Abstract: In mimic gastric juice, the clearance rates of apple polyphenols, tea polypheonls and vitamin C on nitrite were compared to explore the effect of apple polyphenols on the clearance of nitrite. The results showed that apple polyphenols, tea polyphenols and vitamin C could scavenge nitrite to different extents. The clearance rate of nitrite by apple polyphenols exhibited a logarithmic increase with increasing concentration over the low concentration range. Despite tea polyphenols having a slightly higher scavenging effect at low concentration (0.01%－0.02%), the scavenging effect of apple polyphenols against nitrite was stronger when the concentration was greater than or equal to 0.03%. The maximum nitrite scavenging rates of apple polyphenols, tea polyphenols and vitamin C were (98.2± 1.3)%, (97 ± 0.2)% and (88.6 ± 1.0)%, respectively. The nitrite scavenging effect of mixed apple polyphenols and tea polyphenols, resulting in a scavenging rate of (92.6±0.3)% was better than that of either of them alone; similarly, apple polyphenols plus vitamin C also exhibited a higher scavenging rate, which was up to (65.7±0.3)%. The scavenging rate of apple polyphenols plus tea polyphenols plus vitamin C was (90.7± 0.3)%, which was slightly lower than that of mixed apple polyphenols and tea polyphenols but higher than that of apple polyphenols plus vitamin C. The scavenging effect of apple polyphenols reached its maximum level (98.7± 0.2)% after 2 h of incubation. Therefore, apple polyphenols as a natural extract has excellent clearance effect on nitrite in mimic gastric juice.

Key words: nitrite, apple polyphenols, tea polyphenols, vitamin C, clearance effect