The Reduction of Oxidation of Food Products Using Dioxygenases

A novel way of deoxygenating food products by oxygen scavenging enzymes has been developed, especially suitable for food products comprising mono or polyunsaturated fatty acids or both which are very sensitive to oxidation. It has been found that dioxygenases, which are enzymes capable of oxidising substrates by inserting one or two oxygen atoms into the substrate using molecular oxygen, are very effective in oxygen removal in food products. Moreover, no reactive species are formed during this reaction. Furthermore, the substrates for dioxygenases are antioxidants, which have the advantage that a combination-effect can be achieved, particularly because the substrate retains its antioxidant activity after being oxidised. The use of quercetinase and catechinase, both dioxygenases, as oxygen-scavenging enzymes for off-flavour prevention in oil-in-water (o/w) emulsions was found to be highly efficient, and the oxygen concentration could be reduced to zero. The enzymes quercetinase and catechinase were able to deoxygenate o/w emulsion in the presence of the antioxidants quercetin and catechin, respectively. Especially the combination of quercetinase and quercetin resulted in a very effective off-flavour reduction of 80−97% as determined by GC analysis of 7 out of 10 volatiles labeled as off-flavour.