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Influence of Tissue Drying on o ‐Hydroxycinnamic Acid Content in Sweetclover 1
Author(s) -
Haskins F. A.,
Gorz H. J.
Publication year - 1973
Publication title -
crop science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.76
H-Index - 147
eISSN - 1435-0653
pISSN - 0011-183X
DOI - 10.2135/cropsci1973.0011183x001300040025x
Subject(s) - hydroxycinnamic acid , biology , melilotus , nicotiana tabacum , botany , horticulture , biochemistry , antioxidant , gene
A fluorometric procedure was used to study changes in levels of the free and bound forms of the cis and trans isomers of ο ‐hydroxycinnamic acid ( ο ‐HCA) associated with drying sweetclover ( Melilotus ) tissues under various conditions of time and temperature. Leaves, or leaves and stems, of three sweetclover varieties, ‘Spanish,’ ‘Evergreen,’ and ‘Goldtop,’ and two closely related, highly inbred lines ( CuCuBB and CuCubb genotypes) were used. Drying temperatures of 30 and 40 C were used most extensively. When dried at 30 C, leaves lost more than half of their bound cis ‐ ο ‐HCA, and a small amount of free cis ‐ ο ‐HCA (coumarin) was produced. In leaves dried at 40 C, up to 90% or more of the bound cis ‐ο‐HCA was converted to the free form by the enzyme, β ‐glucosidase, and little loss of total ο‐HCA occurred. Thus, levels of free and bound cis ‐ ο ‐HCA were appreciably modified by the drying treatments imposed. Content of trans ‐ ο ‐HCA, on the other hand, was not greatly changed by drying. The results obtained may have application in the drying of leaves of deer's tongue [ Trihsa odoratissima (Walt, ex J. F. Gmel.) Cassini ], an ο ‐HCA‐containing plant used in the tobacco ( Nicotiana tabacum L.) industry.