-dimenthyl pyrazine, and 2-acetyl-3-methy pyrazine and pyrroles including acethl pyrrole and formlyl pyrrole ; and furans including furfural , acetyl furan, 5-methyl furan, 5-methyl furfuralm, and furfuryl alcohol. These pyrazine compounds of a roasted and nutty aroma may be important contributors to the flavor of chicory tea. The aroma concentrate of model system also had a roasted and nutty aroma and the main compounds were methyl pyrazine, 2, 5-dimetyl pyrazine, 2, 6-dimethyl pyrazine and trimethyl pyrazine.