Use of experimental design methodology to prepare Maillard reaction products from glucose and cysteine inhibitors of polyphenol oxidase from eggplant (Solanum melongena).
Polyphenol oxidase (PPO) from eggplant was extracted and partially purified by a two-step fractionation-precipitation using ammonium sulfate and phenylsepharose hydrophobic interaction chromatography. The eggplant PPO extract was characterized concerning its kinetic properties. Optimal conditions to obtain Maillard reaction products (MRPs) with a maximal inhibitory potency (IP) toward PPO activity were determined using the surface response methodology and a four-factor and five-level experimental design. The MRPs were prepared from cysteine (0.25 M) and glucose (0-1 M), at several initial pH values (2-6) and at differing heating times (3-19 h) and temperatures (95-115 degrees C). The maximal IP was obtained after heating a model system of glucose/cysteine (1/0.25 M) at pH 2 for 3 h 20 min at 115 degrees C. The soluble part of this MRP, called MRP(IPmax), was a noncompetitive inhibitor toward eggplant PPO. The IP of MRP(IPmax) on PPO activity was very potent as compared to that displayed by benzoic, p-coumaric, and t-cinnamic acids, as well as sorbic acid and 4-hexylresorcinol. The activity of preincubated PPO at 0 degrees C with MRP(IPmax) was only slightly restored after dialysis or gel filtration.
Cheriot
Sophie C
SC
Conservatoire National des Arts et Métiers, Chaire de Biochimie Industrielle et Agro-Alimentaire, UMR SCALE 1211, 292 Rue Saint Martin, Case 306-75141 Paris Cedex 03, France.
Billaud
Catherine
C
Nicolas
Jacques
J
D019817:Benzoic Acid / Q000494:pharmacology; D004156:Catechol Oxidase / Q000037:antagonists & inhibitors*; D002934:Cinnamates / Q000494:pharmacology; D003373:Coumaric Acids / Q000494:pharmacology; D003545:Cysteine / Q000737:chemistry*; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D005947:Glucose / Q000737:chemistry*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D015416:Maillard Reaction; D011422:Propionates; D032323:Solanum melongena / Q000201:enzymology*; D013011:Sorbic Acid / Q000494:pharmacology; D013997:Time Factors
D002934:Cinnamates; D003373:Coumaric Acids; D004791:Enzyme Inhibitors; D011422:Propionates; C029010:cinnamic acid; D019817:Benzoic Acid; D004156:Catechol Oxidase; C495469:p-coumaric acid; D005947:Glucose; D003545:Cysteine; D013011:Sorbic Acid