Effects of Change in PH and Addition of Sucrose and NaCl on the Emulsifying Properties of Mucilage Obtained from Pereskia aculeata Miller

Development of Oleogel-in-Water High Internal Phase Emulsions with Improved Physicochemical Stability and Their Application in Mayonnaise

Egg-free mayonnaise is receiving greater attention due to its potential health benefits. This study used whey protein isolate (WPI) as an emulsifier to develop high internal phase emulsions (HIPEs) based on beeswax (BW) oleogels through a simple one-step method. The effects of WPI, NaCl and sucrose on the physicochemical properties of HIPEs were investigated. A novel simulated mayonnaise was then prepared and characterized. Microstructural observation revealed that WPI enveloped oil droplets at the interface, forming a typical O/W emulsion. Increase in WPI content led to significantly enhanced stability of HIPEs, and HIPEs with 5% WPI had the smallest particle size (11.9 ± 0.18 μm). With the increase in NaCl concentration, particle size was increased and ζ-potential was decreased. Higher sucrose content led to reduced particle size and ζ-potential, and slightly improved stability. Rheological tests indicated solid-like properties and shear-thinning behaviors in all HIPEs. The addition of WPI and sucrose improved the structures and viscosity of HIPEs. Simulated mayonnaises (WE-0.3%, WE-1% and YE) were then prepared based on the above HIPEs. Compared to commercial mayonnaises, the mayonnaises based on HIPEs exhibited higher viscoelastic modulus and similar tribological characteristics, indicating the potential application feasibility of oleogel-based HIPEs in mayonnaise. These findings provided insights into the development of novel and healthier mayonnaise alternatives.

Edible chitosan-based Pickering emulsion coatings: Preparation, characteristics, and application in strawberry preservation

The long-term application of plant essential oils in food preservation coatings is limited by their poor water solubility and high volatility, despite their recognized synergistic antimicrobial effects in postharvest fruit preservation. To overcome these limitations, a Pickering emulsion loaded with thyme essential oil (TEO) was developed by utilizing hydrogen bonding and electrostatic interactions to induce cross-linking of chitosan particles. This novel emulsion was subsequently applied in the postharvest storage of strawberries. The shear-thinning behavior (flow index <1) and elastic gel-like characteristics of the emulsion made it highly suitable for spray application. Regarding TEO release, the headspace concentration of TEO increased from 0.21 g/L for pure TEO to 1.86 g/L after two instances of gas release due to the stabilizing effect of the chitosan particles at the oil-water interface. Notably, no phase separation was observed during the 10-day storage of the emulsion. Consequently, the emulsion was successfully employed for the postharvest storage of strawberries, effectively preventing undesirable phenomena such as weight loss, a decrease in firmness, an increase in pH, and microbial growth. In conclusion, the developed Pickering emulsion coating exhibits significant potential for fruit preservation applications, particularly for extending the shelf life of strawberries.

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.

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.

Edible mayonnaise-like Pickering emulsion stabilized by pea protein isolate microgels: Effect of food ingredients in commercial mayonnaise recipe

Particle stabilized O/W Pickering emulsion has great potential for making egg-free mayonnaise. In this study, we fabricated pea protein isolate (PPI) microgels by gel-breaking method and applied in mayonnaise-like Pickering emulsion. The effects of acetic acid (pH), sodium chloride (NaCl), and sucrose, which are typically used in commercial mayonnaise were studied. The minimum droplet size (47.0 μm) was found below isoelectric point. The NaCl decreased ζ-potential to almost 0 and risen droplet size to 75.9 μm. The sucrose enhanced the emulsion's viscosity while lowering thixotropic recovery rate. Based on droplet size, viscosity, thixotropic recovery, and microstructure; 350 mmol NaCl and 4 wt% sucrose was finally used to make egg-free mayonnaise-like Pickering emulsion, and showed similar properties compared with commercial mayonnaise, and the thixotropy recovery rate was near 100%. A plant-scale test further confirmed the feasibility. The results showed the PPI microgels had a strong application prospect to form egg-free mayonnaise.

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.

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.