Submit to Molecules Review for Molecules Propose a Special Issue

Journal Browser

Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants

Special Issue Editors
Special Issue Information
Keywords
Published Papers

A special issue of Molecules (ISSN 1420-3049). This special issue belongs to the section "Natural Products Chemistry".

Deadline for manuscript submissions: closed (31 March 2022) | Viewed by 21060

Share This Special Issue

Special Issue Editor

Prof. Dr. Konstantinos Petrotos

E-Mail Website
Guest Editor

Department of Agrotechnology, Laboratory of Food and Biosystems Engineering, University of Thessaly, 41110 Larissa, Greece
Interests: Natural antimicrobials & antioxidants; encapsulation; advanced drying technologies; novel extraction and separation technologies; non-thermal preservation technologies

Special Issue Information

Dear Colleagues,

The chemical antioxidant and antimicrobial products have been accused for certain negative effects on human health, as well as for environmental problems. Therefore, a new trend has been established aiming at the substitution of them by non-hazardous natural bioactive compounds in real life applications. Among them we can consider the application of natural compounds in Agro-Food and Cosmetics sector, as well as in the production of nutraceuticals and natural medicines. The production of commercial products from natural raw materials which can be used as natural antioxidants or/and antimicrobials is a high added value activity and involves novel technologies. Novel “green” technologies like Microwave or Ultrasound assisted extraction or combination of them, High Voltage Discharge or high pressure extraction for the initial production of natural extracts are combined with advanced cross flow membrane technologies (MF, UF, NF and RO) or Industrial Chromatography for separation, purification and concentration of them. In addition, cutting edge, non-thermal preservation technologies like High Pressure, Pulsed Electric Field or Plasma have been emerged to safeguard the produced natural extracts against pathogens and spoilage microorganisms Moreover, low temperature non-destructive technologies like conventional or microwave freeze drying, vacuum microwave drying or electrospray are used for the drying of the purified natural extracts as well as for subsequent encapsulation of them to achieve color and odor masking, protection from oxidation and increase of the bioavailability of the contained natural bio-actives. An interesting aspect of natural product technology is also the use of agrofood-wastes as raw materials in order to gain added value and simultaneously decrease the carbon fingerprint of their production. Finally, novel research on natural products concerning modern instrumental methods for analysis and smart and commercially oriented applications of them, either as natural antimicrobials, or/and as antioxidants, can also be included in the present special issue.

Prof. Dr. Konstantinos Petrotos
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Molecules is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Natural products
Antimicrobial & Antioxidant activity
Applications
Novel Processing Technologies
Advanced Instrumental Analysis

Published Papers (7 papers)

Download All Papers

Research

24 pages, 2084 KiB

Open AccessArticle

Antioxidant, Antimicrobial, and Metabolomic Characterization of Blanched Pomegranate Peel Extracts: Effect of Cultivar

by Tandokazi Pamela Magangana, Nokwanda P. Makunga, Olaniyi Amos Fawole, Maria A. Stander and Umezuruike Linus Opara

Molecules 2022, 27(9), 2979; https://doi.org/10.3390/molecules27092979 - 06 May 2022

Cited by 12 | Viewed by 2174

Abstract

Hot water blanching at 80 °C for 3 min can be used as a novel pre-treatment step in pomegranate peel to preserve the integrity of the phytochemical content within the peel extracts by lowering or inactivating enzymes such as polyphenol (PPO) oxidase and peroxidase (POD) that are responsible for the break-down of phytochemicals within the peel. The aim of this study was to investigate the effect of hot water blanching pre-treatment on yield, bioactive compounds, antioxidants, enzyme inactivation, and antibacterial activity of ‘Wonderful’, ‘Acco’, and ‘Herskawitz’ pomegranate peel extracts. We used a variety of spectrophotometric-based assays and liquid chromatography mass spectrometry (LC-MS)-based approach to characterize and quantify metabolites within the peel extracts. Blanching significantly (p < 0.05) reduced PPO activity in all peel extracts, with the highest PPO reduction in ‘Herskawitz’ peel extracts at 0.25 U/mL. Furthermore, higher antioxidant activity in ‘Herskawitz’ blanched peel extracts using 2,2-diphenyl-1-picryl hydrazyl (DPPH) antioxidant activity, ferric ion reducing antioxidant power (FRAP), and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) radical scavenging activity at 567.78 ± 9.47 µmol Trolox/g DM, 800.05 ± 1.60 µmol Trolox/g DM, and 915.27 ± 0.61 µmol Trolox/g DM, respectively, was noted. ‘Herskawitz’ blanched peel extracts were recorded with the lowest minimum inhibitory concentration (MIC) value of 80 µg/mL for Gram-positive Bacillus subtilis and Gram-negative Klebsiella pneumoniae bacteria strains. A total of 30 metabolites were present in ‘Acco’ and ‘Herskawitz’ peel extracts and were tentatively identified after LC-MS profiling. This study demonstrates that blanched peel extracts from ‘Herskawitz’ cultivar have great potential for commercial use in value-added products in the nutraceutical, cosmeceutical, and pharmacological industries. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Figure 1

16 pages, 1346 KiB

Open AccessArticle

Antimicrobial Properties of Lyophilized Extracts of Olive Fruit, Pomegranate and Orange Peel Extracts against Foodborne Pathogenic and Spoilage Bacteria and Fungi In Vitro and in Food Matrices

by Chrysanthi Mitsagga, Konstantinos Petrotos and Ioannis Giavasis

Molecules 2021, 26(22), 7038; https://doi.org/10.3390/molecules26227038 - 21 Nov 2021

Cited by 6 | Viewed by 2599

Abstract

Several novel antimicrobials with different concentrations of olive, pomegranate, and orange fruit pulp extracts were produced from agricultural byproducts and, after lyophilization, their antimicrobial activity and potential synergistic effects were evaluated in vitro and in food samples against foodborne pathogenic and spoilage bacteria and fungi. The Minimum Inhibitory of the tested bacteria was 7.5% or 10%, while fungi were inhibited at a concentration of 10% or above. The optical density of bacterial and yeast cultures was reduced to a different extent with all tested antimicrobial powders, compared to a control without antimicrobials, and mycelium growth of fungi was also restricted with extracts containing at least 90% olive extract. In food samples with inoculated pathogens and spoilage bacteria and fungi, the 100% olive extract was most inhibitory against E. coli, S. typhimurium, and L. monocytogenes in fresh burger and cheese spread samples (by 0.6 to 1.8 log cfu/g), except that S. typhimurium was better inhibited by a 90% olive and 10% pomegranate extract in burgers. The latter extract was also the most effective in controlling the growth of inoculated fungi (Aspergillus niger, Penicillium italicum, Rhodotorula mucilaginosa) in both yogurt and tomato juice samples, where it reduced fungal growth by 1–2.2 log cfu/g at the end of storage period. The results demonstrate that these novel encapsulated extracts could serve as natural antimicrobials of wide spectrum, in order to replace synthetic preservatives in foods and cosmetics. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Figure 1

18 pages, 2044 KiB

Open AccessArticle

Corn Silage Supplemented with Pomegranate (Punica granatum) and Avocado (Persea americana) Pulp and Seed Wastes for Improvement of Meat Characteristics in Poultry Production

by Stefanos Leontopoulos, Prodromos Skenderidis, Konstantinos Petrotos and Ioannis Giavasis

Molecules 2021, 26(19), 5901; https://doi.org/10.3390/molecules26195901 - 29 Sep 2021

Cited by 6 | Viewed by 2297

Abstract

In the present study, pomegranate peels, avocado peels, and seed vacuum microwave extraction solid by-products were supplemented in corn silage in order to investigate the effects on meat quality and growth rate in broiler chicken. There were 50 broilers, divided in two groups, treated with experimental or usual feed for 43 days (group A: 25 broilers fed with avocado and pomegranate by-products and group B: 25 broilers fed with corn-silage used as control). The results showed that broiler chickens fed with a diet supplemented with a mixture of pomegranate avocado by-products (group A) showed significant differences in chicken leg meat quality, significantly improving the level of proteins and fatty acids content in breast and leg meat, respectively. More specific ω3 and ω6 fatty acids content were three times higher than in group B. Moreover, a protective effect on the decomposition of polyunsaturated fatty acids, induced by free radicals and presented in chicken meat, is based on the evaluation of lipid peroxidation by measuring thiobarbituric acid reactive substances. Pomegranate peels, avocado peels, and seed by-products appeared to have a slight reduction on meat production, while it was found to improve the qualitative chicken meat characteristics. Regarding the production costs, it was calculated that the corn-silage supplementation, used in this study, lead to a 50% lower cost than the commercial corn-silage used for the breeding of broilers. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Figure 1

11 pages, 1090 KiB

Open AccessArticle

Optimization of an Extraction Process to Obtain a Food-Grade Sulforaphane-Rich Extract from Broccoli (Brassica oleracea var. italica)

by Francis González, Julián Quintero, Rodrigo Del Río and Andrea Mahn

Molecules 2021, 26(13), 4042; https://doi.org/10.3390/molecules26134042 - 01 Jul 2021

Cited by 15 | Viewed by 4054

Abstract

Sulforaphane (SFN) is a powerful health-promoting compound found in broccoli in the form of its inactive precursor, glucoraphanin (GFN). SFN formation occurs through the enzymatic hydrolysis of glucoraphanin by myrosinase under specific chemical conditions. Its incorporation in food formulations has been hindered by the thermal instability of SFN and low concentration in Brassicaceae. Then, extracting SFN from broccoli at a temperature below 40 °C appears as an option to recover and stabilize SFN, aiming at delivering it as a nutraceutical. We studied an eco-friendly extraction process to obtain an SFN-rich extract from broccoli. The effect of the broccoli mass/solvent ratio, ethanol concentration in the extractant solution, and extraction time on the recovery of SFN, GFN, phenolic compounds, and antioxidant activity were studied through a Box–Behnken design. The regression models explained more than 70% of the variability in the responses, adequately representing the system. The experimental factors differently affected the bioactive compound recovery and antioxidant activity of the extracts. The extraction conditions that allowed the highest recovery of bioactive compounds and antioxidant activity were identified and experimentally validated. The results may provide the basis for the design of a process to produce a sulforaphane-rich food supplement or nutraceutical by using a GRAS extractant. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Graphical abstract

17 pages, 4805 KiB

Open AccessArticle

Comparison of the Phytochemical Composition and Antibacterial Activities of the Various Extracts from Leaves and Twigs of Illicium verum

by Emirlyn-Cheng Yang, Ya-Yun Hsieh and Li-Yeh Chuang

Molecules 2021, 26(13), 3909; https://doi.org/10.3390/molecules26133909 - 26 Jun 2021

Cited by 7 | Viewed by 2533

Abstract

Previous studies have revealed the numerous biological activities of the fruits of Illicium verum; however, the activities of its leaves and twigs have remained undiscovered. The study aimed to investigate the phytochemical components and antibacterial activity of the various extracts from the leaves and twigs of Illicium verum. The herbal extracts were prepared by supercritical CO₂ extraction (SFE) and 95% ethanol extraction, followed by partition extraction based on solvent polarity. Analysis of antimicrobial activity was conducted through the usage of nine clinical antibiotic- resistant isolates, including Staphylococcus aureus, Pseudomonas aeruginosa and Acinetobacter baumannii. Among the tested samples, the SFE extracts exhibited broader and stronger antibacterial activities against the test strains, with a range of MIC between 0.1–4.0 mg/mL and MBC between 0.2–4.5 mg/mL. Observations made through scanning electron microscopy revealed potential mechanism of the antimicrobial activities involved disruption of membrane integrity of the test pathogens. Evaluation of the chemical composition by gas chromatography-mass spectrometry indicated the presence of anethole, anisyl aldehyde, anisyl acetone and anisyl alcohol within the SFE extracts, demonstrating significant correlations with the antibacterial activities observed. Therefore, the leaves and twigs of Illicium verum hold great potential in being developed as new natural antibacterial agents. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Figure 1

27 pages, 3076 KiB

Open AccessArticle

Optimization of the Vacuum Microwave Assisted Extraction of the Natural Polyphenols and Flavonoids from the Raw Solid Waste of the Pomegranate Juice Producing Industry at Industrial Scale

by Konstantinos Petrotos, Ioannis Giavasis, Konstantinos Gerasopoulos, Chrysanthi Mitsagga, Chryssoula Papaioannou and Paschalis Gkoutsidis

Molecules 2021, 26(4), 1033; https://doi.org/10.3390/molecules26041033 - 16 Feb 2021

Cited by 16 | Viewed by 2162

Abstract

Pomegranate pomace (PP) is the solid waste produced in bulk by the pomegranate juice industry which is rich in polyphenols and flavonoids that can replace the hazardous chemical antioxidants/antimicrobials currently used in the agro-food and cosmetics sectors. In the present work, the vacuum microwave assisted extraction (VMAE) of natural antioxidants from raw pomegranate pomace was investigated and successfully optimized at an industrial scale. For the optimization of PP VMAE a novel, highly accurate response surface methodology (RSM) based on a comprehensive multi-point historical design was employed. The optimization showed that the maximum recovery of PP total polyphenols as well as total PP flavonoids were obtained at microwave power = 4961.07 W, water to pomace ratio = 29.9, extraction time = 119.53 min and microwave power = 4147.76 W, water to pomace ratio = 19.32, extraction time = 63.32 min respectively. Moreover, the optimal VMAE conditions on economic grounds were determined to be: microwave power = 2048.62 W, water to pomace ratio = 23.11, extraction time = 15.04 min and microwave power = 4008.62 W, water to pomace ratio = 18.08, extraction time = 15.29 min for PP total polyphenols and PP total flavonoids respectively. The main conclusion of this study is that the VMAE extraction can be successfully used at industrial scale to produce, in economic manner, high added value natural extracts from PP pomace. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures

Figure 1

27 pages, 5136 KiB

Open AccessArticle

Optimization of Vacuum-Microwave-Assisted Extraction of Natural Polyphenols and Flavonoids from Raw Solid Waste of the Orange Juice Producing Industry at Industrial Scale

by Konstantinos Petrotos, Ioannis Giavasis, Konstantinos Gerasopoulos, Chrysanthi Mitsagga, Chryssoula Papaioannou and Paschalis Gkoutsidis

Molecules 2021, 26(1), 246; https://doi.org/10.3390/molecules26010246 - 05 Jan 2021

Cited by 20 | Viewed by 4148

Abstract

Orange pomace (OP) is a solid waste produced in bulk as a byproduct of the orange juice industry and accounts for approximately 50% of the quantity of the fruits processed into juice. In numerous literature references there is information about diverse uses of orange pomace for the production of high-added-value products including production of natural antioxidant and antimicrobial extracts rich in polyphenols and flavonoids which can substitute the hazardous chemical antioxidants/antimicrobials used in agro-food and cosmetics sectors. In this work and for the first time, according to our knowledge, the eco-friendly aqueous vacuum microwave assisted extraction of orange pomace was investigated and optimized at real industrial scale in order to produce aqueous antioxidant/antimicrobial extracts. A Response Surface Optimization methodology with a multipoint historical data experimental design was employed to obtain the optimal values of the process parameters in order to achieve the maximum rates of extraction of OP total polyphenols and/or total flavonoids for economically optimum production at industrial scale. The three factors used for the optimization were: (a) microwave power (b) water to raw pomace ratio and (c) extraction time. Moreover, the effectiveness and statistical soundness of the derived cubic polynomial predictive models were verified by ANOVA. Full article

(This article belongs to the Special Issue Advanced Production, Analysis and Applications of Natural Antimicrobials and Antioxidants)

► Show Figures