Partial purification of Nigella sativa L. seed lipase and its application in hydrolytic reactions. Enrichment of gamma-linolenic acid from borage oil


Tuter M. , AKSOY H., USTUN G. , RIVA S., SECUNDO F., IPEKLER S.

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY, vol.80, no.3, pp.237-241, 2003 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 80 Issue: 3
  • Publication Date: 2003
  • Doi Number: 10.1007/s11746-003-0683-3
  • Title of Journal : JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
  • Page Numbers: pp.237-241

Abstract

Selective hydrolysis of borage (Borago officinalis L.) oil was catalyzed by two lipase preparations of Nigella sativa L. seeds at 40degreesC in a mixture of borage oil, water, and hexane. Ammonium sulfate-precipitated lipase (Nigella PL) and lipase partially purified by DEAE-ion exchange chromatography (Nigella CPL) exhibited a negative specificity toward gamma-linolenic acid (GLA). Best results were obtained in the experiments conducted with 330 U/g oil of Nigella PL and 200 U/g oil of Nigella CPL. When 330 U/g oil of Nigella PL was used, after 8 h the GLA level rose from 21.9% in the starting oil to 29.6 and 41.8% in TAG and DAG fractions of the product mixtures, respectively (1.5-fold enrichment of GLA in the total unhydrolyzed acylglycerol fraction). At 200 U/g oil enzyme concentration of Nigella CPL, after 77 h maximum GLA enrichment was observed in the DAG fraction. The GLA content of the DAG increased to 34.6%, corresponding to almost 1.6-fold enrichment. The relative inability of Nigella sativa lipase(s) to hydrolyze gamma-linolenoyl moieties of TAG can be used for the enrichment of this acid in the unhydrolyzed acylglycerol fractions of GLA-containing oils.