Agriculture Reference
In-Depth Information
tAble 13.2
Isoflavone content of Representative soy foods (µg/g wet weight)
source
daidzein +
glycosides
genistein +
glycosides
glycitein +
glycosides
total
Soybeans
986
1175
168
2329
Soy concentrate,
ethanol washed
40
97
9
116
Soy isolate
216
521
59
796
Tofu
91
138
22
251
Soy milk,
pasteurized
37
51
7
95
Soy milk, aseptic
process
59
74
10
143
Soy burger, raw
37
66
12
115
Chicken analog
35
79
9
123
Source:
Adapted from Hendrich and Murphy, 2001.
L
i P i D s
w i t h
h
e a L t h
b
e n e f i t s
A large body of evidence implicates the quality and quantity of dietary fats with
risk of diseases, including cardiovascular disease, arthritis, some cancers, and
Alzheimer's disease. Foods with beneficial fatty acid profiles represent a large seg-
ment of functional foods. Removing
trans
fats and saturated fats from foods repre-
sents a class of functional foods for which the enhancement is achieved by removing
a hypercholesterolemic fat when they are replaced with a hypocholesterolemic fat
that is rich in monounsaturated fatty acids and polyunsaturated fatty acids, particu-
larly N-3 fatty acids.. The Mediterranean diet has long been considered beneficial
because one of the primary sources of fat was olive oil, which is rich in monoun-
saturated oleic acid. Kris-Etherton et al. (1999) demonstrated that monounsaturated
fatty acid diets lowered both cholesterol and triglyceride. It was concluded that the
monounsaturated fatty acid diet was preferable to a low-fat diet for reducing cardio-
vascular risk. Chemically, it is lower melting than
trans
fats or saturated fatty acids
such as palmitate and stearate. Thus, population of cell membranes with fatty acids
that are more fluid (de la Lastra et al., 2001) results in healthier tissue. Increasing
levels of unsaturation of fatty acids increases the likelihood of oxidation of the fatty
acids. Oleic acid is a monounsaturated fatty acid and is therefore more stable to
oxidation than polyunsaturated fatty acids (PUFAs), such as linoleic and linolenic.
While the highly liquid PUFAs increase membrane fluidity, the risk of oxidation is
much higher. Lipid oxidation is initiated by the removal of a hydrogen atom from
the methylene side chain of an unsaturated hydrocarbon. The greater the degree of
unsaturation, the more easily the hydrogen is removed. This is described more in the
section on antioxidants.
