Agriculture Reference
In-Depth Information
consumption as a fresh fruit, tuna is used in Mexico in the
preparation of cheese, honey of tuna, crystallized fruit,
raisin-like dried fruit, etc.
effect with such polymers (Medina-Torres
et al
. 2000;
2003). An important application of prickly pear cactus
stem mucilage is in formulations of water-proof materials
and paint. The mucilage is neutral with mainly D-galactose
and L-arabinose residues (Harlay, 1902). The mucilage of
O. ficus-indica
Mill. is neutral and contains arabinose,
galactose, rhamnose and xylose residues (Amin
et al
.
1970). Others suggest that the mucilage is acidic and
contains L-arabinose, D-galactose, L-rhamnose and
D-galacturonic acid (Anderson
et al
. 1925; Sands & Klaas
1929). Parikh and Jones (1965, 1966a, 1966b) reported
that the mucilage of
Opuntia fulgida
consists of a backbone
of β(1, 3)-linked galactose units with branches on carbon
C-6 containing D-galacturonic acid, D-galactose, D-xylose,
L-rhamnose and L-arabinose units. However, the mucilage
of
Opuntia ficus-indica
cv 'Burbank's spineless' contains
both neutral and acidic fractions (Paulsen & Lund, 1979).
Trachtenberg and Mayer (1987) isolated carbohydrate
polymers from
O. ficus-indica
and found galacturonic and
rhamnose residues.
Another application of prickly pear cactus stems is in
cosmetics: cleansing creams, moisturizing creams, sham-
poos and gels. These have been developed by using the
excess fluid (which contains the mucilage), derived from
the process of prickly pear cactus cooking. Other products
include masks and soaps. Production of the red dye aceto-
carmine may also be possible through extraction of the
parasitic insect cochineal
(Dactylopius coccus
), which relies
on prickly pear cactus as the host plant (Flores-Flores &
Tekelenburg, 1995). Cladodes are also used as cattle food
and because of its strength it is used as field fences.
Cladodes
Cladodes, cactus stems, cactus pads, cactus vegetables or
phylloclades, also called 'nopal' or 'nopalito' in Mexico
(the name is used in Mexico for all Cactaceous plants from
the Genus
Piatyopuntia
and
Nopalea
), are the rapidly
growing succulent stems of the prickly pear cactus
(
Opuntia
spp) (Figure 13.2). These are flat, oval or round,
and the surface exhibits groups of thorns. The vestigial true
leaves, often subtended by spines (glochids), are present in
the early stages of growth, but usually begin to abscise by
the time the cladodes reach commercial size. Although the
young stems of many
Opuntia
species can be eaten, most
commercial plantings of cladodes are from
O. ficus-indica
and
O. inermis
. Cladodes are mostly water (92%) and
carbohydrates, including fibre (4-6%) and a little protein
(1-2%). They also contain some minerals, principally
calcium (1%), and moderate amounts of vitamin C and
vitamin A (Table 13.1).
Cladodes are marketed either whole or in slices. Spines
are commonly removed just after harvest or just before
marketing. They are commonly ingested broiled, blended
or as a juice (Guevara & Yahia, 2005). Different products
from cladodes also exist in the local Mexican markets,
especially in combination with other products, including
bread, jelly, jam, candies, wine, vinegar, juice, flavourings
and cheese. Pharmaceutical products include cream, gel,
shampoo, tablets and syrups (Sáenz-Hernández 1995). In
the southern United States, prickly pear cactus stems are
pre-treated by scalding in saline solutions (for texture and
colour stability) and vacuum-packed, yielding a product
with relatively stable colour and texture characteristics and
a shelf-life of 3 months at 4°C. In Chile, prickly pear cac-
tus flour from
O. ficus-indica
is integrated into different
baking processes. Many of these products are intended for
the market of high dietetic fibre content products.
Companies processing cladodes into various foods are
found almost exclusively in Mexico and the greatest vari-
ety of products is found in Mexico and the United States
(Guevara & Yahia 2005).
Composition of
Opuntia
fruit
The isolation and characterization of storage proteins from
the seeds of prickly pear showed that such proteins (molar
masses of ∼6500 g mol
¯
1
) have an amino acid composition
similar to the 2S albumin storage protein family (Ochoa
et al
. 1998).
O. ficus-indica
growing in desert and subde-
sert areas is a potential source of pectins (Majdoub
et al
.
2001; Sawaya
et al
. 1983). The polysaccharide component
of prickly pear peel is characterized by very high neutral
sugar content, mainly consisting of rhamnose and galac-
tose and enough galacturonic acid content to be useful as a
thickening additive (Forni
et al
. 1994).
Composition and uses of cladodes
The characterization of mucilage of prickly pear cactus
stem (Yahia
et al
. in press; Trachtenburg & Mayer 1982)
has been performed with the purpose of using it as a nour-
ishing additive, either as a viscosity-increasing agent or
together with other gums hoping to obtain a synergistic
Nutritional composition and health benefits
Information on the composition of
Opuntia
Spp. is
incomplete. However, cactus fruit and cladodes are valued
because of their high nutrient content, vitamins and
other health components (Hegwood 1990). Chemical
