• Korean Journal of Food Science and Technology
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• v.18 no.4
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• pp.306-312
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• 1986

Color changes of a mixture of 0.8 M glucose, fructose or sucrose and 0.8 M glycine were evaluated by Hunter 'L', 'a', 'b' values during Maillard reaction at the temperature range of $70^{\circ}-100^{\circ}C$. The results suggested the reaction to be devided into three stages. In initial reaction the 'L' and 'a' values decreased slowely, and 'b' rapidly increased to maximum, which were followed by a rapid decrease in 'L' and 'b' and rapid increase in 'a' values at intermediate stage. At final reaction period the both 'L' and 'b' were slowed down in their reduction rate while 'a' decreased rapidly from its maximum point. All of the Hunter values were reached to nea. zero. Linear equations, which can be used for prediction of cole. change in Maillared reaction, of $1/\sqrt{(L_t-L_{\circ})^2\;+\;(a_t-a_{\circ})^2\;+\;(b_t-b_{\circ})^2}\;=\;a(1/t)\;+\;b$ for Hunter values and $1/\sqrt{X\;+\;Y\;+Z}\;=\;a(1/t)\;+\;b$ for CIE tristimulus values were found to have a very high correlation coefficient. Relationships between 'L' and 'a', 'L' and 'b' and 'a' and 'b' were also graphcally compared.

• Food Science of Animal Resources
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• v.41 no.2
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• pp.224-236
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• 2021

The objective of this study was to investigate the effects of quality grade (QG) on the physicochemical composition and eating quality attributes of pork belly and shoulder butt. Seventy-two growing-finishing crossbred pigs were slaughtered and their carcasses were graded according to the Korean pork carcass grading system. Based on the grading criteria, the carcasses were classified into: QG 1+ (n=23), QG 1 (n=23) and QG 2 (n=26) groups. At 24 h postmortem, belly and shoulder butt cuts were collected from the QG groups and used for analysis of meat quality, flavor compounds and eating quality attributes. Results showed that the variation in fat content among QG was approximately 2% in the both cut types. The QG showed no effects on all the quality traits: cooking loss, pH and color of the belly or shoulder butt (p>0.05). Thirty-five flavor compounds comprising mainly fatty acids oxidation/degradation-derived products (e.g., aldehydes) and only few Maillard reaction-derived products (e.g., sulfur-and nitrogen-containing compounds) were identified. However, the QG showed a minor effect on the flavor profiles in both the belly and shoulder butt. Regarding the sensory quality, no effects of the QG were found on all the eating quality attributes (color, flavor, juiciness, tenderness and acceptability) for both the belly and shoulder butt cuts (p>0.05). Thus, it may be concluded that the current pork carcass grading standards do not reflect the real quality and value of the belly and shoulder butt cuts.

• Korean journal of food and cookery science
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• v.10 no.4
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• pp.381-385
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• 1994

The dietary fiber contents of soybean sprout and spinach were changed by heat treatment. Before heat treatment, soybean sprout and spinach had larger amount of insoluble dietary fiber than soluble, and similar proportions of insoluble v/s soluble dietary fibers. After heat treatment, the value of insoluble dietary fiber of soybean sprout and spinach was increased significantly, except for microwave heating short time treatment. It is believed that the increment of insoluble dietary fiber is due to Maillard reaction products and resistant starch after heat treatment. The change of soluble dietary fiber contents of soybean sprout and spinach were not consistent in heat treatment. It is supposed that some soluble dietary fiber was destroyed by heat treatment, and some insoluble dietary fiber was hydrolysed or destroyed to be soluble. Total dietary fiber of soybean sprout and spinach was significantly incereased by all heat treatment, except for microwave heating short time of spinach.

• Journal of Ginseng Research
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• v.24 no.1
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• pp.35-40
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• 2000

The purpose of this study was to investigate the antioxidant activities of water soluble browning reaction products (WS-BRPs) isolated 5\ulcorneron korea red ginseng. Antioxidant activities of WS-BRPs were examined with the various systems. All three WS-BRPs (L, S-1 and S-2) were found to have an ability to linoleic acid, Ox-brain autoxidant, Fe$^{2+}$ ADP/NAD system and cumene hydroperoxide system. Especially, S-2 was had the strongest activity of theses three WS-BRPs to scavenge free radicals such as more effective than S-1, L. MDA determination showed the antioxidant effect on linoleic acid oxidation inhibition ratio of 22.5%, 31.7%, 31.9% and 33.5%, respectivity Especially; Ox-brain autoxidant was strong inhibited activity by 49.52%,62,44,97.54% by addition of various concentration. But three WS-BRPs showed weak inhibitory activity on lipid peroxidation in rat hepatic microsomes induced enzymatically and nonenzymaticallyly

• Food Science of Animal Resources
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• v.21 no.1
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• pp.56-63
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• 2001

In this study, three domestic and one foreign formulas for the infants up to 5 month old were examined to detect chemical changes such as pH, reactive sulfhydryl groups(RSH) content, 5-hydroxymethylfurfral(HMF) content, available lysine content, electrophoresis, and surface color caused by heat treatment for long term storage. In the SDS-polyacrylamide gel electrophoresis, A and B products showed similar pattern, while C product had a clearly distinguishable $\beta$-lacto-globulin band, but in casein, only D product showed a few strong casein band. RSH content, which indicate the extent of whey protein denaturation, ranged from 4.40 to 5.93 mmole/g protein. HMF content. which indicate the extent of Maillard reaction, ranged from 192 to 432 $\mu$mole/100g in formulas. B product showed the highest RSH and HMF content. Available lysine content ranged from 31 to 46 mg/g protein. Among them D product contain the highest available lysine content and others showed no significant difference. In conclusion, the domestic infant formulas showed higher RSH and HMF content than the foreign product and the available lysine content of the domestic products were lower than of the foreign product.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.1
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• pp.121-126
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• 2009

Korean ginseng (Panax ginseng C. A. Meyer) has been used as an important medicinal plant in the Orient for a long time. It has been claimed that ginseng has many beneficial bioactive effects on human health, such as antitumor, antistress, antiaging and enhancing immune functions. Red ginseng possibly have new ingredients converted during steaming and dry process from fresh ginseng. In this study, pharmacological efficacy and ingredient conversion of ginseng by 9 repetitive steaming and drying process were investigated measuring conversion efficiency of acidic-polysaccharide, phenolic compounds and inhibition of peroxide lipides. It was found that acidic-polysaccarides were increased by heat treatment. In addition, maltol of phenolic compounds, strong antioxidant, produced during the process of red ginseng by Maillard reaction. Acidic-polysaccarides and maltol were increased after the 1st and 3rd steaming and drying treatments, but they were decreased gradually after 5th, 7th, and 9th treatments. Antioxidant activity was increased as increasing treatment times of steaming and drying without significance. Effect of red ginseng extract on inhibition of peroxide was increased gradually until after the 7th treatment, but remarkably decreased after the 9th treatment.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.480-486
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• 1998

It was investigated that the reduction of the intense brown color and increase of solubility, and depolymerization of polymerized melanoidins by ozonolysis affect their antioxidative and antimutagenic activities. Melanoidins was depolymerized and decolorized by ozonolysis. Ozone-treated melanoidins revealed a lower antioxidative activity and a higher antimutagenic activity than those of the untreated control. Fractions of ozone-treated melanoidins showed three peaks resemble to that of the melanoidins on Sephadex column chromatogram. Melanoidins of above MW 1,200 showed intense brown color. However, the strongest electron-donating ability was detected in the melanoidins of between MW 750 to 900. Ozone-treated and ozone-untreated melanoidins of between MW 900 to 1,000 revealed the higher antioxidative and antimutagenic activities.

• Korean Journal of Food Science and Technology
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• v.47 no.1
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• pp.95-102
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• 2015

The Maillard reaction is a non-enzymatic reaction between amino and carbonyl groups. During milk processing, lactose reacts with milk protein through this reaction. Infant formulas (IFs) are milk-based products processed with heat-treatments, including spray-drying and sterilization. Because IFs contain higher Maillard reaction products (MRPs) than breast milk, formula-fed infants are subject to higher MRP exposure than breast milk-fed ones. In this study, we investigated the optimization of conditions for minimal MRP formation with the addition of $\small{L}$-carnitine ($\small{L}$-car), pyridoxine hydrochloride (PH), and $\small{DL}$-${\alpha}$-tocopheryl acetate (${\alpha}$-T) in an IF model system. MRP formation was monitored by response surface methodology using fluorescence intensity (FI) and 5-hydroxymethylfurfural (HMF) content. The optimal condition for minimizing the formation of MRPs was with $2.3{\mu}M$ $\small{L}$-car, $15.8{\mu}M$ PH, and $20.6{\mu}M$ ${\alpha}$-T. Under this condition, the predicted values were 77.4% FI and 248.7 ppb HMF.

• Applied Biological Chemistry
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• v.28 no.4
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• pp.261-270
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• 1985

This study was carried out he effects of water activity on the nonenzymatic browning reactions of dry milk powders. Samples (Dry Whole Milk DWM, Nonfat Dry Milk NFDM) stored at $55^{\circ}C$ were analyzed for $O_2,\;CO_2$ and $H_2O$ by Gas chromatographic method. The brown color which developed from the Maillard reaction was also measured by a reflective spectrophotometer. And linear regression equations and the correlation coeffcients were determined for $O_2,\;CO_2$ and brown color vs. storage, and the results are as follows. The amount of brown and off-flavor development increase as the water activities increase about 0.44 Aw during storage. Both DWM and NFDM milk products show a plateau in water absorption between the 0.33 and 0.44 water activities. DWM produced more browning than NFDM which may be partially due to the carbonyl amine reaction. The $CaCl_2$ solution may exude a water activity lower than 0.44 and varies greatly with temperatures. Oxygen is depleted as brown color development.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.644-651
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• 2012

We have investigated the effect of lard fraction extracted with supercritical carbon dioxide (SC-$CO_2$) on the flavor enhancement of maillard reaction product (MRP) based meat flavors. MRP based meat flavors were prepared with low glutamic acid (Glu) hydrolyzed wheat gluten (NaCl concentration: 7.61%(w/v)), ribose, cysteine, garlic juice powder, protease-digested Lentinus edodes powder and lard fractions extracted with SC-$CO_2$. Lard was extracted with SC-$CO_2$ at each of three temperatures (40, 60, and $80^{\circ}C$) and at each of four pressures (30, 40, 50, and 60 MPa). Obtained lard SC-$CO_2$ fractions and MRP based meat flavors with those fractions were analyzed for their total yield, aroma pattern by SMart nose system, and sensorial properties. The extraction yield had no difference as temperature increased from $40^{\circ}C$ to $60^{\circ}C$ and even decreased at $80^{\circ}C$. However, increase in pressure level at $40^{\circ}C$ drastically increased the extraction yield. The aroma patterns of raw lard and lard SC-$CO_2$ fractions with 30 MPa were significantly discriminated from those of SC-$CO_2$ lard fractions extracted with higher pressure by SMart nose system. Aroma pattern of MRP based meat flavors with higher pressure extracted lard fractions also showed significant difference through pattern analysis by the SMart nose system. The MRP based meat flavor with lard SC-$CO_2$ fractions at 50 and 60 MPa were described as less sulfuric, less pungent, and more balanced in roasted meat and sweet attributes from sensory evaluation.