The prickly pear shows its effectiveness as it is natural preservative alternative to nitrites. The credit for the research goes to the University of Catania, which has published two studies on the use of its extract to naturally preserve raw meats. With the advantage of not adding aromatic notes characteristic of other natural preservatives extracts from aromatic herbs and spices, such as rosemary, oregano, cinnamon, sage, thyme, mint, ginger, cloves.
Prickly pear, powerful antibacterial
The prickly pear (Opuntia ficus indica) - originally from Central America - it is widespread in Sicily, from which 90% of Italian production derives. The researchers of the University of Catania have developed and defined an extraction protocol using water, as a non-toxic and ecological alternative to the use of solvents (eg methanol, ethanol, hexane).
The antibacterial efficacy of the extract on raw meat was tested in a first study published in 2018 on Food and Chemical Toxicology. (1) The researchers from Catania applied it to sliced raw beef, a food subject to rapid deterioration where the addition of preservatives is also prohibited.
A systematic review evaluated the effect of prickly pear extract on physical and chemical parameters, the maintenance of color and texture of the meat and microbial growth during storage in domestic refrigeration conditions (+4 ° C). With excellent PERFORMANCE, to be attributed to the rich supply of antioxidant and antimicrobial substances (polyphenols, betacyanin and betaxanthin). The extract thus has:
- highlighted a broad spectrum activity in the test vitro, by inhibiting the growth of all Gram positive and negative strains,
- effectively reduced microbial growth during refrigeration (+4 ° C), keeping it at values below the legal limits for 8 days. Twice, compared with the control sample, (2)
- maintained the color and texture of the beef during the 8 days of storage.
The hamburger study
The second study conducted by researchers from Catania, published in 2019, tested the effectiveness of prickly pear extract in the conservation of hamburger raw beef. (3) Like sliced raw meat, these foods are also highly perishable, with one shelf life average of 3 days at +4 ° C. However, while no additives of any kind are allowed in cuts of meat, in fresh minced meat and meat preparations the use of some additives with antioxidant function (not even preservatives with antimicrobial activity). (4)
The antimicrobial efficacy of the prickly pear extract was confirmed both in the test where it was added by direct application, and in that where the substance was encapsulated in alginate beads. The beef hamburger patties thus treated, after 8 days of storage at +4 ° C, showed significantly lower values of mesophilic bacteria, Enterobacteriaceae e Pseudomonas spp. compared to control samples.
Better results, compared to the control sample, they also emerged in the preservation of the color and structural parameters (hardness, cohesion and elasticity) of the meat.
Prickly pear, a wonder of nature
The antibacterial properties prickly pear cactus have been the subject of research since the early XNUMXs, with surprising results. The extract (of the variety Sabotage) has in fact shown:
- antimicrobial activity against Staphylococcus aureus resistant to antibiotics, Pseudomonas aeruginosa e Enterococcus faecium, (5)
- inhibitory efficacy against Salmonella spp. and Escherichia coli O157:H7,
- growth inhibition of Listeria monocytogenes on fresh apples to undetectable levels. (6)
Extracts of another variety (Villanueva) even counteracted the cholera vibe (Vibrio cholerae). (7)
The health properties of this fruit with its thorny skin are also known in scientific literature. Its consumption is associated with anti-inflammatory and diuretic effects, as well as the contribution to the prevention of cardiovascular diseases, ulcers and diabetes. (8)
(1) Rosa Palmeri, Lucia Parafati, Cristina Restuccia, Biagio Fallico (2018). Application of prickly pear fruit extract to improve domestic shelf life, quality and microbial safety of sliced beef. Food and Chemical Toxicology. 2018. https://doi.org/10.1016/j.fct.2018.05.044
(2) the limit established by reg. EC 2073/05 is equal to 5 × 106 log CFU / g of beef
(3) Lucia Parafati, Rosa Palmeri, Daniela Trippa, Cristina Restuccia and Biagio Fallico (2019). Quality Maintenance of Beef Burger Patties by Direct Addiction or Encapsulation of a Prickly Pear Fruit Extract. Frontiers in Microbiology, 2019. doi: 10.3389 / fmicb.2019.01760
(4) The use of food additives in minced meat and meat-based preparations is governed by reg. EU 601/2014. Some of them - such as alginates (E 401–404), carrageenan (E 407), locust bean gum (E 410) and guar gum (E 412) - are added in meat preparations as stabilizers, to reduce water losses in packaging and to prevent the loss of meat juices during subsequent processing. Others, such as acetic acid (E 260), potassium acetate (E 261), sodium acetate (E 262), ascorbic acid (E 300), citric acid (E 330) etc., are allowed as acidulants or antioxidants in preparations prepackaged fresh minced meat and meat preparations, to which additional ingredients have been added to the additives and / or salt. At the level of Codex Alimentarius, il General Standard on Food Additives (GSFA) indicates the possibility of using - in untreated meats, in whole pieces or cuts (category 08.2.1) - three natural extracts used as dyes: carmine (INS 120), vegetable β-carotenes [INS 160e (ii )] and grape skin extract [INS 163 (ii)]. The β-carotenes and grape skin extracts, which also exert antioxidant functions, can be used in doses up to 5.000 mg / kg of product (GSFA, 2018)
(5) Kim Hae-Nam, Kwon Do-Hoon, Kim Hae-Yun, Jun Hong-Ki (2005). Antimicrobial Activities of Opuntia ficus-indica var. saboten Makino Methanol Extract. Journal of Life Science https://doi.org/10.5352/JLS.2005.15.2.279
(6) Seo, YH, Han, CH, Lee, JM, Choi, SM, Moon, KD (2012). Effects of Opuntia ficus indica extracts on inactivation of Escherichia coli O157: H7 and Listeria monocytogenes on fresh-cut apples. Korean J. Soc. Food Sci. Nutr. 41, 1009-1013
(7) Sanchez, E., Garcia, S., Heredia, N. (2010). Extracts of edible and medicinal plants damage membranes of Vibrio cholerae. Appl. Environs. Microbiol. 76, 6888–6894
(8) V. Jean Magloire Feugang, Patricia Konarski, Daming Zou, Florian Conrad Stintzing and Changping Zou (2006). Nutritional and medicinal use of Cactus pear (Opuntia spp.) Cladodes and fruits. Frontiers in Bioscience. 2006. doi: 10.2741 / 1992
Halmi, S .; Benlakssira, B .; Bechtarzi, K .; Djerrou, Z .; Djeaalab, H .; Riachi, F .; Pacha, YH (2012). Antihyperglycemic activity of prickly pear (Opuntia ficus-indica) aqueous extract. International Journal of Medicinal and Aromatic Plants 2012. https://www.cabdirect.org/cabdirect/abstract/20123332319
Seung Hyun Kim, Byung Ju Jeon, Dae Hyun Kim, Tae Il Kim, Hee Kyoung Lee, Dae Seob Han, Jong-Hwan Lee, Tae Bum Kim, Jung Wha Kim, and Sang Hyun Sung (2012). Prickly Pear Cactus (Opuntia ficus indica var.saboten) Protects Against Stress-Induced Acute Gastric Lesions in Rats. Journal of Medicinal Food. https://doi.org/10.1089/jmf.2012.2282
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".