Food Extruder for Plant Based Proteins

For its ZSK Food Extrud­er, Cope­ri­on has devel­oped a hybrid solu­tion for man­u­fac­tur­ing meat sub­sti­tute prod­ucts. With only a min­i­mum of retro­fitting effort, both tex­tur­ized veg­etable pro­tein (TVP) and high mois­ture meat ana­logues (HMMA) can be pro­duced on this ZSK Food Extrud­er, pro­vid­ing man­u­fac­tur­ers of meat sub­sti­tutes max­i­mum flex­i­bil­i­ty to be able to prof­itably react to chang­ing mar­ket demands, even on short notice.

Coperion’s co-rotat­ing ZSK twin screw extrud­ers are used in the man­u­fac­ture of both TVP and HMMA. Pre­vi­ous­ly, the food extru­sion system’s con­fig­u­ra­tion dif­fered for each appli­ca­tion: While the ZGF cen­tric food pel­letiz­er is attached to the process sec­tion for man­u­fac­tur­ing TVP in order to cut the prod­uct direct­ly at the noz­zle plate, HMMA is dis­charged using a spe­cial­ized cool­ing die which pro­duces a prod­uct strand exhibit­ing a tex­ture close­ly resem­bling that of gen­uine meat.

Using a new­ly devel­oped adapter solu­tion from Cope­ri­on, the ZSK Food Extruder’s dis­charge can now be changed over from a ZGF to a cool­ing die in record time. The machine’s oper­a­tor per­son­nel can per­form the changeover; no elec­tri­cian is need­ed. The ZGF is first opened and moved to the side. Next, after the noz­zle plate is opened by loos­en­ing a few screws; the noz­zle is switched using the adapter, and the cool­ing die is flanged. The same prin­ci­ple func­tions just as quick­ly in reverse when per­form­ing prod­uct changeovers from an HMMA process to TVP.

The Food Extruder’s design, with feed­ing and process sec­tion, remains large­ly unchanged in most cas­es. In com­bi­na­tion with the self-clean­ing pro­file of the extruder’s twin screws, prod­uct con­ver­sion is com­plet­ed in a few minutes.

TVP Extrusion

TVP is used both as a meat sub­sti­tute and as a sup­ple­ment to meat prod­ucts. It can be pro­duced in var­i­ous sizes and forms, as small­er pel­lets or larg­er chunks, bro­ken down or ground. TVP is a dry, expand­ed prod­uct with a long shelf life under nor­mal ambi­ent con­di­tions. TVP requires rehy­dra­tion in water/liquid before use.

When man­u­fac­tur­ing TVP, the extruder’s main inlet is con­tin­u­al­ly fed with bulk raw pro­tein mate­r­i­al using Cope­ri­on K‑Tron’s high accu­ra­cy loss in weight feed­ers and mate­r­i­al han­dling refill sys­tems. Imme­di­ate­ly there­after, water is inject­ed using Cope­ri­on K‑Tron liq­uid feed­ers. In cer­tain cas­es, direct steam injec­tion is applied into the process sec­tion as well. With­in the process sec­tion, mate­ri­als are mixed, knead­ed, and cooked. The prod­uct then moves out of the extrud­er via a noz­zle plate where it is processed such that it achieves a porous, foamy struc­ture with ori­ent­ed fibers. The attached ZGF pelletizer’s knife rotor then imme­di­ate­ly cuts the prod­uct. The TVP gran­ules are then dried to ensure long-term prod­uct stability.

HMMA Manufacturing

HMMA is pri­mar­i­ly used as a high-qual­i­ty meat-ana­logue prod­uct in ready-to-eat meals. By adjust­ing recipe and process para­me­ters, struc­tures of dif­fer­ent meat types can be repli­cat­ed with strik­ing sim­i­lar­i­ty to the orig­i­nal. HMMA’s mois­ture con­tent lies between approx­i­mate­ly 50–80% and must there­fore be refrigerated.

Pro­tein sources used to man­u­fac­ture high-qual­i­ty HMMA are pri­mar­i­ly legumes such as soy, lupine or pea. In cer­tain cas­es, i.e., when man­u­fac­tur­ing meat prod­uct exten­ders, less­er quan­ti­ties of gen­uine meat or fish prod­ucts are added.

The bulk raw pro­tein mate­r­i­al is fed into the extrud­er inlet. Water is then added. With­in the ZSK Food Extruder’s process sec­tion, this mass is then ful­ly mixed and knead­ed. Dis­charge takes place using a cool­ing die that gen­er­ates a meat-like tex­ture which is “frozen in”. The result is a sol­id strand with fiber struc­ture sim­i­lar to meat; the strand is then con­veyed to the next process step.

Ste­fan Geb­hardt, Gen­er­al Man­ag­er of Busi­ness Unit Food & Phar­ma at Cope­ri­on, is con­vinced of the new ZSK Food Extrud­er hybrid design: “The high demand for this hybrid tech­nol­o­gy shows us that it cor­re­sponds exact­ly to the cur­rent mar­ket trend. The need for meat sub­sti­tute prod­ucts is grow­ing steadi­ly and at the same time under­go­ing major changes. With this hybrid machine con­cept that allows pro­duc­tion of TVP and HMMA on one and the same extrud­er, we’re pro­vid­ing meat ana­logue man­u­fac­tur­ers with a solu­tion that gives them a high degree of flex­i­bil­i­ty to be opti­mal­ly pre­pared for rapid­ly chang­ing mar­ket conditions.”