- Email: [email protected]
Separation of Coloured Components of Kecap Manis (an Indonesian Soy Sauce) by HPLC and Capillary Electrophoresis
400
The Maillard Reaction in Foods and Medicine
Separation of Coloured Components of Kecap Manis (an Indonesian Soy Sauce) by HPLC and Capillary Electrophoresis Anton Apriyantono, Santi Marianti, Louise Royle’, Richard G Bailey* and Jennifer M Ames*; Bogor Agricultural Untversity, Lkpartment of Food Technology and Human Nutrition, Kampus IPB Darmaga, PO Bar 220. Bogor 16002, Indonesia, *The University of Reading, Deparfmenf of Food Science and Technology, Whiteknights,Reading RG6 6AP. UK Kecup munis is a typical Indonesian soy sauce and is prepared from black soyabeans, which are subjected to mould and brine fermentation to give moromi. The moromi, coconut sugar and spices are cooked for 1-2 h to give h a p manis. Coconut sugar represents 45-50 % of the total raw materials before cooking. Fractions of the coloured components of a commercial kecap manis were prepared by extracting with solvents possessing a range of polarity. Based on absorbance of the concentrated extracts diluted in a standard volume of methanol, the amount of coloured material extracted from the kecop manis ranged from 0.003% for light petroleum @.pt. 60-80°C) to 0.179?! for acetonitrile, suggesting that the majority of the coloured components of kcup manis are polar and, therefore, not extractable. The ethyl acetate and acetonitrile extracts, as well as the kecop manis were analysed by reversed-phase HPLC and by capillary electrophoresis (CE) with a borate buffer, both with diode array detection. Many of the main components of the solvent extracts could not be detected in the original kecap manis and are probably only minor contributors to the colour of the soy sauce. CE separated far more components of kecap manis than HPLC, but the resolved peaks were observed superimposed on a broad peak or ‘hump’. Ultrafiltration, using a membrane with a cut-off of 10oO daltons, gave a fraction which on analysis by CE showed no hump, indicating that the material responsible must possess relatively high molecular mass. The behaviour of kecap manis on HPLC and CE exhibited many similarities with those of an aqueous xylose-glycine model system heated under reflux for 2 h and analysed using exactly the same conditions.’ This suggests some similarities between the components of kecap manis and those of the model Maillard system. Royle, L.; Bailey, R.G.;Ames, J.M. (1998). Food Chem.. in press.
’
Determination of Dicarbonyl Compounds as Aminotriazines during the Maillard Reaction and in Vivo Detection in Aminoguanidine-Treated Rats Atsushi Araki, Marcus A Glomb, Motoko Takahashi and Vincent M Monnier; Imrifufe o/ Pathology, Case Western Reserve University,2085 Adelberr R d Clevelund8Ohio 44106. USA Aminoguanidine has been proposed as a drug for prophylaxis of diabetic complications in animal experiments. However, the exact mechanism by which aminoguanidine retards or prevents diabetic complications in experimental animals m a i n s unknown. The postulated action of aminoguanidine is to trap dicarbonyl compounds which arc formed during the Maillard reaction and which may have deleterious effects on cells or tissues. Dicarbonyl compounds may react with aminoguanidine to form 3-amino-1,2,4bkzhes. Therefore, we determined 3-amino-1.2,4-triazines (ATZs) formed in the presence of aminoguanidine at various steps along the Maillard reaction. ATZs were identified and measured using a GC-MS method after extraction and derivatization with a TMS reagent. 1. As a model of glucose autoxidation, glucose (100 mM) was incubated with 2 pM Cu” in 100 mM sodium phosphate buffer @H 7.4) at 37’C in the presence of 5 mM aminoguanidine for 8 days. During glucose autoxidation, glucosone-ATZ and glyoxal-ATZ were detected. 2. When glucose (100 mM) was incubated with BSA or lysine in PBS (pH 7.4) at 37°C in the presence of 7 mM aminoguanidme, 3-deoxyglucosone (3-DG>ATZ and methylglyoxal-ATZ were major ATZs. GlyoxalATZ and glucosone-ATZ were also detected. 3. When glycated BSA was incubated with 7 mM aminoguanidine, I-DG-ATZ was a major ATZ and 3-DGATZ. glucosone-ATZ, methylglyoxal-ATZand glyoxal-ATZ were also detected. 4. In plasma from diabetic rats treated with aminoguanidine (1 g/l drinking water) for several days, 3-DGATZ and methylglyoxal-An were about ten times higher than in plasma from non-diabetic rats. Both in vitro and in vivo, 3-DG-ATZ and mcthylglyoxal-ATZ were major products formed by the reaction of dicarbonyl compounds with aminoguanidine. The formation of the ATZs in vivo may well contribute to the preventive action of aminoguanidine in diabetic complications.
The Maillard Reaction in Foods and Medicine
Separation of Coloured Components of Kecap Manis (an Indonesian Soy Sauce) by HPLC and Capillary Electrophoresis Anton Apriyantono, Santi Marianti, Louise Royle’, Richard G Bailey* and Jennifer M Ames*; Bogor Agricultural Untversity, Lkpartment of Food Technology and Human Nutrition, Kampus IPB Darmaga, PO Bar 220. Bogor 16002, Indonesia, *The University of Reading, Deparfmenf of Food Science and Technology, Whiteknights,Reading RG6 6AP. UK Kecup munis is a typical Indonesian soy sauce and is prepared from black soyabeans, which are subjected to mould and brine fermentation to give moromi. The moromi, coconut sugar and spices are cooked for 1-2 h to give h a p manis. Coconut sugar represents 45-50 % of the total raw materials before cooking. Fractions of the coloured components of a commercial kecap manis were prepared by extracting with solvents possessing a range of polarity. Based on absorbance of the concentrated extracts diluted in a standard volume of methanol, the amount of coloured material extracted from the kecop manis ranged from 0.003% for light petroleum @.pt. 60-80°C) to 0.179?! for acetonitrile, suggesting that the majority of the coloured components of kcup manis are polar and, therefore, not extractable. The ethyl acetate and acetonitrile extracts, as well as the kecop manis were analysed by reversed-phase HPLC and by capillary electrophoresis (CE) with a borate buffer, both with diode array detection. Many of the main components of the solvent extracts could not be detected in the original kecap manis and are probably only minor contributors to the colour of the soy sauce. CE separated far more components of kecap manis than HPLC, but the resolved peaks were observed superimposed on a broad peak or ‘hump’. Ultrafiltration, using a membrane with a cut-off of 10oO daltons, gave a fraction which on analysis by CE showed no hump, indicating that the material responsible must possess relatively high molecular mass. The behaviour of kecap manis on HPLC and CE exhibited many similarities with those of an aqueous xylose-glycine model system heated under reflux for 2 h and analysed using exactly the same conditions.’ This suggests some similarities between the components of kecap manis and those of the model Maillard system. Royle, L.; Bailey, R.G.;Ames, J.M. (1998). Food Chem.. in press.
’
Determination of Dicarbonyl Compounds as Aminotriazines during the Maillard Reaction and in Vivo Detection in Aminoguanidine-Treated Rats Atsushi Araki, Marcus A Glomb, Motoko Takahashi and Vincent M Monnier; Imrifufe o/ Pathology, Case Western Reserve University,2085 Adelberr R d Clevelund8Ohio 44106. USA Aminoguanidine has been proposed as a drug for prophylaxis of diabetic complications in animal experiments. However, the exact mechanism by which aminoguanidine retards or prevents diabetic complications in experimental animals m a i n s unknown. The postulated action of aminoguanidine is to trap dicarbonyl compounds which arc formed during the Maillard reaction and which may have deleterious effects on cells or tissues. Dicarbonyl compounds may react with aminoguanidine to form 3-amino-1,2,4bkzhes. Therefore, we determined 3-amino-1.2,4-triazines (ATZs) formed in the presence of aminoguanidine at various steps along the Maillard reaction. ATZs were identified and measured using a GC-MS method after extraction and derivatization with a TMS reagent. 1. As a model of glucose autoxidation, glucose (100 mM) was incubated with 2 pM Cu” in 100 mM sodium phosphate buffer @H 7.4) at 37’C in the presence of 5 mM aminoguanidine for 8 days. During glucose autoxidation, glucosone-ATZ and glyoxal-ATZ were detected. 2. When glucose (100 mM) was incubated with BSA or lysine in PBS (pH 7.4) at 37°C in the presence of 7 mM aminoguanidme, 3-deoxyglucosone (3-DG>ATZ and methylglyoxal-ATZ were major ATZs. GlyoxalATZ and glucosone-ATZ were also detected. 3. When glycated BSA was incubated with 7 mM aminoguanidine, I-DG-ATZ was a major ATZ and 3-DGATZ. glucosone-ATZ, methylglyoxal-ATZand glyoxal-ATZ were also detected. 4. In plasma from diabetic rats treated with aminoguanidine (1 g/l drinking water) for several days, 3-DGATZ and methylglyoxal-An were about ten times higher than in plasma from non-diabetic rats. Both in vitro and in vivo, 3-DG-ATZ and mcthylglyoxal-ATZ were major products formed by the reaction of dicarbonyl compounds with aminoguanidine. The formation of the ATZs in vivo may well contribute to the preventive action of aminoguanidine in diabetic complications.