Recovery Of Antioxidant Compounds Research Articles

Rice Byproduct Compounds: From Green Extraction to Antioxidant Properties.

Currently, rice (Oryza sativa L.) production and consumption is increasing worldwide, and many efforts to decrease the substantial impact of its byproducts are needed. In recent years, the interest in utilizing rice kernels, husk, bran, and germ for the recovery of different molecules, from catalysts (to produce biodiesel) to bioactive compounds, has grown. In fact, rice byproducts are rich in secondary metabolites (phenolic compounds, flavonoids, and tocopherols) with different types of bioactivity, mainly antioxidant, antimicrobial, antidiabetic, and anti-inflammatory, which make them useful as functional ingredients. In this review, we focus our attention on the recovery of antioxidant compounds from rice byproducts by using innovative green techniques that can overcome the limitations of traditional extraction processes, such as their environmental and economic impact. In addition, traditional assays and more innovative methodologies to evaluate the antioxidant activity are discussed. Finally, the possible molecular mechanisms of action of the rice byproduct antioxidant compounds (phenolic acids, flavonoids, γ-oryzanol, and vitamin E) are discussed as well. In the future, it is expected that rice byproduct antioxidants will be important food ingredients that reduce the risk of the development of several human disorders involving oxidative stress, such as metabolic diseases, inflammatory disorders, and cancer.

Conversion of artichoke leftovers to levulinic acid: A biorefinery approach

The valorization of agrifood leftovers from an herbaceous plant widely cultivated in Mediterranean areas (Italy and Spain), Cynara scolymus L., is reported here as part of a zero-waste biorefinery approach. The Globe artichoke (GlobART) variety was selected as the source of artichoke leftovers, which were valorized using the following cascade approach: (i) the recovery of antioxidant compounds (AC) still present in the matrix through sustainable microwave-assisted subcritical water extraction (MA-SWE); and, (ii) the subsequent production of levulinic acid (LevA) via the MW-assisted conversion (225ºC, 2 min, 1500 W) of the cellulosic fraction recovered after initial extraction. Preliminary MW-assisted conversion tests on the post MA-SWE GlobART matrix yielded about a 37% yield of LevA (molar yield) using HCl and p-toluenesulfonic acid (p-TsA). Furthermore, performing a delignification step, mediated by either ultrasound (UAD) or MW (MAD), on the post-MA-SWE GlobART matrix before conversion considerably increased LevA yield (55% and 71% from post-UAD and post-MAD GlobART matrices, respectively, with p-TsA). Finally, reducing the KBr/biomass ratio, when using p-TsA, by half afforded an enhancement in LevA yield up to 80% when starting from the post-extraction and delignified (post MA-SWE-& MAD) GlobART matrix.

Green Extraction Methods for Recovery of Antioxidant Compounds from Epicarp, Seed, and Seed Tegument of Avocado var. Hass (Persea americana Mill.).

The present study compared the extracts obtained from the epicarp, seed, and seed tegument of avocado var. Hass with pressurized liquid extraction (PLE) and ultrasound-assisted extraction (UAE). The extracts were quantified in terms of total phenolic content (TPC) and antioxidant capacity (AC). The PLE extracts had a global yield (X0) like that obtained with UAE using ethanol (Et) as the solvent. For the TPC, the extracts obtained with both techniques showed no significant differences (p > 0.05). On the other hand, the epicarp extracts obtained with PLE had higher values for AC: 829.8 μmol TE/gDe (ABTS) and 3,215.1 μmol Fe2+/g De (FRAP), recorded for UAE/Et. The AC in the avocado residue extracted with PLE suggested a high potential for applications in food, pharmaceutical, and cosmetology products.

Development of active films utilizing antioxidant compounds obtained from tomato and lemon by-products for use in food packaging

This study focused on the recovery of antioxidant compounds from lemon and tomato by-products for use as natural additives in the development of active food packaging formulated using three different polymeric matrices that included low-density polyethylene (LDPE), polylactic acid (PLA), and G-polymer (GP). The films were characterized according to chemical-physical, thermal analyses, and their barrier and mechanical properties. Migration assays were performed to evaluate the release of active compounds from polymeric matrices, which were quantified in the food simulant by high-performance liquid chromatography with a diode array detector and then confirmed via liquid chromatography coupled to mass spectrometry. The antioxidant capacities of the films were determined to evaluate their applicability for use as antioxidant-active packaging. The incorporation of extracts into polymers resulted in different structural changes and enhanced properties according to the nature of the polymeric matrix based on the interactions of the –OH groups of polyphenols and the chemical groups of the polymers. The lemon (LE) and tomato (TE) extracts lead to a substantial improvement in water barrier properties of PLA and GP-based films. The active PLA and GP films released high amounts of polyphenolic compounds (up to 65% for GP containing LE); mainly hesperidin and eriocitrin for LE films, and chrologenic acid for TE films. PLA loaded with lemon extract at 4% was selected as the most suitable for use as antioxidant packaging to extend the shelf-life of foods with high fat content.

Toxicological and bioactivity evaluation of blackcurrant press cake, sea buckthorn leaves and bark from Scots pine and Norway spruce extracts under a green integrated approach

Aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), Scots pine bark (SP), and sea buckthorn leaves (SB) were obtained using maceration and pressurized hot water and tested for their bioactivities. Maceration provided the extraction of higher dry matter contents, including total phenolics (TPC), anthocyanins, and condensed tannins, which also impacted higher antioxidant activity. NS and SB extracts presented the highest mean values of TPC and antioxidant activity. Individually, NS extract presented high contents of proanthocyanidins, resveratrol, and some phenolic acids. In contrast, SB contained a high concentration of ellagitannins, ellagic acid, and quercetin, explaining the antioxidant activity and antibacterial effects. SP and BC extracts had the lowest TPC and antioxidant activity. However, BC had strong antiviral efficacy, whereas SP can be considered a potential ingredient to inhibit α-amylase. Except for BC, the other extracts decreased reactive oxygen species (ROS) generation in HCT8 and A549 cells. Extracts did not inhibit the production of TNF-alpha in lipopolysaccharide-stimulated THP-1 macrophages but inhibited the ROS generation during the THP-1 cell respiratory burst. The recovery of antioxidant compounds from these by-products is incentivized for high value-added applications.

Antioxidant Molecules from Plant Waste: Extraction Techniques and Biological Properties

The fruit, vegetable, legume, and cereal industries generate many wastes, representing an environmental pollution problem. However, these wastes are a rich source of antioxidant molecules such as terpenes, phenolic compounds, phytosterols, and bioactive peptides with potential applications mainly in the food and pharmaceutical industries, and they exhibit multiple biological properties including antidiabetic, anti-obesity, antihypertensive, anticancer, and antibacterial properties. The aforementioned has increased studies on the recovery of antioxidant compounds using green technologies to value plant waste, since they represent more efficient and sustainable processes. In this review, the main antioxidant molecules from plants are briefly described and the advantages and disadvantages of the use of conventional and green extraction technologies used for the recovery and optimization of the yield of antioxidant naturals are detailed; finally, recent studies on biological properties of antioxidant molecules extracted from plant waste are presented here.

Valorisation of Exhausted Olive Pomace by an Eco-Friendly Solvent Extraction Process of Natural Antioxidants.

Exhausted olive pomace (EOP) is the waste generated from the drying and subsequent extraction of residual oil from the olive pomace. In this work, the effect of different aqueous solvents on the recovery of antioxidant compounds from this lignocellulosic biomass was assessed. Water extraction was selected as the best option for recovering bioactive compounds from EOP, and the influence of the main operational parameters involved in the extraction was evaluated by response surface methodology. Aqueous extraction of EOP under optimised conditions (10% solids, 85 °C, and 90 min) yielded an extract with concentrations (per g EOP) of phenolic compounds and flavonoids of 44.5 mg gallic acid equivalent and 114.9 mg rutin equivalent, respectively. Hydroxytyrosol was identified as the major phenolic compound in EOP aqueous extracts. Moreover, these extracts showed high antioxidant activity, as well as moderate bactericidal action against some food-borne pathogens. In general, these results indicate the great potential of EOP as a source of bioactive compounds, with potential uses in several industrial applications.

Ameliorative Effect of Peach Seed Extract on Cyclophosphamide- Induced Cytogenetic and Histological Effects in Mice

Cyclophosphamide (CP) is a frequently used drug for its anticancer and immunosuppressive potential. However metabolism of CP in the body results into toxic chemical compounds (to the liver itself and other non-target vital organs) via oxidative stress, apoptosis induction and finally necrosis. Since there is no escaping of using such medications in spite of their harms this study was designed to access the ability to alleviate the side-effects of CP by using peach seed methanolic extract, due to its nutritional value and therapeutic properties. The peach seed extract has bioactive constituents such as phenols and carotenoids. Methanoloic extract is the most widely used since it offers a high recovery of antioxidant compounds. Mice were divided into five major groups: negative control (untreated group), positive control, was injected (IP) with CP in dose 75mg/kg b. wt., Third group received peach seed extract only in a dose of 500 mg/kg b.w., and the fourth and fifth groups received two doses of Peach seeds extract 500 and 250 mg/kg b.wt. after receiving a single dose of CP intraperitoneally. Assessment of the extract was performed using micronucleus test, mitotic chromosomal aberration assay using bone marrow cells, and liver samples were collected for histopathology. Our results demonstrated that CP induced highly significant e genotoxicity, which recorded 9.49% PE's with micronuclei, comparing to 1.03% as control, while the induction of chromosomal aberrations was recorded as 67.6% against 4.4% as negative control. The histological study on the liver cells recorded noticeable damage with liver cells treated with CP. After peach treatment a significant reduction in CP- induced damage was observed and those groups treated with both extract and CP became nearly similar to the untreated group in all tested parameters. peach methanolic seed extract has the potential to ameliorate the damaging effect of cyclophosphamide at both the genetic and histological levels.

Supercritical Fluid Extraction of Berry Seeds: Chemical Composition and Antioxidant Activity

The influence of supercritical fluid extraction (SFE) and solvent extraction of oils from cloudberry, bilberry, and black currant seeds on the yield, chemical properties, and recovery of antioxidant compounds was investigated. SFE was performed for 1 h at 350 bar and at 50°C and 80°C. Fatty acids, vitamin E, carotenoids, and free radical-scavenging activity (DPPH) were assayed. SFE at 80°C resulted in higher oil yields for cloudberry and black currant seeds. The oils were rich in polyunsaturated fatty acids (PUFAs) (66.8%–75.9% w/w), with high percentages of linoleic and α-linolenic acids. The black currant seed extracts had the highest concentrations of vitamin E (range, 113.0–241.8 mg/100 g oil) and carotenoids (range, 11.5–32.3 mg/100 g oil) and the highest antioxidant activity. The cloudberry seed oils also had high antioxidant content and activity. These findings indicate the potential of SFE for the recovery of PUFA and antioxidant compounds in berry by-products.

Recovery of Antioxidant Compounds from Aronia Filter Tea Factory by -Product: Novel Versus Conventional Extraction Approaches.

Black chokeberry (Aronia melanocarpa L.) by-product from filter tea factory underwent subcritical water extraction (SWE) in order to recover polyphenolics and determine its antioxidant potential. In the current study Box-Behnken design was applied for optimization. Independent variables used in experimental design were temperature (T, 120-200 °C), extraction time (t, 15-35 min) and hydrochloride concentration (c, 0-1.5%). Experimental results were fitted to a second-order polynomial model where multiple regression analysis and analysis of variance were used to determine fitness of the model and optimal conditions. The optimized SWE conditions for maximum responses of total phenols (TP), total flavonoids (TF) and monomeric anthocyanins (MA) contents, and minimum response of IC50 were temperature of 120.4 °C, extraction time of 15.2 min and absence of acidifier. The predicted values of TP, TF, MA and IC50 at these conditions were: 32.8863 mg GAE/g, 23.5164 mg CE/g, 0.5124 mg C3G/g and 0.0055 mg/mL, respectively.

Valorization of Grapefruit By-Products as Solid Support for Solid-State Fermentation to Produce Antioxidant Bioactive Extracts

Solid-state fermentation is a microbial process carried out mostly on the surface of solid materials. Grapefruit by-products are solids that can be used as a substrate-support matrix for fungal growth in solid fermentation. On the other hand, with the fermentation, the valorization of grapefruit by-products can be done because of recovery of secondary metabolites such as antioxidants. Fermentations were done using Raimbault columns as bioreactors. Two mixture levels (50 and 70% moisture content) were evaluated. Fungal growth was analysed online by CO2 quantification for fermentation of grapefruit by-products with Aspergillus niger GH1. Ethanolic extracts were used for antioxidant analyses (FRAP, LOI and DPPH·radical-scavenging). A. niger GH1 showed better growth on grapefruit by-products at 70% moisture content. Recovery of antioxidant compounds and solids reduction (50% of solids loss) was also higher at 70% moisture content. These results suggest that solid-state fermentation has great potential for valorization of grapefruit by-products as a support and a carbon source to produce antioxidants.

Natural antioxidants isolated from Schinus areira leaves by ultrasound-assisted extraction

The aim of this study was to optimize the extraction of antioxidant compounds from Schinus areira leaves using ultrasound assisted extraction and response surface methodology. The effect of sonication time and plant material:solvent ratio were used to optimize the recovery. Results showed that a high recovery of antioxidant compounds from leaves of three different S. areira specimens was achieved under optimized conditions. The leaf extracts obtained displayed a DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity analogous to the well-known antioxidant trolox (EC 50 = 23-46 vs 36.1 µ g/mL, respectively). In addition, these extracts showed a good potency to eliminate superoxide and nitric oxide-radicals as well as a moderate antimicrobial activity against gram positive Staphylococcus aureus and Enterococcus faecalis and yeast. HPLC chromatography analysis of the three S. areira leaf extracts showed different high contents of kaempferol-3- O -rutinoside, quercetin-3- O -galactoside and 3 -O -caffeoylquinic acid. The results showed that the S. areira leaf extracts contained a high amount of antioxidant phenolic compounds, which might be a valuable source to be used as additives in plant-based foods.

Antioxidant phenolic compounds recovery from Mangifera indica L. by-products by supercritical antisolvent extraction

Supercritical Antisolvent Extraction (SAE) was used in the recovery of antioxidant compounds from mango by-products. The antioxidant extract was obtained by solid–liquid extraction using aqueous acetone (80% v/v) and subsequent adsorption/desorption in C18 cartridge. Recovery of antioxidants was performed by SAE using SC-CO2 as antisolvent. The temperature and pressure parameters were varied in the range 35–45°C and 8–15MPa. The SAE process allowed the recovery of about 90% of the initial phenolic compounds, the best recovery was obtained at 40°C and 10MPa and the main compounds were mangiferin, isomangiferin, quercetin 3-O-galactoside, quercetin 3-O-glucoside, quercetin 3-O-xyloside, quercetin 3-O-arabinoside, quercetin and kaempferol. The product obtained was a dry powder, spherical nanoparticles with a particle diameter of 143±40nm with an antioxidant activity of 851.9μMol TE/g and a half inhibition concentration of DPPH radical of 90μg/mL. The analyses performed indicated that SAE processing of natural extracts is effective for improving the activity of natural antioxidant compounds by producing nanoparticles.

Optimization of extraction of phenolic antioxidants from peanut skins

AbstractThis work was conducted to optimize the extraction conditions for the best recovery of antioxidant compounds from peanut skins. The extracts from the peanut skins were obtained by different extraction methods. The extraction conditions were: different ethanol proportions as the solvent (0, 30, 50, 70 and 96% v/v in distilled water), different peanut skin particle sizes (0–1, 1–2 and 2–10 mm and non‐crushed skins), different proportions of solvent/skins (20, 30, 40, 50 and 60 ml g−1), different extraction times (by maceration and shaking) and different numbers of extractions. The different extracts obtained under different extraction conditions were compared with special regard to yield, total phenolic compounds and radical scavenging activity. The results showed that the best delivery of phenolic compounds was reached using 70% ethanol, non‐crushed peanut skins, ratio of solvent/solid of 20 ml g−1, at 10 min shaking and three extractions. The maximum yield of 0.118 g g−1 was recorded for phenolic compounds when extracted at the optimum conditions. Copyright © 2004 Society of Chemical Industry