Effects of polyphenols on the nitrite scavenging and N-nitrosamine formation in simulated gastric acid

In simulated gastric acid,effects of tea polyphenols(TP)and grape seed polyphenols(GP)on nitrite scavenging and nitrosamine formation were determined,and their antioxidant activities were assessed.The content of N-nitrosodiethylamine(NDEA)and nitrite were determined by high performance liquid chromatography(HPLC)and spectrophotometric method,respectively.The results showed that with plant polyphenols contents increasing and reaction times extending,the nitrite scavenging effect of TP and GP increased.The scavenging effect of TP was better than that of GP.With the increase of TP and GP contents,the relative content of NDEA increased gradually.When the contents of TP and GP were 0.5 and 1.0 mg·mL-1,the relative content of NDEA reached the maximum.Afterwards,the content of NDEA declined and finally the NDEA formation was inhibited completely.Antioxidant activity analysis showed that with the increase of polyphenols contents,the antioxidant capacity increased gradually.Also,TP exhibited the higher antioxidant activity than GP.These results confirmed that at least in our experimental conditions,TP and GP had high nitrite scavenging and antioxidant ability,and possessed a dual role of facilitation and inhibition on NDEA formation.