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 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 comprises the amino acid sequence encoded by a nucleotide sequence having at least 95% identity with SEQ ID NO: 8; and is characterized as an enzyme which in an edible oil is capable of transferring an acyl group from a diglyceride to glycerol, and wherein the acyl acceptor substrate has a hydroxy group (—OH).
2. The method according to claim 1 , wherein the diglyceride:glycerol acyltransferase is used in combination with a crystallization inhibitor.
3. The method according to claim 1 , wherein 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.
4. The method according to claim 1 , wherein the edible oil is palm oil.
5. The method according to claim 1 , wherein the amount of diglyceride in the edible oil after admixing with the acyl acceptor substrate and the diglyceride:glycerol acyl transferase is reduced as compared to said edible oil before so admixing.
6. The method according to claim 1 , wherein the diglyceride is a 1,2-diglyceride.
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 acyltransferase enzyme comprises H-309 or comprises a histidine residue at a position corresponding to His-309 in the amino acid sequence of the Aeromonas hydrophila lipolytic enzyme shown as SEQ ID NO: 2.
11. The method according to claim 1 , wherein the acyltransferase is obtainable from an organism from one or more of the following genera: Aeromonas, Streptomyces, Saccharomyces, Lactococcus, Mycobacterium, Streptococcus, Lactobacillus, Desulfitobacterium, Bacillus, Campylobacter, Vibrionaceae, Xylella, Sulfolobus, Aspergillus, Schizosaccharomyces, Listeria, Neisseria, Mesorhizobium, Ralstonia, Xanthomonas and Candida.
12. The method according to claim 1 , wherein the edible oil is a palm oil fraction.