VALORIZAÇÃO DE RESÍDUOS DA INDÚSTRIA FRUTÍCOLA

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Subcritical water extraction as an environmentally-friendly technique to recover bioactive compounds from traditional Serbian medicinal plants

Publication . Nastić, Nataša; Švarc-Gajić, Jaroslava; Delerue-Matos, Cristina; Barroso, M. Fátima; Soares, Cristina; Moreira, Manuela M.; Morais, Simone; Mašković, Pavle; Srček, Višnja Gaurina; Slivac, Igor; Radošević, Kristina; Radojković, Marija

Subcritical water extraction (SWE) has become a popular green extraction technique for the isolation of different classes of compounds from natural matrices. Low price, safety and green character of water, good yields of target compounds and reduced energy consumption, make this technique favorable for potential industrial applications. The purpose of this study was to evaluate antioxidant, antimicrobial and cytotoxic activity of four medicinal plants traditionally used in folk medicine of Serbia. Black mulberry (Morus nigra L.), wall germander (Teucrium chamaedrys L.), wild geranium (Geranium macrorrhizum L.) and comfrey (Symphytum officinale L.) were extracted by subcritical water at different temperatures. Antioxidant activity of the extracts was defined by conventional spectrophotometric methods, such as the total phenolic content (TPC), DPPH-radical scavenging activity (DPPH-RSA), ferric reducing antioxidant power (FRAP) and total antioxidant capacity (TAC) assessed by a DNA-based sensor. Additionally, the main phenolic compounds contributing to the antioxidant activity of the produced extracts were also identified and quantified by high performance liquid chromatography with diode array detection (HPLC-DAD). Antimicrobial properties of extracts were evaluated against eight microbial strains. Furthermore, the cytotoxic activity was observed for two human cancer cell lines and a cell line derived from murine fibroblast.

2018Journal article

Open access

A new source for developing multi-functional products: biological and chemical perspectives on subcritical water extracts of Sambucus ebulus L

Publication . Cvetanović, Aleksandra; Zeković, Zoran; Švarc-Gajić, Jaroslava; Razić, Slavica; Damjanović, Ana; Zengin, Gokhan; Delerue-Matos, Cristina; Moreira, Manuela M.

BACKGROUND To obtain bioactive fractions from plant material subcritical water is notably advantageous in comparison to any other technique. Excellent solvating properties and selectivity combined with finely tuned reactivity of subcritical water enable exploitation of the potential of plants. Herein subcritical water extraction was used for recovery of bioactive compounds from leaves, roots and fruits of Sambucus ebulus L. Extracts obtained were characterized in terms of biological and chemical fingerprints. RESULTS AND DISCUSSION Results obtained by using several antioxidant assays that focused on different mechanisms showed that subcritical water extracts of Sambucus ebulus were powerful antioxidants. Enzyme inhibitory effects were tested against α‐amylase, α‐glucosidase and tyrosinase, and the results showed the anti‐diabetic potential of the extracts as well as its possible use with skin disorders. Antiproliferative properties were detected on three cell lines (A‐549; LS‐174 T; HeLa) and showed prominent cytotoxicity against all tumor cell lines. Inhibitory concentrations obtained were in the range 0.58–8.10 μg mL‐1. Generally, the SCW extracts from leaves exhibited stronger biological activities with higher levels of phenolic compounds compared with the roots and fruits of Sambucus ebulus. Gallic acid, catechin and caffeic acid were identified as major components in these extracts and these components seem to relate with observed biological activity. CONCLUSION The results obtained suggest that Sambucus ebulus has great potential for preparing new phyto‐pharmaceuticals and functional food ingredients. © 2017 Society of Chemical Industry

2018Journal article

Open access

Microwave-assisted extraction of phenolic compounds from Morus nigra leaves: optimization and characterization of the antioxidant activity and phenolic composition

Publication . Radojković, Marija; Moreira, Manuela M.; Soares, Cristina; Barroso, M. Fátima; Cvetanović, Aleksandra; Švarc-Gajić, Jaroslava; Morais, Simone; Delerue-Matos, Cristina

BACKGROUND Morus nigra (mulberry) fruit has been reported as a source of bioactive compounds, although information about their leaves is very limited. Usually, they are considered wastes and have been traditionally used only for tea preparation. The main objective of this work was to explore the valorization of mulberry leaves by polyphenols microwave‐assisted extraction (MAE) and characterization of their antioxidant activity and phenolic composition. A 23 factorial design combined with response surface methodology were applied to characterize the effect of main microwave parameters on total phenolic content (TPC). RESULTS The optimized MAE conditions were 20 mL of ethanol:water (1:1; v/v), 120 °C, 28 min, 0.414 g and medium stirring speed. Under these conditions, TPC was 19.7 ± 2.0 mg gallic acid equivalents (GAE) g‐1 dry plant (DP), and antioxidant activity was 15.3 ± 1.0 mg ascorbic acid (AA) g‐1 DP (ferric reduction activity power –FRAP– assay), 18.6 ± 1.3 mg Trolox equivalents (TE) g‐1 DP (2,2‐diphenyl‐1‐picrylhydrazyl –DPPH– assay) and 186 ± 15 mg TE g‐1 DP (oxygen radical absorbance capacity –ORAC– assay). When compared with ultrasound extraction and Pharmacopeia reference method, MAE was more efficient, representing a valuable technology. Of the 13 compounds identified by HPLC, the most abundant were rutin, chlorogenic, β‐resorcylic and caffeic acids. CONCLUSION These results indicate that mulberry leaves are of potential interest for agro‐food industries as a new source of natural antioxidants.

2018-02Journal article

Open access

Chemical Characterization and In Vitro Bioactivity of Apple Bark Extracts Obtained by Subcritical Water

Publication . Švarc-Gajić, Jaroslava; Cerdà, Víctor; Delerue-Matos, Cristina; Mašković, Pavle; Clavijo, Sabrina; Suarez, Ruth; Cvetanović, Aleksandra; Ramalhosa, Maria João; Barroso, M. Fátima; Moreira, Manuela; Morais, Simone; Withouck, Hannes; Boeykens, Annick

Recently, the value of wood residues has received increasing attention due to the presence of pharmacologically active compounds. In the present study, apple bark was treated with subcritical water (SWE) with the aim of bioactivity determination and chemical analysis by GC–MS applying two different sample preparation protocols and by HPLC. Extracts were screened for their total antioxidant capacity by means of total phenolic (TPC) and flavonoid contents (TFC), ferric reducing antioxidant power (FRAP) and DPPH-radical scavenging activity (DPPH-RSA). Anti-microbial and anti-proliferative activities of the apple bark subcritical water extracts were also examined. Different lignin and cellulose degradation products were identified by GC–MS, as well as naturally present compounds. Identified compounds encompassed organic and fatty acids, alcohols, sugars, phenol, benzaldehyde, cinnamic acid, cinnamaldehyde and azulene derivatives, as well as other organic compounds. Phenolic profiles of apple bark extracts defined by HPLC–PDA analysis revealed that the main contributors were gallic acid (9.4 ± 0.5 mg/g DW) and catechin (8.3 ± 0.4 mg/g DW). The diversity of the extracts composition supports the fact that this medium is able to extract compounds of different polarities, simultaneously acting as catalyst and reactant. The characterized apple bark extracts demonstrated good antioxidant (TPC = 31.47 ± 1.86 mg GAE/g; TFC = 17.40 ± 1.89 mg EE/g; FRAP = 22.45 ± 2.22 mg AAE/g; DPPH-RSA = 22.57 ± 2.24 mg Trolox E/g DW), antimicrobial (MIC = 19.53–156.25 μg/mL) and anti-proliferative activity (IC50 = 19.88–47.44 μg/mL). The findings of this study showed that SWE can be used as an environmentally friendly and safe technique for the valorization of apple tree wood residues, applicable in food and pharmaceutical industries.

2021-05-24Journal article

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