Enzyme-aided recov­ery meth­ods’ help in extract­ing pro­tein from rape­seed press cake

The pur­pose of Katari­ina Rom­mi’s doc­tor­al dis­ser­ta­tion was to devel­op simple, water-sav­ing meth­ods for turn­ing veget­able oil industry co-streams into pro­tein ingredi­ents suit­able for food or cos­met­ic products and thus help to sat­is­fy the increas­ing glob­al demand for pro­tein. Glob­ally, around 34 mil­lion tonnes of rape­seed press cake is pro­duced annu­ally as rape­seed oil by-product. At present, it is primar­ily used as feed for pro­duc­tion anim­als. In Fin­land, the major­ity of oil mills use cold press­ing in rape­seed oil pro­duc­tion. The by-product of this meth­od, rape­seed press cake, con­tains between 32 and 36% of nutri­tion­ally valu­able pro­tein. The mar­ket­ing of rape­seed press cake as nov­el food was approved by the EU in 2014. Sev­er­al tech­no­lo­gies based on alkaline or saline extrac­tion have been developed for enrich­ment of rape­seed pro­tein, but high energy and water con­sump­tion due to dilute con­di­tions and mul­tiple pro­cessing steps lim­it their prof­it­ab­il­ity. As part of the work done for her doc­tor­al dis­ser­ta­tion, Katari­ina Rommi developed enzyme-assisted meth­ods for the enrich­ment of rape­seed pro­tein and stud­ied the factors influ­en­cing pro­tein extract­ab­il­ity and the prop­er­ties of the obtained pro­tein-rich frag­ments. An enzyme that breaks down pec­tin was shown to be par­tic­u­larly effect­ive in facil­it­at­ing pro­tein extrac­tion at reduced water con­tent and without chem­ic­als such as alkali or salt. A techno-eco­nom­ic eval­u­ation of dif­fer­ent extrac­tion schemes also sug­ges­ted sub­stan­tial reduc­tion of energy costs when the extrac­tion was car­ried out at 20% sol­id con­tent. The res­ults indic­ate that enzyme-aided meth­ods are well suited to rape­seed enrich­ment and may offer a techno-eco­nom­ic­ally feas­ible altern­at­ive to alkaline or saline extrac­tion. The res­ults may be applied to the man­u­fac­tur­ing of rape­seed-based pro­tein ingredi­ents in food, feed and oth­er indus­tries. In the study, bio­act­ive rape­seed pep­tide frag­ments were also extrac­ted from rape­seed press cake by pro­teo­lyt­ic enzyme treat­ment; these frac­tions have nov­el applic­a­tion poten­tial in skin care products. The dis­ser­ta­tion is avail­able online at http://​www​.vtt​.fi/​i​n​f​/​p​d​f​/​s​c​i​e​n​c​e​/​2​0​1​6​/​S​1​3​0.pdf Source: Tech­nic­al Research Centre of Fin­land (VTT)