"From ancient crops materials and products for the future" (VeLiCa Project)

The VeLiCa project is aimed at making again gainful the growing of flax and hemp in Regione Lombardia (Northern Italy) where it used to be widespread at the beginning of the 20th century. This target is being pursued by the exploitation of all the parts of the plant to make different products with high-added value according to the “biorefinery” concept. Within this frame, our group is currently investigating both oil and protein content from hempseed (Cannabis sativa L.) because of their rising interest in food industry. To this aim, we are developing “green processes” based on enzyme-catalyzed reactions and environmentally friendly solvents. On one hand, hemp oil is a well-known source of linoleic acid (LA) and alpha-linolenic acid (ALA), which are omega-6 and omega-3 essential fatty acids (FFAs), respectively. Due to the health benefits of these FFAs, there is a great demand for pure and concentrated extracts of those compounds. We have thus studied the enrichment of hemp oil with LA and ALA by using selective lipase-catalyzed hydrolysis. The two classical hydrolytic biphasic systems consisting of either oil/water or oil/isooctane/buffer were compared with a new homogeneous one based on oil and tert-butanol/water. The new system is easier handling and appeared superior to literature protocols. The fatty acid composition of the hydrolyzed hempseed oil was determined by an analytical method based on SPE of the produced FFAs and GC analysis of the corresponding fatty acid methyl esters (FAMEs). When Pseudomonas cepacia lipase was used as the biocatalyst, LA content reached 68% after 24 h. On the other hand, protein content of hempseed, which is comparable to soy’s one, has been reported to be far more digestible and nutritional in all essential amino acids. Chemical and/or enzymatic hydrolysis of vegetable raw materials rich in proteins can produce hydrolyzed vegetable proteins (HVPs) containing bioactive peptides with nutraceutical properties. Defatted hempseed cake was thus hydrolyzed by using two food grade protease cocktails, Flavourzyme and Umamizyme. Hempseed protein hydrolyzates were subjected to ultrafiltration and the antioxidant activity of the fractions <10 kDa was measured by the DPPH radical-scavenging assay and the ferrozine test. A few samples displayed a remarkable Fe2+ chelating ability and were found to exert radical scavenging properties comparable to those of glutathione. Not less important, hempseed cake, that is a usually discarded waste, is here upgraded as a valuable source of peptides for human nutrition. These results suggest that enzymatic hydrolysis of hempseed oil and proteins can be used to produce high added-value products and to set up new productive chains.