Determination of Some Major and Trace Elements in Cladodes of Barbary fig (Opuntia ficus-indica Mill.) by X-ray Fluorescence Spectrometry

Barbary fig (Opuntia ficus-indica) has attracted great attention in extensive rural agriculture for its potential agronomic, medicinal, and environmental benefits. However, there is only incomplete information about its chemical profile. Energy-dispersive X-ray fluorescence (EDXRF) spectrometry was applied to determine the concentrations of 11 major and trace elements (Br, Cr, Cu, Fe, K, Mn, P, Rb, Sr, Yb, and Zn) in cladodes of O. ficus-indica and the adjacent soil. For analytical accuracy, the standard reference materials CRM-IAEA 336 (Lichen) and CRM-NIST 1646a (Estuarine Sediment) were used. The relationships between the chemical elements were established by Pearson's correlation coefficient (r) and principal component analysis (PCA). The results show that K, P, Fe, and Mn were the dominant essential elements in O. ficus-indica cladodes; however, Br, Cr, Cu, Rb, Yb, and Zn were present at low concentrations. The cladodes showed high enrichment with K, Sr, and Br (BEF > 1), but the values of this coefficient were below 1 for the remaining elements. The PCA showed that in the O. ficus-indica cladodes, the higher concentrations of Br, K, and Sr were correlated; conversely, the highest contents of Cr, Cu, Fe, Mn, P, Rb, Yb, and Zn were retained in the soil. The present findings enabled us to determine that O. ficus-indica has a high ability to accumulate K, P, Fe, and Mn in its cladodes. Therefore, the data obtained from the analysis of this cactus will be useful for nutritional and medicinal purposes.

Quality by design approach to optimize cladodes soluble fiber processing extraction in Opuntia ficus indica (L.) Miller

Opuntia ficus indica by-products can be exploited as sources of high-value components for applications in food and other industries. The aim of the present work is to elucidate and optimize the mucilage extraction process from cladodes. The effect of five water-to-biomass ratios (1:1, 1:3, 1:5, 1:7, 1:9 w/v), pH range (2.0, 4.5, 7.0, 9.5, 12.0) and ionic strength (water supplemented with NaCl or CaCl2 at the concentration of 0.1, 1.0, 10.0 and 100.0 mM) were evaluated on mucilage yield. The analysis of the critical factors was done by the response surface methodology. Ultrasound and microwave assisted extractions were evaluated to improve the mucilage recovery and quality. In this work: (1) the development of a multivariate model to predict mucilage recovery on the basis of biomass/water ratio and time of extraction; (2) pH, ionic strength and temperature were found critical process variables by the application of Plackett-Burman design; (3) the optimal operating conditions obtained were found to be: 1:9 biomass/water ratio, pH 12.0, ionic strength 1.0 mM NaCl; (4) ultrasonic or microwave treatments are efficient tools to enhance the recovery of mucilage depending on its final uses. Within a multi-disciplinary approach, this work provides achievements for a more efficient extraction process of soluble polymers from cladodes. Further studies on green assisted extraction tools and their effects in terms of quality of extracts are required in order to obtain high added value bio-products.

Opuntia ficus-indica cladodes as a functional ingredient: bioactive compounds profile and their effect on antioxidant quality of bread

Background

In the context of a balanced diet, the antioxidant-rich food consumption is a preventive way of many degenerative diseases. Consequently, improving the nutraceutical quality of traditional foods such as bakery products is an interesting approach. Considering the present consumer’s demand, cladodes from prickly pear that were traditionally used as a valuable food as well as in folk medicine for the treatment of several chronic diseases were investigated for their use in bread production to improve its functionality.

Methods

Bioactive substances were determined by liquid chromatography-high resolution electrospray ionization mass spectrometry (LC-HRESIMS) analysis. Dough rheological properties were characterized by alveographic measurements. Bread antioxidant quality was evaluated by total phenolics content, DPPH• radical-scavenging, metal (Fe²⁺) chelating and Fe³⁺ reducing power determinations.

Results

LC-HRESIMS analysis of the cladodes extract allowed the identification of 9 flavonoids, 2 phenolics, 1 alkaloid and 1 terpenoid compounds. Cladodes powder enrichment induced important modifications on the dough rheological parameters in terms of the extensibility (L) and deformation energy (W) decrease. Moreover, cladodes powder addition to bread resulted in a decrease in both crust and crumb colour parameters (L*, a* and b*). A 5% supplementation resulted in an increase of the bread yield and bread specific volume by 8.9 and 25%, respectively. Interestingly, Bread containing cladodes powder showed enhanced total phenolics content and antioxidant potential as compared to the control.

Conclusions

Substitution of wheat flour by the cladodes powder at 5% level was optimal for improving the total phenolics content and the antioxidant potential of bread without having any negative effect on its sensory acceptability. Cladodes from Opuntia ficus-indica could be considered as a potential health-promoting functional ingredient in bakery products.