A COMPARATIVE-STUDY OF THE COMPOSITION OF LIPIDS ASSOCIATED WITH STARCH GRANULES FROM VARIOUS BOTANICAL SOURCES

Lipids from highly purified wheat, rice, corn, fababean, lentil, potato and cassava starches were extracted by acid hydrolysis and by selective solvent extraction with chloroform-methanol 2:1 v/v [CM] at ambient temperature, followed by n-propanol-water 3:1 v/v [PW] at 90-100-degrees-C. The acid hydrolyzed extracts which represented the total starch lipid [TSL] content ranged from 0.1% (potato) to 0.8% (corn). The combined action of CM and PW resulted in almost complete removal of starch lipids (> 98.6%) from most of the starches, the exception being wheat, where the solvent extraction efficiency (% TSL) was 96.3%. The free lipids in the CM extracts (% TSL) ranged from 5.0% (corn) to 62% (fababean), whereas the free and bound lipids in the PW extracts ranged (% TSL) from 44.2% (potato) to 94.8% (corn). Neutral lipids (NL) formed the major lipid class in the CM extracts of all starches, while in PW extracts these were NL in corn and cassava, NL and phospholipids (PL) in potato, and PL in wheat, rice and fababean. There was a great variation among the starches with respect to the major components of the lipid classes in both CM and PW extracts. Monoacyl lipids were most abundant in cereal starches (> 78% TSL). The fatty acid composition of NL, GL and PL in CM and PW extracts was determined.