Seafood by-products: solutions for re-circulation back to the food chain

Purpose and goal

The overall project aim was to identify and test strategies for stabilization of fish byproducts against hemoglobin (Hb)-mediated rancidity, thereby facilitating their upgrading to food. Specific goals comprised mapping of current industrial by-product handling, Hb-analyses of by-products, and design of solutions to remove Hb and add antioxidants to by-products. Hurdles for industrial implementation of the developed solutions were also to be identified, along with economic effects of upgrading byproducts to food ingredients. These project aims were fulfilled.

Expected results and effects

Herring by-products had high Hb-levels, with most Hb being interior, why only 10-18% could be rinsed away. Solutions with specific antioxidants in 0.9% NaCl were developed for either dipping of by-products prior to storage or for actual incubation during storage. Effects on preventing rancidity were remarkable; shelf life went from <1 day to>12 days. Industry identifed labelling and cost of antioxidants as critical. Nevertheless buisness models revealed that a gain of 1,8-100 milj SEK per year could be reality if converting backbones from 10 000 t herring to mince or protein isolates

Planned approach and implementation

This project was divided into four work packages (WP´s); all connecting industry and academia. In WP1, current industrial handling & logistics for fish by-products were mapped on site. In WP2, Hb-distribution in herring by-products was analysed and solutions to remove Hb and add in antioxidants were evaluated against prolonged shelf life. In WP3, industrial implementation of the antioxidant solutions were discussed in a workshop, while in WP4, simple business models were built for recirculating the byproducts into food processing. The methodology overall worked fine.