Submit to Molecules Review for Molecules Propose a Special Issue

Journal Browser

► Journal Browser

Analyses and Applications of Phenolic Compounds in Food

Print Special Issue Flyer
Special Issue Editors
Special Issue Information
Keywords
Related Special Issue
Published Papers

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

Deadline for manuscript submissions: closed (30 November 2023) | Viewed by 17028

Share This Special Issue

Special Issue Editors

Prof. Dr. Monica Rosa Loizzo

E-Mail Website
Guest Editor

Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, 87036 Rende (CS), Italy
Interests: food science technology; bioactives from food byproducts; evaluation of shelf-life; development of functional foods
Special Issues, Collections and Topics in MDPI journals

Dr. Ana Teresa Sanches-Silva

E-Mail Website
Guest Editor

National Institute of Agrarian and Veterinary Research, Rua dos Lágidos, Lugar da Madalena, 4485-655 Vila do Conde, Portugal
Interests: food and food packaging analysis; food bioactives; food contaminants; mycotoxins; food packaging migration; development and validation of analytical methods for the determination of food components and food contaminants; mass spectrometry applied to food analysis; development of active packaging with antioxidant properties; edible packaging
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Oscar Núñez

E-Mail Website
Guest Editor

1. Department of Chemical Engineering and Analytical Chemistry, Faculty of Chemistry, University of Barcelona, Martí i Franquès 1-11, E-08028 Barcelona, Spain
2. Research Institute in Food Nutrition and Food Safety, Universitat de Barcelona, Av. Prat de la Riba 171, Edifici Recerca (Gaudí), E-08921 Santa Coloma de Gramenet, Spain
Interests: food authentication; food characterization; food classification; food fraud identification; secondary metabolites; polyphenols; foodomics; bioactive compounds; liquid chromatography; mass spectrometry; high resolution mass spectrometry; ambient mass spectrometry; capillary electrophoresis; chemometrics
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Phenolic compounds are well-known for their antioxidant and free-radical-scavenging abilities, as well as different health properties, including anti-inflammatory, antitumor, and hypoglycaemic properties, among others. Due to these countless positive effects on human health, researchers have intensified their study with the aim of discovering food matrices rich in this class of phytochemicals or agro-industrial residues that can be used as sources of phenols. Moreover, different kinds of products can be functionalized with this class of phytochemicals. Indeed, phenolic compounds have been extensively investigated for their possible applications in the food industry for improving the shelf life of perishable products. In fact, phenols are also able to exert antimicrobial activities, by the capacity to slow the microbial invasion in some products and avoiding the putrefaction of others, mainly in fruits and vegetables. For this reason, several bio-based and synthetic polymers are being functionalized with phenolic compounds to prolong shelf life when used directly in contact with the food matrix as part of combined strategies. However, in food applications, phenolic compounds could be influenced by other food components, processing, and storage conditions. The use of phenolic compounds from natural sources in food is an interesting opportunity for the application and exploitation of their biological activities and allows the production of food without synthetic additives for consumers. This is because the current concern about the impact of food on health influences consumer choices of food based on its formulation. In addition, the distribution and content of phenolic compounds in plant-based food products depend on multiple parameters, such as geographical areas, variety and manufacturing practices. Thus, contents on phenolics can be exploited as a source of analytical data to establish product classification and solve authenticity issues. Several analytical techniques are developed for the extraction and analysis of phenolic compounds. The focus of this Special Issue is to collect and discuss conventional and innovative analytical techniques for food phenolics investigations, as well as their possible applications as food preservatives or functional ingredients for the development of functional food, active food packaging and in food classification and authentication studies.

Prof. Dr. Monica Rosa Loizzo
Dr. Ana Teresa Sanches-Silva
Prof. Dr. Oscar Núñez
Guest Editors

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

phenolics
extraction
identification
applications in food matrix

Related Special Issue

Analyses and Applications of Phenolic Compounds in Food—2nd Edition in Molecules (1 article)

Published Papers (11 papers)

Download All Papers

Research

16 pages, 5059 KiB

Open AccessArticle

Phytoconstituents and Ergosterol Biosynthesis-Targeting Antimicrobial Activity of Nutmeg (Myristica fragans Houtt.) against Phytopathogens

by Adriana Cruz, Eva Sánchez-Hernández, Ana Teixeira, Rui Oliveira, Ana Cunha and Pablo Martín-Ramos

Molecules 2024, 29(2), 471; https://doi.org/10.3390/molecules29020471 - 18 Jan 2024

Viewed by 802

Abstract

In recent years, nutmeg (Myristica fragans Houtt.) has attracted considerable attention in the field of phytochemistry due to its diverse array of bioactive compounds. However, the potential application of nutmeg as a biorational for crop protection has been insufficiently explored. This study investigated the constituents of a nutmeg hydroethanolic extract via gas chromatography-mass spectrometry and vibrational spectroscopy. The research explored the extract’s activity against phytopathogenic fungi and oomycetes, elucidating its mechanism of action. The phytochemical profile revealed fatty acids (including tetradecanoic acid, 9-octadecenoic acid, n-hexadecanoic acid, dodecanoic acid, and octadecanoic acid), methoxyeugenol, and elemicin as the main constituents. Previously unreported phytochemicals included veratone, gelsevirine, and montanine. Significant radial growth inhibition of mycelia was observed against Botrytis cinerea, Colletotrichum acutatum, Diplodia corticola, Phytophthora cinnamomi, and especially against Fusarium culmorum. Mode of action investigation, involving Saccharomyces cerevisiae labeled positively with propidium iodide, and a mutant strain affected in ERG6, encoding sterol C-24 methyltransferase, suggested that the extract induces a necrotic type of death and targets ergosterol biosynthesis. The evidence presented underscores the potential of nutmeg as a source of new antimicrobial agents, showing particular promise against F. culmorum. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Graphical abstract

17 pages, 1034 KiB

Open AccessArticle

Dark-Chocolate-Coated BRS Clara Raisins: Phenolic Composition and Sensory Attributes

by Carolina Olivati, Yara Paula Nishiyama-Hortense, Natália Soares Janzantti, Roberto da Silva, Ellen Silva Lago Vanzela and Sergio Gómez-Alonso

Molecules 2023, 28(20), 7006; https://doi.org/10.3390/molecules28207006 - 10 Oct 2023

Viewed by 1289

Abstract

Dark chocolate dragée confectionary was made with BRS Clara raisins pre-treated with extra virgin olive oil (EVOO). The evaluation of the changes in the phenolic composition (flavonols, hydrocinnamic acid derivatives (HCADs), stilbenes and flavan-3-ol monomers, dimers, and proanthocyanidins (PAs)) resulting from the covering process showed that the chocolate coating was responsible for an increase in the concentrations of flavan-3-ols and PAs when compared to just the raisins. For the flavonols and HCADs, a reduction in the total concentration of compounds was observed when comparing the dragées to the raisins. Furthermore, there was a strong influence of chocolate in the qualitative profile with the emergence of new compounds (quercetin-3-pentoside, kampfterol-3-rutinoside, p-coumaric acid, and caffeoyl-aspartate). The combination of these ingredients (raisins and chocolate) resulted in a dark chocolate coated raisin (DC) with good sensory acceptance and a more complex phenolic composition that may positively contribute to its functional quality. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Graphical abstract

15 pages, 4109 KiB

Open AccessArticle

Chemical and Sensory Properties of Waffles Supplemented with Almond Skins

by Ivo Oliveira, Beatriz Marinho, Urszula Szymanowska, Monika Karas and Alice Vilela

Molecules 2023, 28(15), 5674; https://doi.org/10.3390/molecules28155674 - 27 Jul 2023

Cited by 1 | Viewed by 1370

Abstract

Almonds are one of the most produced nuts worldwide and numerous studies have shown that they have nutritional and medicinal characteristics, which gives them the possibility of being applied in various products. However, several by-products are generated during their production, which have characteristics of interest but remain underutilised, namely, the almond skins. This work aimed to study samples of waffles supplemented with almond skins. The waffles were evaluated for their total polyphenol content, antioxidant capacity, total flavonoids, ortho-diphenols, soluble sugars, starch, texture, and colour. They were also sensorially evaluated using a panel of tasters specialised in this type of evaluation and a quantitative descriptive analysis test (QDA) sensory test. The results showed that the waffles with the highest levels of phenolic compounds as well as the highest antioxidant activity (by the ABTS, DPPH, and FRAP methods) were the waffles supplemented with 10% almond skin. The total phenol contents obtained for the prepared extracts varied between 0.127 mg GAE/g and 0.415 mg GAE/g, the flavonoid contents ranged from 0.067 mg CAE/g to 0.339 mg CAE/g and the ortho-diphenol contents varied between 0.163 mg ACE /g and 0.303 mg ACE/g. Regarding the quantification of soluble sugars, the values were presented in percentage of fresh weight, and ranged from 30.148 to 38.054%; regarding the quantification of starch, the percentages varied from 14.488 to 21.982%. Sensorially, we verified that the samples were statistically different in terms of the descriptors “colour”, “roasted aroma”, and “dissolubility”, with a higher score in these descriptors for the waffles with 10% of almond skin. This process of obtaining waffles, which can be industrialised, is interesting from both a nutritional point of view and for the possibility of creating new, differentiated, and innovative products. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Graphical abstract

14 pages, 1115 KiB

Open AccessArticle

Optimization of the Extraction Conditions of Bioactive Compounds from Ocimum basilicum Leaves Using Ultrasound-Assisted Extraction via a Sonotrode

by Carolina Aloisio, María del Carmen Razola-Díaz, María José Aznar-Ramos, Marcela R. Longhi, Alfonsina E. Andreatta and Vito Verardo

Molecules 2023, 28(13), 5286; https://doi.org/10.3390/molecules28135286 - 07 Jul 2023

Cited by 2 | Viewed by 1087

Abstract

Sweet basil (Ocimum basilicum) leaves are rich in bioactive compounds that present therapeutic benefits for human health. Ultrasonic-assisted extraction (UAE) is frequently used to obtain phenolic compounds from plants/herbal sources. However, few works have developed multi-variable studies to find the optimal conditions to extract the maximum amount of compounds, especially when applied to UAE via a sonotrode. The purpose of this work was to perform a multi-variable study by employing a Box–Behnken design to collect the highest active compound content from Ocimum basilicum leaves. The efficacy of the design was endorsed by ANOVA. The studied parameters for UAE via a sonotrode were the ethanol/water ratio, amplitude, and time. The analyzed responses were the rosmarinic acid, the sum of phenolic acids, and the sum of phenolic compounds content. The optimal conditions were found to be 50% ethanol/water, 50% amplitude, and 5 min. Twenty bioactive compounds were identified by HPLC-ESI-TOF-MS when the extract was collected by applying the optimal conditions. Ocimum basilicum may be appreciated as a valuable source of important bioactive substances for pharmaceutical use. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

15 pages, 5065 KiB

Open AccessArticle

Role of Polyphenols from the Aqueous Extract of Aloysia citrodora in the Inhibition of Aflatoxin B1 Synthesis in Aspergillus flavus

by Laura F. Cadenillas, Christopher Hernandez, Sylviane Bailly, Guillaume Billerach, Vanessa Durrieu and Jean-Denis Bailly

Molecules 2023, 28(13), 5123; https://doi.org/10.3390/molecules28135123 - 30 Jun 2023

Cited by 1 | Viewed by 1160

Abstract

Aflatoxin B1 (AFB1) is a mycotoxin considered a potent carcinogen for humans that contaminates a wide range of crops. Various strategies have been established to reduce or block the synthesis of AFB1 in food and feed. The use of aqueous extracts derived from plants with high antioxidant activity has been a subject of study in recent years due to their efficacy in inhibiting AFB1. In this study, we assessed the effect of Aloysia citrodora aqueous extract on Aspergillus flavus growth and on AFB1 production. A bio-guided fractionation followed by High Performance Liquid Chromatography (HPLC) and Mass spectrometry analysis of the active fraction were applied to identify the candidate molecules responsible for the dose-effect inhibition of AFB1 synthesis. Our results revealed that polyphenols are the molecules implicated in AFB1 inhibition, achieving almost a total inhibition of the toxin production (99%). We identified luteolin-7-diglucuronide as one of the main constituents in A. citrodora extract, and demonstrated that it is able to inhibit, by itself, AFB1 production by 57%. This is the first study demonstrating the anti-Aflatoxin B1 effect of this molecule, while other polyphenols surely intervene in A. citrodora anti-AFB1 activity. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

22 pages, 2786 KiB

Open AccessArticle

Influence of Different Rootstocks on Fruit Quality and Primary and Secondary Metabolites Content of Blood Oranges Cultivars

by María Ángeles Forner-Giner, Manuel Ballesta-de los Santos, Pablo Melgarejo, Juan José Martínez-Nicolás, Dámaris Núñez-Gómez, Alberto Continella and Pilar Legua

Molecules 2023, 28(10), 4176; https://doi.org/10.3390/molecules28104176 - 18 May 2023

Cited by 2 | Viewed by 1106

Abstract

Blood oranges have high concentrations of bioactive compounds that are beneficial to health. In Europe, the cultivation of blood oranges is increasing due to their excellent nutritional properties. In Citrus crops, rootstocks play an important role in juice and can increase the content of bioactive compounds. The morphological, qualitative and nutritional parameters were analyzed in cultivars ‘Tarocco Ippolito’, ‘Tarocco Lempso’, ‘Tarocco Tapi’ and ‘Tarocco Fondaconuovo’ grafted onto Citrus macrophylla and Citrus reshni. ‘Tarocco Lempso’ grafted onto Citrus macrophylla obtained the highest values of weight (275.78 g), caliber (81.37 mm and 76.79 mm) and juice content (162.11 g). ‘Tarocco Tapi’ grafted onto Citrus reshni obtained the most interesting qualitative parameters (15.40 °Brix; 12.0 MI). ‘Tarocco Lempso’ grafted onto Citrus reshni obtained the most intense red juice (a* = 9.61). Overall, the highest concentrations of primary metabolites were in proline, aspartate, citric acid, and sucrose. The results showed that ‘Tarocco Ippolito’ juice grafted onto Citrus reshni had the highest levels of total hydroxycinnamic acids (263.33 mg L⁻¹), total flavones (449.74 mg L⁻¹) and total anthocyanins (650.42 mg L⁻¹). To conclude, ‘Tarocco Lempso’ grafted onto Citrus macrophylla obtained the best values of agronomic parameters, and the cultivars grafted onto Citrus reshni obtained significantly higher concentrations in primary and secondary metabolites. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

16 pages, 1548 KiB

Open AccessArticle

Enhancement of Polyphenols and Antioxidant Activity in Germinated Black Highland Barley by Ultrasonication

by Jie Zhang, Junling Guo, Bin Dang, Wengang Zhang, Wancai Zheng and Xijuan Yang

Molecules 2023, 28(9), 3679; https://doi.org/10.3390/molecules28093679 - 24 Apr 2023

Cited by 3 | Viewed by 1140

Abstract

The aim of this study was to investigate the effect of ultrasonic stress germination (USG) on total phenolic contents (TPC), total flavonoid contents (TFC), the phenolic compositions, and antioxidant activities of black highland barley (BHB). The USG processing parameters, polyphenol profile, phenolic compositions, and antioxidant activities were explored after USG. Results showed that the optimal USG parameters were as follows: 350 W ultrasonic pretreatment power, 30 °C ultrasonication temperature, 25 min ultrasonication time, and 64 h germination time. Under these conditions, the total phenolic content (688.84 ± 5.30 mg/100 g) and total flavonoid content (59.23 ± 0.45 mg/100 g) of BHB were increased by 28.55% and 10.15%, respectively, compared to the untreated samples. In addition, the USG treatment could more effectively enrich bound phenolic acids and free flavonoids, among which the content of catechin was significantly increased by USG and was the main characteristic substance. Moreover, the USG treatment could improve the antioxidant activity and had a higher antioxidant potency composite index (APC index) (97.91%) of BHB. These results indicate that USG might be an effective method to enrich polyphenols and improve antioxidant activity in BHB. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Graphical abstract

17 pages, 21551 KiB

Open AccessArticle

Elucidating Flavonoid and Antioxidant Activity in Edible and Medicinal Herbs Woodwardia japonica (L.f.) Sm. Based on HPLC-ESI-TOF-MS and Artificial Neural Network Model: Response to Climatic Factors

by Xin Wang, Jianguo Cao, Lin Tian, Baodong Liu, Yawen Fan and Quanxi Wang

Molecules 2023, 28(4), 1985; https://doi.org/10.3390/molecules28041985 - 20 Feb 2023

Viewed by 1444

Abstract

Woodwardia japonica is a kind of great potential edible and medicinal fern. In a previous study, it was found that flavonoid and antioxidant activity of W. japonica from different sites were different. However, the cause of the differences has still been unclear, which has restricted the utilization of W. japonica. In this paper, flavonoid and antioxidant activity of W. japonica from nine different regions were determined with the method of a colorimetric assay with UV-VIS spectrophotometry and HPLC-ESI-TOF-MS, and the effects of climate factors on flavonoids and antioxidant activities were evaluated by mathematical modeling and statistical methods. The results showed: (1) total flavonoid content (TFC) of W. japonica from Wuyi Mountain (Jiangxi) was the highest, which might be related to the low temperature; (2) the differences of antioxidant activities of W. japonica might be related to precipitation; (3) five flavonols, two flavones and one isoflavone were tentatively identified in W. japonica; (4) flavonol and isoflavone might be affected by sunshine duration, and flavones were probably related to temperature. In conclusion, the effects of climate factors on flavonoids and antioxidants are significant, which would provide an important basis for further exploring the mechanism of climate affecting secondary metabolites. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

15 pages, 2088 KiB

Open AccessArticle

Polyphenol Profile and In Vitro Antioxidant and Enzyme Inhibitory Activities of Different Solvent Extracts of Highland Barley Bran

by Wengang Zhang, Yongli Lan, Bin Dang, Jie Zhang, Wancai Zheng, Yan Du, Xijuan Yang and Zhonghong Li

Molecules 2023, 28(4), 1665; https://doi.org/10.3390/molecules28041665 - 09 Feb 2023

Cited by 5 | Viewed by 2155

Abstract

Five different solvent extracts of highland barley bran were analyzed and compared for their polyphenol profile, antioxidant activity, and α-glucosidase and α-amylase inhibitory activities. The highland barley bran acetone extract had the highest total phenolic content, total flavonoid content, and antioxidant capacity. It was followed by the methanol and ethanol extracts, while n-butanol and ethyl acetate extracts exhibited lower measured values. Diosmetin, luteolin, protocatechuic acid, vanillic acid, ferulic acid, phlorogucinol, diosmin, isoquercitrin, catechin, and isovitexin were among the most abundant phenolic compounds identified in different solvent extracts, and their concentrations varied according to the solvent used. The highest α-glucosidase and α-amylase inhibitory activity were observed in the ethyl acetate extract of highland barley bran, followed by the acetone and methanol extracts. In contrast, n-butanol and ethanol extracts exhibited lower measured values. The different solvent extracts were effective inhibitors for α-glucosidase and α-amylase with activity reaching to 34.45–94.32% and 22.08–35.92% of that of positive control acarbose, respectively. There were obvious correlations between the phenolic content and composition of different solvent extracts and their in vitro antioxidant activity, α-glucosidase inhibition activity and α-amylase inhibition activity. Black barley bran is an excellent natural raw material for developing polyphenol-rich functional foods and shows good antioxidant and hypoglycemic potential to benefit human health. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Graphical abstract

16 pages, 3423 KiB

Open AccessArticle

Off-Line SPE LC-LRMS Polyphenolic Fingerprinting and Chemometrics to Classify and Authenticate Spanish Honey

by Víctor García-Seval, Javier Saurina, Sònia Sentellas and Oscar Núñez

Molecules 2022, 27(22), 7812; https://doi.org/10.3390/molecules27227812 - 13 Nov 2022

Cited by 3 | Viewed by 1420

Abstract

The feasibility of non-targeted off-line SPE LC-LRMS polyphenolic fingerprints to address the classification and authentication of Spanish honey samples based on both botanical origin (blossom and honeydew honeys) and geographical production region was evaluated. With this aim, 136 honey samples belonging to different botanical varieties (multifloral and monofloral) obtained from different Spanish geographical regions with specific climatic conditions were analyzed. Polyphenolic compounds were extracted by off-line solid-phase extraction (SPE) using HLB (3 mL, 60 mg) cartridges. The obtained extracts were then analyzed by C18 reversed-phase LC coupled to low-resolution mass spectrometry in a hybrid quadrupole-linear ion trap mass analyzer and using electrospray in negative ionization mode. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) were employed to assess the pattern recognition capabilities of the obtained fingerprints to address honey classification and authentication. In general, a good sample discrimination was accomplished by PLS-DA, being able to differentiate both blossom-honey and honeydew-honey samples according to botanical varieties. Multiclass predictions by cross-validation for the set of blossom-honey samples showed sensitivity, specificity, and classification ratios higher than 60%, 85%, and 87%, respectively. Better results were obtained for the set of honeydew-honey samples, exhibiting 100% sensitivity, specificity, and classification ratio values. The proposed fingerprints also demonstrated that they were good honey chemical descriptors to deal with climatic and geographical issues. Characteristic polyphenols of each botanical variety were tentatively identified by LC-MS/MS in multiple-reaction monitoring mode to propose possible honey markers for future experiments (i.e., naringin for orange/lemon blossom honeys, syringic acid in thyme honeys, or galangin in rosemary honeys). Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures

Figure 1

20 pages, 3741 KiB

Open AccessArticle

Polyphenol and Anthocyanin Composition and Activity of Highland Barley with Different Colors

by Hui-Min Jin, Bin Dang, Wen-Gang Zhang, Wan-Cai Zheng and Xi-Juan Yang

Molecules 2022, 27(11), 3411; https://doi.org/10.3390/molecules27113411 - 25 May 2022

Cited by 20 | Viewed by 2761

Abstract

In this research, the composition of free phenols, bound phenols, and anthocyanins and their in vitro antioxidant activity and in vitro α-glucosidase inhibiting activity were observed in different barley colors. The outcomes revealed that the contents of total phenols (570.78 mg/100 gDW), total flavonoids (47.08 mg/100 gDW), and anthocyanins (48.07 mg/100 g) were the highest in purple barley. Furthermore, the structure, composition, and concentration of phenolics differed depending on the colors of barley. The types and contents of bound total phenolic acids and flavonoids were greater than those of free total phenolic acids and flavonoids. The main phenolic acids in blue barley were cinnamic acid polyphenols, whereas in black, yellow, and purple barley, benzoic acid polyphenols were the main phenolic acids, and the main types of flavonoids in black and blue barley were chalcones and flavanones, respectively, whereas flavonol was the main type of flavonoid in yellow and purple barley. Moreover, cornflower pigment-3-glucoside was the major anthocyanin in blue, yellow, and purple barley, whereas the main anthocyanin in black barley was delphinidin-3-glucoside. The dark color of barley indicated richness in the anthocyanins. In addition, the free polyphenol fractions had stronger DPPH and ABTS radical scavenging capacity as compared to the bound ones. In vitro α-glucosidase-inhibiting activity was greater in bound polyphenols than in free polyphenols, with differences between different varieties of barley. Purple barley phenolic fractions had the greatest ABTS radical scavenging and iron ion reduction capacities, as well as the highest α-glucosidase-inhibiting activity. The strongest DPPH radical scavenging capacity was found in yellow barley, while the strongest in vitro α-glucosidase-inhibiting activity was found in anthocyanins isolated from black barley. Furthermore, in different colors of barley, there was a strong association between the concentration of specific phenolic compounds and antioxidant and α-glucosidase-inhibiting activities. The outcomes of this study revealed that all colored barley seeds tested were high in phenolic compounds, and had a good antioxidant impact and α-glucosidase-inhibiting activity. As a result, colored barley can serve as an antioxidant and hypoglycemic food. Polyphenols extracted from purple barley and anthocyanins extracted from black barley stand out among them. Full article

(This article belongs to the Special Issue Analyses and Applications of Phenolic Compounds in Food)

► Show Figures