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Acidity and DAG Content of Olive Oils Recently Produced on the Island of Mallorca
Author(s) -
Shimizu Masao,
Kudo Naoto,
Nakajima Yoshinobu,
Matsuo Noboru,
Katsuragi Yoshihisa,
Tokimitsu Ichiro,
Barceló Isabel,
Mateu Catalina,
Barceló Francisca
Publication year - 2008
Publication title -
journal of the american oil chemists' society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.512
H-Index - 117
eISSN - 1558-9331
pISSN - 0003-021X
DOI - 10.1007/s11746-008-1292-0
Subject(s) - chemistry , hydrolysis , olive oil , glyceride , food science , composition (language) , chromatography , fatty acid , organic chemistry , linguistics , philosophy
In this study, the quality characteristics, i.e., the acidity and acylglycerols, of currently produced Mallorcan oil was analyzed by titration and gas‐chromatographic technique, respectively, in approximately 400 samples of monovarietal olive oil made from three genetic varieties (Arbequina, Empeltre, and Picual) on the island of Mallorca during the 2003/2004 and 2005/2006 seasons, and the differences in the compositions were discussed. Composition analysis showed that free fatty acids (FFAs) and DAGs were produced mainly by hydrolysis of triacylglycerols (TAGs). Fruit storage tests revealed that hydrolysis occurred during storage of olive fruits. The DAG content was higher in oil with higher acidity, but the maximal DAG content was only about 10 with 30% acidity, and the primary isomer found in Mallorcan oil was 1,3‐DAG. However, the chiral‐chromatographic study on the ratio of sn ‐1,2‐DAG to the sum of sn ‐1,2‐DAG and sn ‐2,3‐DAG in a slightly hydrolyzed oil sample indicated that Empeltre and Picual fruits possess an sn ‐3‐enantioselective lipase that leads to accumulation of sn ‐1,2‐DAG. In currently produced Mallorcan oil, significant isomerization appears to occur and hydrolysis of the resulting 1,3‐DAGs seems to lessen DAG accumulation.