Response surface methodology for optimization of the mucilage extraction process from Pereskia aculeata Miller

Membranes composed of poly(lactic acid)/poly(ethylene glycol) and Ora-pro-nóbis (Pereskia aculeata Miller) extract for dressing applications

Wounds are considered one of the most critical medical conditions that must be managed appropriately due to the psychological and physical stress they cause for patients, as well as creating a substantial financial burden on patients and global healthcare systems. Nowadays, there is a growing interest in developing nanofiber mats loaded with varying plant extracts to meet the urgent need for advanced wound ressings. This study investigated the development and characterization of poly(lactic acid) (PLA)/ poly(ethylene glycol) (PEG) nanofiber membranes incorporated with Ora-pro-nóbis (OPN; 12.5, 25, and 50 % w/w) by the solution-blow-spinning (SBS) technique. The PLA/PEG and PLA/PEG/OPN nanofiber membranes were characterized by scanning electron microscopy (SEM), thermal properties (TGA and DSC), Fourier transform infrared spectroscopy (FTIR), contact angle measurements and water vapor permeability (WVTR). In addition, the mats were analyzed for swelling properties in vitro cell viability, and fibroblast adhesion (L-929) tests. SEM images showed that smooth and continuous PLA/PEG and PLA/PEG/OPN nanofibers were obtained with a diameter distribution ranging from 171 to 1533 nm. The PLA/PEG and PLA/PEG/OPN nanofiber membranes showed moderate hydrophobicity (~109-120°), possibly preventing secondary injuries during dressing removal. Besides that, PLA/PEG/OPN nanofibers exhibited adequate WVTR, meeting wound healing requirements. Notably, the presence of OPN gave the PLA/PEG membranes better mechanical properties, increasing their tensile strength (TS) from 3.4 MPa (PLA/PEG) to 5.3 MPa (PLA/PEG/OPN), as well as excellent antioxidant properties (Antioxidant activity with approximately 45 % oxidation inhibition). Therefore, the nanofiber mats based on PLA/PEG, especially those incorporated with OPN, are promising options for use as antioxidant dressings to aid skin healing.

Label free electrochemical sensors for Pb(II) detection based on hemicellulose extracted from Opuntia Ficus Indica cactus

We aim to develop an electrochemical sensor for a divalent metal ion (lead II), a highly toxic water contaminant. We explore a sensor formed with a hemicellulose polysaccharide extracted from the Opuntia Ficus Indica cactus associated with agarose as a sensitive layer deposited on a gold electrode. This sensor combines the functional groups of hemicellulose that could form a complex with metal ions and agarose with gelling properties to form a stable membrane. The sensor demonstrated a loading ability of Pb2+, with higher affinity compared to other metal ions such as Hg2+, Ni2+, and Cu2+, thanks to the chemical structure of hemicellulose. The detection was measured by square wave voltammetry based on a well-defined redox peak of the metal ions. The sensor shows high sensitivity towards Pb2+ with a detection limit of 1.3 fM. The application in river and sea water using the standard addition method for lead detection was studied.

A Critical Appraisal of the Most Recent Investigations on Ora-Pro-Nobis (Pereskia sp.): Economical, Botanical, Phytochemical, Nutritional, and Ethnopharmacological Aspects

Pereskia aculeata Miller and Pereskia grandfolia Haw, known as 'ora-pro-nobis', are unconventional vegetables belonging to the Cactaceae family, native to the Americas and common in the northeast and southeast regions of Brazil. This review attempts to present a balanced account of both the methods used for obtaining extracts from the diverse parts of the plants and the results that were obtained in terms of their applicability to foods and other products with biological activities. Attention will also be devoted to the properties of their bioactives and their applications to real food products. Methods for obtaining extracts from the diverse parts of the plants will be analyzed, as well as the chemical nature of the bioactives that were hitherto identified. Next, the applicability of ora-pro-nobis in either its integral form or in the form of extracts or other products (mucilages) to the production of food and dietary supplements will be analyzed. The species have been extensively investigated during the last few decades. But, the determination of chemical structures is frequently incomplete and there is a need for new studies on texture determination and color evaluation. Further studies exploring the fruit and flowers of P. aculeata are also required.

Selected plants producing mucilage: Overview, composition, and their potential as functional ingredients in the development of plant-based foods

The increase in the preference for vegan and vegetarian diets is directly related to changing eating habits and the need for plant-based alternatives to animal-based products, which are better for health, due to the high content of essential amino acids and lipid profile rich in polyunsaturated fatty acids, and have lower environmental impacts. In this scenario, there is a growing demand for plant-based foods, making it necessary to find new plant-based ingredients for application in foods and beverages. Flaxseed, chia seed, and Barbados gooseberry contain mucilage, a component with potential application in plant-based products. These hydrocolloids can be used as gelling agents, texture modifiers, stabilizers, and emulsifiers in solid and semi-solid foods. This review presents the extraction, characterization, and application of flaxseed, chia seed, and Barbados gooseberry mucilage for use in plant-based foods. It was found that mucilage composition varies due to the extraction method used, extraction conditions, and geographic location of the seed or leaf. However, applications in plant-based foods are currently limited, mainly focused on applying chia mucilage in bakery products and packaging. Research on applying flaxseed and Barbados gooseberry mucilage to plant-based products is limited, though it has been shown to have potential applications in packaging. Mucilage may also increase the nutritional profile of the product and provide better technological, functional, and sensory characteristics. Therefore, because of mucilage's excellent functional and technological properties, it is a promising candidate to act as an ingredient in plant-based food products.

Polysaccharide-Based Hydrogel from Seeds of Artemisia vulgaris: Extraction Optimization by Box-Behnken Design, pH-Responsiveness, and Sustained Drug Release

The current research work focuses on the extraction and optimization of the hydrogel (AVM) from the seeds of Artemisia vulgaris using Box-Behnken design-response surface methodology (BBD-RSM). The AVM was obtained through a hot water extraction process. The influence of different factors, including pH (U = 4 to 10), temperature (V = 25 to 110 °C), seed/water ratio, i.e., S/W ratio (W = 1/10 to 1/70 w/v), and seed/water contact time, i.e., S/W time (X = 1 to 12 h) on the yield of AVM was evaluated. The p-value for the analysis of variance (ANOVA) was found to be <0.001, indicating that the yield of AVM mainly depended on the abovementioned factors. The highest yield of AVM, i.e., 15.86%, was found at a pH of 7.12, temperature of 80.04 °C, S/W ratio of 1/33.24 w/v, and S/W time of 8.73 h according to Design-Expert Software. The study of the pH-responsive behavior of AVM in tablet form (formulation AVT3) revealed that AVM is a pH-responsive material with significantly high swelling at pH 7.4. However, less swelling was witnessed at pH 1.2. Moreover, AVM was found to be a sustained release material for esomeprazole at pH 7.4 for 12 h. The drug release from AVT3 was according to the super case-II transport mechanism and zero-order kinetics.

Pereskia aculeata Miller as a Novel Food Source: A Review

Pereskia aculeata Miller is an edible plant species belonging to the Cactaceae family. It has the potential to be used in the food and pharmaceutical industries due to its nutritional characteristics, bioactive compounds, and mucilage content. Pereskia aculeata Miller is native to the Neotropical region, where it is traditionally employed as food in rural communities, being popularly known as 'ora-pro-nobis' (OPN) or the Barbados gooseberry. The leaves of OPN are distinguished by their nontoxicity and nutritional richness, including, on a dry basis, 23% proteins, 31% carbohydrates, 14% minerals, 8% lipids, and 4% soluble dietary fibers, besides vitamins A, C, and E, and phenolic, carotenoid, and flavonoid compounds. The OPN leaves and fruits also contain mucilage composed of arabinogalactan biopolymer that presents technofunctional properties such as thickener, gelling, and emulsifier agent. Moreover, OPN is generally used for pharmacological purposes in Brazilian folk medicine, which has been attributed to its bioactive molecules with metabolic, anti-inflammatory, antioxidant, and antimicrobial properties. Therefore, in the face of the growing research and industrial interests in OPN as a novel food source, the present work reviews its botanical, nutritional, bioactive, and technofunctional properties, which are relevant for the development of healthy and innovative food products and ingredients.

Microencapsulation of β-carotene using barley residue proteins from beer waste as coating material

This study aimed to produce and characterise microparticles produced from barley residue proteins (BRP) enriched with β-carotene. The microparticles were obtained by freeze-drying five emulsion formulations with 0.5% w/w whey protein concentrate and different concentrations of maltodextrin and BRP (0, 1.5, 3.0, 4.5 and 6.0% w/w), with the dispersed phase consisting of corn oil enriched with β-carotene. The mixtures were mechanically mixed and sonicated, the formed emulsions were freeze-drying. The microparticles obtained were tested for encapsulation efficiency, humidity, hygroscopicity, apparent density, scanning electron microscopy (SEM), accelerated stability and bioaccessibility. Microparticles produced with the emulsion containing 6% w/w BRP had lower moisture content (3.47 ± 0.05%), higher encapsulation efficiency (69.11 ± 3.36%), bioaccessibility value of 84.1% and greater β-carotene protection against thermal degradation. SEM analysis showed that microparticles had sizes ranging from 74.4 to 244.8 µm. These results show that BRP are viable for the microencapsulation of bioactive compounds by freeze-drying.

Extraction Optimization of Mucilage from Seeds of Mimosa pudica by Response Surface Methodology

Mimosa pudica seed mucilage (MPM) is composed of glucuronoxylan, which is a swellable, pH-responsive and non-toxic biomaterial. Herein, we aimed to extract MPM from M. pudica seeds (MP seeds) to ascertain optimization of extraction conditions to get highest yield by response surface methodology, via Box-Behnken design (RSM-BBD). MPM was extracted from MP seeds by a hot water extraction method. The effects of four different parameters on the extraction yield of MPM were evaluated: pH of the extraction medium (1–10), seed/water contact time (1–12 h), the temperature of extraction medium (30–90 °C), and seed/water ratio (1:5–1:35 w/v). The maximum yield of MPM obtained by Design-Expert software was 10.66% (10.66 g/100 g) at pH 7, seed/water contact time of 6 h, extraction temperature of 50 °C, and seed/water ratio of 1:20 w/v. The p values of ANOVA were found to be less than 0.0001, which indicated that the extraction yield of MPM was significantly affected by all the study parameters. The results revealed that pH and extraction temperature were the most significant factors affecting the yield of MPM. MPM in compressed tablet form showed pH-responsive on–off switching behavior at pH 7.4 and 1.2 in a reversible manner. MPM in compressed tablet form sustained the release of itopride for 16 h following a super case-II transport mechanism and zero-order release kinetics.

Pereskia aculeata leaves: properties and potentialities for the development of new products

Pereskia aculeata Mill., known as Ora-Pro-Nobis or Barbados gooseberry, arouse the interest of food and pharmaceutical industries due to its bioactive compounds and mucilage. We conducted a peer-reviewed survey using Web of Science, Scopus, Scielo, Science Direct, and Scifinder platforms, as well as patent bases for new products. We selected articles which highlighted composition of leaves and applications in the development of new products. Mucilage shows great potential in the development of complexes or microparticles to transport active molecules. Reports on anti-inflammatory and anticancer properties of P. aculeata leaves open a research field to obtain pharmaceutical products. Emulsifying properties of mucilage have been explored in food processing. Another potential use is the development of films for functional and/or edible packaging. The polysaccharide chain, the main mucilage constituent, can interact with other biopolymers to be explored in colloidal chemistry for the production of biomaterials in the next years.

The use of alternative food sources to improve health and guarantee access and food intake

To feed and provide Food Security to all people in the world is a big challenge to be achieved with the 2030 Agenda. Undernutrition and obesity are to the opposite of a healthy nutritional status. Both conditions are associated with unbalanced nutrition, absence of food or excess of non-nutritive foods intake. These two nutritional conditions associated with food production are closely related to some goals highlighted by the United Nations in the 2030 Agenda to achieve sustainable world development. In this context, the search for alternative foods whose sustainable production and high nutritional quality guarantee regular access to food for the population must be encouraged. Alternative foods can contribute to Food Security in many ways as they contribute to the local economy and income generation. Popularizing and demystifying the uses of unconventional food plants, ancestral grains, flowers, meliponiculture products, and edible insects as sources of nutrients and non-nutrients is another challenge. Herein, we present an overview of alternative foods - some of them cultivated mostly in Brazil - that can be explored as sources of nutrients to fight hunger and malnutrition, improve food production and the economic growth of nations.

Ora-pro-nobis (Pereskia aculeata Miller): a potential alternative for iron supplementation and phytochemical compounds

Abstract Ora-pro-nobis (OPN) (Pereskia aculeata Miller) is a non-conventional edible plant rich in protein, fibres and minerals. The innovation of this work is based on the sustainability production of the aqueous extract (green solvent) containing iron and bioactive compounds as well as employing a native plant from Brazil. A screening of phytochemicals components, phenolic compounds, flavonoids and tannins contents were performed using OPN extract. The antioxidant activity of the OPN aqueous extract was determined by three different assays as following: 2,2-diphenyl-1-picrylhydrazyl (DPPH•); Ferric Reducing Antioxidant Power (FRAP); and Oxygen Radical Absorbance Capacity (ORAC). The OPN dried leaves presented high protein and minerals contents. Indeed, the Fourier-Transform Infrared Spectroscopy (FTIR Spectroscopy) analysis performed in OPN aqueous extract confirmed the appearance of representative functional groups of the bioactive compounds. Overall the results suggested that it is possible to use simple aqueous solvent to produce OPN extract rich in iron, bioactive compounds and within antioxidant activity that could be potentially used as functional food ingredient.

Amino acid-based hydrophobic affinity cryogel for protein purification from ora-pro-nobis (Pereskia aculeata Miller) leaves

The surfaces of the polyacrylamide cryogels were coated with L-tryptophan (cryogel-Trp) or L-phenylalanine (cryogel-Phe) to enhance crude leaf extract-derived ora-pro-nobis (OPN) protein binding via pseudo-specific hydrophobic interactions. Cryogels functionalized with amino acids were prepared and characterized through morphological, hydrodynamic, and thermal analyses. The adsorption capacities of cryogel-Phe and cryogel-Trp were evaluated in terms of type (sodium sulfate or sodium phosphate) and concentration (0.02 or 0.10 mol∙L^-1) of saline solution, pH (4.0, 5.5, or 7.0), and NaCl concentration (0.0 or 0.5 mol∙L^-1). The cryogel-Phe presented a higher adsorptive capacity, achieving its maximum value (q = 92.53 mg∙g^-1) when the crude OPN crude leaf extract was diluted in sodium sulfate 0.02 mol∙L^-1 + NaCl 0.50 mol∙L^-1, at pH = 7.0. The dilution rate significantly (p < 0.05) affected the recovered protein amount after the adsorption and elution processes, reaching 94.45% when the feedstock solution was prepared with a crude extract 5 times. The zeta potential for the eluted OPN proteins was 5.76 mV (pH = 3.23) for both dilution rates. The secondary structure composition mainly included β-sheets (46.50%) and α-helices (13.93%). The cryogel-Phe exhibited interconnected pores ranging 20-300 μm in size, with a Young modulus of 1.51 MPa, and thermal degradation started at 230 °C. These results indicate that the cryogel-Phe exhibited satisfactory properties as promising chromatography support for use in high-throughput purification of crude leaf extract-derived OPN proteins.

Preclinical studies indicate that INFLATIV, an herbal medicine cream containing Pereskia aculeata, presents potential to be marketed as a topical anti-inflammatory agent and as adjuvant in psoriasis therapy

OBJECTIVES

A previous study reported that the hexane fraction (HF) obtained from Pereskia aculeata leaves showed promising topical anti-inflammatory activity. Intending its future use in clinical practice, a herbal medicine cream named INFLATIV was developed. Its anti-inflammatory and antipsoriatic potential were investigated. INFLATIV was subjected to preliminary accelerated stability tests and to a degradation profile assessment.

METHODS

INFLATIV was prepared at 6% and 12%. The anti-inflammatory activity was assessed by croton oil single and multiple application challenge in mice. Mouse tail test was used for antipsoriatic potential investigation. Cutaneous atrophy test was performed. Preliminary accelerated stability tests were performed together with a degradation profile by GC-MS analysis.

KEY FINDINGS

The anti-inflammatory activity shown by INFLATIV was comparable to dexamethasone. However, the skin atrophy caused by that drug was not observed. INFLATIV modified skin parakeratotic differentiation into orthokeratosis, which revealed its antipsoriatic potential. The ingredients used were suitable to carry the bioactives as they were well permeated by the skin. The preliminary accelerated stability tests indicated that INFLATIV 6% is more stable than 12%.

CONCLUSIONS

The results demonstrated the relevant therapeutic and marketing potentials of INFLATIV, which is likely to be further evaluated in clinical trials for drug registration process with regulatory agencies.

Nutritional assay Pereskia spp.: unconventional vegetable

Pereskia grandifolia Haworth (PGH) and Pereskia aculeata Miller (PAM) are recognized sources of proteins; dietary fiber; vitamins and minerals make this plant leaves, raw, cooked, and braised, an important ally against protein and micronutrient deficiencies. One of the main problems is the presence of antinutritional factors that may interfere in the digestibility and bioavailability of some nutrients. The objective was to evaluate the amino acid profile and the chemical score of the raw leaves and the effects of heating media and time on the total dietary fiber, minerals, trypsin inhibition, oxalic acid and tannins of leaves of PGH and PAM. The samples had similar amino acid profiles and total dietary fiber. With regard to antinutritional compounds, heating the leaves of PGH led to a decrease in trypsin inhibition, primarily after the first minutes of wet cooking. Oxalic acid and tannins predominated in both species. Considering the interaction with time, the variables related to iron and zinc minimized the tannin responses in PGH and PAM, respectively. Heating media and times interfered with the chemical components present in the leaves of Pereskia species and led to high antinutrient retention after heat treatment.

Experimental techniques for the extraction of taro mucilage with enhanced emulsifier properties using chemical characterization

The objective of this study was to analyze existing taro mucilage extraction techniques for extraction of a pure product with high emulsifying action to chemically characterize the mucilage. Five taro mucilage extraction techniques were analyzed which used room temperature, 4 °C, or 80 °C, with or without ethanol precipitation. Protein was detected in the mucilage extracted by each method and is ideal for the emulsifying action. Only mucilage extracted at low temperature and precipitated with ethanol did not contain starch, which is considered an impurity in the product. Therefore, from the tested techniques, cold extraction was found to provide mucilage with good emulsion activity and stability, making it possible to be used as a natural emulsifier. This mucilage is primarily formed by arabinogalactans connected to proteins which form AGP glycoprotein, a macro-molecule responsible for the emulsifying action.

Ultrasound-assisted oil-in-water nanoemulsion produced from Pereskia aculeata Miller mucilage

For the preparation of nanoemulsions, the correct choice of emulsifiers, together with the emulsification methods, directly influences the final product quality. The present study reports the ultrasound-assisted preparation of oil-in-water nanoemulsions produced with mucilage extracted from leaves of Pereskia aculeata Miller (ora-pro-nobis; OPN). The OPN mucilage (%) and soybean oil (%) concentration range, and the process operating parameters, ultrasonic power amplitude (%) and sonication time (min), were optimized based on the mean droplet diameter (d₃₂). The effect of the mucilage and oil concentrations was also investigated by the response variables such as polydispersity, density, turbidity, viscosity, zeta-potential, and interfacial tension. The higher OPN mucilage concentrations (%) with lower amounts of soybean oil (%) favored nanoemulsion formations (116 ≤ d₃₂ ≤ 171 nm) and increased polydispersity, density, and zeta-potential. On increasing OPN mucilage and soybean oil the turbidity of the dispersions increased. All colloidal systems showed Newtonian behavior, and the viscosity in the systems increased due to the greater OPN mucilage concentration in the aqueous phase at a certain oil concentration. In addition, lower values of equilibrium interfacial tension were found with increasing OPN mucilage concentrations. Finally, from the stability test, it can be pointed out that the OPN mucilage concentration should be between 1.0 and 1.5% and the oil concentration should be less than 5%, so that lower d₃₂ values are maintained over time. Therefore, mucilage extracted from OPN and the ultrasound technique can be used in the preparation of nanoemulsions.

Agronomic Cultivation, Chemical Composition, Functional Activities and Applications of Pereskia Species - A Mini Review

BACKGROUND

The exploration of the plant biodiversity as a natural source to obtain sustainable food products and new bioactive pharmaceutical compounds has been growing significantly due to their abundance, safety and economy. Natural pharmaceutical and edible compounds present some advantages when compared to synthetic ones, such as being chemically inert and widely available. In this sense, plants of the genus Pereskia belonging to the Cactaceae family, have been studied. It is an unconventional wild edible plant that contains a large amount of protein and minerals. Studies have demonstrated their biological activities and potential application in different areas such as pharmaceutical, medicinal and food.

OBJECTIVE

This review is focused on the chemical composition, functional properties, applications on pharmaceutical, nutraceutical and food areas and formulation techniques to enhance the stability and bioavailability of bioactive compounds from the underutilized wild edible plant known as ora-pro-nobis (Pereskia aculeata or Pereskia grandifolia).

CONCLUSION

The latest studies involving ora-pro-nobis demonstrated its great potential due to its biological activities, which could stimulate further investigations. The utilization of this plant as a natural source to supplement the diet, or to prepare new food products and pharmaceutical formulations is an attractive approach to explore and fully realize the potential of the rich biodiversity found in Brazil and in other countries.

Optimization of mucilage extraction from chia seeds (Salvia hispanica L.) using response surface methodology

BACKGROUND

Chia mucilage has potential application as a functional ingredient; advances on maximizing its extraction yield could represent a significant technological and economic impact for the food industry. Thus, first, the effect of mechanical agitation time (1-3 h) on the exudation of chia mucilage was analyzed. Then, response surface methodology was used to determine the optimal combination of the independent variables temperature (15-85 °C) and seed: water ratio (1: 12-1: 40.8 w/v) for the 2 h exudation that give maximum chia mucilage yield. Experiments were designed according to central composite rotatable design.

RESULTS

A second-order polynomial model predicted the variation in extraction mucilage yield with the variables temperature and seed: water ratio. The optimal operating conditions were found to be temperature 85 °C and a seed: water ratio of 1: 31 (w/v), reaching an experimental extraction yield of 116 ± 0.21 g kg^-1 (dry basis). The mucilage obtained exhibited good functional properties, mainly in terms of water-holding capacity, emulsifying activity, and emulsion stability.

CONCLUSION

The results obtained show that temperature, seed: water ratio, and exudation time are important variables of the process that affect the extraction yield and the quality of the chia mucilage, determined according to its physicochemical and functional properties. © 2018 Society of Chemical Industry.

Evaluation of technology potential of Aloe arborescens biopolymer in galvanic effluent treatment

Biopolymers have the ability to form gels that can be used in coagulation/flocculation processes. For this reason, the present work evaluated the application of the Aloe arborescens gel as a biopolymer in the treatment of the effluent generated in galvanic processes. The centesimal, thermogravimetric and texture profiles, as well as the functional groups and the biopolymer's performance in the treatment was analyzed. The performance results were evaluated by central composite rotational design 2³. The variables biopolymer concentration, aluminum sulphate and initial pH of the effluent were significant at the confidence level of 95%. The Cr(VI) removal efficiency ranged from 6.37% to 37.74%; significant reductions in dissolved solids (89.80% to 94.13%) and suspended solids (71.06% to 90.00%) were also observed. The treated effluent still presents parameters above the regulatory limits stated by the legislation, therefore, the biopolymer could be used as initial treatment for solids removal.

Lepidium sativum Linn.: a current addition to the family of mucilage and its applications

Mucilage from the last decades has been found to be very attractive, interesting and useful in development of desired pharmaceutical dosage forms. Various applications of plant based mucilage have a wide potentiality in drug formulations. Lepidium sativum Linn. (family: Brassicaceae) is one of the mucilage containing fast growing, edible annual herb. Its various parts (roots, leaves and seeds) have been used to treat various human ailments. It mainly contains alkaloids, saponins, anthracene glycosides, carbohydrates, proteins, amino acids, flavanoids, and sterols as chief phytochemical constituents. Its seed extracts have been screened for various biological activities like hypotensive, anti-microbial, bronchodilator, hypoglycemic and allelopathic, whereas its seed coat mucilage has been isolated using different methods to make it effective excipient of desired functionality as a part of pharmaceutical applications. Through keen references of reported work on Lepidium sativum Linn., in this review, we have focused on its seed coat mucilage isolation methods, chemical constituents, pharmacological profile and versatile application of Lepidium sativum Linn.