• 한국식품영양학회지
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• 제30권5호
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• pp.853-859
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• 2017

This study was conducted in an effort to investigate the effect of Maillard reaction products (MRPs) on enzymatic browning of burdock and their anti-oxidant activity. The MRPs were prepared by heating glucose and amino acids at $90^{\circ}C$, which served to produce a strong inhibitory effect on burdock polyphenol oxidase. As the reaction time of the solution containing glucose and amino acid increased at $90^{\circ}C$, the production of MRPs increased and intensity of the brown color deepened. When MRPs were prepared by heating at $90^{\circ}C$ for five hours, the absorbance of MRPs from glucose and lysine was 6.44, while those of glucose and glycine was 1.95. The MRPs synthesized from the glucose and lysine also reduced the pH of MRPs from 5.60 to 4.51, but those from glucose and glycine decreased slightly from 5.57 to 5.33. The Michealis-Menten constant value ($K_m$) of burdock PPO with pyrocatechol as a substrate was 16.0 mM, and MRPs were a non-competitive inhibitor against burdock PPO. The anti-oxidant activity of MRPs was measured by evaluating its radical scavenging activities of DPPH radicals, ABTS radicals and reducing power. The color intensity of MRPs produced by lysine and glucose were deeper than that produced by glucose and glycine. It was also found that MRPs produced from glucose and lysine exhibited stronger anti-oxidant properties than those produced by glucose and glycine.

• 한국식품영양과학회지
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• 제33권6호
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• pp.1013-1016
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• 2004

토란으로부터 polyphenol oxidase를 추출하여 Maillard reation products(MRPs)가 토란 PPO에 미치는 영향을 조사하였다. 토란 PPO에 대한 MRPs의 저해 효과는 사용한 기질이 (+)-catechin, catechol인 경우에 높게 나타났다. 그리고 MRPs의 토란 PPO 저해 효과는 당의 종류를 달리하여 생성한 MRPs 중에서 fructose와 glucose로 제조한 MRPs의 첨가시 가장 높았으며, glycine과 glucose의 농도가 높아질수록 저해 효과가 증가하였다. 반응 시간에 따른 MRPs의 저해 효과를 조사한 결과, 반응 시간이 길어질수록 MRPs의 변색 정도가 높아졌으며, 이에 따라서 토란 PPO에 대한 저해 효과도 증가하였다.

• 대한지역사회영양학회지
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• 제12권6호
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• pp.790-797
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• 2007

This study was conducted to evaluate the nutrient intakes and the physical activities of mentally retarded persons (MRPs) accommodated in welfare institutions. A total of 194 cases of MRPs (130 males and 64 females) were surveyed through interviews of the 35 caregivers of the institutions during the period from March 2 to 12, 2005. The mean age of the 2nd degree is the highest, and the duration of institution stay of the 2nd degree is the longest. There were no significant differences in height, weight, but there were still significant differences in BMI by the degree of handicap. The MRPs with the 1st degree handicap consumed less nutrients than the MRPs with 2nd or 3rd degree handicaps, except for vitamins C and E. The mean activity factor was $1.737{\pm}0.422$ meaning 'active'. Among the comparative groups, the activity factor of the 2nd handicap degree MRPs was the highest. Note that the percentage of protein is the lowest in the case of the 1st degree handicap. The intake of the folic acid, in particular, was less than the Estimated Average Requirement (EAR) in case of all the MRPs while that of vitamin C, riboflavin and calcium was less than the EAR in case of $65{\sim}80%$ of the MRPs. MRPs with higher activity factors showed higher intakes of most nutrients except vitamin C. MRPs with higher marks in the 'balanced dietary habit' field showed more nutrient intakes. More consumption of vegetables and fruits by the MRPs was recommended. Also, more efficient dietary guidance was recommended for the MRPs.

• 생명과학회지
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• 제22권11호
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• pp.1451-1455
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• 2012

다양한 아미노산과 당을 $90^{\circ}C$에서 반응시켜 생성한 마이얄반응 생성물(Maillard reaction product)은 쑥갓에서 추출한 폴리페놀산화효소(polyphenol Oxidase, PPO)를 강하게 저해하였다. 글리신(glycine)과 포도당을 함유한 반응물으로부터 MRP의 생성은 $90^{\circ}C$에서 반응시간에 따라 직선적으로 증가하였으나 글리신과 포도당의 양은 상대적으로 감소하였다. 반응액에서 MRP의 증가함에 따라 반응액은 쑥갓 PPO활성을 비례적으로 강하게 저해하였다. 실험에 사용한 아미노산과 당중에서 글루타민과 자일로스를 아미노산과 당으로 이용했을 경우에 생성된 MRP가 쑥갓 PPO의 활성에 강한 저해제로 작용하였다. 카테콜을 기질로 사용한 쑥갓 PPO의 마이클레스 상수(Michaelis Menten constant)는 22.0 mM이었으며, MRP는 쑥갓 PPO의 비경쟁적 저해제로 작용하였다.

• 한국식품영양과학회지
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• 제22권5호
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• pp.570-575
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• 1993

양조간장 분말을 Sephadex 겔 여과 크로마토그래피법으로 분획한 후, 가장 갈색도가 높은 melanoidin 관련 물질의 획분인 melanoidin related products(MRPs)을 모아 동결 건조시킨 다음, 이의 free redical scavenger 기능, 항산화 효력상승제의 기능과 금속 킬레이터로서의 기능, 리폭시게나아제 활성 저해능, 그리고 저장안전성 등에 대한 항산화 특성을 고찰한 결과 다음과 같다. MRPs는 첨가농도(혹은 갈색도)의 증가에 따라 과산화물의 생성을 저해하였으며, 그 항산화력은 ${\alpha}-토코페롤$ 보다는 낮았다. 그리고 free redical scavenger로서의 능력을 가지고 있어 리놀레산 혼합물의 산호를 지연 시켰으며, 염화제일철에 의하여 촉매된 산화반응에서 synergistic antioxidative effect를 나타내었다. 또한 양조간장 MRPs는 리폭시게나아제 활성을 저해하여 conjugated dienoic acid 생성량을 감소시켰다. 한편, 이 MRPs는 저장 안전성이 상당히 있어, $50^{\circ}C$에서 15일간 저장되어 있어도 항산화 효과의 상실이 거의 없음이 관찰되었다.

• 한국식품과학회지
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• 제29권2호
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• pp.309-313
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• 1997

Maillard 반응 중 생성된 Maillard 반응생성물(MRPs)에 대한 세균의 생육 패턴을 조사하고자 반응표면분석을 적용하였으며, 세균의 생육배지에 MRPs를 첨가시 균의 생육에 대한 반응표면회귀식의 $R^{2}$는 Bacillus subtilis 및 Bacillus natto 균에서 각각 0.9544 및 0.9598였다(p<0.01). Bacillus subtilis의 생육에 관한 MRPs의 영향에서 Maillard 반응온도가 높고 반응시간이 긴 MRPs 첨가군은 생육이 감소하다가 반응시간이 $8{\sim}12\;hrs$ 범위 및 반응온도가 $150^{\circ}C$ 이상의 생성조건에서 크게 감소하였다. Bacillus natto균에 대한 생육에서는 Maillard 반응시간의 영향을 거의 받지 않았고, $150^{\circ}C$보다 낮은 반응온도에서는 온도가 낮고 용매 pH가 낮아질수록 생성된 MRPs에 대한 균의 생육이 증가하였으나 $150^{\circ}C$ 이상에서는 pH의 영향을 받지 않고 온도가 증가할수록 생성된 MRPs에 대한 균의 생육이 감소하였다. 능선분석에서 Bacillus subtills 균에 대한 생육은 $159.10^{\circ}C$, 9.69시간 및 용매 pH 12.21에서 생성된 MRPS가 가장 생육억제 효과가 컸으며, Bacillus natto균의 생육은 $169.94^{\circ}C$, 9.22시간 및 용매 pH 9.66에서 생성된 MRPs에 의해 가장 크게 억제되었다.

• 한국임상약학회지
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• 제32권1호
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• pp.27-36
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• 2022

Background: Medication-related problems (MRPs) frequently occur during the discharge period. Elderly patients, particularly, are at high risk for these problems due to polypharmacy and the use of potentially inappropriate medications. The purpose of this study was to build and implement collaboration between general hospital and community pharmacies to address MRPs among high-risk elderly patients before/after discharge. Methods: This retrospective study was conducted between June and December of 2020. The inclusion criteria were patients with aged ≥65 years; residents of Jeonju; discharged from Jeonbuk National University hospital; either on medication of exceeding 10 medications (or high-risk medications) after hospitalization through the emergency room, or having severe illness. Patients received medication reconciliation and counselling by hospital pharmacists before discharge and home-visit pharmaceutical care as follow-up by community pharmacists after discharge. Results: Twenty-two patients agreed to home-visit pharmaceutical services. Fifteen and 11 patients completed the first and second home-visit pharmaceutical care service, respectively. Forty-two MRPs were identified in 15 patients. The types of high-frequency MRPs were incorrect administration of drug, adverse drug reactions, medication non-compliance, drug-drug interactions, lifestyle modifications, and expired medication disposal. After consultation with the pharmacist, 34 out of 42 MRPs were resolved. Conclusions: Transitional care for high-risk elderly patients before and after discharge was successfully built and implemented through a collaboration between general hospital and community pharmacies. This study suggests that home-visit pharmaceutical services may have positive effects on the safe use of drugs during the transition period; however, additional research is needed to expand on these findings.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.297-303
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• 2010

The present study compared the Maillard reaction products (MRPs) derived from aqueous and ethanolic fructoseglycine and its oligomer (dimer and trimer) solutions. The pH was lower in glycine (G) than in diglycine (DG) and triglycine (TG) in both aqueous and ethanolic solutions, but the pH difference between the DG and TG was not significant. MRPs derived from the DG had a greater absorbance at 294 and 420 nm in ethanolic solution than in an aqueous solution. In particular, the loss of sugar was higher in ethanolic solution than in aqueous solution. Enolization of fructose was observed in both aqueous and ethanolic MRP solutions; however, enolization was not observed for the G in aqueous MRP solutions. The glycine oligomer content in ethanolic MRP solutions remained higher than that in aqueous MRP solutions. Furthermore, neither diglycine nor triglycine were detected in the G aqueous or ethanolic MRP solutions, while triglycine was detected in both the DG aqueous and ethanolic MRP solutions. Absorption in the ultraviolet-visible (UV-Vis) spectra was higher with MRPs derived from the ethanolic solution than with those derived from the aqueous solution. MRPs derived from the DG in an ethanolic solution showed the highest absorption intensity.

• Preventive Nutrition and Food Science
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• 제15권4호
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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.

• Journal of Ginseng Research
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• 제36권3호
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• pp.256-262
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• 2012

Reactive oxygen species play critical role in kidney damage. Free radical-scavenging activities of Panax ginseng are known to be increased by heat-processing. The structural change of ginsenoside and the generation of Maillard reaction products (MRPs) are closely related to the increased free radical-scavenging activities. In the present study, we have demonstrated the Maillard reaction model experiment using ginsenoside Re and glycine mixture to identify the renoprotective effect of MRPs from ginseng or ginsenosides. Ginsenoside Re was transformed into less-polar ginsenosides, namely Rg2, Rg6 and F4 by heat-processing. The free radical-scavenging activity of ginsenoside Re-glycine mixture was increased in a temperature-dependant manner by heatprocessing. The improved free radical-scavenging activity by heat-processing was mediated by the generation of antioxidant MRPs which led to the protection of LLC-PK1 renal epithelial cells from oxidative stress. Although the free radical scavenging activities of less-polar ginsenosides were weak, they could protect LLC-PK1 cells from oxidative stress. Therefore, MRPs and less-polar ginsenosides contributed to the combined renoprotective effects against oxidative renal damage.