Pressurized hot water extraction of bioactives

In the last years, the fact that water is a "green" solvent capable of tunable their properties by changing temperature has tended to increase publications using pressurized hot water extraction (PHWE) as a "green" extraction technique. PHWE has been established as a special extraction technique employed in obtaining bioactive compounds such as polyphenols, diterpenes and polysaccharides, among others from natural sources. Therefore, the main goal of this review is to provide the reader with a brief description of PHWE fundamentals, an up-to-date overview on the use of PHWE to recover bioactive compounds (2015-present), following our previous work by Plaza and Turner (Trends in Analytical Chemistry 71 (2015) 39-57). The last and future trends in PHWE are presented such as its combination with ionic liquids or deep eutectic solvents as well as its coupling with drying steps in order to get higher extraction yields and dried particle formation from extracts, respectively. (C) 2019 Published by Elsevier B.V

Búsqueda de nuevos ingredientes funcionales naturales procedentes de algas

Tesis doctoral inédita. Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Química-Física Aplicada. Fecha de lectura: 17-12-201

In vitro assessment of the bioavailability of bioactive non-extractable polyphenols obtained by pressurized liquid extraction combined with enzymatic-assisted extraction from sweet cherry (Prunus avium L.) pomace

In vitro digestion and absorption simulation processes of non-extractable polyphenols (NEPs) obtained by pressurized liquid extraction combined with enzymatic-assisted extraction with Promod enzyme (PLE-EAE) from the residue of conventional extraction of sweet cherry pomace were studied. In general, total phenolic and proanthocyanidin contents decreased in each phase of the digestion. However, the antioxidant capacity increased when the digestion process progressed. In addition, the highest total phenolic and proanthocyanidin contents and antioxidant capacity were obtained in the absorbed fraction. NEPs from PLE-EAE extract, digestive fractions, absorbed and unabsorbed fractions were analyzed by ultra-high-performance liquid chromatography coupled to electrospray ionization quadrupole Exactive-Orbitrap mass spectrometry (UHPLC-ESI-Q-Orbitrap-MS). Fifteen NEPs were identified in the intestinal fraction and five in the absorbed fraction after the digestion process. Results obtained in this study define for the first time the bioavailability of antioxidant NEPs obtained from sweet cherry pomace

Enzyme-assisted extraction of bioactive non-extractable polyphenols from sweet cherry (Prunus avium L.) pomace

Sweet cherries processing produces big amounts of wastes mainly constituted by cherry pomace that can be a source of bioactive polyphenols. However, during the extraction process, an important fraction called non-extractable polyphenols (NEPs) remains retained in the extraction residue. This work describes the development of an enzyme-assisted extraction (EAE) method to obtain NEPs from sweet cherry pomace employing three different enzymes. Box-Behnken experimental designs were employed to select the optimal conditions of extraction time, temperature, enzyme concentration, and pH. The total phenolic and proanthocyanidin contents and the antioxidant and antihypertensive capacities were measured. Optimal EAE conditions extracted higher content of proanthocyanidins and with higher bioactivity from extraction residue than alkaline and acid hydrolysis. Moreover, there were higher amounts of bioactive phenolics in the extraction residue than in the sweet cherry pomace extract. The estimation of NEPs molecular weight distribution by HPLC-SEC demonstrated that EAE extracted NEPs with high molecular weight

Separation and identification of peptides in hydrolysed protein extracts from edible macroalgae by HPLC-ESI-QTOF/MS

Macroalgae contain significant amounts of high-quality proteins which, because of their structural diversity, contain a range of yet undiscovered peptides within their primary structures. In this work, an analytical methodology was developed for the separation and identification of peptides present in protein hydrolysates from three different edible macroalgae used for human consumption (Saccharina latissima (brown macroalga), Codium spp. (green macroalga), and Mastocarpus stellatus (red macroalga)). The extraction of aqueous and alkaline soluble proteins was carried out followed by their precipitation with HCl or acetone. The protein extracts obtained were submitted to enzymatic digestion with alcalase and subsequently analyzed by reversed-phase high-performance liquid chromatography-quadrupole-time-of flight mass spectrometry (RP-HPLC-QTOF/MS) and de novo sequencing tool to separate and identify different short chain peptides. Thirty-seven peptides were identified in the hydrolysed protein extracts from the three macroalgae, five of them being common in brown and red macroalgae. After checking against BIOPEP database, several sequenced peptides were found within longer peptides with potential antibacterial activity. Any of the identified peptides had previously been identified in macroalgae

A Sustainable Approach for Extracting Non-Extractable Phenolic Compounds from Mangosteen Peel Using Ultrasound-Assisted Extraction and Natural Deep Eutectic Solvents

Mangosteen (Garcinia mangostana L.) peel is a potential source of phenolic compounds with beneficial properties. Natural deep eutectic solvents (NaDES) have been considered an environmentally friendly and cheap alternative to conventional organic solvents. In this work, a green extraction methodology was developed using ultrasound-assisted extraction (UAE) and NaDES for the extraction of antioxidant non-extractable polyphenols (NEPs) from mangosteen peel. To select the best NaDES to extract NEPs from mangosteen peel, seven NaDES were studied. Antioxidant capacity and total phenolic and proanthocyanidin contents were determined for the extracts. The molecular weights for the NEPs present in those extracts were evaluated by size exclusion chromatography. Experimental results showed that choline chloride&-lactic acid (1:2) was the NaDES allowing the highest antioxidant proanthocyanidin content in the extracts. A Box&-Behnken experimental design was employed to optimize the main parameters in UAE with NaDES: water percentage, ultrasound amplitude, and extraction time. The optimal extraction conditions were 18.8% (v/v) water, 60% ultrasound amplitude, and 15 min as the extraction time. In addition, the cytotoxicity of the NEP extracts obtained under optimal extraction conditions was evaluated. Results indicated for the first time that the use of NaDES in combination with UAE could be a sustainable alternative for the extraction of antioxidant NEPs from mangosteen peel for important applications in the food, pharmaceutical, agrochemical, and cosmetic fields, as the extracts presented low cytotoxicity

Sustainable extraction of proteins and bioactive substances from pomegranate peel (Punica granatum L.) using pressurized liquids and deep eutectic solvents

Pomegranate peel is a source of proteins, bioactive peptides, and phenolic compounds. The simultaneous extraction of these compounds required the use of polluting solvents and reagents that are non-suitable. This work targets the development of green methodologies based on pressurized liquids (PLE) or deep eutectic solvents (DES) for the extraction of these compounds. Extracts were digested with different proteolytic enzymes and different functionalities (antioxidant, hypocholesterolemia, and antihypertensive capacities) were evaluated. Highly antioxidant and hypocholesterolemic extracts and hydrolysates were obtained using PLE while high antihypertensive capacity was observed in the hydrolysates from proteins extracted using DES. Peptides and polyphenols were identified by HPLC-ESI-Q-TOF/MS. Higher amounts of peptides were shown in hydrolysates from DES extracts while hydrolysates from PLE extracts presented higher amounts of phenolic compounds. Some peptides were assigned to proteins from Punica granatum. Both green methods improved the extraction of bioactive compounds from pomegranate peel compared to the non-sustainable method. Industrial relevance: The development of green methodologies which employ sustainable solvents such as pressurized liquids (PLE) and deep eutectic solvents (DES) allows extracting proteins and bioactive compounds from pomegranate peel. In addition, these solvents improve the extraction of health beneficial compounds compared to the non-sustainable and polluting solvents. Therefore, they could be used for the development of nutraceuticals and functional foods or even in medicinal, cosmetic, and pharmaceutical preparations

Revalorization of Passiflora species peels as a sustainable source of antioxidant phenolic compounds

Food industry generates a big amount of residues. Nowadays, there is interest in adding value to these residues with the aim of increasing the sustainability of the food chain and to reduce the environmental impact of this waste whose revalorization could also originate an economical benefit. Passion fruits are cultivated for juice and pulp production generating high amounts of vegetable residues. The scarce information about passion fruit peels confers a high interest to the study of their phenolic profiles. In this work, an efficient extraction method based on pressurized hotwater extractionwas employed to obtain antioxidants from four Passiflora species peels (P. ligularis, P. edulis, P. edulis flavicarpa and P. mollissima). Antioxidant properties of the extracts were tested by in vitro assays and intracellular reactive oxygen species scavenging. P. mollissima and P. edulis peel extracts presented higher antioxidant capacity and phenolic content than P. ligularis and P. edulis flavicarpa. Tentative structural elucidation of 57 phenolics was achieved by high-performance liquid chromatography-quadrupole-time of flight mass spectrometry. Flavones, chalcones and phenolic acids were the polyphenol classes that may contribute to antioxidant capacity of the Passiflora peel

Recovery and determination of cholesterol-lowering compounds from Olea europaea seeds employing pressurized liquid extraction and gas chromatography-mass spectrometry

Our previous work demonstrated the presence of compounds with hypocholesterolemic capacity in olive seeds. These compounds were extracted using CO2-expanded ethyl acetate and identified as tyrosol, hydroxytyrosol, and beta-sitosterol using GC&#-MS. This work describes the extraction of these compounds from different olive seeds using pressurized ethyl acetate. Their solubility in ethyl acetate at temperatures ranging from 40&-200 °C was theoretically predicted by Hansen solubility parameters. The content of these compounds was estimated by GC&#-MS, as well as, the reduction of the micellar cholesterol solubility (RMCS) capacity of extracts enabling to establish the optimum extraction temperature at 100 °C. A GC&-MS method was developed and validated in terms of its analytical characteristics for a sensitive determination and quantification of tyrosol, hydroxytyrosol, and &;946#sitosterol in different olive seeds. Within varieties, Manzanilla seeds presented the highest concentration of tyrosol, hydroxytyrosol, and the lowest concentration of beta-sitosterol, as well as the highest RMCS capacit

Evaluation of the relationship between the peptide profile and the lipid-lowering properties of olive seeds hydrolysates as a tool for tunning hypocholesterolemic functionality

Olive processing generates large amounts of stones with high protein contents. Previous studies have demonstrated that Manzanilla variety olive seed proteins release peptides with lipid-lowering capacity. However, no work has demonstrated their roles in the overall hypolipidemic activity. Moreover, further studies using different olive varieties are required to propose a solid method for the exploitation of olive seeds. Twenty different olive varieties were employed in this work. Proteins were extracted using high-intensity focused ultrasound and digested with Alcalase. The released peptides were identified using proteomic techniques, and their capabilities to reduce the absorption of dietary cholesterol (by inhibiting cholesterol esterase enzyme, binding bile acids, and reducing micellar cholesterol solubility) or the biosynthesis of endogenous cholesterol were evaluated. Peptides with different lipid lowering capacities were obtained from all varieties although the genotype significantly affected the hypolipidemic characteristics. Univariate and multivariate statistical analyses showed strong correlations, positive and negative, between the presence of certain peptides in the hydrolysates and their capacity to reduce exogenous cholesterol absorption and endogenous cholesterol synthesis. Therefore, the selection of the olive seed genotype can direct its lipid-lowering properties,e.g., by promoting the reduction of dietary cholesterol absorption or the inhibition of cholesterol biosynthesis