The dual function of nitrite under stomach conditions is modulated by reducing compounds.
Salivary nitrite plays a role in the lipid peroxidation process of muscle tissue in simulated gastric fluid. The objectives of our study were to elucidate the fate of nitrite in the presence of reducing compounds and to evaluate its effect on lipid peroxidation during digestion. Nitrite at pH 3 (possibly NO(2.), not NO.) can oxidize beta-carotene, but the addition of reducing compounds, ascorbic acid or polyphenols, alters its effect. Ascorbic acid alone promoted the formation of NO. from nitrite only up to pH 3, but the addition of iron ions facilitated the formation of NO. up to pH 5.5. NO prevented membranal lipid peroxidation under stomach conditions. Nitrite, only in the presence of reducing compounds, achieved the same goal but at much higher concentrations. Addition of polyphenols to nitrite synergistically improved its antioxidant effect. Therefore, to promote NO. production and to achieve better control of the lipid peroxidation process in the stomach, a nitrite-rich meal should be consumed simultaneously with food rich in polyphenols.
Department of Food Science, ARO, The Volcani Center, Bet Dagan 50250, Israel.
J
J
Volk
S
S
Gorelik
R
R
Granit
R
R
Kohen
J
J
Kanner
D000818:Animals; D004305:Dose-Response Relationship, Drug; D005419:Flavonoids / Q000494:pharmacology; D005750:Gastric Juice / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015227:Lipid Peroxidation / Q000187:drug effects; D008315:Malondialdehyde / Q000378:metabolism; D008460:Meat; D008954:Models, Biological; D009573:Nitrites / Q000378:metabolism* / Q000494:pharmacology*; D010636:Phenols / Q000494:pharmacology; D059808:Polyphenols; D019163:Reducing Agents / Q000494:pharmacology*; D012463:Saliva / Q000378:metabolism; D013270:Stomach / Q000187:drug effects / Q000502:physiology; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014422:Turkeys; D014920:Wine; D019207:beta Carotene / Q000378:metabolism
D005419:Flavonoids; D009573:Nitrites; D010636:Phenols; D059808:Polyphenols; D019163:Reducing Agents; D017392:Thiobarbituric Acid Reactive Substances; D019207:beta Carotene; D008315:Malondialdehyde