**10. Other aspects**

*Invasive Species - Introduction Pathways, Economic Impact, and Possible Management Options*

juice with *Saccharomyces cerevisiae* and added SO2 (10 mg L<sup>−</sup><sup>1</sup>

the levels of alcohol, sugars and antioxidant activity [52].

1.Economic evaluation of prickly pear fruit production

Sweetener liquid preparation from prickly pear fruit pulp implies enzymatic clarification of pulp juice, its decoloration and its vacuum concentration until 60°Brix (56% of glucose, 44% of fructose approximately). The obtained product shows a density and water activity similar to that of honey and marmalades and its characteristics are similar to other sweetener liquids currently marketed [45, 50]. Alcoholic beverages from *O. ficus-indica* are less known than those from other processed products. Some authors, for obtaining prickly pear wine, inoculated their

obtaining a pH 3.3, and then performed fractional distillation [51]. Besides, prickly pear fruit pulp can be added to other alcoholic beverages such as yakju, increasing

Prickly pear seed oil is another potential product that can be obtained during fruit processing. Linoleic acid is the main fatty acid, and the percentages of PUFAs and MUFAs reach 63.29 and 23.30%, respectively [38]. Besides, other physical and chemical characteristics, such as refractive index, iodine number and saponification number, make it similar to other vegetable oils such as corn or grape seed oil [45].

Nowadays, *O. ficus-indica* cultivation is developed in at least 18 countries in arid and semiarid areas. The extension of this crop is more than 100,000 ha [53]. This does not include naturalized plants or plants cultivated for home consumption. Prickly pear has been used since the sixteenth century as an important subsistence crop in many communities of Africa, Asia, Europe and America, although fruit consumption remains limited to local ethnic markets and there is little export. Only Mexico, Italy, Chile, South Africa and Argentina produce cactus pear in a com-

Mexico is the world's largest producer of prickly pear, accounting for 45% of world production [3, 4]. Other important producing countries of prickly pear are Italy (12.2%) and South Africa (3.7%). The rest of the production is in Argentina, Chile, Bolivia, Peru, Colombia, United States of America, Morocco, Algeria, Libya,

Regarding Mexico, the planted area covers around 50,000–70,000 ha and the gross annual production is 300,000–500, 000 tones. It is the fifth fruit crop in the country and about 20,000 families obtain some income from cactus pear cultivation. Vegetable production, featured by small plots of land cultivation, supposes an additional 12,000 ha of cultivated area [54]. In this country, the cultivation of prickly pear presents the advantage that it produces employment and income in

Italy is the second world producer and the principal world exporter of cactus pear, mostly concentrated (96%) in Sicily with 7000–8300 ha producing about 78,000–87,000 tones per year [55]. South Africa's 1500 hectares produces about 15,000 tones. Other countries where cactus pear is cultivated are South Africa (1500 ha, 15,000 tones of fruit production), Argentina (1650 ha), Brazil (500,000 ha), Chile (934 ha), Peru (5000 tones of fruit production) and California (120 ha) [4]. However, it is difficult to quantify areas and production of prickly pear crop because it is a crop with low economic and social importance in most of

the countries, so that there are not consistent economic data about it [4].

In Mexico, the main producer, the average production is approximately 12.8 t ha<sup>−</sup><sup>1</sup> (400 crates), which are sold at an average price of 3.2 euros each crate. This gives a total of 1280 euros per hectare, and the profit is approximately 340 per hectare, because the costs of tools, weeding, pruning, fertilization, fumigation, harvest and transport, among others [56]. In the case of Italy, the average production is approximately

Tunisia, Egypt, Jordan, Pakistan, Israel, Greece, Spain and Portugal [3, 4].

areas where few other crops can be produced [55].

) and citric acid for

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mercial way [3].

Besides the health benefits of fruit consumption, *O. ficus-indica* presents other multiple applications in different areas:

