Phenolic compounds profile of optimised green and eco-friendly extracts of Eugenia pyriformis leaves: an alternative for antioxidant and antibacterial applications.

The Eugenia pyriformis Cambess (uvaia) is a well-known source of bioactive compounds. This study investigated the efficiency of Ultrasound-Assisted Extraction (UAE) and Enzyme-Assisted Extraction (EAE) in obtaining uvaia leaf extracts with high antioxidant and antibacterial activity. In a first step, different variables of the leaves were employed to define the best conditions for obtaining the extract with the highest total phenolic content. In a second step, the optimised extracts were characterised. In total, twenty-four phenolic compounds were identified through LC-ESI-MS/MS. The EAE in optimised conditions showed a higher amount of total phenolic compounds and antioxidant potential. It was possible to note an analogous potential of antibacterial activity of the extracts, which showed action mainly against Gram-positive bacteria. These findings suggest that the aqueous extracts of uvaia leaves are feasible, economic, and sustainable alternatives for adding value to uvaia leaves, which are an agricultural residue that is generally underutilised.

Extraction of Lipophilic Antioxidants from Native Tomato Using Green Technologies.

Research background: Tomato (Solanum lycopersicum L.) fruit is highly consumed worldwide and contains high amounts of carotenoids and tocopherols, two powerful antioxidants. Native tomato genotypes are rarely used in large-scale market but serve as a reservoir to diversify the species gene pool and can be employed to obtain functional compounds. Extraction methods are currently changing towards cleaner procedures that are more efficient and environmentally friendly, including avoiding toxic or polluting solvents. Experimental approach: In this study, factorial and fractional factorial designs were used to evaluate the efficiency of digestive enzymes, sonication and green solvents to obtain lipophilic antioxidant extracts from native tomato. To monitor the efficiency of the extraction process, spectrophotometric quantification of total carotenoids and antioxidant activity was carried out, and then individual quantification of carotenoids and tocopherols in the extracts was done by HPLC. Results and conclusions: Digestive enzymes and sonication increased the carotenoid content and the antioxidant activity of the obtained extracts when applied individually. However, when these treatments were applied together and in combination with isopropyl acetate, a green solvent, the obtained extracts had the highest carotenoid and tocopherol contents as well as the maximal antioxidant activity. A correlation analysis suggested that antioxidant activity resulted from synergistic effects rather than individual compounds. Tomato extracts were obtained through a rapid and environmentally friendly extraction method and their antioxidant activity was enhanced. Novelty and scientific contribution: Tomato fruits have been the subject of numerous studies; however, functional compound extraction through environmentally friendly methods remains an attractive use of native tomato fruit, enhancing its limited production and harnessing a large amount of tomato product industry. There are few reports where environmentally friendly extraction methods are combined; even rarer are those where green solvents are also used. In this work, the combination of different environmentally friendly extraction methods improved the extraction of carotenoids and tocopherols and allowed to establish a more efficient process. These results could stimulate the use of clean technologies and make the native tomato more attractive for industrial or compound extraction processes.

Early Optimization Stages of Agave lechuguilla Bagasse Processing toward Biorefinement: Drying Procedure and Enzymatic Hydrolysis for Flavonoid Extraction.

Agave lechuguilla agro-waste is a promising renewable material for biorefining purposes. The procurement of added-value co-products, such as bioactive phytochemicals, is required to improve bioprocesses and promote the bio-based economy of the productive areas of Mexico. In this study, we aimed to evaluate the effect of post-harvest management and enzymatic pretreatment as the first stages of the A. lechuguilla valorization process. Four drying methods were compared, and enzymatic hydrolysis was optimized to obtain a flavonoid-enriched extract applying ultrasound-assisted extraction. In both experiments, the total phenolic (TPC) and flavonoid (TFC) contents, HPLC-UV flavonoid profiles, and radical scavenging capacity (DPPH) were considered as response variables. The results demonstrated that light exposure during the drying process particularly affected the flavonoid content, whereas oven-dehydration at 40 °C in the dark preserved the flavonoid diversity and antioxidant functionality of the extracts. Flavonoid glycoside recovery, particularly anthocyanidins, was 1.5-1.4-fold enhanced by enzymatic hydrolysis using the commercial mix Ultraflo© under optimized conditions (pH 4, 40 °C, 180 rpm, and 2.5 h) compared to the unpretreated biomass. The extraction of flavonoids from A. lechuguilla bagasse can be carried out using a scalable drying method and enzymatic pretreatment. This study confirmed the potential of this agro-waste as a source of marketable natural products.

Enzymatic and ultrasonic-assisted pretreatment in the extraction of bioactive compounds from Monguba (Pachira aquatic Aubl) leaf, bark and seed.

The present study aims to characterize leaf, bark and seed of monguba in terms of their physicochemical and bioactive composition, and to determine total phenolic compounds (TPC) and total flavonoids (TF), well as their antioxidant activities (AA), of three organic solvent extracts with and without enzyme pretreatment by ultrasonic assisted extraction. Physicochemical composition was measured by pH, total titratable acidity, total soluble solids, moisture, ashes, lipids, crude protein, raw fiber, total carbohydrates, and water activity as well as, phytochemical composition analysis constituted of sugars, condensed (CT) and hydrolysable tannins (HT), carotenoids, total anthocyanins (TA), and organic acids contents. TPC and TF contents, and UHPLC/PDA/QDa flavonoids and phenolic acids quantification were performed for the solvent extracts. Antioxidant activity was determined by radical scavenging capacity assays (ABTS, DPPH, and ORAC), and reducing power assay (FRAP). Results showed that the leaf stood out with higher concentrations of ash, HT, TA and carotenoids; the bark with higher concentrations of raw fiber, total carbohydrates and organic acids (tartaric, quinic and 3.4-dihydroxybenzoic acids); in contrast, the seeds showed high concentrations of lipids, crude protein, sugars (fructose and sucrose), CT, and high values in all AA. The solvents significantly influenced the extraction of TPC and TF, highlighting ethanol. In general, the enzymatic treatments empowered the phenolic extraction and AA. The monguba seed extracts showed higher concentrations of hydroxycinnamic acids (chlorogenic acid, mainly), and flavanols (catechin and epicatechin), whereas the leaf extracts, flavanones (narigenin), flavonols (rutin, mainly) and flavones (acacetin). The bark extracts stood out for the presence of vanillin. The monguba seed extract can be used in functional foods production.

Enzymatic pretreatment in the extraction process of soybean to improve protein and isoflavone recovery and to favor aglycone formation.

This research aimed to evaluate the pretreatment of soybean with the carbohydrase multi-enzyme complex "Viscozyme L", during the extraction process; in order to improve the recovery of proteins and isoflavones in soybase, and reduce the loss of these compounds through the okara residue. Three concentrations of enzyme were studied at 50 °C, along with an experiment carried out without enzyme addition (control experiment). The results were also evaluated in relation to standard soybase processing. In comparison to the standard and control processes, the enzymatic pretreatment reduced up to 85% the total amount of okara residue. Due to the action of the multi-enzyme complex, protein and total isoflavone recovery increased from 42% to 83% and from 59% to 93%, respectively. The application of Viscozyme L also favored the conversion of conjugated forms of isoflavone to aglycone in the soybase, representing up to 50% of the total isoflavones. The enzymatic pretreatment of soybean with carbohydrase improved the nutritional quality of the soybase, while at the same time reducing residue generation; showing that the proposed food process can be considered environmentally friendly method.

State-of-the-Art Extraction Methodologies for Bioactive Compounds from Algal Biome to Meet Bio-Economy Challenges and Opportunities.

Over the years, significant research efforts have been made to extract bioactive compounds by applying different methodologies for various applications. For instance, the use of bioactive compounds in several commercial sectors such as biomedical, pharmaceutical, cosmeceutical, nutraceutical and chemical industries, has promoted the need of the most suitable and standardized methods to extract these bioactive constituents in a sophisticated and cost-effective manner. In practice, several conventional extraction methods have numerous limitations, e.g., lower efficacy, high energy cost, low yield, etc., thus urges for new state-of-the-art extraction methodologies. Thus, the optimization along with the integration of efficient pretreatment strategies followed by traditional extraction and purification processes, have been the primary goal of current research and development studies. Among different sources, algal biome has been found as a promising and feasible source to extract a broader spectrum of bioactive compounds with point-of-care application potentialities. As evident from the literature, algal bio-products includes biofuels, lipids, polyunsaturated fatty acids, pigments, enzymes, polysaccharides, and proteins. The recovery of products from algal biomass is a matter of constant development and progress. This review covers recent advancements in the extraction methodologies such as enzyme-assisted extraction (EAE), supercritical-fluid extraction (SFE), microwave-assisted extraction (MAE) and pressurized-liquid extraction (PLF) along with their working mechanism for extracting bioactive compounds from algal-based sources to meet bio-economy challenges and opportunities. A particular focus has been given to design characteristics, performance evaluation, and point-of-care applications of different bioactive compounds of microalgae. The previous and recent studies on the anticancer, antibacterial, and antiviral potentialities of algal-based bioactive compounds have also been discussed with particular reference to the mechanism underlying the effects of these active constituents with the related pathways. Towards the end, the information is also given on the possible research gaps, future perspectives and concluding remarks.