Search Results (505)

This study investigated the effect of brief mechanical homogenization using a household blender on the properties of nopal mucilage and its performance in removing potentially toxic elements (PTEs), specifically Pb, Ni, As, Cd, and Zn, from a real cyanidation barren solution. An aqueous extract from Opuntia ficus-indica cladodes was homogenized for 0, 30, or 60 s before spray drying, yielding powders designated as CA, CB, and CC. The powders and water-reconstituted dispersions were characterized and evaluated in coagulation–flocculation assays. Homogenization reduced water activity and average hydrodynamic diameter and significantly modified the ζ potential, although the effects were not proportional to processing time. At 10% w·v⁻¹, the reconstituted mucilages showed frequency-dependent viscoelastic behavior consistent with a transient gel-like organization. All treatments removed more than 98% of Pb, Ni, and As at doses of 200–800 mg·L⁻¹. Cd removal was more variable and significantly affected by mucilage type, whereas Zn showed lower, non-monotonic removal. ESEM–EDS detected PTE-bearing inorganic domains within the recovered flocs, corroborating transfer from the liquid to the solid phase. Overall, mechanical homogenization modified the colloidal, supramolecular, and gel-related properties of spray-dried nopal mucilage, which showed potential as a multifunctional hydrocolloid for treating chemically complex cyanidation process streams. Full article

The use of nondestructive technologies combined with machine learning has emerged as a promising approach for estimating structural and productive traits in agricultural systems. This study evaluated the potential of Unmanned Aerial Vehicle (UAV) imagery integrated with the Random Forest algorithm to predict structural, physiological and productive variables of forage cactus cultivated under semi-arid conditions. The experiment was conducted over two years using four varieties: Orelha de Elefante Mexicana (OEM), Miúda, IPA Sertânia and IPA 20. RGB and red–green–near-infrared (RGNir) orthomosaics, along with a digital elevation model, were used to derive spectral and structural variables, which were related to field measurements. Model performance was assessed using the coefficient of determination (R²). The models showed high predictive performance for dry mass production, particularly for OEM, IPA Sertânia and IPA 20 (R² = 0.85, 0.85 and 0.83). Physiological variables, such as chlorophyll A and B, also showed consistent fits (R² = 0.70 and 0.83), while structural variables, including height and volume, exhibited lower stability. Differences among varieties affected model accuracy, especially for Miúda, due to its architectural characteristics. The integration of UAV imagery and machine learning provides a reliable approach for monitoring forage cactus, although model performance depends on plant structure. Full article

Coagulation–flocculation is widely recognized as a fundamental step in wastewater treatment, as it promotes the aggregation and removal of suspended particles and organic contaminants following the addition of a coagulant. In this study, a bio-based coagulant was prepared from prickly pear (Opuntia ficus-indica) seed residues obtained after essential oil extraction. The extraction process for bioactive agents was successfully modeled using Central Composite Design (CCD)-based Response Surface Methodology (RSM). Optimal extraction was reached at pH 13, PPSM of 7.5 g, 0.75 M NaCl, and 40 min of stirring, providing maximum yields of 69.63 g proteins, 217.075 g total sugars, and 81.416 g polyphenols. The optimized extract was subsequently used as a bio-coagulant for the treatment of wastewater collected from the Chalghoum El Aid–Oued El Athmania wastewater treatment plant (Mila, Algeria). The effects of three operating parameters, initial turbidity, solution pH, and bio-coagulant dosage, on the coagulation–flocculation performance were investigated using a Box–Behnken design (BBD). Process efficiency was evaluated in terms of turbidity, chemical oxygen demand (COD), and organic matter (OM) removal. The raw wastewater exhibited initial values of 200 NTU for turbidity, 640 mg/L for COD, and 25 for organic matter. Statistical analysis revealed that the developed quadratic models were highly significant (p ≤ 0.05) and showed excellent predictive performance, with coefficients of determination (R² ≥ 0.97). Optimal treatment conditions were identified at pH 7, a bio-coagulant dosage of 1 mL/L, and an initial turbidity of 200 NTU. Under these conditions, removal efficiencies exceeded 98% for turbidity and COD and reached 88.08% for organic matter. Furthermore, Fourier-Transform Infrared (FTIR) Spectroscopy analysis confirmed the presence of functional groups responsible for the coagulation activity of the bio-coagulant. These findings highlight the potential of prickly pear seed residues as an effective, sustainable, and low-cost alternative to conventional chemical coagulants in wastewater treatment. Full article

The prickly pear is a crop of socioeconomic relevance in arid regions, and its productivity and chemical composition depend on water availability. The effect of irrigation on the crop’s biochemical quality was evaluated. Cladodes of cultivars: ‘Amarilla Olorosa’, ‘Cristalina’, ‘Dalia Roja’, and ‘Roja Lisa’, were subjected to three treatments: no irrigation (NI), supplemental irrigation (SI), equivalent to 50% of the crop’s evapotranspiration, and full irrigation (FI). Subsequently, cladodes were collected, and total polyphenols and flavonoids, polyphenol profile, and antioxidant capacity were determined. Cladodes under NI had the highest concentrations of flavonoids, although the lowest values of total polyphenols. In the cladode extracts, myricetin, rutin, catechin, as well as caffeic, chlorogenic, dihydroxybenzoic, and vanillic acids were identified. Overall, cladodes grown under FI and SI showed higher levels of phenolic acids (caffeic, chlorogenic, and vanillic), while concentrations of catechin, myricetin, and rutin were higher under SI and NI. Antioxidant capacity was higher in NI cladodes assessed by ABTS and DPPH, while the FRAP assay showed higher values under SI. Among the cultivars, ‘Amarilla Olorosa’ stood out for its high content of bioactive compounds, confirming the potential of nopal cladodes as a source of antioxidant metabolites with agro-industrial applications. Full article

Prickly pear (Opuntia ficus-indica (L.) Mill.) generates substantial agro-industrial by-products, such as press cake, seed, and oil, that remain underexploited despite their recognized phytochemical richness. This study reports the systematic optimization, characterization, and bioactivity profiling of flavonoid-rich extracts recovered from these three matrices. A Box–Behnken design (BBD) coupled with response surface methodology (RSM) was applied to optimize the ultrasound-assisted extraction (UAE) of total flavonoid content (TFC) from press cake using a natural deep eutectic solvent (NADES: fructose–glycerol–sorbitol–water and FGSH), selected through an initial screening of fifteen solvent systems. The quadratic polynomial model showed excellent fit (R² = 0.9852; R²adj = 0.9687; MAPE = 1.31%; Durbin–Watson = 1.857), and optimal extraction conditions were established at 37.6 min extraction time, 35.6% ultrasonic power, and 29.4 °C, yielding a maximum predicted TFC of 54.78 ± 0.49 mg quercetin equivalents (QE)/mL. HPLC-DAD analysis of the press cake extract revealed five isorhamnetin derivatives as the dominant flavonoids, with isorhamnetin-3-O-glucoside (23.18 ± 0.12 mg/g DW) and isorhamnetin-3-O-rutinoside (13.80 ± 0.28 mg/g DW) as the most abundant. Comprehensive bioactivity assessment demonstrated significant antioxidant capacities (CUPRAC: 191.35 ± 3.22 µM AAE; ORAC: 184.44 ± 3.44 µM TE; DPPH: 103.47 ± 9.98 µM TE for press cake extract), potent in cellulo ROS/RNS suppression in a yeast UV-stress model (85.9 ± 1.0% inhibition for press cake), and differential tyrosinase inhibition across fractions (press cake: 32.8%; seed: 57.5%; oil: 83.8%), highlighting the oil as a potent anti-melanogenic ingredient. In silico safety prediction (ProTox-II/pkCSM) confirmed the favorable toxicity profiles of all identified isorhamnetin derivatives (LD₅₀ > 5000 mg/kg; Toxicity Class V). These results collectively position Opuntia ficus-indica by-products as high-value natural sources of bioactive flavonoids with applications in cosmetic, nutraceutical, and dermatological formulations. Full article

Cacti thrive in arid and coastal environments partly through associations with beneficial endophytic and rhizosphere bacteria; however, current knowledge remains limited. This study aimed to assess the diversity of cultivable bacteria associated with Opuntia dillenii and evaluate their potential as Plant Growth-Promoting (PGP) agents. Endophytic bacteria were isolated from cladodes and roots, while rhizobacteria were recovered from rhizosphere soil. Bacterial isolates were identified using morphological characteristics and 16S rRNA/gyrB sequencing, followed by screening for PGP traits, pH and temperature tolerance. A total of 31 isolates were obtained, including 23 endophytes and 8 rhizobacteria, mainly affiliated with Firmicutes, Actinobacteria, and Proteobacteria. Bacillus (35.48%) and Priestia (32.25%) predominated, with Priestia flexa as the most prevalent species. The most frequent PGP traits were phosphate solubilization (80.65%), proteolytic activity (70.97%), siderophore production (67.74%), and nitrogenase activity (64.52%). The highest phosphate solubilization indices were observed for strain R3 (3.41), R6 (3.39) and S6 (3.21), whilst the highest indole-3-acetic acid yields were recorded for C9 (172.88 µg/mL), R11 (96.22 µg/mL) and C3 (90.94 µg/mL), and the strongest siderophore production for C3 (30.37 mm), C7 (27.96 mm) and S7 (27.88 mm). These findings highlight O. dillenii-associated coastal bacteria as promising resources for plant growth and plant stress resilience. Full article

The main causes of lemon fruit senescence and deterioration are fungal diseases and postharvest quality loss. Edible coatings have been proposed to delay quality loss in fresh produce by reducing moisture loss and helping preserve external appearance. Natural functional coatings are increasingly being investigated as potential alternatives to synthetic waxes and preservatives due to environmental and consumer safety concerns. The effect of a natural edible coating based on Opuntia ficus-indica mucilage on extending the shelf-life of lemons during cold storage was investigated. Lemon fruits were treated with the mucilage-based edible coating and subsequently stored under controlled cold conditions. Coated and uncoated lemon fruits were evaluated for their physicochemical properties, including weight loss, total soluble solids, pH, titratable acidity, color, and microbiological analysis, as well as total polyphenol content and antioxidant activity, over a 60-day storage period at 5 ± 0.5 °C and 95% relative humidity. The results showed that the mucilage-based coating improved lemon fruit storage performance, effectively preserving key physicochemical and microbiological parameters over 60 days of cold storage (p ≤ 0.05). In particular, the treatment maintained fruit firmness, reduced weight loss (up to 45%), increased juice content (up to 1.8-fold), and delayed microbial decay compared to control samples. Coated fruits also exhibited higher total polyphenolic content and antioxidant activity than control samples at the end of storage. In addition, using mucilage extracted from cactus pear cladode waste provides a sustainable way to add value to the product, with promising industrial applications as an alternative to synthetic fruit coatings. Full article

Salinity stress remains a major bottleneck for agriculture in arid regions. While Opuntia ficus-indica is known for its resilience, its young cladodes maintain a misleadingly healthy visual appearance and stable biomass even under heavy saline pressure, making traditional vegetation indices and standard statistics unreliable for early diagnosis. The objective of this study was to develop a non-destructive phenotyping framework for the early detection of latent salinity stress in young Opuntia cladodes. Controlled experiments were conducted using hyperspectral data cubes (400–1000 nm) acquired from plants exposed to six distinct salinity levels ranging from 2 to 21 dS m⁻¹. Our methodology integrates these high-dimensional spatial–spectral data with a tailor-made 3D Convolutional Neural Network (3D-CNN). Seven physiological vegetation indices—NDVI, PRI, WI, PSRI, MCARI, SIPI, and NDRE were extracted to track sub-clinical shifts and processed as a volumetric depth dimension within the network to preserve spatial–spectral integrity. The optimized 3D-CNN framework achieved a validation accuracy of 99.7% and a weighted F1-score of 99.1%, delivering 100% precision at critical stress thresholds (13 and 21 dS m⁻¹). Spatial confidence maps (Softmax > 0.95) further confirmed the high reliability of the diagnostic output. Requiring a training duration of approximately 8 s, this framework provides a robust basis for precision early-warning irrigation systems to sustain Opuntia cultivation in challenging environments. Full article

Indole-3-acetic acid (IAA) is an essential phytohormone that regulates several tropic responses in plants and serves as signaling molecule in plant–bacteria interactions. In this study, a high indolic-compound-producing actinobacterial strain, designated OP15, was isolated from the roots of Opuntia ficus-indica as an endophyte and identified as a member of the Streptomyces genus based on 16S rRNA gene sequence analysis. Synthetic dairy wastewater (SDWW) was used as a low-cost fermentation substrate for the production of IAA-equivalent compounds, providing a sustainable approach that links microbial metabolite production with agro-industrial waste valorization. Fermentation conditions were optimized using a Box–Behnken design coupled with response surface methodology. To address model overfitting, a backward elimination procedure was applied, yielding a reduced statistical model (R² = 0.658, adjusted R² = 0.628, predicted R² = 0.583) with adequate predictive performance. Under the optimized conditions (1 g/L NaCl, 1 g/L L-tryptophan, 100% SDWW, 7.5% inoculum, 4.5 days), the model predicted a maximum response of 278.2 µg/mL (95% prediction interval: 230.0–326.4 µg/mL). Experimental validation yielded a response of 296.838 µg/mL, falling within the prediction interval and confirming the model’s reliability within the experimental domain. This agreement supports the model’s utility for process optimization within the experimental domain. In addition, treatment of wheat seeds with the culture supernatant of OP15 isolate significantly (p < 0.05) promoted root length and root dry weight. Overall, these findings highlight the potential of the OP15 strain for the sustainable production of IAA-equivalent compounds using SDWW and support the valorization of dairy effluents as low-cost substrates for biotechnological applications. Full article

Destructive methods for monitoring stress responses remain a bottleneck in precision agriculture. This study presents a non-destructive methodological framework evaluating drought responses in 30 Opuntia ficus-indica plants over four months under five irrigation levels. Cladode traits (color, weight, and thickness) were measured alongside RGB imagery from a UAV and hyperspectral imaging (400–1000 nm). Partial least squares regression (PLSR) models showed high capability to model proline (R² = 0.91), chlorophyll a (R² = 0.97), and total chlorophyll (R² = 0.97) within the experimental dataset. Crucially, these models reflected continuous spectral–physiological variation across the irrigation gradient rather than discrete treatment separation, with key spectral regions identified at 530–600 nm and 550–750 nm. UAV-derived RGB imagery enabled the estimation of plant area and biomass (R² = 0.88). Under extreme drought, cladode thickness decreased by approximately 41%, accompanied by reduced biomass and increased soluble solids (°Brix). While no statistically significant differences were observed among irrigation treatments for biochemical variables, limiting treatment discrimination based on discrete classification, the hyperspectral data successfully captured the underlying continuous physiological variation. Consequently, this work demonstrates the methodological viability of integrating UAV structural phenotyping and hyperspectral analysis as a continuous monitoring tool rather than a rigid classification system. These findings provide a methodological baseline that highlights the need for continuous sensing in CAM plants, though further validation with independent datasets remains essential for wider operational application. Full article

The objective of this study was to evaluate the potential of age Opuntia-derivated digestate (OpDcm) as a nutrient source for photosynthetic microbial consortia (PMC), aiming to reduce dependence on mineral media and promote the valorization of locally available biomass in arid and semi-arid regions. Batch cultures were performed in bubble column photobioreactors (BCPBR) and open raceway (ORPBR) photobioreactors using different proportions of OpDcm and BG11₀ to assess biomass production, chlorophyll a dynamics, and physicochemical responses of a PMC dominated by Nostoc sp. Chemical characterization showed that OpDcm contained higher levels of K, Ca, Mg, and Mn than BG11₀, providing a robust ionic matrix for initial growth; however, potential limitations in P, Mg, and Fe were identified. In both BCPBR and ORPBR systems, OpDcm demonstrated nutrient compositions that stimulated biomass production in the PMC at levels comparable to those achieved with BG11₀ medium. Statistical analyses showed that specific treatments, particularly T1 (10% OpDcm in BCPBR) and T3 (10% OpDcm + 2.5% BG11₀ in ORPBR), produced biomass yields similar to or higher than those obtained with the conventional BG11₀ medium. However, chlorophyll a concentration was lower in OpDcm treatments due to limited light transmission and micronutrient constraints. The N–NH₄⁺ dynamics in BCPBR and ORPBR exhibited pronounced variability among the evaluated culture media, spanning from negligible changes (<1 mg L⁻¹) over the entire cultivation period to sustained ammonium production rates of 2–3 mg L⁻¹ day⁻¹. Morphological analysis confirmed a consortium dominated by Nostoc sp., supported by pH values within the optimal range (8–9). Overall, the use of age-Opuntia-derived digestates demonstrated it can serve as a partial or total substitute for a low-cost nutrient source for cyanobacterial cultivation, underscoring their relevance to circular bioeconomy strategies for producing photosynthetic biomass. Full article

Plant-derived bioactive metabolites have emerged as promising modulators of oxidative stress and inflammation, two interconnected processes involved in the pathogenesis of numerous chronic diseases. Arid ecosystems, particularly the Sonoran Desert, constitute an underexplored source of structurally diverse phytochemicals with significant pharmacological potential. This review provides a comprehensive overview of major classes of plant-derived bioactives, including polyphenols, flavonoids, terpenoids, and alkaloids, with emphasis on their molecular mechanisms of antioxidant and anti-inflammatory action. These compounds exert cytoprotective effects through direct reactive oxygen species (ROS) scavenging and indirect regulation of endogenous defense systems, primarily via activation of the Nrf2/Keap1 pathway and suppression of NF-κB signaling. Additional pathways, including MAPK, PI3K/Akt, AMPK, and mitochondrial regulatory networks, are discussed as critical mediators of redox balance and inflammatory control. Particular attention is given to Sonoran Desert plant species such as Bucida buceras, Phoradendron californicum, Larrea tridentata, Opuntia spp., and Agave deserti, all of which demonstrate promising biological activities associated with enhanced adaptation to environmental stress. Experimental approaches used to evaluate phytochemical bioactivity, including chemical assays, cellular models, omics technologies, and translational strategies, are also examined. Furthermore, this review discusses current limitations related to bioavailability, phytochemical variability, and clinical validation, highlighting emerging nanodelivery systems and precision medicine approaches as potential solutions. Collectively, the evidence supports the therapeutic relevance of Sonoran Desert plant bioactives as multi-target agents for modulating oxidative stress, inflammation, and chronic disease progression. Full article

Opuntia miquihuanensis (Cactaceae: Opuntioideae), a new species endemic to the locality Peña-Aserradero, part of the Sierra Madre Oriental, Tamaulipas, Mexico, is formally described and illustrated. Phylogenetic analyses used maximum parsimony, maximum likelihood and Bayesian inference, based on sequences of trnL-trnF, psbJ-petA, matK, ycf1, ppc and ITS. The micromorphology of spines, epidermis, stoma, and pollen was characterized with scanning electron microscopy. Opuntia miquihuanensis is recovered as a supported species within Opuntia s.str. Full article

Aquaculture effluent appears as an alternative for reuse, given its significant generation. However, its use must be reasonable to avoid damage to the environmental quality of the soil. In this context, the objective was to evaluate the chemical changes in Ultisol cultivated with small prickly pear cactus and irrigated with different dilutions of aquaculture effluent in the supply water. The experiment was conducted at the Water Reuse Experimental Unit, located in the Brazilian semi-arid region, Mossoró, RN, Brazil. Planting was carried out in a randomized block design with five treatments and five replications. A small prickly pear cactus was irrigated weekly for 365 days, with the gross water depth determined based on the crop’s evapotranspiration. During the experimental period, the physical-chemical characterization of the effluent dilutions was conducted every 60 days, with initial and final descriptions of the soil in the 0.0–0.20 m and 0.20–0.40 m layers. Additionally, cation exchange capacity and the exchangeable sodium percentage were determined. Multivariate statistical analysis was applied to understand chemical changes in the soil. The dilutions containing a higher proportion of aquaculture effluent in the supply water, primarily consisting of 100% effluent, exhibited the chemical changes in the soil. Using a dilution containing 25% aquaculture effluent in 75% supply water may be the most viable alternative for water supply in prickly pear cactus irrigation, with non-relevant changes in soil chemical characteristics. Full article

Opuntia ficus-indica (L.) Mill., also named Cactus pear, is a crop widespread in many countries with Mediterranean and subtropical climates, where it represents a valuable source of food. However, in southern Europe, this fruit market is limited to a few months, from summer to autumn. The possibility to extend the ripening period of fruit is represented by the special pruning of the first bloom flush and consequent new development of late flowers and fruits. Extending the cultivation period would allow farmers to maximize the crop’s potential, thereby extending the Cactus pear market season throughout much of the year. In this study, conducted in southern Sardinia (Italy), progressive pruning was applied with the aim of evaluating the fruit characteristics in relation to this type of cultivation, also considering the weather conditions during the experimental period. Morphological traits and physicochemical compositions of fruit picked in four harvests during two sampling seasons from August 2022 to March 2023, and from August 2023 to March 2024 were compared. According to principal component analysis (PCA), most of the observed characters showed significant differences among harvest periods but also between the two seasons of cultivation (year of cultivation: r = 0.722 on PC1), suggesting that the meteorological trend strongly modulated fruit traits. Some fruit qualities were partially lost during the winter months, such as juice acidity and total soluble solids (TSS). October was the month with the highest TSS levels (13.5 ± 0.25), followed by August, January and March. On the other hand, juiciness and fresh weight remained unchanged or even improved in fruit harvested out-of-season. As observed in the redundancy analysis (RDA) a contribution of 54% due to weather variability emerged. In Particular, TSS levels, pH and juice dry matter were associated with high temperatures, solar radiation, and wind intensity. Wind speed was also moderately linked with betalain content. Moreover, high relative humidity was associated with lower pH values, higher water content, and higher fruit fresh weight. A significant difference was found between the two years in betalains content (80.0 ± 3.7 µg·mL⁻¹ in 2022–2023 and 28.2 ± 2.5 µg·mL⁻¹ in 2023–2024). The breakdown in the 2023–2024 season was likely due to the strong heat wave of July 2023 (up to 47 °C), which caused their partial degradation. In light of seasonal variability, this work provides some useful insights for future management of Cactus pear, also considering the possibility of usefully extending the period of cultivation and harvesting. Full article