Arginine-xylose

Conditions for the Synthesis of Antioxidative Arginine-Xylose Maillard Reaction Products... 

Figure 1. Average change in pH with time of the unbuffered arginine—xylose...

Figure 2. Average change in percent maximum antioxidative activity with time of the nonbuffered arginine-xylose reaction mixture. Key O, spectrophotometric assay A, oxygen electrode assay.

Figure 3. Average change in pH with time of the nonbuffered, Tris 7.0, and Tris 8.0 arginine-xylose reaction mixtures. Key O, nonbuffered , Tris 7.0 A,...

Figure 5. Change in pH with time of six nonbuffered arginine-xylose systems possessing different initial pH values.

Figure 8. A comparison of the effects of different organic compounds on the production of antioxidative activity in the arginine-xylose reaction.

Figure 9. A comparison of the change with time in antioxidative activity produced by arginine-xylose in a water system and a pyridine-water system. Key O, water system pyridine—water system.

Effect of Pressure and of Gas Used Solutions containing 30 ml of nonbuffered arginine-xylose were allowed to react in a 50-ml Parr vessel for 10 h at 100°C either at one or five bars of pressure of air, N2, or 02. Prior to starting the reaction, air, nitrogen, or oxygen was bubbled through the solution for one min. 

G. R. Waller, R. W. Beckel, and B. O. Adeleye, Conditions for the synthesis of antioxidative arginine-xylose Maillard reaction products, in B, 1983, 125-140. 

Beckel, R.W. and Waller, G.R. 1983. Antioxidative arginine-xylose Maillard reaction products conditions of synthesis. J. Food Sci. 48, 996—997. 

Sugar D-glucose, D-arabinose, D-xylose or glycolaldehyde. serine, methionine, leucine, isoleucine, tyrosine, arginine. 

An antioxidative Maillard reaction product (AX) can be formed from arginine and xylose. Optimum results were obtained by refluxing 1M arginine-HCl with 1M xylose in water at 100°C for 10-20 h at initial pH of approximately 5. 

Effect of Molar Ratio of Reactants Several mixtures containing different molar ratios of arginine to xylose were refluxed in 25 ml of nonbuffered water for 20 h. The total concentration in all cases was 3.0 M. Figure 7 is a plot of the final activity versus the molar ratio of arginine to xylose, and clearly indicates that the 1 1 ratio was the superior combination. In addition, the bell-shaped... 

Figure 7. Antioxidative activity versus molar ratio of arginine to xylose. 100 jxL of 1 100 dilution of crude.

Relative Antioxidative Activities produced from 2 1 Ratio of Arginine and Xylose under 1 and 5 Bars of Air, Oxygen, and Nitrogen... 

Foster, R. C. "Preliminary isolation and characterization of an antioxidative component of the Maillard reaction between arginine and xylose" M. S. Thesis, Oklahoma State University, Stillwater, Oklahoma, 1980 72 pp. 

Waller el al.47S fixed the total concentration of xylose plus arginine at 3.0 M, but varied the ratio from 0.25 2.75 to 2.75 0.25 (reflux, 20 h). Assessed at a dilution of 1 100, the equimolar mixture clearly gave rise to the highest antioxidative activity, which decreased symmetrically, as the ratio was changed in either directions. Even changing the ratio to 1 2 more than halved the activity. The high concentration for preparing the MRP needs to be noted. 

All the organic additives investigated by Waller et al.47S with the xylose-arginine system had detrimental effects on antioxidative activity, except for pyridine, which doubled it. 

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