Aspects of vegetable structural lipids. I. The lipids of leaf protein concentrate

Abstract

Leaf protein concentrates contain 10 % or more of lipids which have been analysed in detail with a view to establishing both the classes of lipid present and their component fatty acid profiles. Variable factors such as the species of crop, its degree of maturity and the cellular origin of the concentrate fraction have been shown to have a quantitatively important influence on lipid patterns and on yields.

Lipid distributions in green leaf protein concentrates from four tropical leaves

“…The lipid composition of leaf protein preparations is influenced by agronomic factors and by processing and storage conditions (Hudson and Warwick, 1977). The type leaf, stage of maturity, climate, seasonal changes (resulting from different harvesting periods during the year for perennial leaves and grasses), and other factors (irrigation, fertilization) influence the distributions of lipids and of fatty acids (Hawke, 1963;Hudson and Karis, 1973).…”

“…Practically all chlorophylls and most of the expressed lipids are coprecipitated with this first protein coagulum (Hudson and Karis, 1973). The coprecipitated lipids, which might range from 10 to 30% by weight of the green LPC (Byers, 1971; Edwards et al, 1975;Vander Zanden, 1974; Pirie, 1975), impart both positive and negative attributes to the LPC.…”

“…The coprecipitated lipids, which might range from 10 to 30% by weight of the green LPC (Byers, 1971; Edwards et al, 1975;Vander Zanden, 1974; Pirie, 1975), impart both positive and negative attributes to the LPC. On the positive side, these lipids enhance the nutritional quality of the green LPC by contributing important fatty acids, viz., oleic, linoleic, and linolenic acids (Lima et al, 1965; Hudson and Karis, 1973; Betschart and Kinsella, 1975). Negatively, because more than half the fatty acids in LPC are doubly and triply unsaturated (Buchanan, 1969), they are apt to oxidize during storage (Hudson and Karis, 1976; Hudson and Warwick, 1977).…”

“…Additionally, reaction of unsaturated fatty acids with amino acid residues during preparation and storage of LPC has been implicated as one cause of decreased nutritive value (measured by enzymatic digestibility) (Henry and Ford, 1965;Pirie, 1966;Shah et al, 1967; Buchanan, 1969). Most studies on the lipid composition of green LPC's have been limited to fatty acids rather than total lipids (Hudson and Karis, 1973). In this study, we undertook to determine the lipid concentration and composition of the acetone-ethanol extract of green LPC's from tropical leaves.…”

The extended use of fractionation processes

“…Whole l.p., and the green fraction from it, contain 20-30 % of highly unsaturated lipid (Lima, Richardson & Stahmann 1965;Buchanan 1969;Hudson & Karis 1973). Chlorophyll, its breakdown products, and part of the lipid are easily removed by non-polar solvents.…”