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Research background. Microalgae represent an emergent sustainable source of bioactive compounds such as antioxidants, vitamins, minerals and polyunsaturated fatty acids that can ameliorate the nutritional characteristics of foods. The biochemical composition of microalgae could be modulated by varying the culture conditions to enhance the accumulation of biomolecules of interest. The aim of this work is to optimise the nutri-functional properties of two microalgae that can be used in food production. Experimental approach. Nannochloropsis gaditana L2 and Chlorella sp. SM1 were screened for growth, biochemical composition and radical scavenging activity employing four different growth media (algal, BG-11, f/2 and Conway) with different nutrient composition. The feasibility of using Chlorella sp. SM1 cultivated in BG-11 medium, in an under-investigated Mediterranean dairy product ricotta cheese and its effect on the sensory attributes was investigated. Additionally, Arthrospira platensis was used as reference in sensory analysis. Results and conclusions. Nitrate- and phosphate-rich media (BG-11 and algal) enhanced the biomass productivity. However, the highest lipid production (23.10 and 11.86 mg/(L·day) by strains SM1 and L2 respectively) and carbohydrate content (34.79 and 44.84% by SM1 and L2 respectively) were obtained with the nitrate-deficient f/2 medium. Regardless of the used medium, the lipid profile of Chlorella sp. SM1 and N. gaditana L2 remained adequate for different applications with >50% C16-18 as the main fatty acids. Significant increase in oleic acid (C18:1) content was recorded in response to nitrogen deficiency, being the highest in SM1 in f/2 medium (34%). Nitrogen deficiency was also found to enhance phenolic compound (expressed as gallic acid equivalents, 48.8 and 35.1 mg/g in SM1 and L2 respectively) and carotenoid contents (2.2 and 2.0 mg/g in SM1 and L2 respectively). Due to its interesting antioxidant potential, Chlorella sp. SM1 was used at different mass fractions (0.2, 1 and 1.5%) to enrich the ricotta cheese. The sample with 0.2% Chlorella sp. SM1 was found to give the most appreciated product. Novelty and scientific contribution. This study presents the production of an innovative ricotta cheese using Chlorella sp. as a functional ingredient, without altering the manufacturing procedure, while maintaining acceptable sensorial characteristics. The biochemical composition of the used strains varied depending on the culture medium composition, which enabled the accumulation of phytonutrients of interest., Pozadina istraživanja. Mikroalge su sve češći održivi izvor bioaktivnih spojeva, poput antioksidansa, vitamina, minerala i polinezasićenih masnih kiselina, kojima se mogu poboljšati nutritivna svojstva hrane. Biokemijski se sastav mikroalgi može izmijeniti promjenom sastava podloge za uzgoj, s ciljem povećanja prirasta željenih biomolekula. Svrha je ovoga rada bila optimirati hranjiva i funkcionalna svojstva dviju vrsta mikroalgi koje se mogu primijeniti u proizvodnji hrane. Eksperimentalni pristup. Analizirani su rast, biokemijski sastav te sposobnost uklanjanja slobodnih radikala mikroalgi Nannochloropsis gaditana L2 i Chlorella sp. SM1 uzgojenih u četiri podloge različitog sastava (hranjiva podloga za uzgoj algi, BG-11, f-2 i hranjiva podloga Conway). Ispitana je mogućnost primjene alge Chlorella sp. SM1 uzgojene u BG-11 podlozi u proizvodnji sira tipa ricotta, mediteranskog mliječnog proizvoda koji je slabo istražen, te njezinog utjecaja na senzorska svojstva sira. Uz to, mikroalga Arthrospira platensis upotrijebljena je za izradu kontrolnog uzorka za senzorsku analizu. Rezultati i zaključci. Proizvodnja se biomase povećala u podlogama bogatim nitratima i fosfatima (BG-11 i hranjiva podloga za uzgoj algi). Međutim, najveća proizvodnja lipida (dnevno 23,10 mg/L u soju SM1 i 11,86 mg/L u soju L2) i najveći udjel ugljikohidrata (34,79 % u soju SM1 i 44, 84 % u soju L2) postignuti su uzgojem u podlozi f/2 siromašnoj nitratima. Bez obzira na sastav podloge, sastav lipida u mikroalgama Chlorella sp. SM1 i N. gaditana L2, s više od 50 % C16-18 kao glavnim masnim kiselinama, bio je prikladan za različite primjene. Nedostatak dušika doveo je do znatnog povećanja udjela oleinske kiseline (C18:1), i to najviše u soju SM1 uzgojenom u podlozi f/2 (34 %). Također su opaženi povećani udjeli fenolnih spojeva (48,8 mg/L u soju SM1 i 35,1 mg/g u soju L2, izraženo kao ekvivalent galne kiseline) i karotenoida (2,2 mg/g u soju SM1 i 2,0 mg/g u soju L2). Zbog svog zanimljivog antioksidacijskog potencijala, mikroalga Chlorella sp. SM1 primijenjena je u različitim masenim udjelima (0,2; 1 i 1,5 %) za obogaćivanje sira tipa ricotta. Proizvod s najboljiim karakteristikama dobiven je s dodatkom 0,2 % ove mikroalge. Novina i znanstveni doprinos. U radu je prikazana proizvodnja novog sira tipa ricotta s dodatkom mikroalge Chlorella sp. kao funkcionalnim sastojkom, pri čemu se nije mijenjao postupak proizvodnje, a zadržane su prihvatljive senzorske značajke sira. Biokemijski je sastav korištenih sojeva mikroalgi ovisio o sastavu hranjive podloge, pa je time bilo moguće povećati proizvodnju željenih fitonutrijenata.

Background The in vitro activity of the brown seaweed Dictyota spiralis against both Leishmania amazonensis and Trypanosoma cruzi was evaluated in a previous study. Processing by bio-guided fractionation resulted in the isolation of three active compounds, classified as diterpenes. In the present study, we performed several assays to detect clinical features associated to cell death in L. amazonensis and T. cruzi with the aim to elucidate the mechanism of action of these compounds on parasitic cells. Methods The aims of the experiments were to detect and evaluate specific events involved in apoptosis-like cell death in the kinetoplastid, including DNA condensation, accumulation of reactive oxygen species and changes in ATP concentration, cell permeability and mitochondrial membrane potential, respectively, in treated cells. Results The results demonstrated that the three isolated diterpenes could inhibit the tested parasites by inducing an apoptosis-like cell death. Conclusions These results encourage further investigation on the isolated compounds as potential drug candidates against both L. amazonensis and T. cruzi. Graphical Abstract

In the last decades, the consumption of whole wheat has increased because consumers’ awareness has increased toward healthy food. However, breeders’ focus was always attributed to the major components of wheat, but less attention was paid to micronutrients. The aim of this study was to provide new insights on the influence of breeding on total polyphenol content (TPC), phenolic profile, and total antioxidant capacity (TAC) using a set of Tunisian durum wheat landraces, old and modern varieties. Ultra-liquid chromatography multi-stage mass spectrometry (UHPLC–MSn) allowed the identification of eight phenolic acids, which were found in the bound form, while only p-coumaric acid was found in the free form. A significant genotype effect on the TPC (bound, free and total), TAC, and phenolic acid profile was observed. Regarding breeding effect, TPC concentrations were in the order modern > landraces > old. Principal component analysis (PCA) confirmed that the phenolic profile of the studied varieties was mainly conditioned by their genotypic characteristics, and no trend was observed as a function of breeding history. Likewise, clustering analysis highlighted an important genetic diversity, suggesting that the modern variety ‘‘Om Rabia’’ possesses the most interesting phenolic profile. These findings might be useful to breed genetically different and phenolic-rich new varieties.

The aim of this work is to study the extraction of the essential oil as a process that appeared to obtain the bioactive substances among the several extraction processes. A great number of extraction processes are available. In this study, the recent processes were compared with the conventional ones. Also, the economic evaluation of the extraction process plant including energy cost, manual labor, raw materials, and fixed costs were studied. We assessed the costs involved in the extraction process of the bioactive compounds. Carbon dioxide is the most desirable solvent for Supercritical Fluid Extraction (SFE). Its attraction for the extraction of the heat-sensitive compounds is due to its critical temperature (304 °K). Solvent extraction and steam distillation process (SE‒SD) may overcome many disadvantages that conventional solvent extraction and hydrodistillation bring about in the extraction of essential oil. This combination technology has been used in the extraction of essential oil from plant material for high quality, simple technology, and low cost. The microwave assisted hydro-distillation (MAHD) is less tedious and minimizes the risk of the compound degradation at high temperatures. The MAHD presents distinct advantages for the fast and reproducible production process. The study of the ultrasound-enhanced subcritical water extraction process (USWE) showed many advantages such as: time-saving, environment-friendliness, and high efficiency.

The main concern of this work was to find a new biological antisprouting product for potatoes during storage. Ruta chalepensis L. essential oil (RCEO) was for the first time used as a potential sprouting inhibitor for potatoes. To confirm RCEO antisprouting effect, evolution of sprout length and weight loss of potato tubers was determined during a storage period of six weeks under three RCEO different treatments (2%, 4%, and 6%). Sprout final weight was also computed. Then, a screening of RCEO chemical composition was performed. An outstanding antisprouting effect of 6% emulsions concentrations was observed as compared to 2% and 4% emulsions concentrations. Final sprout weight (SW) of untreated samples was 4.66%, while 6% treated samples scored 0.98%. These results were endorsed by high Pearson correlation coefficients (>0.9). Indeed, increasing treatment concentration enhanced the sprout growth inhibition. Identification of RCEO major components showed that 2-undecanone represented 87.18% of total identified components suggesting that this component is the possible active agent of RCEO against potatoes sprouting.

The aim of this study was to compare immunogenic and toxic gluten peptides related to celiac disease (CD). 100 accessions of genotypes selected during the 20th century in Tunisia were in vitro digested and then analyzed by UPLC/ESI-MS technique using an isotopically labeled internal standard. The first MANOVA confirmed a high variability in the content of immunogenic and toxic peptides reflecting high genetic diversity in the germplasm released during the past century in Tunisia, consistently with PCA and clustering analysis results. Our finding showed also important variability in CD epitopes due to growing season's climate scenarios. Moreover, the second MANOVA revealed significant differences between abandoned and modern cultivars' CD-related peptide amounts. Although we could not conclude that there was an augment of allergens in newly selected durum wheat lines compared to abandoned ones, we demonstrated that modern genotype peptides were less sensitive to climate variation, which is a useful indicator for wheat breeders.

The present work had a dual objective: to assess if the evolution of durum wheat from landraces to modern genotypes as function of breeding programs impacted proteins and starch fractions, as well as starch properties. Flours and starches isolated from Tunisian durum wheat landraces, old and modern lines were thoroughly characterized for their compositional, morphological, and gel properties. Statistical results showed significant (p ≤ 0.05) differences among the studied set. Protein and starch fractions assessment revealed that modern genotypes had the highest total starch and albumin contents, old genotypes had the highest amylose and glutenin contents, and landraces had the highest protein and gliadin contents. Starch properties screening allowed several findings: no significant (p > 0.05) differences were found among starch granules morphology, significant (p ≤ 0.05) differences were recorded in terms of technological properties, and old genotypes had the highest starch gel hardness. Overall, these results indicated that the influence of genotype on flour and starch properties was more relevant than breeding history.

Leishmaniasis represents a serious threat to the health as one of the most important neglected tropical diseases as designated by the World Health Organization. The disease is endemic in 82 countries, among them Tunisia is an indigenous area for cutaneous Leishmaniasis. In a previous work, two tritepenic acids namely oleanolic and maslinic acids have been isolated from olive leaf extract. In the present paper, the in vitro activity against amastigotes stage of Leishmania (L.) infantum and Leishmania (L.) amazonensis was investigated. Maslinic acid showed the highest activity, against L. amazonensis, with an IC50 of 1.417 ± 0.401 µg/mL and a selectivity index of 9.405. Although, the oleanolic acid exhibit a better activity against L. infantum with an IC50 of 0.999 ± 0.089 µg/mL and selectivity index of 8.111.

In this study, milk thistle seeds growing in different areas in Tunisia were cold pressed and the extracted oils were examined for their chemical and antioxidant properties. The major fatty acids were linoleic acid (C18:2) (57.0%, 60.0%, and 60.3% for the milk thistle seed oils native to Bizerte, Zaghouan and Sousse, respectively) and oleic acid (C18:1) (15.5%, 21.5%, and 22.4% for the milk thistle seed oils originating from Bizerte, Zaghouan and Sousse, respectively). High performance liquid chromatography (HPLC) analysis showed the richness of the milk thistle seed oils (MTSO) in α-tocopherol. The highest content was recorded for that of the region of Zaghouan (286.22 mg/kg). The total phenolic contents (TPC) of Zaghouan, Bizerte, and Sousse were 1.59, 8.12, and 4.73 Gallic Acid Equivalent (GAE) mg/g, respectively. Three phenolic acids were also identified (vanillic, p-coumaric, and silybine), with a predominance of the vanillic acid. The highest value was recorded for the Zaghouan milk thistle seed oil (83 mg/100 g). Differences in outcomes between regions may be due to climatic differences in areas. Zaghouan’s cold-pressed milk thistle seed oil had a better quality than those of Bizerte and Sousse, and can be considered as a valuable source for new multi-purpose products or by-products for industrial, cosmetic, and pharmaceutical utilization.

6cfu/g of mesophilic aerobic bacteria (MAB). Lactic acid bacteria (LAB) and yeasts dominated the microflora of these samples. They varied from 10 5 to 10 8 cfu/g. The LAB/yeasts ratio arising from microbial counts were varied between 1/1 and 200/1. More than 50% of the analysed samples were deprived of Enterococcus. The content of contaminating microflora like coliforms and mesophilic Bacillus ranged from 10 2 to 10 4 cfu/g. The ratio

Therapy against Acanthamoeba infections such as Granulomatous Amoebic Encephalitis (GAE) and Acanthamoeba Keratitis (AK), remains as an issue to be solved due to the existence of a cyst stage which is highly resistant to most chemical and physical agents. Recently, the activity of Olive Leaf Extracts (OLE) was demonstrated against Acanthamoeba species. However, the molecules involved in this activity were not identified and/or evaluated. Therefore, the aim of this study was to evaluate the activity of the main molecules which are present in OLE and secondly to study their mechanism of action in Acanthamoeba. Among the tested molecules, the observed activities ranged from an IC50 of 6.59 in the case of apigenine to an IC50 > 100 μg/ml for other molecules. After that, elucidation of the mechanism of action of these molecules was evaluated by the detection of changes in the phosphatidylserine (PS) exposure, the permeability of the plasma membrane, the mitochondrial membrane potential and the ATP levels in the treated cells. Vanillic, syringic and ursolic acids induced the higher permeabilization of the plasma membrane. Nevertheless, the mitochondrial membrane was altered by all tested molecules which were also able to decrease the ATP levels to less than 50% in IC90 treated cells after 24 h. Therefore, all the molecules tested in this study could be considered as a future therapeutic alternative against Acanthamoeba spp. Further studies are needed in order to establish the true potential of these molecules against these emerging opportunistic pathogenic protozoa.

Background Thymus algeriensis Boiss. et Reut. (Lamiaceae), popularly known as “mougecha” or “mazoukcha” is prolific in Mediterranean regions, mostly in North Africa, and is used in folk medicine to treat of stomach diseases. Methods In this study, animals were induced with gastric ulcers using HCl/ethanol (0.3 M HCl/60% ethanol) and treated orally with essential oil of Thymus algeriensis (EOTa) in various doses ranging from 54 mg/kg body weight to 180 mg/kg body weight. Result The dose found to be effective was 180 mg/kg body weight, since this dose brought about a maximum reduction in lesion index in female rats. In gastric tissues, levels of total glutathiones (GSH, GST and GPx) and thiobarbituric acid reactive substances (TBARS) were evaluated. The activities of the antioxidant enzymes, catalase (CAT) and superoxide dismutase (SOD) were measured. Histopathological changes were observed using a cross section of gastric tissue. Chemical analysis revealed the presence of 13 components accounting for 77.7% of the essential oil from dried leaves. Oral administration of EOTa (54, 117 and 180 ml/kg) inhibited HCl/ethanol-induced ulcers. Lesion index was significantly reduced in ulcer induced animals treated with EOTa (HCl/ethanol + EOTa) compared to those ulcerated with HCl/ethanol but with no treatment given. Females showed a greater resistance to ulcers and gastric lesions occurred less often than in males. GSH, pH, enzymic antioxidants, and adherent mucus content were all significantly increased. Conclusion From the data presented in this study, it can be concluded that male rats are more sensitive to gastric ulcers induced by HCl/ethanol than females.

Protozoan diseases, such as leishmaniasis, are a cause of considerable morbidity throughout the world, affecting millions every year. In this study, two triterpenic acids (maslinic and oleanolic acids) were isolated from Tunisian olive leaf extracts and their in vitro activity against the promastigotes stage of Leishmania ( L .) infantum and Leishmania ( L .) amazonensis was investigated. Maslinic acid showed the highest activity with an IC 50 of 9.32 ± 1.654 and 12.460 ± 1.25 μg/ml against L. infantum and L. amazonensis , respectively. The mechanism of action of these drugs was investigated by detecting changes in the phosphatidylserine (PS) exposure, the plasma membrane permeability, the mitochondrial membrane potential and the ATP level production in the treated parasites. By using the fluorescent probe SYTOX® Green, both triterpenic acids showed that they produce a time-dependent plasma membrane permeabilization in the treated Leishmania species. In addition, spectrofluorimeteric data revealed the surface exposure of PS in promastigotes. Both molecules reduced the mitochondrial membrane potential and decreased the ATP levels to 15% in parasites treated with IC 90 for 24 h. We conclude that the triterpenic acids tested in this study, show potential as future therapeutic alternative against leishmaniasis. Further studies are needed to confirm this.

The catalytic activity of thermolysin during the hydrolysis of n -(3-[2-furyl]acryloyl)-Gly-Leu amide is noticeably enhanced in the presence of sugars and polyols. A series of polyhydroxylic additives were tested and the degree of activation was found to depend on both the concentration and nature of the additive. Sucrose and trehalose were found to yield the higher activation effect whereas glycerol was found to yield an inhibition of thermolysin in a large domain of concentration. A mechanism of activation based on the lowering of the energy barrier for the enzymatic reaction is proposed. This free energy barrier lowering is very likely due to water structure modification by the additives.

The chemical composition, antioxidant and antimicrobial activities, and the preservative effect ofThymus capitataessential oil againstListeria monocytogenesinoculated in minced beef meat were evaluated. The essential oil extracted was chemically analyzed by gas chromatography-mass spectrometry. Nineteen components were identified, of which carvacrol represented (88.89%) of the oil. The antioxidant activity was assessedin vitroby using both the DPPH and the ABTS assays. The findings showed that the essential oil exhibited high antioxidant activity, which was comparable to the reference standards (BHT and ascorbic acid) with IC50values of 44.16 and 0.463μg/mL determined by the free-radical scavenging DPPH and ABTS assays, respectively. Furthermore, the essential oil was evaluated for its antimicrobial activity using disc agar diffusion and microdilution methods. The results demonstrated that the zone of inhibition varied from moderate to strong (15–80 mm) and the minimum inhibition concentration values ranged from 0.32 to 20 mg/mL. In addition, essential oil evaluatedin vivoagainstListeria monocytogenesshowed clear and strong inhibitory effect. The application of 0.25 or 1% (v/w) essential oil ofT. capitatato minced beef significantly reduced theL. monocytogenespopulation when compared to those of control samples (P-value <0.01).