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Antioxidant Capacity of Honeys from Various Floral Sources Based on the Determination of Oxygen Radical Absorbance Capacity and Inhibition of in Vitro Lipoprotein Oxidation in Human Serum Samples
Abstract
Honeys from seven different floral sources were analyzed for in vitro antioxidant capacity and total phenolic content. Antioxidant capacity was measured by the oxygen radical absorbance capacity (ORAC) assay and by monitoring the formation of conjugated dienes as an index of the inhibition of copper-catalyzed serum lipoprotein oxidation. ORAC values ranged from 3.1 to 16.3 micromol Trolox equivalent/g honey. The darkest colored honeys, such as buckwheat honey, had the highest ORAC values. A linear correlation was observed between phenolic content and ORAC activity of the investigated honeys (p < 0.0001, R (2) = 0.9497). The relationship between the ORAC activity and inhibition of lipoprotein oxidation by the honeys yielded a correlation coefficient of 0.6653 (p = 0.0136). This work shows that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants.
... Antioxidant capacity of honey depends on the floral and geographical origin, climatic conditions, processing, storing and handling of honey. The greatest influence on the antioxidant activity of honey has been contributed to its botanical origin (Frankel et al., 1998;Gheldof et al., 2002;Al-Mamary et al., 2002;Beretta et al., 2005;Shivani et International Journal of Zoological Investigations al., 2021). Many researchers have reported that antioxidant activity is strongly correlated with phenolics content. ...
... Also, the antioxidant activity of dark honeys is higher than of the light honeys (Al-Mamary et al., 2002;Aljadi and Kamaruddin, 2004;Berreta et al., 2005). Honey serves as a source of natural antioxidants (Vit et al., 1997;Antony et al., 2000;Nagai et al., 2001;Gheldof et al., 2002;Al-Mamary et al., 2002;Aljadi and Kamaruddin, 2004;Beretta et al., 2005;Kucuk et al., 2007), which play an important role in food preservation and human health by combating damage caused by oxidizing agents e.g. oxygen, namely reducing the risk of heart disease, cancer, immune-system decline, cataracts, different inflammatory processes, etc. (The National Honey Board, 2003). ...
... oxygen, namely reducing the risk of heart disease, cancer, immune-system decline, cataracts, different inflammatory processes, etc. (The National Honey Board, 2003). The antioxidants present in honey include --(i) enzymatic: catalase (Schepartz, 1966), glucose oxidase, peroxidase and (ii) nonenzymatic substances: ascorbic acid, a-tocopherol (Crane, 1975), carotenoids, amino acids, proteins, organic acids, Maillard reaction products (Al-Mamary et al., 2002;Gheldof et al., 2002;Schramm et al., 2003;Aljadi and Kamaruddin, 2004). Honey possesses more than 150 polyphenolic compounds, including flavonoids, flavonols, phenolic acids, catechins, and cinnamic acid derivatives. ...
Honey is a natural food product produced when the nectar and sweet deposits from plants are gathered, modified and stored in the honeycomb by honey bees. From ancient times honey has been used in therapeutic purposes especially in cough, colds, skin wounds and various gastrointestinal diseases. In this study multifloral honey samples were investigated in order to assess their total phenolic content by Folin-Ciocalteau method and their potential antioxidant activity by 2,2 diphenyl-1-picrylhydrazyl (DPPH) and ABTS free radical scavenging methods. Results of this study revealed that all honey samples possess total phenolic and antioxidant activity irrespective of climatic or floral variation.
... Afin d'utiliser les flavonoïdes comme marqueurs botaniques, il est indispensable de réaliser une étude comparative avec la composition phénolique du nectar (avec hydrolyse et sans hydrolyse) (Cabras et al., 1999;Ferreres et al., 1996aFerreres et al., , 1993Martos et al., 2000a;Truchado et al., 2009). Aussi, la prise en compte de l'environnement visité par les abeilles est un élément important à associer à la caractérisation des composés phénoliques (Gheldof et al., 2002a(Gheldof et al., , 2002bTomás-Barberán et al., 1993a). Par exemple, les miels costaricains et brésiliens sont riches en myricétine (respectivement 45% et 70%) (Tomás-Barberán et al., 1993a) qui sont par ailleurs des composés caractéristiques des miels d'eucalyptus (Martos et al., 2000a(Martos et al., , 2000bTruchado et al., 2009). ...
... Nos données sont cependant en deçà des valeurs les plus élevées observées. Ainsi, les miels d'arbousier (Arbutus unedo) et de Sarrasin (Fagopyrum esculentum) possèdent respectivement une valeur ORAC (moyenne) de 21 μmol ET/g de miel (Beretta et al., 2005) et de 16 μmol ET/g de miel (Gheldof et al., 2002a). Soit une activité d'environ 5 à 4 fois supérieure aux échantillons guyanais les plus actifs. ...
... Selon Gheldof et al. (2002a) il serait possible de discriminer des miels issus de deux zones géographiques d'une même région à travers leurs activités ORAC. Mais, d'une part, les données bibliographiques sont insuffisantes pour étayer cette hypothèse en Amérique du Sud et, d'autre part, nos résultats montrent qu'il n'y a pas de zone de récolte en Guyane produisant un miel ayant une activité antioxydante atypique. ...
La présente étude a pour objectif principal de caractériser la composition chimique et pollinique des miels de Guyane afin d’ydéceler des marqueurs permettant de justifier la provenance du produit. Des spectres polliniques ont été établis et les fractions volatiles des miels ont été piégées par HS-SPME. Le dosage des composés phénoliques etla mesure de l’activité antioxydants des échantillons ont aussi été réalisés.L’étude des grains de pollens montre une importante diversité pollinique. Elle s’explique par la présence significative d’espècesspontanées et d’un climat favorisant les floraisons multiples. Les principaux taxons du répertoire guyanais ainsi que les potentiels marqueurs botaniques de la spécificité régionale ont été répertoriés. Cette étude permet à la Guyane de disposer d’une première banque de pollens apicole. Une première proposition de l’origine botanique des miels de Guyane a été formulée.L’étude de la fraction volatile des miels montre une composition principalement dominée par des composés non terpéniques oxygénés suivi par les monoterpènes oxygénés. L’analyse statistique des données positionne les 87 échantillons de miels dans 4 groupes chimiques. Enfin, les résultats du dosage des composés phénoliques ainsi que ceux de l’activité antioxydante des miels semble montrer, au premier abord, la présence de composés phénoliques. Ces données ouvrent la perspective d’une étude de ces molécules d’intérêt biologique dans les miels de Guyane.
... From this result, it is possible to conclude that the application of the rye bran WEAX as a carrier exhibits protective effect of bee products antioxidants during encapsulation process and due to high As reported by Zalibera et al., the antioxidant activity for honeys of various floral origins ranges from 15-114 µmol TE 100 g −1 [35]. According to Gheldof and Engeseth, the ORAC value of honey is strongly dependent on its floral source and takes values in the range 320-1630 µmol Trolox equivalent 100 g −1 honey [36]. The native honey Frémy's salt (221.8 µmol TE 100 g −1 d.m.) and DPPH (291.2 µmol TE 100 g −1 d.m.) antioxidant activity was in a range characteristic for honeys, thus consistent with the literature data. ...
... There are no data on the antioxidant activity of fixed royal jelly preparations in the literature. It is commonly claimed that thermal treatment of bee products such as honey or royal jelly leads to chemical degradation of their bioactive ingredients [36,[41][42][43]. However, an increase in the antioxidant activity of bee products because of heat treatment may also be observed. ...
The aim of the research was to use bioactive heteropolysaccharides isolated from rye bran to obtain innovative systems for the controlled release of bioactive compounds. The core of the obtained encapsulates was honey and royal jelly. It was shown for the first time that preparations effectively ameliorated inflammatory response in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, decreasing the secretion of interleukin 6 (IL-6), tumor necrosis factor α (TNF-α) and nitric oxide (NO). The in vitro digestion process revealed that bee products’ encapsulates were stronger oxidative stress reducers and had sustained ability to reduction in inflammation state mediators. The lack of inhibitory effect on migration rate of human microvascular endothelial cells (HMEC-1) endothelial cells and mouse embryonic fibroblasts (NIH-3T3), both cell models involved in wound healing process, additionally identified these preparations as agents potentially used in the management of inflammatory response. In the process of a simulated digestion in vitro, the innovative microcapsules showed 85% higher biostability and two to ten times better bioavailability, compared to natural bee products.
... The antioxidant activity of honey is due to a wide variety of compounds, such as flavonoids, phenolic acids, tocopherols, ascorbic acid, and enzymes including catalase or superoxide dismutase [14,59,60]. In addition, melanoidins, products of the Maillard reaction, were described as the main components responsible for the radical-scavenging capacity of honey [61,62]. ...
... Up to 3.5 % (w/w) Iran honey PVA 10 % (w/w), CM-chitosan up to 3.5 % (w/w), water 85 % (w/w). 60 Co Gamma-ray (radiation method) up to 40 kGy; 60 Co Gamma-ray followed by 3 cycles of freeze-thawing (combinational method). ...
Honey is a natural product rich in several phenolic compounds, enzymes, and sugars with antioxidant, anticarcinogenic, anti-inflammatory, and antimicrobial potential. Indeed, the development of honey-based adhesives for wound care and other biomedical applications are topics being widely investigated over the years. Some of the advantages of the use of honey for wound-healing solutions are the acceleration of dermal repair and epithelialization, angiogenesis promotion, immune response promotion and the reduction in healing-related infections with pathogenic microorganisms. This paper reviews the main role of honey on the development of wound-healing-based applications, the main compounds responsible for the healing capacity, how the honey origin can influence the healing properties, also highlighting promising results in in vitro and in vivo trials. The challenges in the use of honey for wound healing are also covered and discussed. The delivery methodology (direct application, incorporated in fibrous membranes and hydrogels) is also presented and discussed.
... Excessively long storage affects the composition of honey and alters the biological activity of its components [3,7]. It should be underlined that honey also demonstrates antioxidant [2,[9][10][11], immunomodulatory, and anti-inflammatory properties [12]. In view of the fact that the ageing process and degenerative diseases have their basis in free radicals, one way to ...
... Dżugan et al. [38] found the highest antioxidant activity (DPPH) in buckwheat honey (82.41%) and the lowest in rapeseed honey (21.81%). Other authors [10] also confirmed high antioxidant activity in buckwheat honey (17.0 mmol Trolox/g) compared to soybean, sweet clover, fireweed, and acacia honeys (8.3, 6.1, 3.1 and 3.0 mmol Trolox/g). ...
The antioxidant activity of honey depends on the botanical origin, which also determines their physicochemical properties. In this study, a multivariate analysis was used to confirm potential relationships between the antioxidant properties and colour parameters, as well as the content of seven elements in five types of artisanal honey (rapeseed, buckwheat, linden, black locust, and multifloral). The type of honey was found to significantly influence most of its physicochemical properties, colour parameters, and the content of potassium, manganese and copper. Antioxidant parameters were shown to be significantly positively correlated with redness and concentrations of copper and manganese, but negatively correlated with the hue angle and lightness. The principal component analysis confirmed that the darkest buckwheat honey had the highest antioxidant activity in combination with its specific colour parameters and content of antioxidant minerals (manganese, copper and zinc). The level of these parameters can be potentially used for the identification of buckwheat honey.
... There are several nutritional constituents of honey that can function as antioxidant agents, for instance: Vitamin C, organic acid, phenolic acid, flavonoids, and β-carotene (Gheldof, 2002). There are lots of flavonoids and phenolic compounds have been isolated and structurally determined from honey (Vulic et al., 2015;Ramanauskiene et al., 2012;Alvarez-Suarez et al., 2014). ...
The aim of this research to isolate and identify and to test the antioxidant activity of extract and fraction of polyfloral honey originated from Bone regency, South Sulawesi. The results showed that methanol gave results in flavonoid, tannin, saponnin, steroid, and alkaloid with IC50 value of DPPH method of 683,153 µg/mL. DCM extract gave positive results for tannin, steroid and alkaloid with IC50 values of 701,743 µg/mL. n-hexane extract positively contains tannin and alkaloid with IC50 1709,536 µg/Ml, water extract positevely contains tannin, sapponin steroid, alkaloid with IC50 value 1698,345 µg/mL. Pure honey contains all aspects tested with IC50 values 2826,471 µg/mL. This showed extracts and sample have weak antioxidant activity.
... Except for the sugars, honey is composed of other compounds such as enzymes, amino acids, organic acids, vitamins soluble in water, minerals and aromatic compounds. Honey is rich in phenolic acids and flavonoids which act as natural antioxidants, eliminating free radicals and inhibiting cell membrane lipids oxidation and protection of deoxyribonucleic acid (DNA), having antimicrobial, or anticancer activity [5,6]. The phenolic compounds in honey originate from the plants that are used to collect the nectar by honeybees, so the content of phenolic compounds depends on the botanical and geographical origin of honey [7]. ...
Thermal liquefaction at low temperature is very time consuming and microwaves or an ultrasonic bath can be used to accelerate the process of dissolving sugar crystals. Phenolic compounds, such as phenolic acids or flavonoids, are an important group of secondary metabolites of plants and become honey from the nectar of blossoms. In this study, how the content of phenolic acids and flavones in honey were affected by liquefaction of honey using a microwave oven was studied. The concentration of tested compounds in untreated honey and in honey liquefied in a hot water bath, ultrasonic bath and microwave oven at four microwave power levels were determined by reversed phase liquid chromatography combined with multichannel electrochemical detection. A significant decrease in the content of all compounds was observed for all melting treatments. The phenolic compounds concentration decreased on average by 31.1–35.5% using microwave at intensities 270, 450 and 900 W and the time required for the sugar crystal melting was more than 20 times less than in the case of the 80 °C water bath. The temperature of samples after the end of microwave liquefaction was 76–89 °C. Significantly higher losses of phenolic compounds were observed during ultrasound treatment (48.5%), although the maximum temperature of honey was 45 °C, and at the lowest microwaves power (50.6%).
... The results demonstrated that that honey may be used as a healthy alternative to sugar in many products and thereby serve as a source of dietary antioxidants. [38] WOUND HEALING: Use of honey as a wound dressing has been in vogue since time immemorial. It was only in 1930s and 1940s, when the synthetic antibiotics took over and honey became a thing of literary attention. ...
A natural sweetener, honey has innumerable pharmacological properties in addition to its nutritive value. Honey has been in human use since 8000 years and has been traditionally used by almost all systems of medicine including Islamic medicine. Although chemical composition varies according to the botanical source, carbohydrates constitute a major portion of its composition. Fructose is in abundance followed by glucose. There are many other constituents present in small amounts like proteins, enzymes, amino acids, minerals, trace elements, vitamins, aromatic compounds and poly-phenols which contribute to various medicinal properties of honey. Honey has been in use traditionally for treatment of various ailments like gastritis, diarrhoea, ophthalmic conditions, skin infections, wounds etc. Enough evidence is now present supporting antimicrobial, antioxidant, wound healing and other potentials medicinal properties of honey. We systematically searched published papers on the subject in the databases of Web of Science, Scopus, PubMed, Science Direct, Crossref and Google Scholar between 1st January 2000 and July 2022 with an aim to review pharmacological and therapeutic potentials of honey. Owing to investigated pharmacological and therapeutic potentials of honey we conclude that honey can be looked upon as a safe and efficacious alternative in management and prevention of various disorders. Key words: Honey, Pharmacological, Therapeutic, Antimicrobial, Antioxidant.
... For phenolic compounds, GC-MS and HPLC are commonly used [37], whereas the HMF content is frequently determined by capillary electrophoresis [38] and UV/VIS spectrophotometry [24]. The antioxidant activity in vitro is commonly determined using the DPPH* (2,2-diphenyl-1-picrylhydrazyl), ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) assays [39][40][41][42]. ...
Honeys are commonly subjected to a series of post-harvest processing steps, such as filtration and/or radiation treatment and heating to various temperatures, which might affect their physicochemical properties and bioactivity levels. Therefore, there is a need for robust quality control assessments after honey processing and storage to ensure that the exposure to higher temperatures, for example, does not compromise the honey’s chemical composition and/or antioxidant activity. This paper describes a comprehensive short-term (48 h) and long-term (5 months) study of the effects of temperature (40 °C, 60 °C and 80 °C) on three commercial honeys (Manuka, Marri and Coastal Peppermint) and an artificial honey, using high-performance thin-layer chromatography (HPTLC) analysis. Samples were collected at baseline, at 6 h, 12 h, 24 h and 48 h, and then monthly for five months. Then, they were analysed for potential changes in their organic extract HPTLC fingerprints, in their HPTLC-DPPH total band activities, in their major sugar composition and in their hydroxymethylfurfural (HMF) content. It was found that, while all the assessed parameters changed over the monitoring period, changes were moderate at 40 °C but increased significantly with increasing temperature, especially the honeys’ HPTLC-DPPH total band activity and HMF content.
... The field of preventive medicine is increasingly interested in using plant-derived antioxidants rather than synthetic ones [130][131][132]. Therefore, further exploration and characterization of natural resources are needed. ...
Traditional remedies for the treatment of various ailments are gaining popularity. Traditionally, one of the most valuable therapeutic herbs has been Picrorhiza kurroa Royle ex Benth. Traditional and folk uses of P. kurroa include chronic constipation, skin-related problems, burning sensation, chronic reoccurring fever, jaundice, heart problems, breathing, digestion, allergy, tuberculosis, blood-related problems, prediabetes and obesity, laxative, cholagogue, and liver stimulatory. Phytoconstituents such as glycosides, alkaloids, cucurbitacins, iridoids, phenolics, and terpenes in P. kurroa have shown promising pharmacological potential. In order to uncover novel compounds that may cure chronic illnesses, such as cardiovascular, diabetes, cancer, respiratory, and hepatoprotective diseases, the screening of P. kurroa is essential. This study comprehensively evaluated the ethnopharmacological efficacy, phytochemistry, pharmacological activity, dose, and toxicity of P. kurroa. This review provides comprehensive insights into this traditional medication for future research and therapeutic application. The purpose of this review article was to determine the pharmacological effects of P. kurroa on a variety of disorders. P. kurroa may be a natural alternative to the standard treatment for eradicating newly evolving diseases. This study is intended as a resource for future fundamental and clinical investigations.
... These compounds have been shown to cause damage to animal cells, damage that can contribute to the acceleration of cancer, cardiovascular disease, and other age-related diseases (Aruoma, 1998). Phenolic compounds found in honey and other plant materials are known to have antioxidant capacities that can help eliminate or reduce free radicals in the body (Gheldof, 2002). These compounds may help reduce the negative effects of free radical formation. ...
Honey has been used for medicinal purposes for thousands of years. It is rich in sugars such as glucose and fructose, but it also contains small amounts of vitamins, minerals, amino acids, and antioxidants such as phenolic acids and flavonoids. These nutrients help to make honey a unique, natural health product. Its market niche as a health product is growing, and current research supports the potential of honey as a medicinal product. This 3-page fact sheet describes health aspects of honey deriving from the floral source and color, beneficial compounds, anti-microbial properties, and anti-inflammatory properties. Written by Sara Marshall, Liwei Gu, and Keith R. Schneider, and published by the UF Department of Food Science and Human Nutrition, April 2015.
... Ce qui prouve qu'en élevage standard, des efforts devraient être orientés à la fois sur les apports alimentaires équilibrés et la préservation du confort de l'habitat pour extérioriser les performances du poulet dans le délai requis. Ainsi, le recours du miel dans l'alimentation du poulet nécessite en amont la connaissance d'un large inventaire de ses vertus nutritionnelles et médicamenteuses notamment antioxydantes, antistress et antimicrobiennes ( Gheldof et Engeseth, 2002 ; Lefief-Delcourt, 2010).. Bankovas et al. (2002) puis Bogdanov (2006) ont montré que celui-ci renferme des glucides, des oligo et macroéléments, des acides aminés essentiels et autres facteurs actifs agissant en synergie pour le bon fonctionnement de l'organisme animal. Plusieurs études ont montré d'une part l'efficacité du miel comme complément alimentaire (Obun et al., 2015) et d'autre part comme moyen de lutte contre le stress dans les différents systèmes d'élevage (Sanjay Kumar et al. ,2015,). ...
Le miel est un produit renfermant des propriétés nutritives susceptibles de stimuler les performances zootechniques des volailles. L’objectif de cette étude était de déterminer le taux d’incorporation optimal du miel dans les rations des poulets de chair. Un échantillon de 105 poussins de chair a été réparti en trois lots de 35 sujets et chaque lot subdivisé en 5 répétitions de 7 sujets. Les lots traités 1 et le traité 2 ont reçu des doses du miel dans la ration alimentaire respectivement au démarrage 0,5% et 1%, en croissance 1% et 2% et en finition 1% et 4%. Le premier lot a servi de témoin. Les lots ont été comparés sur les variables de croissance pondérale. Les résultats ont montré au cours de la phase de démarrage une amélioration significative (P < 0,05) sur la consommation volontaire des aliments (30,5g contre 34,8g), du GMQ (22,7 g/jour contre 23,4g/ jour), l’IC (1,3 contre 1,4)et le poids vif à 14 jours (359g contre 377g).Par contre au cours de là phase de croissance, aucune différence significative n’a été notée dans la ration contenant 1% de miel. En revanche pendant la phase de finition, une amélioration significative a été observée sur tous les paramètres étudiés. Cette étude suggère l’utilisation du miel à la dose de 0,5% pendant les phases de démarrage et de croissance et à 1% au cours de la phase de finition.
... It also contains some amino acids, vitamins, and enzymes with some antioxidants [8]. Diverse geographic regions with vegetations may be the major factors for varieties of honey [9]. Generally honey constitutes some elements like Mn, Na, K,Li, Rb, Cu, Mg, Zn and Fe [10,11]. ...
Ayurveda is known as the oldest practice system in traditional medicine. This medicine system science is closely associated with social, psychological and spiritual with the living society. From ancient period, many works have been done and documented in Ayurveda and charaka Samhita. World Health Organisation reported that more than six billion people depend primarily on ethno medicine. Now it is considered as an important alternative therapy among known other practices. Animals and their by-products form important ingredients have been considered for the preparation of medicine. Since seventh century, Ayurvedic bhasmas are known in India for curing of many chronic ailments. Bhasmas are commonly known as ‘biological nanoparticles’ and it is derived from animal's derivatives through incineration. These bhasmas have been orally administered by mixing with honey to reduce the adverse effect of these drugs. In this study there six bhasmas and honey samples were taken for X-Ray fluorescence (XRF) spectroscopy analysis. Presence of these elements has showed their significance in therapeutically potent even in low doses. Now it has given novel health care look in Ayurved for tribal areas as well as modern society.
... Other phytochemical components found in honey include flavonoids, ascorbic acid, catalase, peroxidase, and carotenoids. These components are primarily responsible for honey's antioxidative effect (20). Honey's phytochemical content is also affected by its floral and geographical origins, as well as its processing, handling, and storage (21). ...
Obesity is a metabolic disorder that has become critically prevalent throughout the world. Obesity has been linked to other chronic diseases such as diabetes mellitus, cardiovascular diseases and cancer. Natural products such as honey have been investigated for their potential effect on obesity. Hence, this study systematically reviewed the recent literature concerning the effects of honey on obesity in obese animal models and in people with obesity. The Ovid MEDLINE, PubMed, Scopus, Web of Science and Google Scholar electronic databases were searched for relevant articles. A total of 130 relevant articles were obtained from the initial search. Following a thorough screening, nine articles were selected for data extraction, including six animal studies and three clinical trials. In most of the animal studies, honey demonstrated an anti-obesity effect by reducing body weight, body fat composition and adipocyte size, among others. However, supplementation of honey in clinical trials showed conflicting results. Even though honey supplementation did not demonstrate any weight-reducing effect in some of the clinical trials, none of the trials showed that honey increases body weight. However, the results should be interpreted with caution as most of the studies involved animal models and there is a limited number of high quality, randomized, controlled clinical trials.
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https://inplasy.com/inplasy-2022-6-0038/ PROSPERO, identifier 10.37766/inplasy2022.6.0038.
... However, this value depends on many factors, primarily on the chemical composition of honey. The physicochemical properties of honey depend on the botanical source and geographical origin; for instance, the pH of honey may depend on the pH of plant nectar visited by bees in different geographical regions, as well as soil pH [22]. In this study, the pH values of the honey samples ranged from 4.03 (thyme honey) to 4.52 (mint honey) ( Table 1). ...
Honey’s authenticity is a major concern for producers and consumers, and this prompts research into reliable methods to determine the source of honey (botanical and geographical). This study aimed to find the botanical origin of seven samples of monofloral honey (acacia, thyme, tilia, rape, raspberry, mint and sunflower) based on pollen analysis and identification of the physicochemical characteristics of these types of honey. For these types of honey, the following parameters were determined: color, electrical conductivity, free acidity, moisture content, pH, hydroxymethylfurfural content and sugar content. Alongside pollen analysis, these methods succeeded in classifying the analyzed samples as monofloral honey. Non-destructive methods of analysis such as Fourier transform infrared spectroscopy, the determination of the rheological behavior of honey in the negative domain and the determination of the thermal behavior were also employed to characterize the honey samples. The best differentiation between samples was achieved in the spectral region between 950 and 750 cm−1, which is of interest for carbohydrate analysis in IR spectroscopy. In the negative interval, the viscous and elastic modules intersected at different temperatures, these temperatures being influenced both by the moisture of the analyzed samples and the botanical origin.
... Honeys nutritional and healing properties since early beginning makes it an important component of traditional remedy (12)(13)(14)(15). Current opinions suggest honey not only as nutritional supplement but also highlight its properties like non-peroxide dependent and antioxidant (16). ...
Honey is popular all over the world and used commonly in medicines and food. This study was designed to compare the natural and commercial honey for their antioxidant enzymes. In this study, 11 different honey samples were collected from different areas of Balochistan. The activity of different antioxidant enzymes like superoxide dismutase, peroxidase and catalase enzymes were measured and compared by standard curves of pure enzymes. Moreover, protein content was also determined by using Bradford Assay. Results showed that highest protein content was found in one of the natural honey samples (4.42 ± 0.02 U/mg). Enzyme's superoxide dismutase showed highest activity of (4.93 ± 0.06 U/mg), whereas secondly peroxidase activity of (0.34 ± 0.02 U/mg) and thirdly catalase activity of (0.22 ± 0.01 U/mg) was observed in different natural honey samples. The current study demonstrated that higher concentration of protein content and antioxidant enzymes were found in natural honey which means they are good source of antioxidants. Therefore, antioxidant enzymes can be used as markers for determining the purity and quality of honey.
... Therefore, elevated antioxidant level of L. aspera in T3 samples as revealed in the present study is a clear indication of a strong defense of the plant in stress conditions to prevent lipid peroxidation. Furthermore, enhanced levels of phenol and flavonoid concentrations of the experimental in T3 over T4 samples could be related to the higher antioxidant activities (Gheldof and Engeseth 2002;Holasova et al. 2002). It has already been established that phenolic compounds are linked with the protection of living cells from the cytotoxic effects of H 2 O 2 (Nakayama 1994). ...
The phytoremediation potential and enzymatic defense of a medicinal herb Leucas aspera was studied in the crude oil contaminated soil. The productivity, antioxidants, and phytochemical and functional group profiles of the plant species in stress conditions were investigated. Besides, changes in enzymes, beneficial bacterial population, and physico-chemical and total oil and grease (TOG) profiles in the contaminated soil were also studied. The results showed improvement in physico-chemical conditions, increase in beneficial bacterial population (4.1–5.4 folds), and decrease in TOG (31.3%) level of the contaminated soil by end of the experimental trials. The L. aspera treated contaminated soil showed enhancement in dehydrogenase (32.3%), urease (102.8%), alkaline phosphatase (174.4%), catalase (68.5%), amylase (76.16%), and cellulase (23.6%) activities by end of the experimental trials. Furthermore, there were significant variations in leaf area index, chlorophyll, and biomass contents of the experimental plant as against the initial level and control. Besides, the significant reduction in IC50 values (24–27.4%) of L. aspera samples grown in contaminated soil confirms the strong antioxidant enzymatic defense of the plant species against the crude oil associated abiotic stress. The Fourier-transform infrared (FT-IR) analysis confirmed the uptake and metabolism of aliphatic hydrocarbons, aldehydes, alkyl halides, and nitro compounds by the experimental plant from the contaminated soil.
... Honey is well stocked with phenolic acids and flavonoids, which manifest a broad array of its biological effects and serve as naturally occurring antioxidants. The presence of a variety of these compounds makes honey an excellent antioxidant nominee with a similar capacity as many other fruits (Gheldof & Engeseth, 2002;Keskin et al., 2021;Pyrzynska & Biesaga, 2009). ...
Honey is a delicious, sweet liquid with infinite nutritional properties. Being a cherished human food, honey had been utilized by Homo since the dawn of time. It is a highly saturated and viscous sugar solution with a variety of additional ingredients including organic acids, proteins, minerals, vitamins, amino acids, polyphenols, aroma compounds, and approximately 500 enzymes. This diversified chemical profile of honey accounts for its immense dietary and medicinal uses in both present and historic generations and civilizations. The literature archive suggests that honey exerts numerous health-constructive effects including hypocholesterolemic, cardioprotective, antihypertensive, hepatoprotective, gastroprotective, neuroprotective, nephroprotective, antibacterial, antiviral, antifungal, antioxidant, anti-inflammatory, antiarrhythmic, antileishmanial, antithrombotic, antinociceptive, and immune-boosting properties. Oxidative stress is the key player in the progression of degenerative changes in many vital organs such as skin, liver, pancreas, and reproductive organs. Honey has the distinct advantage of carrying components that can help with regenerative healing by acting as an anti-bacterial, antioxidant, and anti-inflammatory agent. Keeping in view the regenerative potential of honey, this review is envisioned to apprehend the potential role of honey in boosting the regeneration of various vital organ systems. Promoting the natural regenerative abilities of tissues can help in mitigating the progression of degenerative changes and abate the burden of various degenerative maladies.
... Studies have demonstrated that the antioxidant activity of honey is primarily provided by the phenolic compounds present in its structure and then, by the other components [6]. ...
The biologically active potential of honey is mainly provided by phenolic compounds, which include a broad spectrum of active molecules with a wide structural diversity, from phenolic acids to flavonoids. The major purpose of this research was to determine the total polyphenol content and the flavones content of some polyfloral honey samples correlated with their antioxidant potential. The investigations were carried out on five samples of honey and their botanical origin was performed by melissopalynological analysis in the Laboratory of the Advanced Horticultural Research Institute Cluj-Napoca. Furthermore, the honey samples introduced in this study have been classified as belonging to the polyfloral honey assortment. The analysis of the total polyphenol content, the flavones content and the antioxidant activity revealed the most valuable polyfloral honey sample of the five samples, by correlating the increased total polyphenol content (70.86 mg of gallic acid equivalents per 100 g of honey sample), with a strong antioxidant activity (8.03 Trolox milliequivalents per 100 g of honey sample) and a significant flavones content (8.71 mg Quercetin per 100 g honey sample).
... The synthetic resin of honey carotenoid plays a significant role in 'aromatic secondary metabolites' of plant origin (Ferreres et al., 1992). The level of these compounds in honey is 5-1300 mg/kg (Al-Mamary et al., 2002;Gheldof and Engeseth, 2002). In honey, they are mostly phytochemical, phenylic acids and phenolic acid derivatives. ...
... The synthetic resin of honey carotenoid plays a significant role in 'aromatic secondary metabolites' of plant origin (Ferreres et al., 1992). The level of these compounds in honey is 5-1300 mg/kg (Al-Mamary et al., 2002;Gheldof and Engeseth, 2002). In honey, they are mostly phytochemical, phenylic acids and phenolic acid derivatives. ...
... A previous study has indicated that the TPC and antioxidant capacity of mature honey was significantly higher than that of immature honey [11]. The TPC of honey samples was in line with the reported in the literature at 5.6-50 mg GAE/100 g [45,46]. Our data did not support the claim that honey with a proline content greater than 180 mg/kg was mature honey, because the proline content of our honey reached 212 ± 13 mg/kg on the first day. ...
Honey maturity, a critical factor for quality evaluation, is difficult to detect in the current industry research. The objective of this study was to explore the changes in the composition and find potential maturity indicators of rape honey at different maturity stages through evaluating physicochemical parameters (moisture, sugars, pH, electrical conductivity, total protein, total phenols, total flavonoids, proline, and enzyme activity), the antioxidant capacity, and volatile components. The relevant results are as follows: 1. As the maturity increased, the moisture, sucrose, and maltose content of rape honey gradually decreased, while the glucose, fructose, and total protein content gradually increased. The activities of diastase, invertase, and β-glucosidase showed a significant increase with the elevation of ripening days, and the activity of glucose oxidase reached the highest before completely capping. 2. The antioxidant capacity of honey increased with the increase in honey maturity. There is a significant and strong correlation between the bioactive components of rape honey and antioxidant capacity (p < 0.01, |r| > 0.857). 3. Thirty-five volatile components have been identified. Nonanal, benzaldehyde monomer, and benzaldehyde dimer can be used as potential indicators for the identification of honey maturity stages. Principal component analysis (PCA) based on antioxidant parameters and volatile components can identify the maturity of honey.
... The composition of honey comprises mainly simple sugars and water. However, more than 200 other constituents, such as enzymes, amino acids and organic acids, carotenoid-like substances, Maillard reaction products, vitamins, minerals and polyphenols, are present in honey [1]. Most of these compounds represent bioactive molecules, giving the biologically active properties of honey. ...
Bioactive molecules from the class of polyphenols are secondary metabolites from plants. They are present in honey from nectar and pollen of flowers from where honeybees collect the “raw material” to produce honey. Robinia pseudoacacia and Helianthus annuus are important sources of nectar for production of two monofloral honeys with specific characteristics and important biological activity. A high-performance liquid chromatography–electro spray ionization–mass spectrometry (HPLC–ESI–MS) separation method was used to determine polyphenolic profile from the two types of Romanian unifloral honeys. Robinia and Helianthus honey showed a common flavonoid profile, where pinobanksin (1.61 and 1.94 mg/kg), pinocembrin (0.97 and 1.78 mg/kg) and chrysin (0.96 and 1.08 mg/kg) were identified in both honey types; a characteristic flavonoid profile in which acacetin (1.20 mg/kg), specific only for Robinia honey, was shown; and quercetin (1.85 mg/kg), luteolin (21.03 mg/kg), kaempferol (0.96 mg/kg) and galangin (1.89 mg/kg), specific for Helianthus honey, were shown. In addition, different phenolic acids were found in Robinia and Helianthus honey, while abscisic acid was found only in Robinia honey. Abscisic acid was correlated with geographical location; the samples collected from the south part of Romania had higher amounts, due to climatic conditions. Acacetin was proposed as a biochemical marker for Romanian Robinia honey and quercetin for Helianthus honey.
... This correlation shows that among the phenolic compounds responsible for the antioxidant potential of the different honey samples, flavonoids have a significant responsibility. These results are in agreement with those of some authors who reported the involvement of phenolic compounds, especially flavonoids, in the manifestation of the antioxidant activity of honey [18,34,37,[43][44][45]. However, a weak correlation (R = 0.22) was observed between the antioxidant activity of the chloroform fraction by DPPH method (DPPH CHCl 3 ) and the content of total phenolic compounds (TPC). ...
Aims: Although the honey produced in Côte d'Ivoire is widely used in households, there is no technical sheet mentioning its chemical composition. Thus, the present study aimed to fill this gap while studying the chemical composition and antioxidant power of eleven honey samples from nine localities in Côte d'Ivoire.
Methodology: The identification of secondary metabolites in the different honey samples was carried out by TLC and by color reaction tests. The quantification of these was performed by spectrophotometry. The antioxidant power of the honey samples was studied by DPPH and FRAP methods.
Results: All honey samples contains secondary metabolites from various families, with varying contents of total phenolic compounds and flavonoids. Overall, the honey samples showed a notable antioxidant profile, making them good free radical scavengers. The relationship established between the different variables analyzed showed in some cases positive and significant correlations.
Conclusion: The results of this study show that the honey produced in Côte d'Ivoire is of good quality. Therefore, its recurrent consumption could contribute to fighting certain pathologies caused by oxidative stress.
... It's abundant nutrient content, includes; sugars such as fructose and glucose, minerals such as magnesium, potassium, calcium, sodium chloride, sulphur, iron and phosphates, as well as vitamins B1, B2, B6, B5, B3 and C (14). Honey can also be seen as a natural produce of bees and it comprise various compounds such as carbohydrates, normal minerals, proteins, vitamins, organic acids, enzymes and antioxidants such as catalase, peroxidases, alkaloids, polyphenols and flavonoids (15). ...
Assessment of effects of honey on the prostate functions and testosterone level in adult male wistar rats at
statistical significant of P<0.05. Twenty four adult male wistar rats were procured from the Department of Human
Physiology, College of Medicine, Abia state University, Uturu, Abia state, Nigeria. They were ethically and
scientifically handled. Groups A, B and C received 0.15ml/Kg Body Weight(KBW), 0.30ml/KBW, 0.60ml/KBW of
honey respectively, once daily. Group D was control. Three rats were selected at random after 4 weeks. The blood
was collected for serum testosterone, Prostatic Acid Phosphatase (PAP) and Prostate Specific Antigen (PSA)
levels. The prostate gland was preserved for histomorphology. The result showed significant correlation between
honey and testosterone, PSA and PAP serum levels after four weeks. There was significant increase in serum
testosterone and PSA after 4 weeks in groups B and C. There was significant increase in serum PAP after 4 weeks
in group C. There was significant difference comparing 4 weeks and 8 weeks serum levels of testosterone in
groups B and C. After 4 weeks, there was statistically significant increase in the relative prostate weight. Honey
intake could be regarded as risk factor for Benign Prostate Hyperplasia and Cancer of Prostate.
... Therefore, elevated antioxidant level of Leucas aspera in T3 samples as revealed in the present study is a clear indication of strong defense of the plant in stress condition to prevent lipid peroxidation. Further, enhanced level of phenol and avonoid concentrations of the experimental in T3 over T4 samples could be related with the higher antioxidant activities (Gheldof andEngeseth 2002, Holasova et al. 2002). It has already been established that phenolic compounds are linked with protection of living cells from the cytotoxic effects of H 2 O 2 (Nakayama 1994). ...
The response of an indigenous medicinal herb Leucas aspera in crude oil polluted habitat was studied. The productivity, antioxidants, phytochemical and functional group profiles of the plant species in stress conditions were investigated. Besides, changes in enzymes, beneficial bacterial populations and physico-chemical conditions and total oil and grease (TOG) contents in the contaminated soils were also studied. The results showed improvement in physico-chemical conditions, increase in beneficial bacterial population (4.1-5.4 folds) and decrease in TOG (31.3%) level of the contaminated soils by end of the experimental trials. The activities of dehydrogenase, urease, alkaline phosphatase, catalase, amylase and cellulase have increased in the range of 23.6-174.4% after introduction of L. aspera in the contaminated soils . Further, there were significant variations in leaf area index, chlorophyll and biomass contents of the experimental plant as against the initial level and control. Besides, the results also revealed significant deviations in the antioxidant and phytochemical profiles of L. aspera suggesting the enzymatic defense of the plant species in the crude oil contaminated soils. The fourier-transform infrared (FT-IR) analysis confirmed the uptake and metabolism of some hydrocarbon components by the experimental plant from the contaminated soils.
... Honey is a natural sweet viscous fluid produced by honey bees from the nectar of flowering plants, which they collect and transform by combining with their salivary secretions, and deposit, dehydrate and store in the honey comb to ripen (Rebiai & Lanez, 2015). Essentially, natural honey is a sticky and viscous solution with a content of 80-85% carbohydrate (mainly glucose and fructose), 15-17% water, 0.1-0.4% protein, 0.2% ash, and minor quantities of amino acids, enzymes and vitamins as well as other substances like phenolic antioxidants (Gheldof & Engeseth, 2002;James et al., 2009;Jeffrey & Echazarreta, 1996;National Honey Board, 2003;White & Doner, 1980). The composition, colour, aroma, and flavour of honey depend mainly on the flowers, geographical regions, climate, and honey bee species involved in its production, and are also affected by weather conditions, processing, manipulation, packaging, and storage time (Escuredo et al., 2014;Kadri et al., 2017;Silva et al., 2016;Tornuk et al., 2013). ...
Sour honey is a natural product produced by Trigona species, which is a stingless bee. The distribution of this honey is very low because of the limited knowledge and has resulted in being less popular in terms of industrial production and quality standard. The objective of the present study is the biochemical and bioactivity analysis of 7 sour honeys (Trigona species) and one sweet honey collected from Nagaland, Northeast India. The biochemical and physiochemical screening of all samples was performed. The results of these tests are certainly encouraging its utilization as food supplements. In the antioxidant assay, the honey samples have exhibited 31-81% (P > 0.05) of inhibition on DPPH as compared to standard ascorbic acid. Antibacterial test of the 7 sour honey samples has displayed a zone of inhibition ranging from 12 ± 0.21 mm to 17 ± 0.5 mm (P > 0.05)against Escherichia coli. The catalase and oxidase tests conducted on the isolated microbial colonies from honey samples expressed positive results. In HPLC analysis, the retention time of the highest peak in all samples (3.79- 3.84) was identical to the retention time of standards (3.79-3.87) at dilution 10⁻⁵ and a percentage of the area was nearly similar in all honey samples (11.93-14.84%) except SH6 which has 19.92%. In brief, the beneficial effects of stingless bee honey in different contexts, such as biochemical components, physicochemical properties, quantification of sugars, antioxidant and antibacterial activity has experimented and all the results were positive. Further, these honey samples may have the probable potential for many nutraceuticals.
... (Garedew et al., 2003). The composition and properties of honey are strongly affected by the bee species, edaphoclimatic conditions and pollen source (Gheldof and Engeseth, 2002). Ávila et al. (2019) has concluded stingless bee honey can be clustered according to the source of pollen. ...
The quality of honey produced by stingless bees can be affected by a variety of factors. Different seasons may have an influence on stingless bee behaviour while different flower sources may affect the properties of stingless bee honey. Thus, this study aimed to determine the antioxidant and antimicrobial properties of stingless bee honey from different multifloral sources collected during dry and rainy seasons. Honey was collected from hives placed in two different areas with multifloral (area A and B). The difference between these areas was area A only planted with two types of flowers (with stevia) and area B with more than two flowers. Pollen in the honey samples was identified to confirm the seasonal variations. The antioxidative potential of the honey samples was determined using total phenolic content (TPC), DPPH and FRAP assays and total carotenoid content (TCC). Antimicrobial properties were analysed using well diffusion method (mm) against the foodborne pathogens Escherichia coli, Staphylococcus aureus, Listeria monocytogenes and Salmonella enterica serovar Typhimurium. The results revealed that honey harvested during the dry season showed higher antioxidant properties compared to those harvested in the rainy season. The highest antioxidant activities were measured in honey samples taken from area B. Nevertheless, honey harvested in both seasons showed antimicrobial properties against all tested food pathogens, with the dry season samples showing the highest inhibition. Surprisingly, only honey from area A present showed no antimicrobial effect against E. coli. This study showed that the antioxidant and antimicrobial properties of multifloral stingless bee honey are strongly affected by seasonal differences and the distribution of the flowering plant
In the cultivation of cocoa plants there are by-products, one of which is cocoa leaves. This by-product comes from periodic pruning of cocoa plants which has not been utilized optimally. Phenolic compounds contained in the cocoa leaves are known as bioactive compounds which also have a role as antioxidants. The content of bioactive compounds in cocoa leaves can be extracted from plant tissues by extraction method. The objective of this research was to achieve cocoa leaf extract with the highest antioxidant content using the maceration method. Extraction by maceration on old cocoa leaves with a variety of solvents, namely methanol, acetone, and ethyl acetate. The results showed that the extract of old cocoa leaves with methanol as a solvent showed the highest content of polyphenolic compounds. A yield of 7,129% was attained from old cocoa leaves with total phenolic content of 349,952 ± 0,051 mg EAG/g sample, EC 50 antioxidant value of 287,958 ± 0.144, and antioxidant activity of 86,928 % RSA. The yield of phenolic compounds and antioxidant activity contained in cocoa leaf extract (sequentially from the highest) were obtained with methanol solvent, followed by acetone and ethyl acetate solvents. Keywords: Antioxidant activity, Bioactive, Cocoa leaf, Methanol solvent, Yield
In this study, we investigated whether adding of red paprika powder to mayonnaise improved its quality characteristics and storage stability. The quality characteristics, antioxidant activities, and oxidative and emulsion stabilities of mayonnaise prepared with red paprika powder (RPP) at different concentrations (0.5-3%) were compared to mayonnaise without RPP. The results demonstrate that an increase in RPP concentration significantly decreases the L value of the mayonnaise, whereas its a and b values significantly increased (p⟨0.05). The pH decreased as RPP increased. Furthermore, the antioxidant activities of mayonnaise were improved by adding RPP, according to the DPPH and ABTS radical scavenging activities, FRAP, and total phenolic content. The mayonnaise containing RPP had a peroxide value approximately 3.62 times lower than that of mayonnaise without RPP. The emulsion stability increased with addition of RPP between 0.5-2%; however, it decreased at, 3%. These results suggest that the addition of RPP (<2%) could improve mayonnaise quality, antioxidant activities, and storage duration.
To understand the antioxidant properties of buckwheat honeys, we investigated their antioxidant effects on hydroxyl radical-induced DNA breaks in the non-site-specific and site-specific systems, the physicochemical properties, antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity, chelating, and reducing power assays), total phenolic content and individual phenolic acids were also determined. Total phenolic content of buckwheat honeys ranged from 774 to 1694 mg PA/kg, and p-hydroxybenzoic and p-coumaric acids proved to be the main components in buckwheat honeys. All the buckwheat honey samples possess stronger capability to protect DNA in the non-site-specific systems than in the site-specific systems from being damaged by hydroxyl radicals. In the non-site-specific and site-specific system, buckwheat honeys samples prevented ()OH-induced DNA breaks by 21-78% and 5-31% over control value, respectively.
Insulin resistance (IR) is the central link to metabolic syndrome (MS), and IR prevention has become the key to overcoming this worldwide public health problem. A diet rich in simple sugars is an important pathogenic factor in IR development. To investigate the effect of honey on IR compared to the sugar-water diet, we analyzed phenolics and oligosaccharides in jujube honey and rape honey based on LC-MS and silane derivatization/GC-MS. The effects of different diets on glucose and lipid profile, histopathology and IR-related mechanism pathways were analyzed and compared by equal sugar levels intervention of fructose, fructose + glucose and two kinds of unifloral honey (high-/low-dose) in rats. The results suggested that sugar-equivalent honey, which differs from sugar solution, especially 17.1 g/kg BW jujube honey rich in phenolics (1.971 mg/100 g of isoquercitrin) and oligosaccharides (2.18 g/100 g of turanose), suppressed IR via maintaining glucose (OGTT and ITT) and lipid (TC, TG, LDL-C, HDL-C, and NEFA) homeostasis, improving histological structural abnormalities of the liver, adipose and skeletal muscle, reducing oxidative stress (GSH-Px and MDA) and inflammation (IL-6 and TNF-α), modulating the NF-κB (NF-κB gene expression was down-regulated to 0.94) and IRS/PI3K/AKT signaling pathways (e.g., AKT and GLUT2 expression in liver increased by 4.56 and 13.37 times, respectively) as well as reshaping the gut microbiota. These revealed a potential nutritional contribution of substituting honey for simple sugar in the diet, providing a theoretical basis for controlling IR development via dietary modification and supplementation.
Objective: This study aimed at investigating the effect of high sucrose diet on male reproductive function and if Nigerian honey could exert a protective role. Methods: Twenty-four (24) rats were randomly divided into four equal groups of six animals and given water (control); honey (H); high sucrose solution (30%w/v) (HSS); and both high sucrose solution (30%w/v) and honey (HSS+H). Each rat on honey received a daily dose of 10ml honey/kg/5ml of distilled water. Food intake, body weight, organ weight, fasting blood glucose, LH, FSH, testosterone and sperm functions were assessed. Results: This revealed that sperm motility (p<0.05) and count increased in the HSS+ H and H- fed rats compared with HSS fed and control rats. Head and tail abnormalities sperm were also significantly reduced in the H fed rats (p<0.05).MDA level in the liver and not in the testes was significantly increased in the HSS fed rats compared with control while SOD activity was significantly increased in HSS+H rats compared with the HSS fed rats. Conclusion: The results indicate that sucrose feeding impact negatively on sperm function while Nigerian honey supplementation confers protective function on male reproduction.
The antioxidant potential of honey comes from various components including phenolic acids, enzymes (catalase, glucose oxidase), flavonoids, vitamins, organic acids, and Maillard reaction products that are nascently present in raw honey. Hence, it would be highly beneficial for consumers to develop honey-based candies such as honey drops and lozenges that can maintain health benefits of its precursors. This study is focused on evaluating the changes in chemical profiles of honey, specifically phenolic content and hydroxymethylfurfural (HMF) formation upon formulation of raw honey into honey lozenges and honey drops and evaluation of antioxidant properties of honey-based products using different antioxidant assays. Our results indicate that in comparison with raw honey, honey lozenges and drops contain higher total phenolic and HMF components, as well as exhibit greater antioxidant properties as is determined by multiple antioxidant assays.
Fruits and vegetables are highly perishable in nature. Several factors could affect the quality and shelf life of fruits and vegetables. Packaging materials (usually made up of polymers, proteins, lipids, polysaccharides, etc.,) are incorporated with essential oil (EO) which is high in antimicrobial and antioxidant compounds that can enhance the shelf life of fruits and vegetables without affecting their quality. However, the use of EO for postharvest preservation can alter the organoleptic properties of fresh produce. Exploiting synergistic interactions between several EOs, encapsulation of EO, or combining EO with non-thermal techniques such as irradiation, UV-C, cold plasma, ultrasound, etc., may help in preventing the spoilage of food products at lower concentrations without altering their organoleptic properties. This review aims to discuss the overview and current scenario of packaging film with EO for the preservation of fruit and vegetables. We have also discussed the spoilage mechanism of fruits and vegetables, mode of action of EOs, and the effect of EO with packaging film on antimicrobial and sensory properties of fruits and vegetables.
The rich bioactive compounds of medicinal rosemary, as well as their antioxidant activity has led to its wider application in the pharmaceutical, cosmetic and food industries. In the present work, seasonal variations of phenolic, flavonoid content and antioxidant activity were evaluated. This experiment was performed based on a complete randomised design with three replications. The total content of flavonoids and some phenolic compounds (caffeic acid and quercetin) increased when plants received sunlight for a longer period of time than the colder seasons. On the other hand, the highest antioxidant activity was observed in rosemary, which was accompanied by an increase in the important phenolic composition of rosmarinic acid in the cold season. Overall, this study can provide useful information about the best harvest period for rosemary to produce the desired compounds for use in the food, pharmaceutical and plant industries.
Macroalgae are a suitable source of ingredients due to the high content in proteins, carbohydrates and minerals, but also in several secondary metabolites with many different properties and applications like phenolic compounds, carotenes and carotenoids. Among them, fucoxanthin is a pigment found exclusively in marine organisms such as algae species and in larger quantities in brown macroalgae, being one of the major carotenoids that have call the attention of researchers in the last few years, because of the diverse properties such as antioxidant, anticancer, anti-inflammatory, neuroprotective and antiobesity activities [1, 2]. Between the common edible brown algae species in the Mediterranean culture is Undaria pinnatifida, also called Wakame, it is known for its high concentration in fucoxanthin.
In this work U. pinnatifida was used as sample matrix to follow the kinetic extraction of fucoxanthin (t, 3 min to 7 days) at different temperatures (T, 5 – 85ºC) and solvent proportions (S, 0-100 % of hydroalcoholic mixtures of ethanol, v/v). The responses used were the fucoxanthin content (determined in HPLC-DAD) in the extracted material (mg Fx/g E). Theoretical models were used and assembled in multivariable form for simultaneous fitting of the 250 experimental points generated in the experimental design. All predictions made by the models were satisfactorily fitted to the experimental data, statistically validated, and used in the prediction and optimization steps. The results showed that shorter t, higher T and medium S values, obtaining ~6 mg Fx/g E.
This process is especially important at an industrial level because it allows to control the kinetic process of fucoxanthin extraction at the desirable conditions in order to maximize the extraction yield and reduce its production costs related with solvent and energy consumption, helping to guide the choice for an efficient and sustainable way to produce extracts rich in fucoxanthin.
El uso indebido e indiscriminado de los antibióticos en las últimas décadas, para profilaxis de enfermedades tanto en el hombre como en los animales, ha detonado una alarma en el mundo de la medicina microbiológica, ya que dichos microorganismos han respondido de una manera peligrosa, con la llamada resistencia bacteriana, por eso es necesario reconocer, investigar y aplicar en nuestro campo profesional, las opciones alternas que existen en medicina veterinaria. Los objetivos comprendidos en el presente estudio son los de establecer si la miel de la abeja Apis mellífera (abeja común de la miel) y la miel de la Tetragonisca angustula (abeja angelita o virgencita) obtenidas de nuestra flora regional, poseen alguna característica antibacteriana que logre inhibir el desarrollo microbiano en las diferentes concentraciones bacteriales de siembra, para posteriormente analizarlos y compararlos entre sí estadísticamente. A los resultados obtenidos se les hizo un análisis comparativo y descriptivo de la media poblacional, utilizando para esto el programa Software estad.graphad.instat versión 3.06 (2003). Se buscó las diferencias entre parejas estadísticamente significativas P<0.005 aplicando la prueba de rangos múltiples o Test de Tukey-Kramer. Las mieles puras tanto de la Apis mellifera como de la Tetragonisca angustula presentaron la mayor inhibición en concentraciones bacterianas in vitro de 1x10-4 UFC. Las mieles diluidas de la Apis mellifera y Tetragonisca angustula al 20% no presentaron suficiente inhibición ante las concentraciones de 1x10-1,1x10-2 y 1x10-3 UFC. El resto de las diluciones no presentaron una diferencia marcada entre sí por lo que se consideraron en general inhibitorias para las cuatro concentraciones. Todas las mieles estuvieron dentro de un rango de 21.2 mm como máximo y 11 mm como diámetro mínimo; el máximo obtenido, correspondió a la miel pura de la abeja Apis mellifera ante la concentración de 1x10-4 UFC y el mínimo correspondió a la miel de la Tetragonisca angustula en dilución al 20% ante la concentración bacteriana de 1x10-1 UFC. En todos sus estados la miel fue superior al control positivo: oxitetraciclina al 10%. En conclusión, se comprobó durante este estudio que la miel de la abeja Apis mellífera y de la Tetragonisca angustula, puras y diluidas al 50 y 20%, poseen propiedades antibacteriales que las hacen efectivas para detener el crecimiento de las colonias del Staphylococcus aureus coagulasa positivo, en un ensayo in vitro y que las concentraciones mínimas inhibitorias de la miel dependen de la concentración bacteriana y del estado puro o diluido de las mismas mieles. Se podría recomendar que, para próximos estudios de esta índole, sea necesario establecer antes, la presencia y cantidad de las enzimas catalasa y glucoxidasa en la miel sometida a estudio; además de obtener el porcentaje de humedad específico para la misma.
The addition of honey to mixed beverages is interesting due to its contribution to the sweet taste, as well as because it is a dietary source of bioactive compounds. In this study, we investigated the chemical composition and sensory acceptance of an apple and passion fruit mixed beverage with added honey. The addition of honey did not produce a noticeable change in instrumental color but led to an increase in total soluble solids contents, and FRAP (20%), TEAC (72%), and DPPH (62%) values. The honey mixed beverages exhibited a better phenolic compound profile with an increase in catechin contents and an enrichment of quercetin when compared to the control mixed beverage, as well presenting good sensory acceptance. In conclusion, our results show that the addition of honey can be an alternative for improving the nutritional and sensorial characteristics of an apple and passion fruit mixed beverage.
In this study, we assessed the antioxidative ability of 23 natural sources in a meat model system at the same addition level (1.0%). We evaluated the free radical (2,2-diphenyl-1-picrylhydrazyl, DPPH) scavenging ability of natural plant sources and their peroxides, as well as their aldehyde-inhibiting ability in pork patties, over 10 days of cold storage. It was found that blueberries, cherries, onions, black tea, and clove buds (20.6–25.0 mg AA/g) have a higher DPPH scavenging ability than that of other natural sources (10.80–16.7 mg AA/g) ( P < 0.05 ). Moreover, it was found that peroxides in pork patties are largely inhibited by red wine, lettuce, and red ginseng ( P < 0.05 ), whereas aldehydes are significantly inhibited by blueberries, chokeberries (aronia), blackcurrant, clove buds, elderberries, ginger, and cinnamon ( P < 0.05 ). These inconsistencies detected in the antioxidative ability of these 23 natural sources indicate that it is important to perform comprehensive and practical assessments of the potential antioxidative ability of natural sources. In addition, it is assumed that the interactions between natural plant sources and meat components affect the inhibition of lipid oxidation in meat and meat products.
We design a honey antibiotic detection system (HADS), which provides honey antibiotic residue rapid on-site detecting solution relying on simple sample preparation tactics, lateral-flow immunochromatographic assay (LFIA)-based strip and handheld sensor reader. Relying on the quantum dot microsphere probes conjugated to the antibiotic monoclonal antibodies, the LFIA strip can simultaneously detect sulfonamides (SAs) and tetracyclines (TCs) in high sensitivity with extremely low detecting limits of 0.4 μg/kg and good specificity. Moreover, the fabricated LFIA strips can be well conserved in vacuum-sealed bags at 4 °C for at least 6 months. Combining with the handheld sensor reader, both SAs and TCs can be quantitatively and automatically measured in high accuracy. All the operations including sample preparation and detection can be finished within 20 min at room temperature on site without any extra devices or complicated operations.
The effect of adding dry honey to turkey breast meat on oxidative stability was measured using TBA, volatile headspace, and oxidative stability index. Ground turkey breast meat was mixed with different concentrations of dry honey (0, 1, 5, 10, 15, and 20%) then cooked in polyethylene bags to 72 C. Oxidative stability measurements were taken for raw meat and cooked meat and for cooked meat after 48 h of storage at 4 C. The proximate composition of the raw meat was 73.9% moisture, 23.2% protein, and 1.3% fat. Gas headspace analysis determined hexanal to be the most abundant volatile compound. Hexanal content decreased as the amount of added honey increased in both freshly cooked meat and in meat stored for 48 h at 4 C. The TBA values also decreased with increasing levels of added honey in the freshly cooked and 48-h-stored meats. The percentage inhibition of oxidation for the 5, 10, 15, and 20% samples increased from 50 to 76% for the freshly cooked meat and from 34 to 88% for the 48-h-stored meat. The oxidative stability index increased with increasing concentrations of honey from 0.28 h (control) to 7.73 h (20% honey). Addition of up to 15% honey inhibited the development of oxidative compounds in cooked turkey meat, with little further inhibition observed compared to 20% honey.
BACKGROUND Data continue to accumulate supporting a proatherogenic role for oxidized low-density lipoprotein (Ox-LDL). Antioxidant micronutrients such as ascorbate, alpha-tocopherol, and beta carotene, levels of which can be favorably manipulated by dietary measures without side effects, could be a safe approach in inhibiting LDL oxidation. In fact, in vitro studies have shown that all three antioxidants can inhibit LDL oxidation. The present study was undertaken to ascertain both the safety and antioxidant effect of combined supplementation with alpha-tocopherol, ascorbate, and beta carotene on LDL oxidation.
METHODS AND RESULTS The effect of combined supplementation with alpha-tocopherol (800 IU/d) plus ascorbate (1.0 g/d) and beta carotene (30 mg/d) on copper-catalyzed LDL oxidation was tested in a randomized, placebo-controlled study in two groups of 12 male subjects over a 3-month period. Blood samples for the lipoprotein profile, antioxidant levels, and LDL isolation were obtained at baseline and at 3 months. Neither placebo nor combined antioxidant therapy resulted in any side effects or exerted an adverse effect on the plasma lipoprotein profile. Compared with placebo, combined antioxidant therapy resulted in a significant increase in plasma ascorbate and lipid standardized alpha-tocopherol and beta carotene levels (2.6-, 4.1-, and 16.3-fold, respectively). At baseline, there were no significant differences in the time course curves and kinetics of LDL oxidation as evidenced by the thiobarbituric acid reacting substances (TBARS) assay and the formation of conjugated dienes. However, at 3 months, combined supplementation resulted in a twofold prolongation of the lag phase and a 40% decrease in the oxidation rate. The combined antioxidant group was also compared with a group that received 800 IU of alpha-tocopherol only. Although the combined antioxidant group had significantly higher ascorbate and beta carotene levels than the group supplemented with alpha-tocopherol alone, there were no significant differences between the two groups with respect to LDL oxidation kinetics.
CONCLUSIONS Combined supplementation with ascorbate, beta carotene, and alpha-tocopherol is not superior to high-dose alpha-tocopherol alone in inhibiting LDL oxidation. Hence, alpha-tocopherol therapy should be favored in future coronary prevention trials involving antioxidants.
An earlier edition of Methods of melissopalynology was published in Bee World 51(3): 125–138 (1970), and has been widely used. It is now republished with minor corrections and updating, and with two significant additions. The acetolysis method is included, which has not previously been commonly used in melissopalynology; also the literature list is enlarged so that it provides an introduction to the extensive literature on palynology, which is scattered over many journals.
The water-soluble antioxidant capacity of 19 samples of honey from 14 different floral sources was determined by a spectrophotometric assay. The highest concentration of antioxidants measured was 20.3 times that of the lowest, showing that great variation exists in the chemical nature of honey from different floral sources. Antioxidant content was positively correlated with both water content and honey colour. Because of the health benefits of dietary antioxidants, floral source should be a factor in evaluating the potential of honey as an antioxidant-containing food supplement.
Isoflavonoids are compounds present in many legumes, but are derived in the human diet mainly from soybeans and various soybean-based food products. The major isoflavonoids occurring in soy are the glycosides of genistein and daidzein. The metabolic products of genistein metabolism in humans have not been clearly shown. The two main products of daidzein metabolism in humans appear to be equol and O-desmethylangolensin. Increasing evidence suggests that oxidative modification to low-density lipoprotein is involved in atherogenesis, and that natural antioxidants that prevent or inhibit oxidative damage to low-density lipoprotein may beneficially influence atherogenesis. In the present experiments, the effects of genistein and daidzein, and the daidzein metabolites equol and O-desmethylangolensin on Cu2+-induced oxidation of lipoproteins in serum were examined. Three concentrations of each compound (0.1 μM, 1 μM, 10 μM) were tested for antioxidant activity in six individual serum samples. All compounds tested inhibited lipoprotein oxidation. The minimum concentration for significant inhibition was 1 μM for genistein and daidzein (P < 0.05), and 0.1 μM equol and O-desmethylangolensin (P < 0.05). Equol and O-desmethylangolensin were more potent inhibitors of in vitro lipoprotein oxidation in serum than the two major dietary isoflavonoids. This study has demonstrated that soybean isoflavonoids and metabolic products of daidzein metabolism inhibit lipoprotein oxidation in vitro. Human intervention studies are needed to determine if these compounds can influence oxidation in vivo.
The inhibitory effect of honey on polyphenol oxidase (PPO) and on browning reactions was studied in apple slices, grape juice, and model systems. Browning was prevented by immersing apple slices in a honey solution. Grape juice preparations with added honey exhibited less browning and retained a higher concentration of polyphenols than juices made with no added honey. In model solutions of caffeoyl tartrate and epicatechin, the browning rate was inversely proportional to the added honey concentration. A kinetic study showed that honey is noncompetitive with epicatechin. Preincubation of PPO with honey progressively decreased the PPO activity with time. The compound responsible for this inhibitory effect of honey appeared to be a small peptide with an approximate molecular weight of 600.
Lipoprotein oxidation is a process thought to be involved in atherogenesis. Dietary antioxidants that prevent or inhibit oxidative damage to lipoproteins may help to prevent atherosclerosis. Both black and green teas can be major dietary sources of flavonoids and other phenolics with antioxidant activity. Results of previous studies suggest that green tea may have a greater antioxidant potential than black tea. The aim of this study was to assess and compare the effects of black and green tea on in vitro lipoprotein oxidation. The tea extracts were prepared using a method similar to that used to prepare infusions of tea for drinking. Antioxidant activities of seven black teas and four green teas were assessed using an in vitro assay that measures Cu2+ -induced oxidation of lipoproteins in human serum. All tea extracts inhibited in vitro lipoprotein oxidation in human serum to a similar extent. No significant difference in antioxidant activity was found between black and green tea. Caffeine prepared to a comparable concentration to that found in tea had no effect on lipoprotein oxidation. Further studies are required to determine the importance of these findings in relation to possible protective effects of black and green tea consumption against atherogenesis and cardiovascular disease.© 1999 Society of Chemical Industry
The purpose of this study is to provide a comprehensive survey on the compositional properties of LDL (e.g., lipid classes, fatty acids, antioxidants) relevant for its susceptibility to oxidation, on the mechanism and kinetics of LDL oxidation, and on the chemical and physico-chemical properties of LDL oxidized by exposure to copper ions. Studies on the occurrence of oxidized LDL in plasma, arteries, and plaques of humans and experimental animals are discussed with particular focus on the use of poly- and monoclonal antibodies for immunochemical demonstration of apolipoprotein B modifications characteristic for lipid peroxidation. Apart from uptake of oxidized LDL by macrophages, studies describing biological effects of heavily or minimally oxidized LDL are only briefly addressed, since several reviews dealing with this subject were recently published. This article is concluded with a section on the role of natural and synthetic antioxidants in protecting LDL against oxidation, as well as some previously unpublished material from our laboratories.
Fluorescence spectroscopy is a rapid, sensitive method for characterizing molecular environments and events. In spite of its utility, food researchers have been slow to adopt fluorescence methodology, partly because its value has gone unrecognized. This article presents a brief overview of the theory of fluorescence spectroscopy, together with some examples of applications of this technique to illustrate its potential for addressing key problems in food science.
The total antioxidant activity of 12 fruits and 5 commercial fruit juices was measured in this study using automated oxygen radical absorbance capacity (ORAC) assay. On the basis of the wet weight of the fruits (edible portion), strawberry had the highest ORAC activity (micromoles of Trolox equivalents per gram) followed by plum, orange, red grape, kiwi fruit, pink grapefruit, white grape, banana, apple, tomato, pear, and honeydew melon. On the basis of the dry weight of the fruits, strawberry again had the highest ORAC activity followed by plum, orange, pink grapefruit, tomato, kiwi fruit, red grape, white grape, apple, honeydew melon, pear, and banana. Most of the antioxidant capacity of these fruits was from the juice fractions. The contribution of the fruit pulp fraction (extracted with acetone) to the total ORAC activity of a fruit was usually less than 10%. Among the commercial fruit juices, grape juice had the highest ORAC activity followed by grapefruit juice, tomato juice, orange juice, and apple juice.
Previously, some fruits were shown to contain high antioxidant activities. In this paper, we report the antioxidant activities of 22 common vegetables, one green tea, and one black tea measured using the automated oxygen radical absorbance capacity assay with three different reactive species: a peroxyl radical generator, a hydroxyl radical generator, and Cu2+, a transition metal. Based on the fresh weight of the vegetable, garlic had the highest antioxidant activity (micromol of Trolox equiv/g) against peroxyl radicals (19.4) followed by kale (17.7), spinach (12.6), Brussels sprouts, alfalfa sprouts, broccoli flowers, beets, red bell pepper, onion, corn, eggplant (9.8-3.9), cauliflower, potato, sweet potato, cabbage, leaf lettuce, string bean, carrot, yellow squash, iceberg lettuce, celery, and cucumber (3.8-0.5); kale had the highest antioxidant activity against hydroxyl radicals followed by Brussels sprouts, alfalfa sprouts, beets, spinach, broccoli flowers, and the others. The green and black teas had much higher antioxidant activities against peroxyl radicals than all these vegetables. However, the tea also showed a prooxidant activity in the presence of Cu2+, which was not found with any of the vegetables studied.
The flavonoid profiles of 12 different unifloral French honey samples were analysed by HPLC to evaluate if these substances could be used as markers of the floral origin of honey. In this analysis, the characteristic flavonoids from propolis and/or beeswax (chrysin, galangin, tectochrysin, pinocembrin and pinobanksin) were separated from those originating mainly from nectar and/or pollen (polyhydroxylated flavonoid aglycones), which would be related to their floral origin. All the analysed samples contained a common flavoniod profile consisting of polyhydroxylated flavonoid agylcones including 8-methoxykaempferol, kaempferol, quercetin, isorthamnetin luteolin and apigenin, suggesting that flavonoid analysis does not generally prove differences between French monofloral honey samples. However, some individual honey samples showed potential floral markers. Thus, heather honey was characterized by the presence of myricetin, calluna honey by ellagic acid and citrus honey by the flavanone hesperetin. In other samples, the relative amount of 1 individual flavonoid could be related to the floral origin. Thus, sunflower honeys contained an important relative amount of quercetin, and in alder honey only 8-methoxylkaempferol was detected. This preliminary study shows that flavonoid and phenolic compound analyses could be a very valuable complementary biochemical technique in the objective determination of the floral origin of some specific monofloral honey samples, but further studies with a larger number of samples is necessary to confirm the observed differences.
We previously described a rapid headspace gas chromatographic method for the determination of hexanal, an important decomposition product of n-6 polyunsaturated fatty acid (PUFA) peroxidation in rat liver samples and human red blood cell membranes. This method was applied to the measurement of Cu2+ catalyzed-oxidation of freshly prepared human low density lipoproteins (LDL) from 10 healthy adult volunteers. A twofold variation in oxidative susceptibility was found by this assay for hexanal and other volatiles. Hexanal values correlated significantly (P < 0.05) with total polyunsaturated fatty acid (PUFA), 18:2 and n-6 PUFA contents of LDL; but poorly with 20:4 and with vitamin E. Therefore, in addition to alpha-tocopherol, other endogenous antioxidants and factors may contribute to LDL's resistance to oxidation. This simple, rapid and sensitive method for oxidative susceptibility provides a useful component in the analysis of the prooxidant/antioxidant status of biological samples. The method is used routinely in our laboratories to determine specific peroxidation products of n-6 and n-3 PUFA.
The current emphasis on screening the environment for man-made genotoxic and carcinogenic compounds detracts from studies on the possible health hazard or beneficial effects of naturally occurring agents to which humans are exposed daily. The simple phenolics, which are ubiquitous among plants, used as food additives, and ingested daily in milligram quantities, belong to this category of compounds. They induce double-strand DNA breaks. DNA adducts, mutations and chromosome aberrations in a great variety of test systems. However, they can suppress the genotoxic activity of numerous carcinogenic compounds in both in vitro and in vivo assays. This dual function of dietary phenolics also becomes evident when their carcinogenic or anticarcinogenic potential is examined. Some, but not all, phenolics induce precancerous lesions, papillomas and cancers, act as cocarcinogens, and exert a promoting effect in various rodent assays. On the other hand, phenolics have proved to be potent inhibitors of carcinogenesis at the initiation and promotion stages induced by carcinogens and promoters of different molecular structures. The extent to which a health hazard or protective activity of complex dietary mixtures is due to their phenolic content remains an unresolved issue. In addition, these multiple, occasionally contradictory functions of simple phenolics make it difficult to propose their use as chemopreventive agents.
The kinetics of the oxidation of human low density lipoprotein (LDL) can be measured continuously by monitoring the change of the 234 nm diene absorption. The time-course shows three consecutive phases, a lag-phase during which the diene absorption increases only weakly, a propagation phase with a rapid increase of the diene absorption and finally a decomposition phase. The increase of the dienes is highly correlated with the increase of MDA or lipid hydroperoxides. The duration of the lag-phase is determined by the endogenous antioxidants contained in LDL (vitamin E, carotenoids, retinylstearate). Water-soluble antioxidants (ascorbic acid, urate) added in micromolar concentrations prolong the lag-phase in a concentration-dependent manner. The determination of the lag-phase is a convenient and objective procedure for determining the susceptibility of LDL from different donors towards oxidation as well as effects of pro- and antioxidants.
Increasing evidence indicates that oxidative modification of low‐density lipoprotein (LDL) is causally related to atherosclerosis. Oxidatively modified LDL (oxLDL), in contrast to native LDL, is taken up avidly by macrophages, leading to formation of lipid‐laden foam cells. Foam cells are pathognomonic of the atherosclerotic fatty streak. Modified LDL may also promote atherosclerosis by many other mechanisms, such as recruitment and retention of monocyte‐macrophages, T‐lymphocytes, and smooth muscle cells in the arterial intima, and cytotoxicity toward endothelial cells and macrophage‐derived foam cells. The “oxidation hypothesis of atherosclerosis” is supported by a number of in vivo findings, such as the presence of oxLDL in atherosclerotic lesions, and increased titers of autoantibodies against modified LDL in patients with atherosclerosis.
As a corollary of the oxidation hypothesis of atherosclerosis, antioxidants that can inhibit LDL oxidation may act as antiatherogens. This conception is supported by animal studies showing that antioxidants such as probucol, butylated hydroxytoluene, and α‐tocopherol can slow the progression of atherosclerosis. Epidemiological and clinical data indicate a protective role of dietary antioxidants against cardiovascular disease, including vitamin E, β‐carotene, and vitamin C. Likewise, basic research studies on LDL oxidation have demonstrated a protective role for antioxidants, present either in the aqueous environment of LDL or associated with the lipoprotein itself. More studies are needed to establish the effectiveness and determine the required doses of specific antioxidants to prevent and possibly treat cardiovascular disease.
Epidemiological studies strongly suggest that high intakes of foods rich in beta carotene, as well as those rich in vitamin E or vitamin C, reduce the risk of some but not all cancers and cardiovascular disease. It is difficult to determine whether these antioxidant nutrients per se are the sole protective agents or whether other factors associated with foods containing them contribute to the foods' protective effects. With respect to vitamin E, a number of studies where dietary and supplementary vitamin E were clearly differentiated, a reduced risk of certain cancers or cardiovascular disease from supplemental vitamin E but not from dietary vitamin E was demonstrated. This provides strong presumptive evidence that high intakes of vitamin E per se provide a health benefit. Only a few intervention studies with specific nutrients are available and results are inconsistent.
Although the role of free radicals has continued to capture the imagination of scientists, the interest in nutritional aspects of free radicals is relatively recent. Oxidative stress, which often arises as a result of the imbalance in the human antioxidant status, has been implicated in ageing and in a number of human diseases such as cancer, atherosclerosis, malaria and in rheumatoid arthritis. This review discusses the current status of free radicals in nutrition and dietary antioxidants and considers the possibility that use of a range of antioxidants, which have been carefully evaluated, combined with methods for measuring oxidant generation, would help to delineate the contribution of nutrients to the modulation of the consequences of free radicals in the human body.
Flavonoids are polyphenolic antioxidants naturally present in vegetables, fruits, and beverages such as tea and wine. In vitro, flavonoids inhibit oxidation of low-density lipoprotein and reduce thrombotic tendency, but their effects on atherosclerotic complications in human beings are unknown. We measured the content in various foods of the flavonoids quercetin, kaempferol, myricetin, apigenin, and luteolin. We then assessed the flavonoid intake of 805 men aged 65-84 years in 1985 by a cross-check dietary history; the men were then followed up for 5 years. Mean baseline flavonoid intake was 25.9 mg daily. The major sources of intake were tea (61%), onions (13%), and apples (10%). Between 1985 and 1990, 43 men died of coronary heart disease. Fatal or non-fatal myocardial infarction occurred in 38 of 693 men with no history of myocardial infarction at baseline. Flavonoid intake (analysed in tertiles) was significantly inversely associated with mortality from coronary heart disease (p for trend = 0.015) and showed an inverse relation with incidence of myocardial infarction, which was of borderline significance (p for trend = 0.08). The relative risk of coronary heart disease mortality in the highest versus the lowest tertile of flavonoid intake was 0.42 (95% CI 0.20-0.88). After adjustment for age, body-mass index, smoking, serum total and high-density-lipoprotein cholesterol, blood pressure, physical activity, coffee consumption, and intake of energy, vitamin C, vitamin E, beta-carotene, and dietary fibre, the risk was still significant (0.32 [0.15-0.71]). Intakes of tea, onions, and apples were also inversely related to coronary heart disease mortality, but these associations were weaker. Flavonoids in regularly consumed foods may reduce the risk of death from coronary heart disease in elderly men.
The susceptibility of low density lipoprotein (LDL) to oxidative modification can be determined by analyzing the lag phase for initiation of diene formation in isolated LDL exposed to Cu2+. However, the applicability of this assay for clinical studies is limited by the requirement of a preparative ultracentrifugation of LDL and that the influence of water soluble antioxidants and other lipoproteins is not accounted for. The present paper describes a modification of this assay allowing determination of lag phase for lipoprotein diene formation in serum. The formation of dienes in serum exposed to Cu2+ begins following the consumption of serum alpha-tocopherol, correlates to the formation of thiobarbituric acid reactive substances (r = 0.987, n = 8), is inhibited by the addition of ascorbic acid and is absent in lipoprotein-deficient serum. It is also accompanied by an increased mobility of serum lipoproteins on agarose gel electrophoresis and with an ability of serum to displace isolated copper-oxidized LDL from binding sites mediating degradation in mouse peritoneal macrophages. The coefficient of variance of the analysis is below 3%. It is concluded that this technique allows analysis of lipoprotein oxidation susceptibility in serum samples and may prove to be useful in clinical analysis of the lipoprotein oxidation susceptibility.
A relatively simple but sensitive and reliable method of quantitating the oxygen-radical absorbing capacity (ORAC) of antioxidants in serum using a few microliter is described. In this assay system, beta-phycoerythrin (beta-PE) is used as an indicator protein, 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) as a peroxyl radical generator, and 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox, a water-soluble vitamin E analogue) as a control standard. Results are expressed as ORAC units, where 1 ORAC unit equals the net protection produced by 1 microM Trolox. The uniqueness of this assay is that total antioxidant capacity of a sample is estimated by taking the oxidation reaction to completion. At this point all of the nonprotein antioxidants (which include alpha-tocopherol, vitamin C, beta-carotene, uric acid, and bilirubin) and most of the albumin in the sample are oxidized by the peroxyl radical. Results are quantified by measuring the protection produced by antioxidants. This solves many problems associated with kinetics or lag-time measurements. A linear correlation of ORAC value with concentration of serum. Trolox, vitamin C, uric acid, and bovine albumin is demonstrated. The coefficient of variation within a run is found to be about 2% and from run to run about 5%. Trolox, alpha-tocopherol, vitamin C, beta-carotene, uric acid, and bilirubin completely protect beta-PE from oxidation, while bovine albumin protects beta-PE only partially. On a molar basis, the relative peroxyl radical absorbance capacity of Trolox, alpha-tocopherol acid succinate, uric acid, bilirubin, and vitamin C is 1:1:0.92:0.84:0.52. Bovine albumin per unit weight has a lower peroxyl absorbing capacity than these antioxidants.(ABSTRACT TRUNCATED AT 250 WORDS)
In this review of the scientific literature on the relationship between vegetable and fruit consumption and risk of cancer, results from 206 human epidemiologic studies and 22 animal studies are summarized. The evidence for a protective effect of greater vegetable and fruit consumption is consistent for cancers of the stomach, esophagus, lung, oral cavity and pharynx, endometrium, pancreas, and colon. The types of vegetables or fruit that most often appear to be protective against cancer are raw vegetables, followed by allium vegetables, carrots, green vegetables, cruciferous vegetables, and tomatoes. Substances present in vegetables and fruit that may help protect against cancer, and their mechanisms, are also briefly reviewed; these include dithiolthiones, isothiocyanates, indole-3-carbinol, allium compounds, isoflavones, protease inhibitors, saponins, phytosterols, inositol hexaphosphate, vitamin C, D-limonene, lutein, folic acid, beta carotene, lycopene, selenium, vitamin E, flavonoids, and dietary fiber. Current US vegetable and fruit intake, which averages about 3.4 servings per day, is discussed, as are possible noncancer-related effects of increased vegetable and fruit consumption, including benefits against cardiovascular disease, diabetes, stroke, obesity, diverticulosis, and cataracts. Suggestions for dietitians to use in counseling persons toward increasing vegetable and fruit intake are presented.
The antioxidant and prooxidant behavior of flavonoids and the related activity-structure relationships were investigated in this study using the oxygen radical absorbance capacity assay. Three different reactive species were used in the assay: 2,2'-azobis(2-amidino-propane) dihydrochloride, a peroxyl radical generator; Cu(2+)-H2O2, mainly a hydroxyl radical generator; and Cu2+, a transition metal. Flavonoids including flavones, isoflavones, and flavanones acted as antioxidants against peroxyl and hydroxyl radicals and served as prooxidants in the presence of Cu2+. Both the antioxidant and the copper-initiated prooxidant activities of a flavonoid depend upon the number of hydroxyl substitutions in its backbone structure, which has neither antioxidant nor prooxidant action. In general, the more hydroxyl substitutions, the stronger the antioxidant and prooxidant activities. The flavonoids that contain multiple hydroxyl substitutions showed antiperoxyl radical activities several times stronger than Trolox, an alpha-to copherol analogue. The single hydroxyl substitution at position 5 provides no activity, whereas the di-OH substitution at 3' and 4' is particularly important to the peroxyl radical absorbing activity of a flavonoid. The conjugation between rings A and B does not affect the antioxidant activity but is very important for the copper-initiated prooxidant action of a flavonoid. The O-methylation of the hydroxyl substitutions inactivates both the antioxidant and the prooxidant activities of the flavonoids.
Several methods have been developed to measure the total antioxidant capacity of a biological sample. The use of peroxyl or hydroxyl radicals as pro-oxidants in the oxygen radical absorbance capacity (ORAC) assay makes it different and unique from the assays that involve oxidants that are not necessarily pro-oxidants. An improvement in quantitation is achieved in the ORAC assay by taking the reaction between substrate and free radicals to completion and using an area-under-curve technique for quantitation compared to the assays that measure a lag phase. The interpretation of the changes in plasma or serum antioxidant capacity becomes complicated by the different methods used in detecting these changes. The interpretation also depends upon the conditions under which the antioxidant capacity is determined because the measurement reflects outcomes in a dynamic system. An increased antioxidant capacity in plasma or serum may not necessarily be a desirable condition if it reflects a response to increased oxidative stress. Similarly, a decrease in plasma or serum antioxidant capacity may not necessarily be an undesirable condition if the measurement reflects decreased production of reactive species. Because of these complications, no single measurement of antioxidant status is going to be sufficient, but a "battery" of measurements, many of which will be described in Forum articles, will be necessary to adequately assess oxidative stress in biological systems.
Honeys from different floral sources were evaluated for their antioxidant content and for their ability to inhibit enzymatic browning in fruits and vegetables. Antioxidant contents of honeys vary widely from different floral sources, as do their abilities to protect against enzymatic browning. Polyphenol oxidase (PPO) activity was reduced over a range of approximately 2-45% in fruit and vegetable homogenates, corresponding to a reduction in browning index by 2.5-12 units. Soy honey was particularly effective when compared to clover honey, which had a similar antioxidant content. When compared to commercial inhibitors of browning, honeys were less effective; however, in combination they added to the effectiveness of metabisulfite and ascorbic acid. Honey has great potential to be used as a natural source of antioxidants to reduce the negative effects of PPO browning in fruit and vegetable processing.
Lipid oxidation is a major deteriorative factor in meats. Sources of natural antioxidants that are as effective as commercially available antioxidants are desired. The objective of this research was to investigate honey as an inhibitor of lipid oxidation in ground poultry. The antioxidant content of different varieties of honey was investigated spectrophotometrically and honey's effectiveness in reducing oxidation of ground poultry determined by monitoring thiobarbituric acid reactive substances (TBARS). Buckwheat honey had the highest antioxidant content and acacia honey the lowest. Honeys of different floral sources differed in their protection against lipid oxidation. Buckwheat honey (5%, w/w) reduced TBARS approximately 70%, whereas acacia honey reduced TBARS approximately 34% at 3 days of storage at 4 degrees C. In comparison to butylated hydroxytoluene and tocopherol (0.02% of total fat), honey (at 5% of the weight of the meat) was much more effective at preventing oxidation. Honey has great potential as an antioxidant source and may result in greater acceptability of meat products and prevent negative health implications of oxidized meats.