• Food Science of Animal Resources
• /
• v.38 no.5
• /
• pp.995-1007
• /
• 2018

Changes in the physicochemical properties of ready-to-feed liquid infant formula (LIF) stored at different temperatures (10, 20, 30, and $40^{\circ}C$) for 6 mon, focusing on 5-hydroxymethylfurfural (HMF) content, color, pH, fat globule size distribution, and rheological properties were determined. The HMF content increased with storage time, and LIF stored at $40^{\circ}C$ had a higher HMF content than that of LIF stored at $10^{\circ}C$. The lightness ($L^*$) decreased while redness ($a^*$) and yellowness ($b^*$) increased with increasing HMF content. The fat globule size and pH of LIF stored at $10^{\circ}C$ did not change. However, in the case of LIF stored at $30^{\circ}C$ and $40^{\circ}C$, the fat globule size increased and the pH decreased during storage for 6 mon. LIF stored at $40^{\circ}C$ had a higher apparent viscosity (${\eta}_{a,10}$) than that of LIF stored at $10^{\circ}C$, and the shear-thinning behavior of LIF stored at higher temperature was stronger than that of LIF stored at low temperature. The physicochemical changes of LIF during storage were accelerated by Maillard reaction (MR) at higher storage temperatures. Therefore, even if LIF is aseptically manufactured, we recommend that sterilized LIF should be stored at low temperature in order to minimize quality changes during storage.

• Applied Biological Chemistry
• /
• v.31 no.1
• /
• pp.58-64
• /
• 1988

Two kinds of honey, acacia and buckwheat, supplied by the producer have been stored at $5^{\circ}C,\;20^{\circ}C,\;and\;35^{\circ}C$ for one year to study storage qualities. Titratable acidity of the honey-increased with time specially at the elevated temperatures: the acidity of bukwheat increased 1.7 times at the end of storage at $35^{\circ}C$. Viscosity decreased with time and elevated temperatures. Viscosity of acacia honey at $35^{\circ}C$ was 1/12 the value at $5^{\circ}C$ and that of buckwheat was 1/3. Hydroxymethylfurfural(HMF) content increased slowly with time at $20^{\circ}C$, whereas. fast increase was observed at $35^{\circ}C$. HMF content of acacia honey after four months of storage exceeded the HMF limit of Codex, 40mg/kg. Buckwheat honey showed the same level after six months. It was noticeable fact that HMF content decreased significantly with time at $5^{\circ}C$. Diastase activity decreased with time and elevated temperature, and that of acacia honey was below 8 which is the Codex limit after six months of storage at $35^{\circ}C$. Buckwheat honey showed the same level of the activity after eight months. Fructose and glucose content decreased significantly with increased temperature. The ratio of fructose to glucose increased with temperature and maltose was detected in the sample stored at $35^{\circ}C$.

• Journal of the Korean Data and Information Science Society
• /
• v.24 no.3
• /
• pp.487-493
• /
• 2013

This experiment was conducted to investigate the possibility that milking speed traits can be improved by estimating their genetic parameters and to provide basic information when the goals for dairy cattle improvement are established. The amount of milk within the first three minutes (3MG) was 8.97 Kg and 57% of total milk was produced within 3 minutes, but it was lower than that of the recommended level (70%). The highest milk flow (HMF) and average milk flow (DMHG) in the main milking phase were 3.66kg/min and 2.43kg/min, respectively, which were lower than those of the recommended levels (4.0 5.0kg/min and 3.0 4.0kg/min), suggesting slower milking speed of domestic dairy cattle compared to that of foreign dairy cattle. The heritability estimates on the highest milk flow (HMF), maximum milk flow (HMG) in one minute and average milk flow (DMHG) in the main milking phase were 0.35, 0.31 and 0.29, respectively, which are suitable for the improvement of traits with medium heritability. The genetic correlation between total milk yields (MGG) and average milk flow (DMHG) in the main milking phase was 0.591, while the genetic correlations among milking speed traits including the highest milk flow (HMF), maximum milk flow (HMG) in one minute and average milk flow (DMHG) in the main milking phase were in the range of 0.889 0.997.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.6
• /
• pp.911-916
• /
• 2013

This study investigated changes in the chemical components and enzyme activities from hydroponic-cultured ginseng roots (HGR) and leaves (HGL) with various heating temperatures (90, 110, 130, and $150^{\circ}C$) for 2 hours. The UV-absorbance and browning intensity of heated ginseng significantly increased with heating temperature. 5-HMF contents also significantly increased with increasing heating temperature. The free sugars (fructose, glucose, and sucrose) were detected and sucrose content decreased, but fructose and glucose content increased with increasing heating temperature. Malic, citric, lactic, and oxalic acid contents were 817.52, 722.25, 122.06, and 18.43 mg%, respectively, in HGR and 682.84, 338.21, 90.37, and 0 mg%, respectively, in HGL at $150^{\circ}C$. Tyrosinase and ACE inhibitory activities significantly increased with heating temperature. These results show that various components and activities of HGT and HGL significantly increase with heating temperature.

• Korean Journal of Agricultural Science
• /
• v.36 no.2
• /
• pp.225-232
• /
• 2009

The ratio of saccharification and formation of furans during the acid hydrolysis of agar with oxalic acid and sulfuric acid were examined base on the contents of the agar and acids. The ratio of saccharification in oxalic acid appeared to be 51~59% somewhat higher than 49~61% of sulfuric acid. Formation of the furans during the acid hydrolysis increased proportional to the contents of agar and acid. The relative formation ratio was high 10~47% for furfural (FUR) and 15~29% for hydroxy-methyl furfural (HMF) in 0.5~1.25% sulfuric acid rather than those of oxalic acid. When comparing the removal efficiency of the furans using an alkali treatment, steam stripping and hydrophobic resins, FUR was eliminated 60% by the alkali treatment, 62~90% by steam stripping and 71~75% by Amberlite XAD4 and 7HP, while HMF was removed to low levels of 10.5%, 4~17% and 13~25%, respectively. The loss of reducing sugar was also observed in process of the removal of furans, and the loss rate was the level of 2~4% in alkali treatment, 11~16% in steam stripping and 7~9% in Amberlite resins.

• Applied Biological Chemistry
• /
• v.42 no.2
• /
• pp.152-155
• /
• 1999

Effects of pH, amino acids, hydrolyzed protein and potassium phosphate on caramelization were investigated for improvement of its reaction rate. The caramelization was performed with starch syrup at $110^{\circ}C$ and the different color functions-metric saturation(Suv), 5-hydroxymethylfurfural (HMF) contents and absorbance at 420 nm were measured. As the pH was raised from 4 to 10, the reaction rate (Suv/hr) was increased by 31.9% along with significant increase in HMF content and absorbances at 420 nm. Among the several amino acids, arginine and glycine were very effective for improvement of caramelization, which may be due to Maillard reaction. When $K_2HPO_4$ were added in different ratio with arginine, glycine, HVP or HAP, the effects of arginine and HAP on thee rate were markedly enhanced while the effects of glycine and HVP were rather reduced.

• Korean Journal of Veterinary Service
• /
• v.19 no.2
• /
• pp.172-179
• /
• 1996

This study was to investigate the properties such as amounts of moisture, inverted sugar, cane sugar and 5-(hydroxymethyl)-2-furfural (HMF) in feeding-honey(n=45) and wild-honey (n=3) harvested in Chonbuk area from April to November 1995. The results obtained were summarized as follows ; The average percentages of moisture in both feeding- and wild-honey was 20.2%(range, 17.5~23.1) and 20.7%(19.4~22.2). And those of inverted sugar/cane sugar in both honeies were 64.4%(55.8~69.3)/6.8%(1.0~l5.7) and 68.9%(68.5~69.8)/3.1%(2.5~3.7), in seasonal analysis those were 65.9%/5.3% in spring, 65.7%/6.6% in summer, 62.1%/8.0% in autumn, respectively. On the other hand, the average amounts of HMF in both honeies were 44.86mg/kg(22.6~68.6) and 7.0mg/kg(6.2~7.6), its average difference between both honeies were about 37.86mg/kg regardless of region and season.

• Applied Chemistry for Engineering
• /
• v.30 no.3
• /
• pp.280-289
• /
• 2019

5-hydroxymethylfurfural (HMF) and its derivatives, 2,5-furandicarboxylic acid (FDCA) or 2,5-diformylfuran (DFF), are regarded as the "sleeping giants" owing to their wide range of applications and a good alternative source for the production of significant chemicals in almost all kind of industries. This mini-review briefly covers the aspects related to the syntheses, transformation, and applications for the biomass-derived platform chemicals from past to most recent. Many scientific efforts have continuously been made to find out the environmental benign applicable ways in order to achieve the full advantage of these renewable materials because of not only to protect the globe but also shield the future of new generations. One of the best solutions could be the development and utilization of platform chemicals from the natural biomass.

• The Korean Journal of Food And Nutrition
• /
• v.28 no.5
• /
• pp.745-751
• /
• 2015

This study was performed to investigate the quality characteristics such as pH, total acidity, browning index, 5-hydroxymethylfurfural (5-HMF), fructose, S-allyl-L-cysteine (SAC), total polyphenol, and DPPH radical scavenging activity of aged garlic at different aging temperatures and periods. Aging temperature and period had a significant (p<0.05) effect on the quality characteristics of garlic. The pH in aged garlic significantly (p<0.05) decreased with increasing aging temperatures and periods, while the total acidity, browning index, and 5-HMF levels increased. The 5-HMF levels in garlic aged at 60 and $70^{\circ}C$ increased from 0.08~3.30 and from 0.05~106.07 mg/100 g, respectively. The fructose content in garlic aged at $60^{\circ}C$ gradually increased from 0.77 to 14.57%, while that of garlic aged at $70^{\circ}C$ increased from 1.07 to 19.75% until day 30, after which it decreased. The SAC level in raw garlic was 47.09 mg/100 g. The SAC contents of aged garlic differed significantly according to aging temperature and period. The SAC levels in garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were in the range of 15.28~100.5 and 12.41~85.55 mg/100 g, respectively. The total polyphenol contents of garlic aged at $60^{\circ}C$ and $70^{\circ}C$ were 6.01 and 6.67 fold higher, respectively, than those in raw garlic. The DPPH radical scavenging activity of aged garlic also showed a tendency to increase during aging.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.3
• /
• pp.495-500
• /
• 1998

To compare the extent of heat treatment in domestic infant formula, pH,titratable acidity, undenatured whey protein contents, HMF contents and protein-reducing substances of three commercial products (A, B, C) were measured. The pH of B products was lowest and the titratable acidity of B product was highest. The contents of undenatured whey protein per 100ml serum were 0∼30mg(A products), 90∼130mg(B products)and 80∼90mg(C products), respectively. Distinct differences of undenatured whey protein contents according to the manufacturer and infat's stage in age could be observed. The HMF contents of tested products showed 10.9∼21.5umol/L and B-2 product(B products for the second stage of 5∼9 month) was the highest among tested products. The protein-reducing substances showed 4.46∼9.50mg K4Fe(CN)6/100ml serum nd B-2 product was the highest among tested products.