Influence of colour type and previous cultivation on secondary metabolites in hypocotyls and leaves of maca (Lepidium meyenii Walpers).
BACKGROUND
Maca is an Andean crop of the Brassicaceae family which is mainly known for its fertility-enhancing properties following consumption. The hypocotyls display various colours ranging from white to black. Each colour has different biological effects. The aim of this study was to analyse the concentrations of major secondary metabolites in hypocotyls and leaves of maca in a controlled planting experiment in the Peruvian Andes at 4130 m above sea level. The effects of colour type and of previous cultivation of the field were examined.


RESULTS
In the hypocotyls, the colour type effect was significant for most secondary metabolites; exceptions were beta-sitosterol and campesterol. The lead-coloured, yellow and violet maca hypocotyls were rich in glucosinolates, macaene and macamides, respectively. Previous cultivation affected macaene, campesterol and indole glucosinolate concentrations. Effects on metabolite concentrations in the leaves were minor. Hypocotyls were richer in macaene, macamides and glucosinolates than were leaves, and were poorer in beta-sitosterol and total phenols.


CONCLUSIONS
Colour type has to be considered in maca production, as colour associates with variations in concentrations of distinct bioactive metabolites. Leaves may be interesting for animal nutrition purposes as they contain essentially the same secondary metabolites as the hypocotyls but in clearly lower concentrations.
Clément
Céline
C
ETH Zurich, Institute of Plant, Animal and Agroecosystem Sciences, 8092 Zurich, Switzerland.
Diaz Grados
Diego A
DA
Avula
Bharathi
B
Khan
Ihklas A
IA
Mayer
Andrea C
AC
Ponce Aguirre
Dante D
DD
Manrique
Ivan
I
Kreuzer
Michael
M
D000383:Agriculture / Q000379:methods; D000531:Altitude; D002784:Cholesterol / Q000031:analogs & derivatives / Q000032:analysis; D005961:Glucosinolates / Q000032:analysis; D018546:Hypocotyl / Q000737:chemistry* / Q000378:metabolism; D007211:Indoles / Q000032:analysis; D029686:Lepidium / Q000737:chemistry* / Q000145:classification / Q000254:growth & development* / Q000378:metabolism; D008041:Linoleic Acids / Q000032:analysis / Q000737:chemistry; D008042:Linolenic Acids / Q000032:analysis / Q000737:chemistry; D009753:Nutritive Value; D009928:Organ Specificity; D010169:Palmitic Acids / Q000032:analysis / Q000737:chemistry; D010568:Peru; D010840:Phytosterols / Q000032:analysis; D010858:Pigmentation; D018515:Plant Leaves / Q000737:chemistry* / Q000378:metabolism; D053284:Polyunsaturated Alkamides; D012855:Sitosterols / Q000032:analysis*; D012987:Soil / Q000032:analysis; D013045:Species Specificity
D005961:Glucosinolates; D007211:Indoles; D008041:Linoleic Acids; D008042:Linolenic Acids; C450177:N-benzyl-5-oxo-6,8-octadecadienamide; D010169:Palmitic Acids; D010840:Phytosterols; D053284:Polyunsaturated Alkamides; D012855:Sitosterols; D012987:Soil; C550388:n-benzyl palmitamide; C550390:5-oxo-6E, 8E-octadecadienoic acid; C021273:campesterol; C025473:gamma-sitosterol; D002784:Cholesterol