Synergistic effect of BSA on antioxidant activities in model food emulsions

Abstract

Sunflower oil-in-water emulsions containing TBHQ, caffeic acid, epigallocatechin gallate (EGCG), or 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox), both with and without BSA, were stored at 50 and 30°C. Oxidation of the oil was monitored by determination of the PV, conjugated diene content, and hexanal formation. Emulsions containing EGCG, caffeic acid, and, to a lesser extent, Trolox were much more stable during storage in the presence of BSA than in its absence even though BSA itself did not provide an antioxidant effect. BSA did not have a synergistic effect on the antioxidant activity of TBHQ. The BSA structure changed, with a considerable loss of fluorescent tryptophan groups during storage of solutions containing BSA and antioxidants, and a BSA-antioxidant adduct with radical-scavenging activity was formed. The highest radicalscavenging activity observed was for the isolated protein from a sample containing EGCG and BSA incubated at 30°C for 10 d. This fraction contained unchanged BSA as well as BSA-antioxidant adduct, but 95.7% of the initial fluorescence had been lost, showing that most of the BSA had been altered. It can be concluded that BSA exerts its synergistic effect with antioxidants because of formation of a protein-antioxidant adduct during storage, which is concentrated at the oil-water interface owing to the surface-active nature of the protein. SCHEME 1a Values with the same superscript letter in each row are not significantly different (P > 0.05). ABTS, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt; for other abbreviations see Table 1.

Antioxidative activity and emulsifying properties of cuttlefish skin gelatin modified by oxidised phenolic compounds

“…Therefore, gelatin modified with oxidised tannic acid had the ability to retard TBARS formation in the oil-in-water emulsion system. This result was in agreement with Almajano and Gordon (2004) who reported that interaction of BSA and epigallocatechin gallate (EGCG) could induce the formation of a BSA-antioxidant adduct and cause a synergistic increase in the oxidative stability of sunflower oil-in-water emulsion effectively, when compared with BSA or EGCG alone.…”

Effect of Processing and Storage Parameters on the Oxidative Deterioration of Oil-in-Water Emulsions

“…Certain proteins at pH values below their pI can form positively charged emulsion droplets that are less susceptible to metal-promoted oxidation. 3 Although, it is well known that oxidation is accelerated as temperature increases, 4 there are limited published data on temperature dependence of oxidation rate in oil-in-water emulsions, which concern mostly subzero or low temperatures. 5,6 A body of recent research 7,8 has focused on homogenized, protein-stabilized oil-in-water emulsions, by elucidating their susceptibility at temperature-related microstructural irregularities.…”

Effect of Compositional Factors against the Thermal Oxidative Deterioration of Novel Food Emulsions

“…11 A synergistic effect of bovine serum albumin with phenolic antioxidants was recently proposed as the main mechanism of inhibition against the oxidative deterioration of food emulsions. 12 However, a better knowledge of the factors that determine the development of lipid oxidation in emulsions where proteins constitute the stabilizing interface can lead to their optimized use as food ingredients. 13 This research work initially focuses on the effect of several compositional parameters (such as type and content of protein and lipid phase) against the lipid autoxidation of simple model oil-in-water emulsions.…”