Abstract:
This work is part of an approach to valorizing local plant resources through the study of
the prickly pear cactus (Opuntia ficus indica), a xerophytic plant widely distributed in arid and
semi arid areas of Algeria. Recognized for its richness in bioactive compounds (pectins,
flavonoids, mucilages, phenolic acids, vitamins and minerals), which represents a promising
source for the development of high value added products in the agri food, cosmetic and
pharmaceutical sectors.
The main objective of this work was to optimize the conditions for extracting pectin from
prickly pear cacti, considering different extraction methods (acid chemical, complexing agents,
etc.). It was confirmed that the extraction method significantly influ ences the quantity and
quality of extracted pectin. Extraction with acid hydrolysis gave a yield of 1.2%, compared to
extraction by ultrasound and complexing agent, which showed different yields depending on
the experimental conditions.
The acid hydrolysis extraction, which showed the best yield, was optimized by an
experimental design to establish a mathematical model. The optimal extraction conditions are:
a temperature of 90°C, an acid concentration of 0.10 and an extraction time of 45 minutes, with
an optimal yield of 1.2%. The extracts obtained from the prickly pear cactus pads were
thoroughly characterized. The initial moisture content of the pads revealed a significant water
content, reflecting the succulent nature of the plant tiss ue. The extracted pectin was analyzed
for its moisture content, equivalent weight, as well as its methoxyl content (MeO 4.71%),
allowing its gelling capacity to be evaluated. The content of galacturonic acid, the main
constituent of pectin, was determined (46.11%), as was the degree of esterification (DE 84.6%),
a key indicator of its technological functionality. In addition, an infrared spectroscopy (IR)
analysis made it possible to identify the characteristic functional groups, confirming the
polysacchari de nature of the product obtained and the presence of ester and hydroxyl groups
These data confirm the potential of the prickly pear as a strategic raw material for
sustainable industrial applications, while contributing to the economic development of
disadvantaged regions and the fight against desertification.
