Hemoglobin-mediated lipid oxidation of herring filleting co-products during ensilaging and its inhibition by pre-incubation in antioxidant solutions

Abstract

The aims of this study were to investigate the role of hemoglobin (Hb) in lipid oxidation development during ensilaging of herring filleting co-products, and, to inhibit this reaction by pre-incubating the co-products in water or physiological salt, with/without different antioxidants. Results showed that both peroxide value (PV) and 2-thiobarbituric acid reactive substances (TBARS) gradually increased during 7 days of ensilaging at 22 °C in absence of antioxidants. The increase in TBARS was proportional to the Hb levels present, while PV was less affected. A Hb-fortified Tris-buffer model system adjusted to pH 3.50 confirmed that Hb changed immediately from its native oxyHb to the metHb state, which facilitated heme group release and thus probably explains the increased PV and TBARS during ensilaging. Pre-incubating the co-products for 30 s in a solution containing 0.5% rosemary extract was the most promising strategy to inhibit lipid oxidation both in the co-products during pre-processing storage and during the actual ensilaging. The solution could be re-used up to ten times without losing its activity, illustrating that this methodology can be a scalable and cost-effective strategy to extend the oxidative stability of herring co-products allowing for further value adding e.g., into a high-quality silage.

Effect of antioxidants on lipid oxidation in herring (Clupea harengus) co-product silage during its production, heat-treatment and storage

“…The increasing PV and TBARS values in controls during 7 days of ensilaging suggest that the herring’s endogenous antioxidants such as α-tocopherol and ascorbic acid 35 – 37 , as well as low molecular weight (LMW) peptides produced during the ensilaging 5 , were not sufficient in inhibiting lipid oxidation. Possible reasons for this could be due to the fact that both ascorbic acid and tocopherol are quickly consumed during storage and processing of herring, even at cold temperatures 12 , 13 , 38 , while the peptides primarily act by chelating metal ions 39 , which are not main pro-oxidants in the herring silage 15 . α-Tocopherol provides antioxidative protection by scavenging lipid peroxyl and alkoxyl radicals, with the formed tocopherol radical then being reduced to α-tocopherol by ascorbic acid 40 .…”

“…The acidic pH used in ensilaging (i.e. pH 3.50) changes Hb from its native oxyhemoglobin (oxyHb) to the methemoglobin (metHb) state, facilitating heme group release, which can then promote lipid oxidation via heme-mediated peroxide cleavage 15 – 17 . The negative consequences of lipid oxidation are well-known, e.g.…”

Considering Two Aspects of Fish Welfare on African Catfish (Clarias gariepinus) Fillet throughout Postmortem Condition: Efficiency and Mechanisms

“…Ref. [ 43 ] indicated lipid oxidation development in minced trout muscle was retarded by bleeding during storage at +2 °C.…”

“…In the current study, bleeding removed approximately 45% of blood from bled muscles. The consequence of bleeding is retarding lipid oxidation development, which is confirmed by the amount of MDA in bled fish fillets [ 43 ]. Additionally, the higher pH in bled fillets compared to unbled fillets would be an alternative reason to reduce the formation of met-Hb and Hb-deoxygenation and minimize lipid oxidation progress.…”

Divergent Reactivity of Hemoglobin Isoforms α2Aβ2 and α2Dβ2 from Meleagris gallopavo in Native and Fatty Acid-Modified States

“…Hemoglobin (Hb)-mediated lipid oxidation is a harmful phenomenon that affects the quality of muscle foods, as well as animal and human health. , Thus, understanding the structural and functional characteristics of various Hb isoforms, as they relate to redox status, is of significant interest. Considering the recent increase in poultry consumption worldwide and the relative susceptibility of turkey muscle foods to lipid oxidation in part due to endogenous, pro-oxidant, Hb, we aimed to understand functional characteristics of the coexpressed HbA and HbD isoforms from turkeys.…”