Tryptophan Depletion and Formation of α-Aminoadipic and γ-Glutamic Semialdehydes in Porcine Burger Patties with Added Phenolic-Rich Fruit Extracts

Abstract

The effect of added fruit extracts on the oxidation of muscle proteins in porcine burger patties subjected to cooking and chill storage was studied. Extracts from arbutus berries (Arbutus unedo L., AU), common hawthorns (Crataegus monogyna L., CM), dog roses (Rosa canina L., RC), and elm-leaf blackberries (Rubus ulmifolius Schott, RU) were prepared, characterized, added to burger patties (3% of total weight), and evaluated as inhibitors of protein oxidation. Negative (no added extract, C) and positive control (added quercetin, 230 mg/kg, Q) groups were also included in the design. Protein oxidation was assessed by means of tryptophan loss using fluorescence spectroscopy (FS) and formation of the specific protein carbonyls alpha-aminoadipic (AAS) and gamma-glutamic semialdehyde (GGS) using liquid chromatography and mass spectroscopy (LC-MS). Both advanced methodologies (FS and LC-MS) were found to be reliable and specific protein oxidation measurements that allow us to gain chemical insight into protein oxidation. The mechanisms likely involved in the oxidative reactions affecting proteins during cooking and storage of burger patties are profusely discussed. Phenolic-rich fruit extracts protected tryptophan residues against oxidation and inhibited the formation of both semialdehydes in burger patties during cooking and subsequent chill storage. In general, RC, RU, and AU were the most effective inhibitors of protein oxidation, with this effect being more intense than that of pure polyphenols like quercetin. These fruit extracts could be considered functional ingredients as their antioxidant actions contribute to the enhancement of the nutritional value of the meat products.

Dog rose (Rosa canina L.) as a functional ingredient in porcine frankfurters without added sodium ascorbate and sodium nitrite

“…Apparently, in this study lysine was more easily oxidized compared to proline and arginine, which was also found by Utrera et al (2011). Nevertheless, opposite results were published by Ganhão, Morcuende, and Estévez (2010b) and Armenteros, Heinonen, Ollilainen, Toldrá, and Estévez (2009) in which higher amounts of GGS and lower amounts of AAS were found in different meat products. The formation of both specific protein carbonyls from meat proteins involves the irreversible loss of essential amino acids and hence, the nutritional value of meat products (Estévez, 2011).…”

Protein-Lipid Interactions in Different Meat Systems in the Presence of Natural Antioxidants – a Review

“…initiation, propagation and termination, prevention of initiation by binding the substrate (ROS-the so--called reactive oxygen species) or neutralization of compounds accelerating the oxidation process (UV-Vis radiation, Unauthenticated Download Date | 5/10/18 6:05 PM transition metal ions, lipoxygenase), free radical scavenging, decomposition of the reactive products of lipid oxidation (hydroperoxides and non-radical substances) or the formation of the protective layer on the surface of the interface in multiphase systems [Brewer, 2011]. Some plant extracts containing phenolic compounds were reported to inhibit both lipid oxidation and deterioration of nutritional quality of meat proteins Ganhão et al, 2010b]. Phenolic compounds were suggested to act against oxidation-induced damage of myofi brillar protein by two mechanisms: metal chelation (leading to inactivation of nonheme iron prooxidant effect) and radical scavenging (they could be scavengers of iron-and lipid-mediated reactive oxidant species) [Estévez et al, 2008].…”

“…Litchi fl owers may be an effective natural antioxidant to reduce lipid and protein oxidation for frozen cooked meat products [Ding et al, 2015]. Ganhão et al [2010b] reported that using extracts from dog roses, common hawthorns, elmleaf blackberries, and arbutus berries during processing and storage of burger patties resulted in the inhibition of muscle protein oxidation. The application of fruit extracts as antioxidant and functional ingredients may increase the nutritional quality of the meat products.…”

Effect of ethanolic fl ax (Linum usitatissimum L.) extracts on lipid oxidation and changes in nutritive value of frozen-stored meat products

“…Some ethanolic plant extracts contained phenolic compounds were also reported to inhibit both lipid oxidation and deterioration of nutritional quality of meat proteins [Hęś et al 2007, Ganhao et al 2010. Phenolic compounds were suggested to act against oxidationinduced damage of myofi brillar protein by two mechanisms: metal chelation (leading to inactivation of nonheme iron prooxidant effect) and radical scavenging (they could be scavengers of iron-and lipid-mediated reactive oxidant species) [Estevez et al 2008].…”