|Cactus pear. Image source: Depositphotos|
Plants belonging to the Opuntia genus (Cactae family), thrive in the warm and dry climates of the Mediterranean basin, Central America and Africa. The most investigated and commercially exploited species in this genus is Opuntia ficus-indica; it is valued for its large, sweet fruits characterized by fairly high sugar content and low acidity.1 Opuntia fruits are commonly known as cactus pears, Indian figs, or prickly pears.
The cactus grows wild, and can spread rapidly beyond the cultivation borders, with plants reaching up to 4-5 meters in height. The flowers (white, yellow and red) open up in early May and the fruit ripen in late summer or early fall. According to the statistics from 2001, Mexico accounts for about 79.4% of the total global production of prickly pears.2 Opuntia ficus-indica is also grown in Chile and Brazil, as well as Malta, Spain, Greece, Turkey and Italy, and in the northern belt of Africa - in Libya, Tunisia and Morocco.
Food applications. The pads of the cactus plant are rich in soluble and insoluble dietary fibers, and, upon removing the outer skin and spines, may be consumed in salads or as a side dish. Cactus pear fruits are typically eaten fresh, although they can also be made into jams, jellies, sweets, syrups, juices, and alcoholic beverages. Cactus pear juice is often distilled into an aromatic liqueur or an alcoholic drink called colonche (Mexico). Pigments extracted from the fruits have found applications in the food, cosmetic and pharmaceutical industries.1,3
From the nutritional aspect, Opuntia ficus indica fruit juice is rich in proteins, minerals and vitamins, such as vitamin E and beta-carotene.4 Recent analyses conducted by Brunswick Laboratories confirmed significant levels of ascorbic acid and alpha-tocopherol in cactus pear juice (0.78 mg/ml and 3.67 µg/ml, respectively). Nineeten amino acids were also detected in cactus pear juice, with the greatest observed levels of proline, glutamine and serine. O. ficus-indica fruit juice is a good source of essential amino acids that the body cannot produce on its own.
From the functional point of view, the fruits and juice of this plant are rich in betalain pigments,5 flavonoids like quercetin, kaempferol and isorhamnetin, and various carotenoids with marked antioxidant activity.6 The high content of betalains, both betacyanins (red-violet color) and betaxanthins (yellow color), makes cactus pear fruits especially attractive as an alternative source of extractable natural colorants. At the moment, red beets are the primary source of betalain pigments.
Biological activity. Various biological effects have been attributed to Opuntia fruits and juice in multiple in vitro studies, such as antioxidant,7-9 antiulcerogenic,7 and anticancer activities.10,11 One study reported the main flavonoid constituents of cactus pear fruit juice to be flavonol glycosides, especially isorhamnetin glycosides.7 In the same study, ferulic acid was reported as the main representative of the hydroxycinnamic acid family of compounds.
Chavez-Santoscoy et al. tested the antioxidant capacity of nine prickly pear (Opuntia spp.) juices and found the ORAC assay results to range from 17 to 25 µmol TE/ml.11 These ORAC values were at least two times greater than the ORAC values reported earlier for red and white grape, strawberry, plum, orange, grapefruit, kiwi, apple and pear.12 Brunswick Labs recently determined the ORAC 5.0 assay score for cactus pear juice to be 111 µmol TE/ml. It is important to note that the content of phenolic compounds of prickly pear juice, as well as its antioxidant capacity, may depend on the cultivar and the growing region.9,11
Antiulcerogenic activity of Opuntia ficus indica (L.) Mill. fruit juice was demonstrated in a rat model.7 In this study, the gastric mucosa of rats treated for 9 days with water and ethanol showed necrotic lesions, while the gastric mucosa of animals treated with O. ficus indica fruit juice and ethanol appeared almost normal. Pretreatment with cactus pear fruit juice preserved mucosal integrity, and preserved continuous layers of epithelium.
Chavez-Santoscoy et al. tested the effects of nine prickly pear juices in four cancer cell lines: mammary, prostate, colon and hepatic.11 Normal fibroblast cells served as the control. The juice extracted from Moradillo pears had the highest flavonoid content and diminished both prostate and colon cancer cell viability, but also impeded the growth of normal fibroblasts. The juice extracted from Rastrero pears effectively inhibited the growth of all four cancer cell lines without affecting normal fibroblast viability. This study demonstrated intervarietal differences in phytochemical composition and biological effectiveness of prickly pear juice in in vitro antioxidant and anticancer assays.
Until recently, cactus pear fruits have been relatively underrepresented in the literature on functional foods. However, the importance of this crop is evident from the wide variety of applications it already has in the food industry. The health-promoting potential of this plant still needs to be thoroughly investigated and confirmed clinically, in independent studies and clinical trials. Due to the increasing consumer demand for alternatives to synthetic colorants and antioxidants in food products, betalain pigments and antioxidant components from cactus pear fruits will likely find their place on the growing functional foods market.
- Gurrieri S, Miceli L, Lanza CM, et al. Chemical characterization of Sicilian prickly pear (Opuntia ficus indica) and perspectives for the storage of its juice. J Agric Food Chem. 2000;48(11):5424-31.
- SAGARPA Análisis Agropecuario de TUNA. Servicio de Información Agropecuaria y Pesquera. 2001. Available at: www.siap.sagarpa.gob.mx
- Joubert E. Processing of the fruit of five prickly pear cultivars grown in South Africa. Int J Food Sci Tech. 1993;28:377–387.
- El-Gharras H, Hasib A, Jaouad A, et al. Chemical and physical characterization of three cultivars of Moroccan yellow prickly pears (Opuntia ficus-indica) at three stages of maturity. Cienc. Tecnol. Aliment. 2006;5(2): 93-99.
- El-Gharras H, Hasib A, Jaouad A, et al. Stability of vacuolar betaxanthin pigments in juices from Moroccan yellow Opuntia ficus indica fruits. Int J Food Sci Tech. 2008;43:351–356.
- Feugang JM, Konarski P, Zou D, et al. Nutritional and medicinal use of cactus pear (Opuntia spp.) cladodes and fruits. Front Biosci. 2006;11:2574–2589.
- Galati EM, Mondello MR, Giuffrida D, et al. Chemical characterization and biological effects of Sicilian Opuntia ficus indica (L.) Mill. Fruit juice: antioxidant and antiulcerogenic activity. J Agric Food Chem. 2003;51:4903–4908.
- Kuti JO. Antioxidant compounds from four Opuntia cactus pear fruit varieties. Food Chem. 2004;85:527-533.
- Dehbi F, Hasib A, Bouaziz M, et al. Effect of phenolic compounds and betalain pigments on the antioxidant capacity of Moroccan prickly pear juices. Nature & Technology, Journal B- Agronomic & Biological Sciences. 2013;09:02-07.
- Zou DM, Brewer M, Garcia F, et al. Cactus pear: a natural product in cancer chemoprevention. Nutr J. 2005;4:25-36.
- Chavez-Santoscoy RA, Gutierrez-Uribe JA, Serna-Saldivar SO, et al. Phenolic composition, antioxidant capacity and in vitro cancer cell cytotoxicity of nine prickly pear (Opuntia spp.) juices. Plant Foods Hum Nutr. 2009;64:146-152.
- Wang H, Cao G, Prior RL. Total antioxidant capacity of fruits. J Agric Food Chem. 1996;44:701–705.
Jasenka Piljac Zegarac is a scientist and freelance writer. She holds a PhD in biology and a BS degree in biochemistry, and contributes on a regular basis to several health and science blogs. She may be contacted for assistance with a variety of science and medical writing projects.