CHEMICAL COMPOSITION OF PEAR CACTUS MUCILAGE AT DIFFERENT MATURITY STAGES

The pear cactus (nopal, Opuntia ficus-indica) mucilage is a hydrocolloid that it helps to regulate the cellular water content in the plant for survive during long periods drought, is composed mainly of neutral and acidic sugars and the concentration of those can change due to the maturity stages of the cladodes or pear cactus. For this reason, the hypothesis of this work was that the maturity stages of pear cactus mucilage produce change in the chemical composition and the aim of this work was to characterize pear cactus mucilage of three different stages of maturity, namely, tender, young, mature according to their proximal chemical composition, analysis of functional groups, identification, and quantification of sugars as well as the elemental microanalysis of the respective pear cactus. The results showed that the mature pear cactus mucilage exhibited the highest content of ash, fiber, and total sugars, with 34.8, 47.5 and 14.32 g 100 g^-1, respectively, and uronic acid with 34.5 %, with respect to the other mucilage. The functional groups identified in the three mucilage (O-H, C-H of methylene, C=O of carboxylic, C-N of amines, and C-O bonds of primary and secondary alcohol) were same, however did show differences in the band intensity between the three mucilage. Chemical elements (minerals) such as potassium, magnesium, calcium, phosphorus, sulfur, silicon, and chlorine were identified in the different pear cactus samples. The content of total sugars, fiber, ash, calcium crystals and uronic acids showed an increase with the increase in the maturity stage of the pear cactus. The results generated could be a potential and relevant for its application in removal of heavy metals present in bodies of water.