Chemical and Functional Characterization of Extracts from Leaves and Twigs of Acacia dealbata

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Potential application of propolis extracts to control the growth of stemphylium vesicarium in 'Rocha'pear

PA54101 PA54102 PA54103 UIDB/04077/2020Stemphylium vesicarium (Wallr.) E. G. Simmons is the pathogen responsible of brown spot disease in pear and has become one of the main concerns for European pear producers. In Portugal, S. vesicarium is responsible for significant yield reduction and economic losses in "Rocha" pear (Pyrus communis L. cv Rocha) production. Considering the antimicrobial potential of propolis, the high incidence of brown spot in pears and the emergence of fungicides resistance in S. vesicarium, this study aimed to evaluate the potential of Portuguese propolis as an alternative strategy to control brown spot disease in "Rocha" pear. In vitro assays showed that propolis extracts were able to inhibit up to 90% the S. vesicarium mycelial growth. In vivo assays in artificially wounded and inoculated "Rocha" pears showed that, compared to the control, the disease incidence decreased up to 25% and the lesions diameter up to 57%, in fruits treated with propolis. Moreover, propolis seems to be more efficient in reducing the disease incidence when applied after pathogen inoculation (curative assay) than when applied before pathogen inoculation (prophylactic assay). Thus, the results suggest that propolis extracts have potential to be applied as part of an integrated approach for the control of brown spot of pear.publishersversionpublishe

Maceration of Waste Cork in Binary Hydrophilic Solvents for the Production of Functional Extracts

Publisher Copyright: © 2023 by the authors.Waste-grade cork samples of Quercus cerris were subjected to maceration extraction using 7 different solvents, including pure water (I), pure acetone (II), 75% aqueous ethanol (III), 75% aqueous methanol (IV), 75% aqueous acetone (V), 50% aqueous acetone (VI), and 25% aqueous acetone (VII). The extract yields, extract compositions, as well as antioxidant and antimicrobial activities of the extracts were analyzed. The results showed that maceration extraction was highly efficient, particularly with binary solvents resulting in up to 6% extract yield and up to 488 mg GAE/g extract total phenolic content. The extracts exhibited a variable antioxidant activity determined by DPPH and FRAP methods as well as antimicrobial activity against gram-positive bacteria and fungus determined by agar diffusion test. The CIELAB color parameters of extracts were correlated with maceration time, and the correlation was highest with pure water extracts. The FT-IR spectra of acetone-extracted cork revealed six key markers of phenolic compounds with the presence of peaks at approximately 2920 cm−1, 2850 cm−1, 1609 cm−1, 1517 cm−1, 1277 cm−1, and 1114 cm−1. The overall results suggest that the maceration of waste cork in binary solvents and pure acetone are green alternatives to conventional Soxhlet extraction for the production of polar extracts.publishersversionpublishe

Evaluation of Industrial Sour Cherry Liquor Wastes as an Ecofriendly Source of Added Value Chemical Compounds and Energy

There has been a growing interest in the recovery and valorization of chemical products from biomass wastes. In the present study pomace from sour cherry liquor was analyzed in order to evaluate its potential for valorization. Two different samples of liquor pomace and two different extraction methods were screened through determination of their phenolic content (HPLC/PDA) and antioxidant activity (FRAP and DPPH assay). Results obtained showed that skins (pomace without kernel) presented a higher extraction yield, polyphenolic content and antioxidant activity than pomace with kernel (skin+kernel). Decoction at 100 °C allowed a higher recovery of phenolic compounds, but, maceration with water at 25 °C was considered a more sustainable process. HPLC analyses allowed the identification and quantification of phenolic compounds such as cyanidin-3-O-glucoside, (+)catechin and (−)epicatechin and some phenolic acids. The analyzed by-products might be a promising source of natural polyphenolic compounds, which can act as a new eco-friendly antioxidant ingredient, with potential to be incorporated in nutraceutical formulations or applied in food or cosmetic industries. The residues remaining after extraction have a high calorific value and fat content, suggesting its valorization as a source of energy or through the extraction of value-added oil.proofinpres

Evaluation of Industrial Sour Cherry Liquor Wastes as an Ecofriendly Source of Added Value Chemical Compounds and Energy

There has been a growing interest in the recovery and valorization of chemical products from biomass wastes. In the present study pomace from sour cherry liquor was analyzed in order to evaluate its potential for valorization. Two different samples of liquor pomace and two different extraction methods were screened through determination of their phenolic content (HPLC/PDA) and antioxidant activity (FRAP and DPPH assay). Results obtained showed that skins (pomace without kernel) presented a higher extraction yield, polyphenolic content and antioxidant activity than pomace with kernel (skin+kernel). Decoction at 100 °C allowed a higher recovery of phenolic compounds, but, maceration with water at 25 °C was considered a more sustainable process. HPLC analyses allowed the identification and quantification of phenolic compounds such as cyanidin-3-O-glucoside, (+)catechin and (−)epicatechin and some phenolic acids. The analyzed by-products might be a promising source of natural polyphenolic compounds, which can act as a new eco-friendly antioxidant ingredient, with potential to be incorporated in nutraceutical formulations or applied in food or cosmetic industries. The residues remaining after extraction have a high calorific value and fat content, suggesting its valorization as a source of energy or through the extraction of value-added oil.proofpublishe

Exploring the Multifaceted Potential of a Peptide Fraction Derived from <i>Saccharomyces cerevisiae</i> Metabolism: Antimicrobial, Antioxidant, Antidiabetic, and Anti-Inflammatory Properties

The rising demand for minimally processed, natural, and healthier food products has led to the search for alternative and multifunctional bioactive food components. Therefore, the present study focuses on the functional proprieties of a peptide fraction derived from Saccharomyces cerevisiae metabolism. The antimicrobial activity of the peptide fraction is evaluated against various foodborne pathogens, including Candida albicans, Candida krusei, Escherichia coli, Listeria monocytogenes, and Salmonella sp. The peptide fraction antioxidant properties are assessed using FRAP and DPPH scavenging capacity assays. Furthermore, the peptide fraction’s cytotoxicity is evaluated in colorectal carcinoma and normal colon epithelial cells while its potential as an antidiabetic agent is investigated through α-amylase and α-glucosidase inhibitory assays. The results demonstrate that the 2–10 kDa peptide fraction exhibits antimicrobial effects against all tested microorganisms, except C. krusei. The minimal inhibitory concentration for E. coli, L. monocytogenes, and Salmonella sp. remains consistently low, at 0.25 mg/mL, while C. albicans requires a higher concentration of 1.0 mg/mL. Furthermore, the peptide fraction displays antioxidant activity, as evidenced by DPPH radical scavenging activity of 81.03%, and FRAP values of 1042.50 ± 32.5 µM TE/mL at 1.0 mg/mL. The peptide fraction exhibits no cytotoxicity in both tumor and non-tumoral human cells at a concentration up to 0.3 mg/mL. Moreover, the peptide fraction presents anti-inflammatory activity, significantly reducing the expression of the TNFα gene by more than 29.7% in non-stimulated colon cells and by 50% in lipopolysaccharide-stimulated colon cells. It also inhibits the activity of the carbohydrate digestive enzymes α-amylase (IC50 of 199.3 ± 0.9 µg/mL) and α-glucosidase (IC20 of 270.6 ± 6.0 µg/mL). Overall, the findings showed that the peptide fraction exhibits antibacterial, antioxidant, anti-inflammatory, and antidiabetic activity. This study represents a step forward in the evaluation of the functional biological properties of S. cerevisiae bioactive peptides