Tetracycline adsorption/desorption by raw and activated Tunisian clays.

Clay-based adsorbents have applications in environmental remediation, particularly in the removal of emerging pollutants such as antibiotics. Taking that into account, we studied the adsorption/desorption process of tetracycline (TC) using three raw and acid- or base-activated clays (AM, HJ1 and HJ2) collected, respectively, from Aleg (Mazzouna), El Haria (Jebess, Maknessy), and Chouabine (Jebess, Maknessy) formations, located in the Maknessy-Mazzouna basin, center-western of Tunisia. The main physicochemical properties of the clays were determined using standard procedures, where the studied clays presented a basic pH (8.39-9.08) and a high electrical conductivity (446-495 dS m-1). Their organic matter contents were also high (14-20%), as well as the values of the effective cation exchange capacity (80.65-97.45 cmolckg-1). In the exchange complex, the predominant cations were Na and Ca, in the case of clays HJ1 and AM, while Mg and Ca were dominant in the HJ2 clay. The sorption experimental setup consisted in performing batch tests, using 0.5 g of each clay sample, adding the selected TC concentrations, then carrying out quantification of the antibiotic by means of HPL-UV equipment. Raw clays showed high adsorption potential for TC (close to 100%) and very low desorption (generally less than 5%). This high adsorption capacity was also present in the clays after being activated with acid or base, allowing them to adsorb TC in a rather irreversible way for a wide range of pH (3.3-10) and electrical conductivity values (3.03-495 dS m-1). Adsorption experimental data were studied as regards their fitting to the Freundlich, Langmuir, Linear and Sips isotherms, being the Sips model the most appropriate to explain the adsorption of TC in these clays (natural or activated). These results could help to improve the overall knowledge on the application of new low-cost methods, using clay based adsorbents, to reduce risks due to emerging pollutants (and specifically TC) affecting the environment.

Experimental data and modeling of sulfadiazine adsorption onto raw and modified clays from Tunisia.

In recent years, the increasing detection of emerging pollutants (particularly antibiotics, such as sulfonamides) in agricultural soils and water bodies has raised growing concern about related environmental and health problems. In the current research, sulfadiazine (SDZ) adsorption was studied for three raw and chemically modified clays. The experiments were carried out for increasing doses of the antibiotic (0, 1, 5, 10, 20, and 40 µmol L-1) at ambient temperature and natural pH with a contact time of 24 h. The eventual fitting to Freundlich, Langmuir and Linear adsorption models, as well as residual concentrations of antibiotics after adsorption, was assessed. The results obtained showed that one of the clays (HJ1) adsorbed more SDZ (reaching 99.9 % when 40 µmol L-1 of SDZ were added) than the other clay materials, followed by the acid-activated AM clay (which reached 99.4 % for the same SDZ concentration added). The adsorption of SDZ followed a linear adsorption isotherm, suggesting that hydrophobic interactions, rather than cation exchange, played a significant role in SDZ retention. Concerning the adsorption data, the best adjustment corresponded to the Freundlich model. The highest Freundlich KF scores were obtained for the AM acid-treated and raw HJ1 clays (606.051 and 312.969 Ln µmol1-n kg-1, respectively). The Freundlich n parameter ranged between 0.047 and 1.506. Regarding desorption, the highest value corresponded to the AM clay, being generally <10 % for raw clays, <8 % for base-activated clays, and <6 % for acid-activated clays. Chemical modifications contributed to improve the adsorption capacity of the AM clay, especially when the highest concentrations of the antibiotic were added. The results of this research can be considered relevant as regard environmental and public health assessment since they estimate the feasibility of three Tunisian clays in SDZ removal from aqueous solutions.

Nutritional quality of fresh and heated Aleppo pine (Pinus halepensis Mill.) seed oil: trans-fatty acid isomers profiles and antioxidant properties.

Numerous studies have focused on trans fatty acids (TFA) technologically produced by partial hydrogenation of oils. However, TFA can also be present in fresh oils. For this reason, cis fatty acid (CFA), TFA and conjugated linoleic acid (CLA) of fresh and heated Aleppo pine seed oil (APSO) at frying temperature (180 °C) were evaluated and correlated with the antioxidant characteristics. Results showed that fresh APSO had a low oleic/linoleic ratio O/L (0.4). Total TFA in fresh APSO reached 1%. The predominant TFA was 18:2 n-6 (t9, t12) in both fresh and heated APSO. Individual TFA increased with significant differences (p < 0.05) with heating time. CLA occurred after 4 h and significantly increased (p < 0.05) accounting 10% of total TFA after 10 h. Total TFA are negatively correlated with α-tocopherol, γ-tocopherol (p < 0.05) and carotenoïds (p < 0.01) and positively correlated with remaining DPPH. Oil stability index (OSI) showed significant negative correlation with TFA (r = -0.925; p = 0.008). A principal component analysis (PCA) showed a clear discrimination between fresh and heated oils. Temperature, heating time, unsaturation degree and antioxidants are combined factors which significantly affect the isomerization rate and nutritional quality of APSO.

Food Composition Databases: Does It Matter to Human Health?

Food provides humans with more than just energy and nutrients, addressing both vital needs and pleasure. Food habits are determined by a wide range of factors, from sensorial stimuli to beliefs and, once commanded by local and seasonal availability, are nowadays driven by marketing campaigns promoting unhealthy and non-sustainable foodstuffs. Top-down and bottom-up changes are transforming food systems, driven by policies on SDGs and by consumer's concerns about environmental and health impacts. Food quality, in terms of taste, safety, and nutritional value, is determined by its composition, described in food composition databases (FDBs). FDBs are then useful resources to agronomists, food and mechanical engineers, nutritionists, marketers, and others in their efforts to address at maximum human nutrient needs. In this work, we analyse some relevant food composition databases (viz., purpose, type of data, ease of access, regularity of updates), inspecting information on the health and environmental nexus, such as food origin, production mode as well as nutritional quality. The usefulness and limitations of food databases are discussed regarding what concerns sustainable diets, the food 'matrix effect', missing compounds, safe processing, and in guiding innovation in foods, as well as in shaping consumers' perceptions and food choices.

Dietary olive oil effect on antioxidant status and fatty acid profile in the erythrocyte of 2,4-D- exposed rats.

BACKGROUND: Oxidative stress produced by reactive oxygen species (ROS) has been linked to the development of several diseases such as cardiovascular, cancer, and neurodegenerative diseases. This study investigates the possible protective effect of extra virgin olive oil (EVOO), lipophilic fraction (OOLF) and hydrophilic fraction (OOHF) on oxidative stress and fatty acid profile of erythrocytes in 2,4-D treated rats. METHODS: Male Wistar rats were divided randomly into eight groups: control (C), (2,4-D) at a dose of 5 mg/kg b.w., (2,4-D/EVOO) was given 2,4-D plus EVOO, (2,4-D/OOHF) that received 2,4-D plus hydrophilic fraction, (2,4-D/OOLF) treated with 2,4-D plus lipophilic fraction, (EVOO) that received only EVOO, (OOHF) was given hydrophilic fraction and (OOLF) treated with lipophilic fraction. These components were daily administered by gavages for 4 weeks. RESULTS: 2,4-D treatment lead to decrease of antioxidant enzyme activities, namely, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR) associated with a higher amount of MDA level. Erythrocyte membranes' fatty acid composition was also significantly modified with 2,4-D exposure. EVOO and hydrophilic fraction supplemented to rats with or not 2,4-D treatment enhanced the antioxidant enzyme activities and reduced the MDA level. However, lipophilic fraction did not show any improvement in oxidative damage induced by 2,4-D in spite its richness in MUFA and vitamins. CONCLUSION: EVOO administered to 2,4-D-treated rats protected erythrocyte membranes against oxidative damage by means of preventing excessive lipid peroxidation to increase the MUFA composition and increase maintaining antioxidants enzymes at normal concentrations.

Phenols, Flavors, and the Mediterranean Diet.

Phenols or phenolics are a class of compounds that have one or more hydroxyl groups attached to a 6-carbon aromatic ring, they occur as plant secondary metabolites, having in common the antioxidant activity. Their average daily intake varies widely around the world. Many researchers consider coffee, tea, wine, cocoa products, fruits and vegetables as the main sources of polyphenols in different diets. However, spices and culinary herbs have been referred to as the foods richest in polyphenols. Despite spices and culinary herbs are used in small amounts as seasonings, their contribution to the dietary supply of phytonutrients should not be disregarded. A diet rich in a variety of polyphenols (and other phytonutrients) has potential health benefits, namely in the prevention of chronic diseases and cancer. In addition, flavor and color are the most important factors for the selection of food by consumers. A multitude of endogenous food compounds, including phenolics, are involved in food flavor. The presence of phenolic compounds in the food matrix has been mainly associated with the perception of bitter taste and tactile sensation of astringency. However, these compounds can also impact the color and aroma notes of fruits and vegetables. Thus, understanding the sensory impact of these substances and relationships with consumers' approaches towards phenolic-rich fruits and vegetables may help find strategies to increase the consumption of such foods. A well-known example of a tasty, healthy and sustainable dietary model is the Mediterranean Diet. In this study, we summarize the dietary intake of some polyphenols from different dietary patterns around the world and the contribution of natural phenolic compounds to the flavor of food and beverages, in particularly those associated to the Mediterranean Diet.

Phenolic Substances in Foods and Anticarcinogenic Properties: A Public Health Perspective.

The interest in polyphenols from vegetable sources has been progressively increased because of the demonstrated correlation between their abundance in certain foods or food preparations of traditional importance and heritage, and the answer of anti-inflammatory strategies in hospitalized patients in the presence of polypehnol-rich foods (as a complementary therapy). Consequently, research involving the accessory role of polyphenols as anti-tumoral aids have been carried out with the aim of finding new additional strategies. The purpose of this paper to evaluate the role of phenolic compounds in foods with reference to health effects for human beings. The importance of these molecules has been evaluated by the health and safety perspectives in terms of: fight to cardiovascular diseases; prevention of chronic-degenerative disorders; general antioxidant properties; and anticarcinogenic features. Moreover, the role of polyphenols-rich foods as anticancer agents has been discussed with relation to two distinct "action plans" on the public hygiene level: the promotion of human health on the one side (for non-hospitalized and normal subjects), and reliable contrasting strategies in cancer patients.

Analysis of Main and Healthy Phenolic Compounds in Foods.

Background: In the last few decades, the media has been overwhelming the consumer with various dietary requirements that some of which lead to no avail. On the other hand, the Mediterranean diet, which stems from a very ancient lore, stands as one of the most effective diets whose conspicuous and positive results are still impacting the lives of many Mediterranean locals. The "Mediterranean Diet" is an umbrella term that is used to denote a plethora of natural ingredients used in the culinary tradition of the region, and which comprises but is not limited to olive oil, cereals, wine, fruits, dried fruits, and spices. MD components are known for being rich in antioxidant compounds. Polyphenols belong to the category of antioxidants that occur in the above-mentioned Mediterranean foods. Objective: The current review aims at presenting main classes of phenols from plant foods, their role as dietary components, and an overview on analytical methods for their extraction from food matrices, their separation, detection and quantification. Conclusions: The discrimination of phenols is not an easy matter, and several methods are described in the literature, mainly chromatographic methods, which are herein reviewed. In short, phenols are mainly found in vegetable foods in which the Mediterranean Diet is rich. The health effects of some phenols and analytical methods are herein revised. Highlights: Phenols or Phenolics is a designation corresponding to compounds that have one or more hydroxyl groups attached to a 6-carbon aromatic ring. Phenols in foods occur mainly as secondary metabolites of vegetables, often found in polymeric forms (polyphenols). Phenols from foods are mainly simple phenols (e.g., caffeic acid), flavonoids, the most varied and ubiquitous class (e.g., catechin, quercetin), stilbenes (resveratrol), lignans, and tannins. In addition to the wide range of polyphenols present in foods, the compounds are quantitatively and qualitatively distributed in a heterogenous way in the different compartments of the food matrix. This structural and compartmental diversity leads to an important variability of the physicochemical properties impacting otherwise the extraction of phenols. Total phenols are determined by the Folin Cioucalteau method, as described in European Pharmacopeaea.

Review of the Role of Fluid Dairy in Delivery of Polyphenolic Compounds in the Diet: Chocolate Milk, Coffee Beverages, Matcha Green Tea, and Beyond.

Dairy-based functional beverages have been a growing segment as consumer demands for health foods have shifted focus from simply enhancing lifespan to protecting health. Green tea is often limited in use because of poor bioavailability and disagreeable taste. However, milk is considered an ideal platform for the delivery of active polyphenolic compounds in green tea. Furthermore, the antioxidant enzymatic activity and antioxidant index of polyphenols in green tea have been known to be protected through interaction with dairy proteins inside the unstable intestinal environment. In addition, consumption of green tea infused with milk has been found to have a significant impact on reducing skin wrinkles and roughness in elderly subjects, through a decrease in lipid peroxidation and a concomitant reduction in oxidative stress. A similar affinity has been observed between antioxidants in coffee and milk proteins. Dark chocolate has been known to contain significant phenolic content and antioxidant activity. The activation of protein complex NF-κB, which is responsible for cell survival, was found to be significantly reduced upon consumption of cocoa with water, whereas consuming cocoa with milk had no effect on the bioavailability of the phenolic compounds in cocoa. The popularity of dairy as the source for polyphenol fortified beverages in the diet will be dictated by optimization of the technology for maximizing the bioavailability of the antioxidants.

Homocysteine enhances LDL fatty acid peroxidation, promoting microalbuminuria in type 2 diabetes.

BACKGROUND: We aimed to establish the relationship between glycated haemoglobin (HbA(1c)), hypertension and microalbuminuria onset in type 2 diabetes. We also intended to ascertain the metabolic action of homocysteine on LDL fatty acids and on renal function. METHODS: The study was carried out on 200 patients with type 2 diabetes and 200 healthy subjects. HbA(1c), apolipoprotein B (apo B) and microalbuminuria were measured using immunoturbidimetric methods. Cholesterol, peroxide, urea and uric acid were assayed using colorimetric methods. Creatinine clearance was calculated using the Cockroft-Gault equation. Homocysteine was measured by immunological fluorescence polarization. LDL fatty acids were quantified by gas chromatography. RESULTS: Creatinine and microalbuminuria significantly increased in type 2 diabetes when compared with controls. Microalbuminuria was significantly correlated with HbA(1c) and with the presence of high blood pressure. Homocysteinaemia significantly correlated with creatinine clearance in diabetes. Linoleic acid (C18:2omega6) did not differ between groups. C18:2omega6/C18:3omega3 ratio was three times higher in diabetics than in controls. Total saturated fatty acids, homocysteine, H(2)O(2) and LDL-thiobarbituric reactive substances significantly increased in microalbuminuric when compared with normoalbuminuric diabetes. Total polyunsaturated fatty acids, arachidonic acid (C20:4omega6), LDL-cholesterol, apo B and creatinine clearance significantly decreased in microalbuminuric when compared with normoalbuminuric diabetes. CONCLUSION: Microalbuminuria onset is associated with renal protein oxidation that is preceded by LDL fatty acid oxidation. The latter is initiated by H(2)O(2) produced from an auto-oxidation of homocysteine and increased metabolism of arachidonic acid towards its pro-inflammatory eicosanoids. An oxidative stress state is the common ground of diffused vasculopathy.

Food Crises and Food Safety Incidents in European Union, United States, and Maghreb Area: Current Risk Communication Strategies and New Approaches.

Globalization has created a dynamic market, which has dramatically intensified interchanges of goods and information as well as the flow of people among nations. This international phenomenon offers the consumer a choice between a wide variety of foods from diverse locations. However, there are challenges to improving food security and safety on a global scale; the major question is how food safety can be guaranteed while increasing the complexity of food supply chains. A food produced in a certain location usually contains ingredients, additives, and preservatives from different and distant origins. Although countries take several food control measures, their institutional and regulatory frameworks diverge widely, as do the definitions of food crisis, food incidents, and risk management approaches. The present review discusses some past food safety issues and lessons learned. Convergences and differences in the regulatory framework of food control agencies in different regions of the world are herein revealed. Emerging risks are also discussed, particularly the spread of antibiotic resistance in the food chain and the environment, as well as the rise of new antibiotic-resistant pathogenic strains with broader tolerance to environmental factors.

How the Addition of Spices and Herbs to Virgin Olive Oil to Produce Flavored Oils Affects Consumer Acceptance.

With the aim to expand the olive oil market to a larger number of consumers who are not familiar with the sensory characteristics of virgin olive oil, the use of novel products known as "flavored olive oils", obtained by adding different kind of spices and aromatic herbs, is spreading in many countries. In order to test consumer acceptability of this type of product, in a country (Tunisia) in which virgin olive oil is regularly consumed, flavored olive oils were prepared by adding aromatic extracts of thyme, oregano, a mix of herbs (used as pizza seasoning), rosemary, and basil to a monovarietal Chemlali virgin olive oil and a consumer test on 206 subjects was performed. Selected quality parameters (free acidity, peroxide number, oxidative stability, specific absorption at K232 nm and K270 nm) were also measured and no significant variations were detected. Slight differences were found concerning the content of minor compounds (chlorophylls, carotenoids and total phenols). On the other hand, notable differences were seen in the profiles of volatile compounds, which appeared to be responsible for the observed variability in consumer acceptance. Although the unflavored oil was more appreciated than the flavored ones, among the latter, thyme flavored olive oil was the most appreciated.

Effects of irrigation regimes on fatty acid composition, antioxidant and antifungal properties of volatiles from fruits of Koroneiki cultivar grown under Tunisian conditions.

The olive tree is generally grown under rain-fed conditions. However, since the yield response to irrigation is great, even with low amounts of water, there is increasing interest in irrigated agriculture. The main goal of this study was, therefore, to investigate the effect of irrigation regimes on olive (Olea europaea L., cv. Koroneiki) obtained from an intensively-managed orchard in a semi-arid area with a Mediterranean climate in Tunisia. Different irrigation treatments 50% ETc, 75% ETc and 100% ETc were applied to the olive orchard. Accordingly, the effects of three irrigation regimes on volatile compounds, fatty acid composition and biological activities of Koroneiki cultivar were studied. The total profile of the volatile constituents of all samples revealed the predominance of 3-ethenylpyridine (from 14.9-19.6%), phenylethyl alcool (from 7.8-19.2%) and benzaldehyde (from 9.0 to 13.8%). During watering level treatments studied, the major fatty acids were oleic, palmitic and linoleic. Antioxidant activity of the fresh fruit volatiles cultivated at a watering level of 100% ETc was higher than that obtained under 50 and 75% Etc. The results of antifungal activity showed that the fruits volatiles of the three irrigation treatments had varying degrees of growth inhibition against the microorganisms tested.

Hypolipidimic and antioxidant activities of virgin olive oil and its fractions in 2,4-diclorophenoxyacetic acid-treated rats.

OBJECTIVE: We examined the effects of extra virgin olive oil (EVOO) and its hydrophilic and lipophilic fractions on serum lipids, oxidative stress, and morphologic and functional liver damages induced by 2,4-diclorophenoxyacetic acid (2,4-D). METHODS: Male Wistar rats were divided randomly into eight groups: control; 2,4-D at a dose of 5 mg/kg of body weight (2,4-D); 2,4-D plus EVOO (2,4-D/EVOO); 2,4-D plus the hydrophilic fraction (2,4-D/OOHF); 2,4-D plus the lipophilic fraction (2,4-D/OOLF); only EVOO (EVOO); only the hydrophilic fraction (OOHF); and only the lipophilic fraction (OOLF). These components were administered daily by gavage for 4 wk. RESULTS: A hepatic architecture aberration, increased activities of aspartate and alanine aminotransferase enzymes, total and low-density lipoprotein cholesterol, and malondialdehyde (MDA) level, and a decreased antioxidant defense system were observed in the 2,4-D group. The administration of EVOO restored the damage caused by 2,4-D by a significant decrease of plasma total and low-density lipoprotein levels and a moderate increase of high-density lipoprotein cholesterol. The 2,4-D/OOHF group exhibited a pronounced enhancement of the antioxidant defense system by an increase of superoxide dismutase, catalase, and glutathione peroxidase levels and a decrease of plasma and liver MDA levels. However, less improvement in the liver histoarchitecture and antioxidant status was observed in rats supplemented with OOLF diet, despite its richness in α-tocopherol. CONCLUSION: Extra virgin olive oil may be a potential functional food source of antioxidants than can decrease the frequency of cardiovascular diseases and liver damage.

Effects of olive oil and its fractions on oxidative stress and the liver's fatty acid composition in 2,4-Dichlorophenoxyacetic acid-treated rats.

BACKGROUND: Olive oil's beneficial effects are not only related to its high content of oleic acid, but also to the antioxidant potential of its polyphenols. In this study, we assess the effects of virgin olive oil and its fractions on 2,4-D- induced oxidative damage in the liver of rats. METHODS: Male Wistar rats were randomly divided into eight groups of ten each: (C) a control group, (D) group that received 2,4-D (5 mg/kg b.w.), (D/EVOO) group treated with 2,4-D plus extra virgin olive oil, (D/OOHF) group that received 2,4-D plus hydrophilic fraction, (D/OOLF) group treated with 2,4-D plus lipophilic fraction, (EVOO) group that received only extra virgin olive oil, (OOHF) group given hydrophilic fraction and (OOLF) group treated with lipophilic fraction. These components were daily administered by gavage for 4 weeks. RESULTS: A significant liver damage was observed in rats treated with 2,4-D via increased serum levels of transaminases and alkaline phosphatase, hepatic lipid peroxidation and decreased hepatic antioxidant enzyme activities, namely, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase. The liver's fatty acid composition was also significantly modified with 2,4-D exposure. However, extra virgin olive oil and hydrophilic fraction intake during 2,4-D treatment induced a significant increase in the antioxidant enzyme activities and a decrease in the conjugated dienes (CD) and thiobarbituric acid-reactive substances (TBARs) levels in the liver. The lipophilic fraction supplemented to 2,4-D- treated rats did not show any improvement in the liver oxidative status while a marked improvement was detected in the hepatic fatty acid composition of rats supplemented with olive oil and the two fractions. CONCLUSION: We concluded that the protective effect of olive oil against oxidative damage induced by 2,4-D is mainly related to the antioxidant potential of its hydrophilic fraction.