Method for reducing 1,2-diglyceride content of an edible oil
The present application provides a method of reducing and/or removing diglyceride from an edible oil, comprising admixing an edible oil with an acyl acceptor substrate and a diglyceride:glycerol acyltransferase, wherein the diglyceride:glycerol acyltransferase is characterized as an enzyme which in an edible oil is capable of transferring an acyl group from a diglyceride to glycerol. The diglyceride:glycerol acyltransferase can comprise the amino acid sequence motif GDSX. The present invention also relates to the use of a diglyceride:glycerol acyltransferase in the manufacture of an edible oil, for reducing and/or removing diglyceride from said edible oil and to the use of said enzyme in the manufacture of a foodstuff comprising an edible oil for improving the crystallization properties of said foodstuff.
1. A method for reducing 1,2-diglyceride content of an edible oil comprising:
admixing the edible oil with an acyl acceptor substrate and a diglyceride: glycerol acyl transferase (DGAT), wherein:
in the edible oil the DGAT transfers an acyl group from a diglyceride to a glycerol;
the acyl acceptor substrate has a hydroxy (—OH) group; and,
the edible oil is one or more of the following oils: oils extracted from or derived from palm oil, palm olein, palm stearin, palm mid fraction or olive oil;
wherein the DGAT reduces diglyceride in palm oil in an assay comprising admixing 1 gram of palm oil containing 7% diglyceride with 50 mg glycerol and 10 μl of the DGAT with stirring and heating at 40° C. for 20 hours.
2. The method of claim 1 , wherein:
the DGAT contains an amino acid sequence motif, and that motif is GDSX (SEQ ID NO: 73), wherein X is L, A, V, I, F, Y, H, Q, T, N, M or S.
3. The method of claim 1 , wherein the DGAT is obtainable from an organism from Aeromonas, Streptomyces, Saccharomyces, Lactococcus, Mycobacterium, Streptococcus, Lactobacillus, Desulfitobacterium, Bacillus, Campylobacter, Vibrionaceae, Xylella, Sulfolobus, Aspergillus, Schizosaccharomyces, Listeria, Neisseria, Mesorhizobium, Ralstonia, Xanthomonas or Candida .
4. The method of claim 3 wherein the DGAT is obtainable from an Aeromonas organism .
5. The method according to claim 1 , wherein the DGAT is used in combination with a crystallization inhibitor.
6. The method according to claim 1 , wherein the edible oil is palm oil.
7. The method according to claim 1 , wherein the acyl acceptor is one which is soluble in an edible oil.
8. The method according to claim 1 , wherein the acyl acceptor substrate is an alcohol.
9. The method according to claim 8 , wherein the acyl acceptor substrate is glycerol.
10. The method according to claim 1 , wherein the edible oil is a palm oil fraction.