Candelilla Wax Extracted by Traditional Method and an Ecofriendly Process: Assessment of Its Chemical, Structural and Thermal Properties.

A comparative study was carried out on the chemical, structural and thermal properties of candelilla wax from four wax-producing communities in Mexico, which was obtained by two extraction processes, the conventional one using sulfuric acid (SA) and an eco-friendly alternative process using citric acid (CA) as the extracting agent. The waxes were analyzed by basic chemistry (acidity, saponification, ester indexes, and others), color, Fourier transform infrared spectroscopy (FTIR), Raman micro-spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC), and hardness and brittleness measurements. The waxes obtained by the environmentally friendly process showed differences in their physicochemical properties when compared to waxes from the conventional process. In addition, they showed some improvements, such as lighter shades and harder waxes, suggesting that the new environmentally friendly process is a viable option.

Mexican Oregano (Lippia graveolens Kunth) as Source of Bioactive Compounds: A Review.

Lippia graveolens is a traditional crop and a rich source of bioactive compounds with various properties (e.g., antioxidant, anti-inflammatory, antifungal, UV defense, anti-glycemic, and cytotoxicity) that is primarily cultivated for essential oil recovery. The isolated bioactive compounds could be useful as additives in the functional food, nutraceuticals, cosmetics, and pharmaceutical industries. Carvacrol, thymol, ß-caryophyllene, and p-cymene are terpene compounds contained in oregano essential oil (OEO); flavonoids such as quercetin O-hexoside, pinocembrin, and galangin are flavonoids found in oregano extracts. Furthermore, thermoresistant compounds that remain in the plant matrix following a thermal process can be priced in terms of the circular economy. By using better and more selective extraction conditions, the bioactive compounds present in Mexican oregano can be studied as potential inhibitors of COVID-19. Also, research on extraction technologies should continue to ensure a higher quality of bioactive compounds while preventing an undesired chemical shift (e.g., hydrolysis). The oregano fractions can be used in the food, health, and agricultural industries.

Spray-drying encapsulation of microwave-assisted extracted polyphenols from Moringa oleifera: Influence of tragacanth, locust bean, and carboxymethyl-cellulose formulations.

In this work, polyphenols from Moringa oleifera (Mor) leaves were extracted by microwave-assisted extraction (MAE) and encapsulated by spray-drying (SD). Particularly, we explored the influence of tragacanth gum (TG), locust bean gum (LBG), and carboxymethyl-cellulose (CMC) as wall-materials on the physicochemical behavior of encapsulated Mor. Single or combined wall-material treatments (100:00 and 50:50 ratios, and total solid content 1%) were tested. The results showed the wall-material had a significant effect on the process yield (55.7-68.3%), encapsulation efficiency (24.28-35.74%), color (yellow or pale-yellow), total phenolic content (25.17-27.49 mg GAE g-1 of particles), total flavonoid content (23.20-26.87 mg QE g-1 of particles), antioxidant activity (DPPH• = 5.96-6.95 mg GAE g-1; ABTS•+ = 5.61-6.18 mg TE g-1 of particles), and particle size distribution (D50 = 112-1946 nm) of the encapsulated Mor. On the other hand, SEM analysis showed smooth and spherical particles, while TGA and DSC analyses confirmed the encapsulation of bioactive compounds based on the changes in thermal peaks. Finally, XRD analysis showed that the particles have an amorphous behavior. The encapsulated Mor produced with individual TG or CMC demonstrated better properties than those obtained from mixed gums. Thus, TG or CMC might be feasible wall materials for manufacturing encapsulated Mor that conserve the phenolic content and antioxidant activity.

Antioxidant activity of polyphenolic compounds obtained from Euphorbia antisyphilitica by-products.

In this study, an alternative extraction technique, ultrasound-assisted extraction, was used to extract the polyphenolic fraction from two different residues of the candelilla plant (Euphorbia antisyphilitica). These metabolites were further analyzed to evaluate their bioactivity as antioxidants. In addition, their functional groups were identified by Fourier transform infrared (FTIR) spectroscopy. The antioxidant assays showed statistically significant differences between the phenolic extracts, with citric acid residues (CAR) exhibiting a higher oxidant effect than sulfuric acid residues (SAR). The CAR from San Jerónimo (SJ) cultivar showed decreased IC50 values (179.441 ± 7.92 µL mL-1, DPPH•), and its polyphenolic fraction was able to inhibit lipid oxidation (70.31 ± 2.50%). FTIR analysis subsequently revealed the presence of functional groups related to polyphenolic compounds, such as hydroxy, carbonyl, carbon double bond, and amine groups. In addition, FTIR spectra showed slight differences in phenolic compounds, due to the strong acid treatment involved in the extraction of wax. The present study demonstrated that candelilla by-products from citric acid-wax extraction have a polyphenolic fraction with strong antioxidant activity, which may be useful in food and pharmaceutical products.

Euphorbia antisyphilitica Zucc: A Source of Phytochemicals with Potential Applications in Industry.

Euphorbia antisyphilitica Zucc, better known as the candelilla plant, is one of the 10 non-timber forest products of greatest economic importance in the desert and semi-desert regions of Mexico. Moreover, it is a potential source of some functional phytochemicals such as polyphenolic compounds, wax and fiber, with potential applications in food, cosmetic and pharmaceutical industries. Thus, this review aims to describe these phytochemicals and their functional properties as antimicrobial, antioxidant, reinforcing and barrier agents. In addition, a suitable valorization of the candelilla plant and its byproducts is mandatory in order to avoid negative effects on the environment. This review provides, for the first time, an overview of the alternative methodologies for improving candelilla plant production, pointing out some of the agricultural aspects of the cultivation of this plant.

Evaluation of the Conditions for the Synthesis of Silver Nanoparticles from Orange Peels and its Antibacterial Effect.

AIMS: To use an agroindustrial waste (orange peels) as a source of polyphenols as a reducing medium for obtaining silver nanoparticles by greener method. BACKGROUND: Several techniques have been employed for AgNPs synthesis, nevertheless, most of them involve the use of toxic chemicals in the process. The use of fungi, bacteria, and plant extracts as subtracts for green synthesis is an ecofriendly alternative, although hypothetic, route for AgNPs large scale synthesis. In the case of plant extracts, it is believed that polyphenols are the biomolecules responsible for the reduction and stabilization of the Ag+ ions into AgNPs, being a sustainable and ecological option; polyphenols could be obtained from plant waste and agroindustrial subproducts. OBJECTIVE: To develop an efficient, greener, and low-cost method of AgNPs production using natural products. METHODS: The basic principle of silver nanoparticles synthesis is the interaction in a mixture of silver nitrate (source of Ag+ ions) and the orange peel extract (reducing and stabilizing agent) under certain conditions. Five treatments were carried out, evaluating several parameters during AgNPs synthesis such as pH, orange peel extract-silver nitrate ratio, time and conditions of incubation, irradiation of UV light, irradiation of microwave, and temperature. RESULT: The synthesis of silver nanoparticles from an agroindustrial waste as the orange peel was successfully carried out and checked by visual evaluation, UV-Vis spectroscopy, and EDS analysis. The particle size was estimated between 42.82 nm to 151.75 nm, having a spherical and ovoid morphology. DISCUSSION: Through the analysis of several synthesis conditions, it has become possible to establish a suitable treatment to increase antibacterial yield and evaluate morphology and size traits in order to acquire the best conditions for a future industrial scale synthesis. CONCLUSION: The orange peel aqueous extract resulted as a great source of polyphenols, allowing the successful synthesis of silver nanoparticles in mild conditions. Thus, obtained AgNPs revealed an increased antibacterial effect and potential against Gram-positive bacteria such as Staphyloccocus aureus.

Polyphenolic Profile and Antioxidant Activity of Leaf Purified Hydroalcoholic Extracts from Seven Mexican Persea americana Cultivars.

Persea americana (avocado) is a fruit consumed worldwide; however, since avocado leaves are apparently a natural ingredient that can be used as a traditional medicine, they can be a potential source of bioactive compounds. This study aimed to analyze the antioxidant activity of seven Mexican avocado leaf extracts by DPPH•, ABTS•+, and lipid peroxidation (LPO), and to identify the compound profile by liquid chromatography coupled to mass spectrometry/electron spray ionization. The highest free radical-scavenging activity was observed for Platano Delgado and Criollo 6 avocado cultivars havin IC50 values of 271.86 ± 13.69 and 269.56 ± 6.53 for DPPH• and ABTS•+ radicals, respectively, while the best result for lipid oxidation inhibition was registered in Criollo 6 cultivar extract. In this study forty-one compounds were detected in avocado leaves of the the seven cultivars analyzed, and of these compounds, eighteen phenolics were identified for first time in such plant material. The present study demonstrated that Mexican cultivars of Persea americana possess diverse polyphenolic compounds with strong antioxidant activity, which might be useful in the food and pharmaceutical industries.

Free Radical-Scavenging Capacities, Phenolics and Capsaicinoids in Wild Piquin Chili (Capsicum annuum var. Glabriusculum).

The total phenolic compounds content, free radical-scavenging capacity and capsaicinoid content in populations of wild Piquin chili (C. annuum) were studied. Aqueous and hydroalcoholic extracts from nine ecotypes were evaluated. High contents of phenolic compounds and free radical-scavenging capacities were observed for both extracts; however, the values that were found for the hydroalcoholic phase were substantially higher. LC-MS analysis allowed for the detection of 32 compounds, where apigenin-8-C-glucoside followed by vanillic acid 1-O-ß-o-glucopyranosylester (Isomer I or II) and 7-ethoxy-4-methylcoumarin were the most widely distributed; they were found in more than 89% of the ecotypes. The diversity of identified phenolic compounds was different among ecotypes, allowing them to be distinguished by chemical diversity, free radical-scavenging capacities and heat Scoville units. The total capsaicinoid content was higher in Population I (23.5 mg/g DW) than in Populations II and III, which had contents of 15.3 and 10.7 mg/g DW, respectively. This variability could lead to phytochemical exploitation and the conservation of the natural populations of wild chili.

Influencia del solvente de extracción en el contenido fenólico y nivel de capacidad antioxidante de un suplemento alimenticio comercial de hojas de Moringa oleifera / Influence of extraction solvent on phenolic content and antioxidant capacity level of a commercial food supplement from Moringa oleifera leaves

The objective of this research was to evaluate the effect of extraction solvent on phenolic compounds content (total phenols, total flavonoids) and antioxidant capacity levels (DPPH, ABTS and FRAP) of a commercial food supplement from Moringa oleifera leaves. The content of total phenols, total flavonoids and total non-flavonoids ranged from 55.98 to 226.20 mg ChlAE/g, from 17.63 to 23.46 mg CatE/g and from 38.34 to 202.73 mg CatE/g mg/g, respectively, while condensed tannins were not detected in none of the extracts. Non-flavonoids compounds were the most abundant group of phenolics in all the extracts ranging from 68 to 90% of the total phenols content. Levels of antioxidant capacity ranged from 22.43 to 124.93, 101.03 to 245.25 and 77.06 to 214.17 µmolTE/g in ABTS, DPPH and FRAP, respectively. In addition, EtOH 50% and EtOH 100% extracts showed the highest and lowest content in phenolics content and antioxidant capacity level. Finally, data obtained in the content of phenolics and antioxidant capacity levels of the present study are higher than most of data of scientific literature reported previously by other authors(AU)

El objetivo de esta investigación fue evaluar el efecto del solvente de extracción en el contenido de compuestos fenólicos (fenoles totales, flavonoides totales) y los niveles de capacidad antioxidante (DPPH, ABTS y FRAP) de un suplemento comercial de hojas de Moringa oleifera. El contenido de fenoles totales, flavonoides totales, no-flavonoides totales oscilaron de 55.98 a 226.20 mg ChlAE/g, de 17.63 a 23.46 mg CatE/g y de 38.34 a 202.73 mg/g, respectivamente, mientras que no fue detectada la presencia de taninos condensados en ninguno de los extractos. Los compuestos fenólicos noflavonoides fueron el grupo más abundante de compuestos fenólicos en todos los extractos y oscilaron de 68 a 90% del total de los fenoles totales. Los niveles de capacidad oscilaron de 22.43 a 124.93, de 101.03 a 245.25 y de 77.06 a 214.17 µmolTE/g en ABTS, DPPH y FRAP, respectivamente. Además, los extractos con EtOH 50% y EtOH 100% mostraron el contenido más alto y más bajo de fenólicos y niveles de capacidad antioxidante, respectivamente. Finalmente, los datos obtenidos en el contenido de compuestos fenólicos y los niveles de capacidad antioxidante del presente estudio son más altos que la mayoría de los datos reportados previamente en literatura por otros autores(AU)

Impact of extraction techniques on antioxidant capacities and phytochemical composition of polyphenol-rich extracts.

In this work, impact of extraction methods (maceration, decoction, MAE, and UAE) on TPC, antioxidant activity, and the mass fraction of phenolics in several plant extracts (Punica granatum, Juglans regia, Moringa oleifera, and Cassia fistula) was investigated. The results showed that, despite the nature of matrix, the highest values of TPC in all samples were obtained by MAE as follows: PP (18.92±0.11), ML (15.19±0.11), HL (12.69±0.16), and WS (12.80±0.11) mg GAEg-1 respectively, and exhibited potent antioxidant activity (from 0.28±0.01 to 5.34±0.02mgGAEg-1), representing sources of powerful antioxidants. The LC-MS2 analysis revealed a wide range of phenolics, highlighting their content in phenolic acids, flavonoids and lignans. The presence of different phenol molecules demonstrated that the extraction method had influence on phytochemical profile. Finally, due to its high extraction efficiency, MAE was the more effective extraction technique.

Ultrasound-assisted extraction of polyphenols from native plants in the Mexican desert.

Several plants that are rich in polyphenolic compounds and exhibit biological properties are grown in the desert region of Mexico under extreme climate conditions. These compounds have been recovered by classic methodologies in these plants using organic solvents. However, little information is available regarding the use of alternative extraction technologies, such as ultrasound. In this paper, ultrasound-assisted extraction (UAE) parameters, such as the liquid:solid ratio, solvent concentration and extraction time, were studied using response surface methodology (RSM) for the extraction of polyphenols from desert plants including Jatrophadioica,Flourensiacernua, Turneradiffusa and Eucalyptuscamaldulensis. Key process variables (i.e., liquid:solid ratio and ethanol concentration) exert the greatest influence on the extraction of all of the phenolic compounds (TPC) in the studied plants. The best conditions for the extraction of TPC involved an extraction time of 40min, an ethanol concentration of 35% and a liquid:solid ratio ranging from 8 to 12mlg(-1) depending on the plant. The highest antioxidant activity was obtained in the E. camaldulensis extracts. The results indicated the ability of UAE to obtain polyphenolic antioxidant preparations from desert plants.