Upcycling side streams: value is decided on the slaughter line

According to the European Fat Processors and Renderers Association (EFPRA), up to half of every animal raised for food production is not intended for human consumption: hides, bones, blood, fatty tissue and offal, which arise as animal by-products. The association's member companies collect 18 million tonnes of animal by-products every year in Europe and the United Kingdom, and process them mainly into feed, fertilisers and fuels.¹

According to the European Fat Processors and Renderers Association (EFPRA), up to half of every animal raised for food production is not intended for human consumption: hides, bones, blood, fatty tissue and offal, which arise as animal by-products. The association's member companies collect 18 million tonnes of animal by-products every year in Europe and the United Kingdom, and process them mainly into feed, fertilisers and fuels.¹

No pan-European statistics exist on the return of these materials to food production. The route is discussed under the heading of upcycling; in technical terms it can be defined more precisely. A life cycle assessment study commissioned by the Swiss Federal Office for the Environment distinguishes two directions, following a systematic approach developed by Beretta and Hellweg:

Valorisation denotes the processing of a co-product-material that inevitably arises alongside the meat at slaughter – into food,
Recovery its processing into products that are not intended for human consumption.² Biogas falls under recovery, gelatine under valorisation.

Which of these two routes remains open is decided earlier than the process technology would suggest.

The moment of classification

For whether a stream remains fit for food use depends not on the subsequent processing, but on the status it is assigned at the moment of slaughter.

Regulation (EC) No 1069/2009 divides animal by-products into three categories according to health risk.³ Category 3 carries the lowest risk and covers, among other things, material from animals that were judged fit for human consumption at slaughter. Only this material is eligible for a return to food production. EFPRA describes this category as material that is fit for human consumption at the time of slaughter.¹ What is decisive, therefore, is a point in time, not a condition.

If a stream is declared for feed use, or is not collected separately and chilled, it leaves the food chain. The Regulation makes no provision for a later return, irrespective of the actual condition of the material.

How far this decision lies from technical feasibility is shown by an example from the Swiss study: offal is fit for consumption and requires no elaborate processing. Because demand is low, it goes mainly for export or is classified as Category 3 slaughter waste, according to the study.² The process would be available. The demand is not.

For the legal classification, however, this visual difference is immaterial. In 2014 the Court of Justice of the European Union ruled in Case C-453/13 that such material must be classified as mechanically separated meat as soon as the process alters the muscle fibre structure more than occurs at cut surfaces – regardless of whether the bone structure remains intact. The judgment rules out classification as a meat preparation.⁶ For cattle, sheep and goats the process is excluded in any case: the Regulation on transmissible spongiform encephalopathies, a group of diseases of the central nervous system, prohibits the production of mechanically separated meat from their bones.⁷ For all other species, the product must be labelled as mechanically separated meat with the species stated.

That does not make the material worthless: if the process does not alter the bone structure and the calcium content is close to that of minced meat, the product may – subject to the corresponding microbiological evidence – be used in meat preparations that are heated before consumption, and in meat products. For material from other processes, only heat-treated meat products are eligible.⁸

It is therefore not the technology alone that determines the value of the material, but the legal classification that follows it. At the next level, the room for manoeuvre narrows further.

If this window is missed, the blood is physically unchanged – but in legal terms no longer a food. This decision is irreversible: once material has been classified as an animal by-product, it may not return to the food chain.

The blood is then separated by centrifugation into liquid plasma and the cellular constituents containing the haemoglobin; both fractions are spray-dried.

The product range of the Italian manufacturer Haripro shows how differently the fractions can be used. The company offers plasma proteins with 70 and 80 per cent protein content; they are water-soluble, have a high immunoglobulin content according to company information, and serve the meat products industry as a functional protein. Two products are derived from the cellular fraction: a dark red, readily soluble haemoglobin powder marketed as a colourant for the meat industry, and a white protein powder obtained by hydrolysis that is suitable as a natural flavour carrier.¹⁰

KU Leuven has investigated the functionality of plasma in a cooked emulsified sausage model. If phosphate is omitted without replacement, the cooking loss rises from 0.6 to 5.7 per cent. An addition of two per cent blood plasma reduces it to 0.9 per cent; statistically, there is thus no difference from the phosphate-containing reference.¹¹

With haemoglobin, a circle closes: the side stream returns as a colourant to the product it came from. Both plasma and haemoglobin are obtained solely by mechanically separating the blood, without chemical digestion.

Three product stages are common: gelatine as a gelling and stabilising agent, for example in fruit gums and wine gums; collagen peptides from further enzymatic hydrolysis, which no longer gel but dissolve in cold water and remain almost neutral in taste – which is why they can be used in beverages, food supplements and cosmetics; Edible films and casings for meat and sausage products are also in use, such as those made by Devro – part of the SARIA Group since 2023.¹⁵

The residues of collagen production are used as well: from these, Gelita recovers, according to its own information, pure phosphates for fertilisers, proteins intended for aquaculture, and fats for renewable biofuels.¹⁶

The market for these products is consolidating. Darling Ingredients and the Tessenderlo Group are combining their collagen and gelatine businesses Rousselot and PB Leiner under the name Nextida¹⁷; the German Federal Cartel Office cleared the merger on 27 April 2026.¹⁸

For meat processing companies, the question of using side streams begins not in processing but at slaughter. Separate collection, rapid chilling and full traceability determine which streams arise fit for food use. This is an irreversible decision: once material has left the food chain, it remains feed or a technical product.

Whether the effort pays off is decided by the application. Each fraction¹⁹ has its own function. Plasma protein binds water even after heating and thus reduces the use of phosphate in cooked emulsified sausage. Gelatine cannot do this; its gel melts during cooking. More processing therefore does not automatically bring a greater return. What is decisive is which substance a side stream replaces in the particular formulation – and whether the changeover pays off given a company's own size and volume of material.

The processes are ready. The bottleneck is not in the processing technology, but at the slaughter line.