Carotenoids, Phenolic Profile, Mineral Content and Antioxidant Properties in Flesh and Peel of Prunus persica Fruits during Two Maturation Stages

Carotenoids and phenolic profile, antioxidant activity as well as concentrations of selected macronutrients (K, N, Mg, Ca and Na) and micronutrients (Zn, Cu and Mn) in flesh and peel of peach fruit were recorded at two harvest dates. Predominant mineral was potassium, followed by calcium, magnesium and sodium. The concentration of most micronutrients was greater in the peel than in the flesh especially in early season. The concentration of most elements in flesh and peel decreased during fruit maturation. Total carotenoids content varied with respect to the cultivar. β-cryptoxanthin and β-carotene were the major carotenoids in both tissues and flesh contain the lowest amounts. Neochlorogenic acid, chlorogenic acid, catechin, epicatechin, gallic acid, rutin, quercetin-3-O-galactoside, cyanidin-3-O-glucoside, cyanidin-3-O-rutinoside, were detected in both peel and flesh, with chlorogenic acid and catechin being the predominant components. Peel extracts showed markedly higher antioxidant activities, when estimated by ABTS or DPPH assays, than the flesh counterparts, consistent with the observed higher phenolic content. Overall, total phenolics levels increased at full ripening stage in both peel and flesh. The results found herein provide important data on carotenoids, phenolic and macro- and micronutrient changes during fruit growth, and emphases peach fruit as a potential functional food

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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.</p> <p>Conclusion</p> <p>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.</p

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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.</p> <p>Conclusion</p> <p>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.</p

Evaluation of Pigments, Phenolic and Volatile Compounds, and Antioxidant Activity of a Spontaneous Population of Portulaca oleracea L. Grown in Tunisia

Portulaca oleracea L., commonly known as purslane, is a weed with worldwide distribution and considerable medicinal uses due to its high levels of phytochemical compounds. However, until now, few studies have been conducted on the biochemical characterization of P. oleracea grown in Tunisia, a possible area of its origin as other North African countries. Therefore, the aim of the present study was to determine the phytochemical composition and antioxidant potential of leaves and stems from a Tunisian spontaneous population of purslane. Particularly, samples were analyzed for their proximate composition, pigments, and volatiles, whereas ethanolic and aqueous extracts were evaluated for their composition in phenolic compounds and in vitro antioxidant activities. Stems showed higher content of moisture (89.9%) and anthocyanins (4.61 &micro;g g&minus;1 dry matter, DM), whereas leaves revealed higher chlorophyll concentrations (7.42 mg g&minus;1 DM). Significantly higher levels of phenolic compounds and antioxidant capacities (p &lt; 0.05) were obtained in ethanolic extracts, compared with water extracts, irrespective of the analyzed plant part. A high antioxidant activity of stems was obtained, especially when extracted with ethanol. Headspace gas chromatography-mass spectrometry (GC-MS) analyses revealed six volatile classes with monoterpene hydrocarbons, oxygenated monoterpenes, and non-terpene derivatives as the highly represented compounds. Limonene (17.3&ndash;32.2%), carvone (38&ndash;46%), 2,6-dimethylcyclohexanol (2.2&ndash;6.4%), and nonanal (3.4&ndash;3.8%) were the most abundant volatiles. Based on the results of the present study, Tunisian purslane should deserve major consideration as an edible vegetable due to its richness in phytochemical compounds and, hence, for its potential health effects

Perspective of dental medicine students learning in remote biochemistry laboratories during COVID-19

Students at the Monastir Faculty of Dental Medicine were required to remain inside during the COVID-19 pandemic for their own safety and in accordance with official directives. It is evident that learners’ perceptions are a recognized indicator of the efficiency of any teaching approach. Therefore, we focused on students' input on the validity of online biochemistry laboratories to assure their preferences with the finest teaching approaches. The study included 116 undergraduate dental students from the Faculty of Dental Medicine of Monastir. The survey has 40 questions. This investigation covered (i) information technology tool accessibility, (ii) course presentation, interactions in a virtual classroom, teachers’ availability, and (iii) preferred learning styles. The percentages were then determined for each item and assessed. Our results showed that almost students were equipped with computers, smartphones and tablets but have encountered some connectivity issues. Moreover, participants find courses well presented, approved class interactions, and were satisfied with teachers’ availability. Nevertheless, students were not already prepared for entirely online learning. Despite, the overall positive perception among students toward remote education during the COVID-19 outbreak; they preferred considering shared learning between face-to-face and online once the pandemic is over

Phytochemical Compounds from the Crop Byproducts of Tunisian Globe Artichoke Cultivars

The phytochemical composition in two Tunisian globe artichoke cultivars (bracts, leaves, and floral stems) was evaluated in the plant byproducts. The results indicated that the bracts contain the highest levels of total phenols, o-diphenols, and flavonoids, whereas tannins seem to be more abundant in the leaves. Bracts from the 'Violet d'Hyères' cultivar possessed more total phenols (160.8 mg/g DW), flavonoids (64.9 mg/g DW), and anthocyanins (15.3 μg/g DW) than the 'Blanc d'Oran' bracts (134.5 mg/g DW, 51.2 mg/g DW, and 8.3 μg/g DW, resp.). Sixty-four volatile compounds were identified in the headspace of globe artichoke material, particularly in the bracts. The volatile profile showed that sesquiterpene hydrocarbons and non-terpene derivatives were the main volatiles emitted by the bracts in both cultivars. These results suggest that globe artichoke byproducts might represent a potential source of natural compounds, which could be used as nutraceuticals or as ingredients in the design of functional foods

Biochemical characterization and antioxidant activities of the edible part of globe artichoke cultivars grown in Tunisia

A renewed interest was observed recently in the globe artichoke as a promising source of polyphenols, a heterogeneous class of secondary metabolites characterized by various well-documented healthy properties. However, only few studies characterized Tunisian cultivars. Therefore, the present study aimed at evaluating the chemical parameters [fatty acids (FA), volatiles and phenolic derivatives content] in the edible part, the receptacle, of two globe artichoke cultivars (‘Violet d’Hyéres’ and ‘Blanc d’Oran’), including their antioxidant activities. FA profiles of the receptacles showed that the most abundant acids were linoleic and palmitic ones. Forty-one volatile compounds, accounting for 97.6 - 96.3% of the receptacle aroma emission were identified. Sesquiterpenes hydrocarbons represented the main chemical class, in particular β-selinene followed by β-caryophyllene reached the highest levels in ‘Violet d’Hyéres’ (48.7% and 14.5%, respectively). Total phenols and tannins (P ≤ 0.05), o-diphenols and flavonoids (P ≤ 0.01) were significantly higher in the receptacles of ‘Violet d’Hyéres’ cultivar (73.0, 17.2, 15.4 and 12.2 mg 100 g−1 of fresh weight, respectively). The antioxidant activity was notably phenolic derivatives content-dependent where the higher values were observed in ‘Violet d’Hyéres’ cultivar. Results suggested that globe artichoke receptacles could represent a good source of health-promoting polyphenols with high antioxidant activity and this fact could encourage their consumption. Further investigations are needed to evaluate the variation of the considered compounds in other Tunisian cultivars

Changes in biochemical compounds in flesh and peel from Prunus persica fruits grown in Tunisia during two maturation stages.

Plants can synthesize tens to hundreds of thousands of primary and secondary metabolites with diverse biological properties and functions. Fatty acids (FA), phenolic compounds (PC) and volatile compounds (VC) of flesh and peel from three Prunus persica cultivars were evaluated at the Regional Centre of Agricultural Research - Experimental Farm (Sidi Bouzid, Tunisia) during two maturation stages. Palmitic, oleic and linoleic acids are the most abundant FA in Prunus persica cultivars. A genetic effect on FA composition was observed throughout the two sampling periods. Peel was rich in oleic acid with the highest content (31.3% on total FA) in 'O'Henry' cultivar at the commercial ripening date; flesh was rich in linoleic acid with the highest content (44.7% on total FA) in 'Sweet Cap' cultivar at the full ripening date. The monounsaturated/polyunsaturated fatty acids ratios were higher in the commercial ripe than in the full ripe fruits. The analysis of the composition of the VC led to the characterization of 98 different compounds, showing a very high variability among the cultivars. The full ripe fruit (peel and flesh) exhibited the highest total number of terpenoids. Commercial ripe peels were richest in the percentage of hydrocarbons. Comparing cultivars, 'Sweet Cap' cultivar showed the lowest contents of alcohols in peel and flesh of full ripe fruit but highest in peel of commercial ripe fruit, and lowest content of aldehydes in peel and flesh of commercial ripe fruit but highest in peel of ripe ones and the highest ones of lactones. Among PC, the highest contents were observed for o-diphenols and the values showed varietal influence. Total phenols contents decreased during ripening process (p < 0.05) in both peel and flesh tissues, except found for 'Sweet Cap' cultivar. In conclusion, to achieve better FA composition and greater VC and PC production of the peach fruit, P. persica cultivars should be harvested at the commercial ripening date

Effect of three irrigation regimes on Arbequina olive oil produced under Tunisian growing conditions

This study investigated the effect of irrigation amount on the concentration of phenolic compounds in olive (Olea europaea L., cv. Arbequina) oil 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. Oil quality, evaluated using the parameters established to determine the quality level of virgin olive oils (acidity, K232, K270 and peroxide index) was slightly affected by irrigation. However, results showed that irrigation positively affected both fruit and oil quality. In fact, the least irrigation regime (T1), showed a significantly higher content of oleic acid (70.08%), whereas olive oils from more irrigated trees (T2 and T3) had higher contents of palmitic acid (11.64% and 13.14%, respectively) and lower of linoleic acid (approximately 12.7%). However, content of phenolic compounds (hydrophilic and lypophilic), in the oils extracted, strongly differed. In fact, different irrigation regimes applied not only affected the total amount of phenols which were proportional to irrigation (193.2 and 271.87mgkg-1 for T1 and T3, respectively) except for T2 but also their HPLC profiles. Contrarily to phenols, insignificant differences were observed in the concentration of [alpha]-tocopherol between the irrigation treatments studied.Fatty acids Virgin olive oil Phenols Pigments [alpha]-Tocopherol Sensory analysis Irrigation

Prunus persica by-products: A source of minerals, phenols and volatile compounds

Large amounts of peach (Prunus persica) leaves and stems are by-products deriving from peach tree cultivation and canned industries. This work aimed to evaluate mineral nutrients, phenolic and volatile profile and anti- oxidant activities from the by-products of five peach cultivars (Early Maycrest, Sweet Cap, O’Henry, Flordastar and Rubirich). Minerals showed significant variations with respect to peach by-product. N showed higher contents in peach leaves among macronutrients, while Mn showed higher contents among micronutrients. Stems had high levels of Ca and traces of micronutrient levels. The HPLC-DAD phenols analysis showed twelve compounds identified (neochlorogenic and chlorogenic acids, catechin and epicatechin, gallic, caffeic, syringic, ferulic and coumaric acids, quercetin-3-rutinoside, quercetin-3-galactoside, cyanidin-3-glucoside, cyanidin-3-galactoside). Flavonols showed the highest values (quercetin-3-galactoside with 70.79–232.16 mg 100g-1 DW, quercetin-3-rutinoside with 63.88–206.37 mg 100g-1 DW), while the least content was observed for anthocyanins. Cultivar had a sig- nificantly (P &lt; 0.05) impact on phenolic compounds. Comparing by-products, stems showed higher levels of phenols. The GC-MS volatile compounds analysis revealed 43 compounds in different percentages and occur- rences, depending on the cultivar and the by-product. Benzaldehyde was detected as the major volatile leaf component (70–95%), whereas myrcene (18–21%) and terpinolene (18–26%) were found to be the most im- portant compounds in stems. Methanolic extracts of mature leaves were characterized by lower antioxidant capacity. Finally, peach by-products could represent a natural source of minerals, volatiles and phenolic com- pounds with high antioxidant activities having a great potential use in food products as natural flavouring agents and as nutraceutical supplements and pharmaceutical and cosmetic molecules