Phoenix dactylifera L. seeds: a by-product as a source of bioactive compounds with antioxidant and enzyme inhibitory properties

Date (Phoenix dactylifera L.) seeds are a valuable and abundant by-product with various potential food applications and a source of functional and bioactive ingredients. In this study, date seeds from eight cultivars (Ourous “OUR”, Tazizaout “TAZ”, Tazarzeit “TAR”, Tazoughart “TAG”, Ouaouchet “OUC”, Oukasaba “OUK”, Delat “DEL” and Tamezwertn'telet “TWT”) cultivated in the M'zab oasis (south of Algeria) were analyzed for their chemical and phytochemical compositions, antioxidant capacities and in vitro inhibition of some enzymes. Variations in chemical compositions were observed in the studied date seeds. The greatest contents of total phenolic compounds (476 mg GAE per g dw), total flavonoids (6.52 mg QE per g dw), anthocyanins (1.26 mg Q3GE per g dw), flavonols (3.36 mg Q3GE per g dw), proanthocyanidins (85.13 mg CE per g dw), and ascorbic acid were detected in the seeds of the TAG cultivar. All extracts manifested good antioxidant activities tested by ORAC and FRAP assays. The OUC and OUR extracts displayed the most potent antioxidant capacity against DPPH˙ free radicals (IC50 = 37.30 μg ml−1) and ABTS˙+ cation radicals (IC50 = 13.89 μg ml−1), respectively. The antioxidant activity evaluated through a xanthine/xanthine oxidase system demonstrated that the TAZ extract was more efficient as a superoxide radical scavenger (IC50 = 9.08 μg ml−1). Date seed extracts (DSE) exhibited inhibitory activities on enzymes, showing substantial potential as skin-whitening, neuroprotective, anti-hyperglycemic or anti-hyperlipidemic agents; the inhibitory potential was tested using tyrosinase (TYR), acetylcholinesterase (AChE), α-glucosidase (α-GLU) and lipase. All date seed cultivars were able to inhibit tyrosinase and α-glucosidase in a dose-dependent manner reaching the maximum inhibition

Evaluation of Acute and Subacute Toxicity of Fumaria officinalis Alkaloids in Mice

Background: Fumaria officinalis is largely used in traditional medicine due to its efficiency in the treatment and prevention of numerous diseases and its large spectrum of therapeutic effects. Its multiple beneficial properties are due to its richness in bioactive substances, particularly isoquinoline alkaloids. However, few studies have addressed the toxicity of this plant. Objectives: The present work aimed to study acute and subacute toxicity of alkaloids extracted from F. officinalis using Swiss albino mice as the in vivo model. Methods: Alkaloids from the aerial parts of F. officinalis were extracted and administered to male and female Swiss albino mice. The acute and subacute toxicities were studied by monitoring the weight and histopathological study of animal bodies and organs (e.g., liver, heart, spleen, and kidneys). Results: The results revealed that mice treated with increasing doses developed serious symptoms of toxicity (i.e., respiratory problems, tremors, coma, and paralysis leading the death) and lost weight. The LD50 was estimated at 1341.11 mg/kg permitting its classification as a low-toxic plant. The microscopic observations demonstrated disturbances in the kidney and liver, but not the heart and spleen. Conclusion: The alkaloids of the aerial parts of F. officinalis expressed severe toxicity in mice, particularly at high doses. Nevertheless, the neutral fraction of alkaloids is more indicated

Physicochemical Characteristics and Nutritional Compositions of Some Date (Phoenix dactylifera L.) Fruit Cultivars

A comparative study was carried out for eight mature date fruit cultivars to assess physicochemical and nutritional values. Results showed that fruit and flesh weights and seed sizes indicated wide diversity among studied cultivars. The highest pH, acidity, and ash levels were obtained from Tazizaout and Oukasaba cultivars; protein contents varied from 0.47 (Tazizaout) to 0.31 g/100g DM (Delat), while free amino acids concentrations were found between 1.47 (Oukasaba) and 0.79 g/100g DM (Tazarzeit). Total carbohydrates were ranged from 96.28 to 84.51 g/100g DM. The date is low in fat, the highest concentration was 0.11 g/100g DM. Principal Component Analysis indicated that Ourous and Delat cultivars have specific characteristics and can be distinguished from the other cultivars

Optimization of Peroxidase Activity of Turnip (Brassica rapa) Using Response Surface Methodology

The present study is focused on the determination of optimized activity conditions of peroxidase (POD) of turnip (Brassica rapa). The enzyme is extracted from turnip with 0.5M Na2HPO4 (pH7.0). Peroxidase activity is evaluated by monitoring the oxidation of guaiacol to tetraguaiacol in the presence of hydrogen peroxide (H2O2). Before the optimization of peroxidase activity from a turnip by response surface methodology (RSM), a preliminary step is conducted for each studied parameter (pH, temperature, and NaCl concentration). Further, RSM following Box-Behnken design is used in order to refine the optimization of the conditions. Response surface analysis showed that parameter values with the highest peroxidase activity are 5.9, 29.8°C, and 1.07M for pH, temperature, and NaCl, respectively. Under these experimental conditions, peroxidase activity is found to be 4027.25U/mg. The obtained experimental value agrees with that of the calculated one, indicating the pertinence of the developed model for the optimization of peroxidase activity

Biological control of soft rot induced by Dickeya solani with Trichoderma asperellum on potato tubers: Relationship with susceptibility of variety

Pectobacteriaceae are plant pathogens responsible for serious diseases on many crops of interest including potato. Currently, regarding the several disadvantages of conventional control by chemicals, the application of bio-agents as alternatives is increasingly being explored. The present investigation was conducted in order to evaluate the antibacterial activity of the fungal strain Trichoderma asperellum T34 as an antagonist against phytopathogen Dickeya solani on tubers of three potato varieties (Agata, Monalisa, and Picobello). For this, half-tubers were inoculated by T34 suspension with concentrations of 10 3 and 10 5 cells mL −1 at 6, 9, and 12 h before bacterial infection ( D. solani at concentrations of 10 7 and 10 8 cfu mL −1 ). The results of infection assays without the antagonist indicated that Picobello variety was the least sensitive to soft rot, Monalisa and Agata varieties showed medium and high sensitivity, respectively. The antagonism assays revealed strong antibacterial activities, manifested by the regression of softened tissues gradually with the time of preincubation with T34, leading to a complete disappearance of disease symptoms using 12 h. Hence, the application of antagonistic Trichoderma strains as antimicrobial agents in the control of harmful plant pathogens is a subject of great interest and can be considered a promising strategy to handle soft rot diseases

Effects of sun-drying on physicochemical characteristics, phenolic composition and in vitro antioxidant activity of dark fig varieties

peer reviewedThe aim of this investigation was to study the effects of sun-drying on some physicochemical parameters, phenolic profiles, and antioxidant activities of three dark fig varieties. Sun-drying led to a decrease of weight and moisture content, an increase of sugar content, but not affect acidity. HPLC analysis revealed the presence of 22 phenolic compounds (14 phenolic acids and 8 flavonoids), including eight compounds that were detected for the first time. Phenolic acid contents decreased after sun-drying by about 29%, except cinnamic and gallic acids that were increased. Fresh dark fig contained high levels of flavonoids, particularly cyanidin 3-rutinoside and quercetin 3-rutinoside; sun-drying caused decrease in flavonoid contents by about 86%. There are a lot of antioxidant bioactive components besides the phenolic compounds as studied in this work; therefore, the reduction of phenolic compound content by sun-drying could mainly contribute to the reduction of antioxidant activity of the dark figs

Valorization of date palm biodiversity: physico‐chemical composition, phenolic profile, antioxidant activity, and sensory evaluation of date pastes

3 Figuras.-- 4 TablasThis work is a contribution to the valorization of the Algerian date palm agrobiodiversity by studying some nutraceutical properties of date pastes from less important cultivars. A commercial date paste, prepared from Ghars variety, was compared to two date pastes prepared from the secondary cultivars Tamjouhert and Tazarzeit. Physico-chemical characteristics, phenolic profile (HPLC-DAD), and antioxidant activity were assessed for both date fruits and pastes. The sensory evaluation of date pastes was conducted through triangular, ranking, and hedonic tests. The results revealed that the transformation of date fruits into pastes caused a significant increase in phenolic content and antioxidant capacity, a decrease in sugar content in parallel with the appearance of hydroxymethylfurfural and furfural. The elaborated date pastes were characterized by a relatively low level of sugar (72.17–74.14 mg/100 g), a high amount of phenolic compounds (> 290 mg/kg DW), and a potent antioxidant activity. Seventeen phenolic compounds were identified by HPLC with global quantities for date fruits of 113 (Tamjouhert cv.) and 100 mg/kg DW (Tazarzeit cv.) and that were increased twofold after transformation to date pastes. The sensory analysis for the obtained date pastes indicated high scores of acceptability in comparison with the commercial paste. The obtained results showed clearly that these secondary cultivars possess several potentialities; this may help to valorize them by turning a part of their production into several added-value products such as date past.The authors are grateful to the Algerian Ministry of Higher Education and Scientific Research for the financial support, especially the General Direction of Scientific Research and Technological Development and to the date palm producers’ association at M’zab Valley. This research was also supported by the Spanish Ministry of Economy and Competitiveness and co-funded by a European Social Fund (ESF) (project AGL2016-79088R) and the Spanish Ministry of Economy and Competitiveness Ramon y Cajal Programme (RyC 2012–10456).Peer reviewe

Comparative Study of Fig Volatile Compounds Using Headspace Solid-Phase Microextraction-Gas chromatography/Mass Spectrometry: Effects of Cultivars and Ripening Stages

Aroma is one of the essential parameters that determine fruit quality. It is also an important feature of varietal characterization and so valuable for agro-biodiversity identification and preservation. In order to characterize changes in the aroma fingerprint through fig development, the main objective of the present research was to study the volatile organic compound (VOC) profiles of figs (Ficus carica L.) from three cultivars, Taamriwthe (TH), Azegzaw (AZ), and Averkane (AV), at three ripening stages (unripe, ripe, and fully ripe). Analyses was performed using Headspace Solid-phase Microextraction and gas chromatography coupled with mass spectrometry. Results revealed the presence of 29 compounds that were grouped into different chemical classes. Aldehydes comprised the most abundant VOCs identified in all the studied figs, while alcohols, ketones, and terpenes comprised the minor compounds found in TH, AZ, and AV figs, respectively. Different aroma descriptors were identified throughout the ripening stages of figs; fruity and green aromas were dominant in all cultivars, while a fatty aroma scarcely occurred in figs. A gallery plot representation demonstrated that certain VOCs differentiate the studied cultivars and the different ripening stages of figs. Principal component analysis findings demonstrated characteristic VOCs of distinct ripening stages and cultivars, those VOCs can be used as fingerprints to distinguish different cultivars and/or ripening stage

A Sustainable Extraction Approach of Phytochemicals from Date (<i>Phoenix dactylifera</i> L.) Fruit Cultivars Using Ultrasound-Assisted Deep Eutectic Solvent: A Comprehensive Study on Bioactivity and Phenolic Variability

The present study aimed to evaluate the efficacy of natural deep eutectic solvents (NADESs) on the extraction of phytochemicals from eight Algerian date fruit cultivars (Phoenix dactylifera L.). In this study, lactic acid/sucrose-based NADESs were used as an alternative to conventional chemical solvents using the ultrasound-assisted extraction (UAE) method. The obtained extracts were assessed for the determination of bioactive compound contents, phenolic composition, antioxidant activity, and enzyme inhibitory potential. The results showed a considerable variation in phytochemical compositions and related activities between cultivars, where the greatest contents of total phenolics (1288.7 mg GAE/100 g), total flavonoids (53.8 mg QE/100 g), proanthocyanidins (179.5 mg CE/g), and total triterpenoids (12.88 mg OAE/100 g) were detected in the fruits of the Ourous cultivar. The same cultivar displayed the highest antioxidant capacity against DPPH• free radical (595 mg AAE/100 g), ABTS•+ cation radical (839 mg TE/100 g), and ferric reducing antioxidant potential (704 mg AAE/100 g). All extracts manifested moderate antioxidant activities tested by phosphomolybdenum, NO•, and linoleic acid lipid peroxidation assays. These extracts also exhibited interesting levels of in vitro enzyme inhibition; the Ourous cultivar gave the best inhibitory activity against α-amylase and acetylcholinesterase with 45 and 37%, respectively. HPLC-DAD-MS detected a total of five compounds, with phenolic acids and flavonoids being the main phenolics identified in the extract. The phenolic composition exhibited significant variability among cultivars. Notably, the highest amounts were revealed in the Tazizaout cultivar, with the predominance of gallic acid. The results confirmed that the combination of UAE and NADESs provides a novel and important alternative to chemical solvents for sustainable and environmentally friendly extraction and can represent a good alternative in food and pharmaceutical industry applications

Phenolic profile, antioxidant activity and enzyme inhibitory capacities of fruit and seed extracts from different Algerian cultivars of date (Phoenix dactylifera L.) were affected by in vitro simulated gastrointestinal digestion

The aim of the present study was to evaluate the influence of the digestive process (gastric and intestinal phases) on the stability of the individual and total phenolic (TPC) and flavonoid (TFC) contents, antioxidant activity and enzymes inhibitory potential of extracts from date fruits (pulp) and seeds from eight Algerian cultivars of date palm (Phoenix dactylifera). The obtained results showed a considerable increase in the TPC for both samples when exposed to digestion conditions. The TFC was higher after gastric digestion compared to intestinal digestion. Along the digestion process, the release of individual phenolics (phenolic acids and flavonoids) analyzed by ultra-high-performance liquid chromatography (UHPLC) showed different behavior in seed and fruit extracts. The digestion increased the scavenging of 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and peroxyl (oxygen radical absorbance capacity, ORAC) radicals in both samples. However, ferric reducing antioxidant power (FRAP) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging capacity were reduced in date seed extracts, while the fruit extracts showed an increase at the end of digestion process. The enzymes inhibitory potential of date seeds extracts decreased after digestion and was maintained or enhanced in fruit extracts. Thus, it seems that the date fruit extracts had more bioaccessible components compared to seed extracts. (C) 2020 SAAB. Published by Elsevier B.V. All rights reserved.Algerian Ministry of Higher Education and Scientific Research; Laboratoires Hors Murs (Montpellier, France); project INTERREG - MD.NET: When Brand Meets People; FCT - Foundation for Science and TechnologyPortuguese Foundation for Science and Technology [UIDB/05183/2020]; FCTPortuguese Foundation for Science and TechnologyEuropean Commission [SFRH/BD/145243/2019, DL 57/2016/CP1361/CT0022