Cover Image
close this bookFood Chain No. 18 - July 1996 (ITDG, 1996, 16 p.)
View the document(introduction...)
View the documentGreetings
View the documentMoringa oleifera - a multipurpose tree
View the documentThe design and fabrication of food processing equipment
View the documentLetter to the editor
View the documentAsia pages
View the documentUse of prickly pear fruit
View the documentIs the west always best?
View the documentBread making
View the documentSeasonal profits from the Freezit-making machine
View the documentSimple methods of quality assurance

Use of prickly pear fruit

FURTHER READING

Barbera, G. Carimi, F. and Inglese, P. 1988. La coltura del ficodindia e possibili indinzzi produttivi. Frutticoltura. Anno L - n. 10 37-43.

Sepa, E. and Sz, C. 1990. Chemical and physical characteristics of prickly pear (Opuntia ficus indica) pulp. Rev. Agroquim. Tecnol. Aliment. 30(4): 551-555.

Sz, C. and Sepa, E. 1993. Agro-industrial uses for cactus pear Alimentos 18(3): 29-32.

Sz, C. 1985. The prickly pear (Opuntia ficus indica): a cultivar with prospects. Alimentos 10 (3): 47-49.

Russell, C. F. and Felker, P. 1987. Economic Botany 41(3):433-445.

Wessels, A.B. 1988. Spineless Prickly Pears. Perskor Publishers, Cape Town. 61p.

While the prickly pear cactus now grows in many countries around the world, its fruit is not widely used outside Latin America. Dr Carmen Sz briefly reviews the composition of the fruit and products that can be made from it.

The prickly pear cactus originated in America and now has spread widely to Africa, Mediterranean countries and the Middle East. It is a hardy plant that thrives in marginal semi-arid areas. While it mainly grows wild, plantations now exist in countries including Chile, Mexico, Brazil and Italy. The fruit is generally eaten fresh or used to make home-made drinks. The limited bibliography available however, describes methods for manufacturing dehydrated fruit, jams and canned fruit.

The fruit has a fairly high sugar content (as shown in Table 1) and unusually most of the sugars are glucose and fructose which give it a very sweet taste. The fruit is also unusual in being of low acidity, having a high pH of 6.37 which influences the way it is processed. Most fruits are considerably more acid with a pH below 4.2. This higher acidity controls the growth of food poisoning micro-organisms and so such fruits can be preserved by pasteurization, or heating, to about 80°C for a few minutes. Due to its lower acidity and higher pH, prickly pear can support the growth of potentially dangerous food poisoning organisms which means that it has to be heated to 121°C in a pressure cooker to ensure safe preservation, in a similar way to vegetables. Alternatively the pH can be lowered by the addition of acid; for example lemon juice. Table 2 shows the typical composition of the fruit pulp.

Table 1. Chemical composition of cactus per pulp (g/100g)

Parameter

% fresh fruit

Moisture

83.80

Protein

0.82

Fat

0 09

Crude fibre

0.23

Ash

0.44

Total sugar

14.06

Vitamin C (mg %)

20.33

carotene (mg 5)

0.53

Sepa and Sz (1990)

Table 1. Technological characteristics of cactus per pulp (g/100g)

Parameter

% fresh fruit

Pulp and seeds

49.60

Peel

50.40

pH

6.37

Acidity (% citric acid)

0.06

°Brix (TSS)

14.06

Total solids

16.20

Pectin

0 17

Sepa and Sz (1990)

The fruit has a very intense purple/red colour which makes its products very attractive. This is due to pigments known as betalains (which are common in beet-root).

CACTUS FRUIT PRODUCTS.

In Mexico there are a number of traditional prickly pear products. These include nopalitos, the young soft leaf pads of the plant that are used like green beans and served with meat. Non spiny varieties are preferred. Another product, melcocha, is made by boiling the peeled fruit down to the consistency of toffee, while a strong wine, colonche, is made by fermentation. In Sicily the use of the purple fruit is being examined as a source of natural red food colourants, whilst in South Africa the production of jams and syrups to pour over ice cream is common.

The Ministry of Agriculture in Chile is aware of the potential of this underutilized fruit and is funding investigations in our department to develop new products. We are examining methods of preservation and improving the 'mouth feel' caused by the high viscosity of the juice. We have also produced a very acceptable crystallized leaf product for use in bakeries. An area of particular interest is the production of a fruit gel that can be cut with a knife and eaten with cheese or as a desert. The main problem with this at present is retaining the attractive red/purple colour.

Another use for cactus pear is as animal forage. In the northeast of Brazil, the cactus pear has been grown as a fodder crop for many years. In south Texas, cactus pear is widely known as an emergency drought feed for cattle. Authors suggest that cactus pear can be grown as a fodder crop on land presently deemed marginal for other crops (e.g. maize and sorghum) because of its greater water-use efficiency. Cactus pears produce a high fresh-weight yield for semi-arid ecosystems.

Dr Carmen Sz works at the University of Chile Department of Agroindustry and Food Science, Casilla 1004, Santiago, Chile