• Food Science of Animal Resources
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• v.31 no.2
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• pp.241-249
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• 2011

This study was conducted to analyze ash content, mineral composition, hydroxy methyl furfural (HMF) content, stable carbon isotope ratio, and SDS-polyacrylamide gel electrophoresis patterns to investigate the quality characteristics of various honeys harvested from different sources and to identify differences useful for distinguishing honey sources. Ash content was 0.046-0.012% in acacia honey, 0.565-1.318% in chestnut honey, 0.06-0.582% in polyfloral honey, and 0.237-0.893% in native bee honey. Potassium content was high in order of chestnut honey>native bee honey>polyfloral honey>acacia honey. The Na/K ratio was 0.92-1.97 in acacia honey, 0.02-1.59 in chestnut honey, 0.02-5.30 in polyfloral honey, and 0.22-0.51 in native bee honey. The HMF content was 9.60-12.85, 10.15-25.75, 9.7-33.5, and 6.25-21.5 mg/kg in acacia, chestnut, native bee, and polyfloral honeys, respectively. HMF content was the highest in native bee honey. A 59 kDa protein band was revealed in all samples by SDS-PAGE analysis. Protein bands of 32.1, 31.9, and 33.5 kDa were revealed in some chestnut honeys, and protein bands of 32.3 and 32.5 kDa were shown in native bee honeys. A protein band of 72 kDa was also confirmed in some chestnut honeys.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.54-59
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• 2008

This study was conducted to investigate the effect of pH on the formation of furfural compounds from glucose and fructose reacting with amino acid enantiomers in the Maillard reaction. Hydroxymethylfurfural (HMF) content was highest at pH 4.0, and decreased with increasing pH. HMF was significantly higher in glucose-based systems than fructose-based systems. Furfuryl alcohol (FFA) and 5-methyl-2-furaldehyde (MF) were not increased with increasing pH, and only small amounts were formed. In addition, 2-furaldehyde (F) was found to increase in the systems, as pH increased. However, the content was small and variable. 2,5-Dimethyl-4-hydroxy-3(2H)-furanone (DMHF) was only found in Glc/D-Asn, Glc/L-Lys and Fru/D-Lys system, but the content was not increased with increasing pH. 2-acetylfuran (AF) was higher in Glc (or Fru)/L-Lys and Glc (or Fru)/D-Lys systems at pH 7.0. However, at pH 4.0, the content of AF was higher in the Glc (or Fru)/Gly and Glc (or Fru)/L-Asn systems. Therefore, this study aimed to observe the effect of pH, sugars and amino acid enantiomers on the production of furfural and related compounds by the Maillard reaction. A clear tendency was observed for some classes of compounds to be more easily formed at higher or lower pH. HMF was more readily formed at lower pH, while FFA, F, DMHF and MF were inhibited by acidic conditions. Particularly, compounds like FFA, F and MF were not affected by pH changes. In addition, DMHF and MF were only formed in L-Lys and D-Lys system.

• Journal of Life Science
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• v.17 no.2 s.82
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• pp.286-292
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• 2007

Free amino acids and volatile compounds of fresh garlic and its liqueur were investigated to search elution profile of those components as basic data for development of garlic liqueur. The garlic was soaked in 20% alcohol solution and then sampled every week for 5 weeks. The major free amino acids were L-aspartic acid, L-glutamic acid, L-arginine, L-alanine, L-proline, L-asparagine and L-serine. Neutral amino acids such as L-threonine, L-proline, L-valine and L-leucine, and aromatic amino acids such as tyrosine and phenylalanine were eluted over 80% of those content in fresh garlic after 3 weeks of soaking, but acidic, basic and sulfur containing amino acids were below 80% even after 5 weeks. Sulfide compounds such as diallyl trisulfide, diallyl disulfide, methyl allyl disulfide, 2-vinyl-4H-1,3-dithi in, 3-vinyl-3,4-dihydro-1,2-dithiin, 3,5-diethyl-1,24-trithiolane, isobutyl isothiocyanate and diallyl sulfide were identified as major volatile compounds of fresh garlic by using GC/MS. Among volatile compounds of fresh garlic, allyl alcohol, diallyl disulfide, 3,5-diethyl-1,2,4-trithiolane, diallyl trisulfide and 3,4-dimethoxy furan were eluted to liqueur, but those compounds except 3,5-diethyl-1,2,4-trithiolane were lowered in liqueur during soaking. Furfural, 5-methylfurfural, 5-hydroxymethylfurfural, dimethyl pyrazine, furfuryl alcohol, 3-hydroxy-2-bytanone and 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyr-an-4-one were generated newly and their content increased in liqueur during soaking.

• Food Science and Preservation
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• v.2 no.2
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• pp.293-301
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• 1995

Quality changes of Korean native-bee honey were investigated during processing and preseration at different temperature. There were no changes of HMF(Hydroxy methyl furfural) and proline contents, color and diastase activity in Korean native-bee honey, when the honey separated from honey combs at 20$^{\circ}C$ and 40$^{\circ}C$. However, at 50 and 80$^{\circ}C$, browning of Korean native-bee honey was shown, HMF content was increased rapidly and proline content and diastase activity were decreased. There were no changes of chemical composition in Korean native-bee honey during storage at 4$^{\circ}C$ for 6 months. But color was darken and HMF content was increased slowly in Korean native-bee honey during storage at 20$^{\circ}C$. During storage at 30$^{\circ}C$ and 40$^{\circ}C$, HMF content was increased highly, proline content, diastase activity and total acidity was decreased rapidly. It is recommended that Korean native-bee honey is separated from honey comb and purified at less than 40$^{\circ}C$ and stored at 4$^{\circ}C$ through 20$^{\circ}C$.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.102-109
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• 1991

Quality of three kinds of honey from acacia, chestnut and polyflower sources, was evaluated by physicochemical and GC-MS analysis in respect to some chemical composition. The average contents of moisture, ash, HMF(hydroxy methyl furfurol) and free acidity were 19.7% , 0.028% , 18.28mg/kg and 8.85meq/kg , respectively, in acacia honey, 19.1% , 0.05% , 18.47mg/kg and 10.24 meq/kg , respectively, in polyflower honey, and 18.9% , 0.050% , 20.21mg/kg, 12.28meq/kg respectively, in chestnut honey. The average contents of glucose and fructose ranged from 31.0 to 32.0% and from 35.0 to 36.0% , respectively, in all three kinds of honey. The average ratio of fructose to glucose was 1.14 in all three kinds of honey. Fatty acid composition in honey identified by GC-MS analysis was dodecanoic acid, 10-hydroxy-2-decanoic acid, 6,9-undecadienoic acid, tetradecanoic acid, 12-(acetyl oxy) -9-octadecenoic acid and 14-octadecenoic acid. The content of 10-hydroxy-2-decenoic acid was about 10% in three kinds of honey.

• Korean Journal of Food Science and Technology
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• v.46 no.4
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• pp.432-437
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• 2014

This study was carried out to examine the quality properties of honey in Korean commercial markets. The moisture content, stable carbon isotope ratio, invert sugar, cane sugar, and hydroxy-methylfurfural (HMF) contents of honey were measured according to the Korea Food Code and AOAC's (Association of Official Analytical Chemists) official methods. The stable carbon isotope ratio ranged from -25.18‰ to -12.60‰, which clearly differed between honey of $C_3$ origin (flower) and $C_4$ origin (artificial). Results of quality measurements revealed a moisture content of 18.12 to 19.70%, fructose content of 36.10 to 43.94%, glucose content of 22.61 to 31.91%, sucrose content of 1.56 to 4.75%, invert sugar content of 64.89 to 72.79%, and HMF content of 4.10 to 78.66 mg/kg. These values demonstrate that the quality of the tested honey meets the standard criteria of the Korean Food Code and Codex. However, it is necessary to reconsider the appropriate criteria for imported honey because it is circulated in the market through a long distribution process.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.867-874
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• 2000

Kochujang, which is one of most favorable fermented hot seasonings in Korea, has swelling problem and color changes during distribution. To stop the gas formation, heat treatments were conducted at $50^{\circ}C\;to\;70^{\circ}C$ for 5 to 15 min. at the beginning or after 40 days fermentation. Yeast were not detected at $60^{\circ}C$ for 15min. heat treatment and bacteria were not effected in number that is concerned in fermentation of kochujang. At above heat treatment, there was no effect ${\alpha}-amylase$ but ${\beta}-amylase$ activity was increased in heat treated kochujang. The acid protease activity was higher than nonheat treated kochujang after 60 days fermentation but neutral protease decreased after 80 days fermentation. The L, a and b value by Hunter were gradually decreased during fermentation and ${\Delta}E$ value showed difference in kochujang heated before fermentation. The total hydroxy methyfurfural content was increased, and carotenoid and capsanthin in heated kochujang decreased during fermentation.