Processing-bioprocessing of oilseed rape in bioenergy production and value added utilization of remaining seed components

Summary

Cruciferous oilseed crops accumulate relatively high concentrations of oil, proteins and dietary fibres (DF) in their seeds, in addition to bioactive components as glucosinolates and myrosinase isoenzymes (thioglucohydrolase; EC 3.2.1.147). When mixed in the presence of moisture, myrosinase isoenzymes and associated components transform glucosinolates into various types of products, which reduces the value of the extracted oil and the remaining seed components, as well as producing unwanted environmental effects due to smell and toxicity. This gives a need for special care concerning myrosinase inactivation as the initial step during processing of oilseed rape, including technologies applied for biodiesel/bioenergy production. The myrosinase inactivation is thus a critical processing step, which needs to be performed at conditions with limited negative effects on other seed components, including proteins and glucosinolates. New bioprocessing technologies are now developed at levels that allow technology transfer from laboratory scale through pilot plant to industrial scale. The extraction of glucosinolates from the seed components remaining after oil separation-pressing and/or extraction is technically possible and has proven successful with the use of bioprocessing technologies. This is also the case concerning isolation of active myrosinases. The possibilities therefore exist for extraction and formulation of glucosinolates as “natural product derived” food and plant protection agents. With the great amounts of partly de-oiled rapeseed meal resulting from bioenergy/biodiesel production, the new bioprocessing technologies call thus for attention in relation to environmental friendly production of food (vegetable oil, protein and DF products), feed and other non food products.