Five cuts from herring (Clupea harengus): Comparison of nutritional and chemical composition between co-product fractions and fillets

[Display omitted] •Head, backbone, viscera + belly flap, and tail made up ∼ 60 % of the whole herring weight.•All cuts were rich protein (up to 19.2% ww) with balanced essential amino acids.•Substantial amounts of LC n-3 PUFAs & LC MUFAs were identified in the co-products..•All cuts were rich in Vit E, D, and B12, as well as I, Se, Ca, and heme-Fe.•The co-products did not pose any risk to human health based on Hg, Pb, and Cd. Weight distribution, proximate composition, fatty acids, amino acids, minerals and vitamins were investigated in five sorted cuts (head, backbone, viscera + belly flap, tail, fillet) emerging during filleting of spring and fall herring (Clupea harengus). The herring co-product cuts constituted ∼ 60 % of the whole herring weight, with backbone and head dominating. Substantial amounts of lipids (5.8–17.6 % wet weight, ww) and proteins (12.8–19.2 % ww) were identified in the co-products, the former being higher in fall than in spring samples. Co-product cuts contained up to 43.1 % long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) of total FA, absolute levels peaking in viscera + belly flap. All cuts contained high levels of essential amino acids (up to 43.3 %), nutritional minerals (e.g., iodine, selenium, calcium, and iron/heme–iron), and vitamins E, D, and B12. Co-products were, in many cases, more nutrient-rich than the fillet and could be excellent sources for both (functional) food and nutraceuticals.