title: Oil and squalene in amaranthus grain and leaf.
abstract: Amaranthus grain of 104 genotypes from 30 species was investigated for oil and squalene contents and fatty acid profiles. The overall average oil content in Amaranthus grain was 5.0%, ranging from 1.9 to 8.7%. Squalene concentration in extracted oils ranged from trace to 7.3%, with an average concentration of 4.2%. The average contents of three major fatty acids in Amaranthus grain were 22.2, 29.1, and 44.6% for palmitic, oleic, and linoleic, respectively. The average fat content in dried mature leaves of 45 Amaranthus genotypes was 1.63%, ranging from 1.08 to 2.18%. The squalene concentration in leaf lipid extracts averaged 0.26%, ranging from trace to 0.77%, which is much lower than that from seeds. The major fatty acids of leaf extracts were linolenic, linoleic, and palmitic. Linolenic ranged from 56.5 to 62.0% of total fatty acids; linoleic, from 15.5 to 24.7%; and palmitic acid, from 13.5 to 15.5%. As for the fatty acid compositions at different growth stages, fatty acid content in leaf lipid was lower in mature leaves than in young leaves. The saturated/unsaturated ratio decreased when the leaf grew to maturity. Principal component analysis (PCA) was carried out on compositional characteristics of grain. The first two components accounted for 70% of the total variance (38.3 and 21.7%, respectively). There was a positive correlation between oil content and squalene yield, and a negative correlations were found between linoleic and either of the other two major fatty acids, palmitic and oleic. The taxonomic relationship among the species was also elucidated by PCA.
authors.affiliation: Department of Botany, The University of Hong Kong, Pokfulam Road, Hong Kong, People's Republic of China.
authors.forename: Han-Ping
authors.initials: HP
authors.lastname: He
authors.forename: Harold
authors.initials: H
authors.lastname: Corke
mesh_terms: D027721:Amaranthus / Q000737:chemistry* / Q000235:genetics; D000704:Analysis of Variance; D005838:Genotype; D019787:Linoleic Acid / Q000032:analysis; D019301:Oleic Acid / Q000032:analysis; D019308:Palmitic Acid / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry*; D010938:Plant Oils / Q000032:analysis*; D012639:Seeds / Q000737:chemistry*; D013185:Squalene / Q000032:analysis*
chemical_list: D010936:Plant Extracts; D010938:Plant Oils; D019301:Oleic Acid; D019308:Palmitic Acid; D013185:Squalene; D019787:Linoleic Acid