Pilot-Scale Antioxidant Dipping of Herring (Clupea harengus) Co-products to Allow Their Upgrading to a High-Quality Mince for Food Production

Abstract

To enable production of high-quality mince from herring backbones, a scalable antioxidant strategy is needed due to the high susceptibility of herring muscle to lipid oxidation. We here measured the stabilizing effect of lab-/pilot-scale predipping of herring backbones (30−500 kg) in antioxidant solutions prior to production of mechanically separated mince (MSM). The antioxidants were (i) Duralox MANC, a mixture of rosemary extract, ascorbic acid, α-tocopherol, and citric acid, and (ii) rosemary extract with or without isoascorbic acid. Delivery of the key rosemary-derived antioxidant components carnosol and carnosic acid was monitored during the dipping process and ice/frozen storage. Predipping in 2% Duralox MANC gave MSM with 26.7− 31.7 mg/kg carnosol + carnosic acid and extended the oxidation lag phase from <1 to 12 days during ice storage and from <1 to 6 months during frozen storage compared to control. Dipping in 0.2% rosemary extract with or without 0.5% isoascorbic acid solution gave MSM with 20.6−28.2 mg/kg carnosol + carnosic acid and extended the lag phase to 6 days and 9 months during ice and frozen storage, respectively. Our results confirmed, in pilot scale, that predipping herring coproducts in antioxidant solutions is a promising strategy to utilize these raw materials for, e.g., mince and burger production rather than for low value products as fish meal.

Oxidative Stability of Side-Streams from Cod Filleting—Effect of Antioxidant Dipping and Low-Temperature Storage

“…Besides the protective effect during storage until further processing, the antioxidant may also stabilize the lipids under the actual processing of the side-streams if the antioxidant is not depleted during storage. Antioxidant treatment of herring side-streams before recovery of proteins using mechanical separation or before ensilaging had a pos-itive effect on the stability during ice or ambient storage, respectively [23,24]. Whether pre-processing stabilization can also prevent oxidation during other types of valorization processes remains to be shown.…”