Abstract
Among the browning reaction of various foods, the Maillard reaction has been studied extensively and it is known that the reaction products show antioxidative activity. In the previous papers, the authors observed that the easy formation of metal-protein complex and iron-fatty acid complex, and those complex thus formed did not promote the rancidity of oil.
In this paper the relation between the binding ability of melanoidin (M) and metal and characteristics of M-metal complex was investigated. M prepared from a mixture of glycine and D-xylose by heating at 100°C for 5hr, was fractionated by Sephadex G 25 or thin-layer chromatography (TLC).
M and fractionation components with Sephadex G 25 and TLC were reacted at 50°C with some inorganic metals (copper sulfate, ferrous chloride, zinc nitrate and magnesium chloride). The precipitated complex was separated by centrifugation, and the amount of adduct formed with those materials, and metal content in those complex, and IR spectrum and TLC of those complex were measured.
The results obtained were as follows :
1) It was found that the easy formation of M-metal complex and the amount of M-metal complex increased with the reaction time of M with metal. And also the longer reaction time of glycine with xylose rendered greater the formation of M-metal complex. For M, the amount of adduct with iron was the most, and these with copper, zinc and magnesium came in the followed order.
2) As for gel-filtration on Sephadex G25, this fraction gave same pattern as the M and metal in M-metal complex.
3) TLC chromatographic method of M-metal complex gave one spot, and from the above results, it was concluded that the M-metal complex forms.
