PHYSICOCHEMICAL CHARACTERIZATION OF THE NOPAL (Opuntia ficus-indica) CLADODE DEHYDRATED FRACTIONS

Opuntia ficus-indica, which is usually known as nopal, belongs to the family Cactaceae. Nopal is an economically important crop with various applications including its consumption when it is incorporated into foods and beverages. It is also used for pharmaceutical and cosmetic purposes, and it has recently been employed to obtain biodegradable films and coating for fruits because it displays antioxidant, anti-cancer, anti-viral, and anti-diabetic properties, which have all been well documented through research. In this context, we aim to characterize the integral form of nopal cladodes, which were previously dried, ground, and sifted. First, the cladodes were cut into cubes and dried in an oven with forced air circulation (60 °C/12 h). The dried material was ground and sieved into three different granulometries (45, 80, and 120 mesh). The fractions were characterized in terms of their moisture, ash, lipid, and protein content, presence of phenolic compounds, FTIR spectra, microstructure (by scanning electron microscopy, or SEM) and antioxidant activity (by using the DPPH radical). The fractions showed similar moisture (~ 10%) and ash (~ 19 %) values, but different lipid content, which was higher in the thinnest fraction (2.60%). The analyzed nopal fractions also differed in terms of the antioxidant capacity, as revealed by DPPH, and the presence of phenolic compounds: the thinnest fraction afforded the highest values (60.60% and 13.50 mg of garlic acid/g of powder). SEM showed the difference in particle size between the fractions and evidenced that fibers were present in the thicker fractions corresponding to the material retained in the 45-mesh sieve. In conclusion, the sieving process does not interfere in the centesimal composition of the material, except for the lipid content. However, the values for antioxidant capacity and phenolic compounds increase the powder with the smallest particle size (120 mesh) provides the highest values.