The effect of some amino acids on the oxidation of linoleic acid and its methyl ester

Abstract

Manometric studies of the effect of certain amino acids on oxidation (measured as oxygen consumption) of linoleic acid, as well as the methyl esters of linoleic acid and linolenic acid dispersed in water or phosphate buffers at pH 7 to pH 5 have shown that The amino acids tested (except cysteine) have a potential antioxidative effect. The antioxidative capacity of different amino acids may be rather different (it is especially pronounced in the case of histidine and tryptophane). Under suitable conditions extremely low amino acid concentrations may have rather strong effect. The antioxidative efficiency is less pronounced than in earlier experiments with linoleate at pH>7, and decreases with decreasing pH. There may be a tendency towards a prooxidative inversion with relatively high amino acid concentrations, or at low pH. The antioxidative effect is enhanced and a prooxidative effect may be lowered or inverted into an antioxidative one by an addition of phosphate, or an emulsifier like Tween. A strong inhibitory effect is obtained by combined addition of phosphate and emulsifier like Tween, together with the amino acid. The antioxidative tendency was stronger in the case of methyl linoleate than with linoleic acid, and was also stronger with methyl linoleate than with methyl linolenate.

Gum Arabic: More Than an Edible Emulsifier

“…There is increasing experimental evidence that associate the antioxidant function with its protein fraction, mainly by amino acid residues such as histidine, tyrosine and lysine, which are generally considered as antioxidants molecules (Marcuse, 1960(Marcuse, , 1962Park et al, 2005).…”

Bioactive Properties of Japanese Fermented Fish Paste, Fish Miso, Using Koji Inoculated With Aspergillusoryzae

“…Fermentation with A. oryzaecould improve the reducing power of minced horse mackerel paste via koji fermentation. Some amino acids such as lysine, glycine, valine, and histidine, which are present in fish miso peptides, have been reported to exhibit antioxidant activities [43,44,45]. Notably, histidine exhibits a strong radical-scavenging activity due to the decomposition of its imidazole ring.…”

Kalapuolisäilykkeiden säilyvyys

“…Niinpä alaniinin ja histidiinin vaikutukset olivat vähäiset pH 7.s;ssä, mutta pH 9.s;ssä jo varsin Taulukko 1. Aminohappojen silliöljyn hapettumista hidastava vaikutus (Marcuse 1960 huomattavat. Aminohapon pitoisuuden kasvaessa antioksidatiivinen teho aluksi lisääntyi, mutta väheni sivuutettuaan maksimimikohdan, joka eri aminohapoilla oli hiukan erilainen.…”

“…Aminohapon pitoisuuden kasvaessa antioksidatiivinen teho aluksi lisääntyi, mutta väheni sivuutettuaan maksimimikohdan, joka eri aminohapoilla oli hiukan erilainen. Histidiinin ja alaniinin vaikutukset jopa muuttuivat antioksidatiivisista pro-oksidatiivisiksi (Marcuse 1962). Vastaava muutos tapahtuu myös useilla varsinaisilla primäärisillä antioksidanteilla, esimerkiksi tokoferoleilla.…”

“…Varsinkin pH 7.s:ssä oli ero huomattava. Sen sijaan pH 9.s:ssä tokoferolilisäys vain hiukan tehosti aminohappojen voimakasta vaikutusta (Marcuse 1960).…”