Peppermint 471
et al., 1993). A qualitative study of free aglycones from one clone of M. piperita was
carried out weekly for two months by Voirin et al. (1994). They found that the
flavonoid pattern of the whole plant remained invariable. Principal component analysis
recognized three flavonoid groups, corresponding to three terpenoid groups. The
study of the effects of photoperiodic treatments showed that the flavonoid pattern is
affected by day length.
The variability of the enantiomeric distribution of biologically active chiral terpenes
in M. piperita plants from different geographical origins was evaluated by solid
phase microextraction–gas chromatography–mass spectrometry (Ruiz del Castillo et
al., 2004) For all chiral terpenes, the enantiomeric composition varied within a very
narrow range all over the samples. The enantiomeric composition of chiral terpenes
appeared to be independent of the geographical origin of the plant and, thus, any
alteration in the characteristic value may be related to an adulteration or inadequate
sample handling.
The stereoselective synthesis and organoleptic properties of p-menthane lactones
7 a-h are described by Jean-Marc Gaudin (2000). Apart from correcting the published
data concerning these compounds, this work has also allowed an unambiguous
identification of 7a, 7 b and 7g in Italo Mitcham black peppermint oil. In addition,
these lactones are of considerable interest to the perfume industry, due to their exceptional
odour intensity and typical coumarin-like note. Areias et al. (2001) proposed a reversed-
phase high-performance liquid chromatography procedure for the determination of
ten phenolic compounds (eriodictyol 7-O-rutinoside, eriodictyol 7-O-glucoside, luteolin
7-O-rutinoside, luteolin 7-O-glucoside, hesperetin 7-O-rutinoside, apigenin 7-O-
rutinoside, rosmarinic acid, 5,6-dihydroxy-7,8,3¢,4¢-tetramethoxyflavone, pebrellin
and gardenin B) in peppermint.
28.5 Commercial uses............................................................................
Peppermint oil, peppermint extract and peppermint leaves are obtained from M.
piperita plant. In 1998, the peppermint oil was used in 102 cosmetic formulations as
a fragrance component. Peppermint extract was used in 35 formulations as a flavouring
agent and fragrance component. Peppermint leaves were used in two formulations
(Anonymous, 2001).
28.5.1 Uses in food industry
Chemical constituents with antioxidant activity found in high concentrations in plants
determine their considerable role in the prevention of various degenerative diseases
(Hu and Willett, 2002). Besides the fruits and vegetables that are recommended at
present as optimal sources of such components, the supplementation of human diet
with herbs, containing especially high amounts of compounds capable of deactivating
free radicals (Madsen and Bertelsen, 1995), may have beneficial effects. The
incorporation of seasoning based on herbs into everyday meals may be of crucial
importance. The benefits resulting from the use of natural products rich in bioactive
substances has promoted the growing interest of pharmaceutical, food and cosmetic
industries as well as of individual consumers in the quality of herbal produce. Among
the important constituents participating in the cell defence system against free radicals
are phenolic compounds and also ascorbic acid and carotenoids (Diplock et al., 1998,
Szeto et al., 2002).