Rafik Balti
University of Sfax
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Publication
Featured researches published by Rafik Balti.
International Journal of Biological Macromolecules | 2016
Nadhem Sayari; Assaâd Sila; Baha Eddine Abdelmalek; Rihab Ben Abdallah; Semia Ellouz-Chaabouni; Ali Bougatef; Rafik Balti
Chitin was recovered through enzymatic deproteinization of the Norway lobster (Nephrops norvegicus) processing by-products. The obtained chitin was characterized and converted into chitosan by N-deacetylation, the acid-soluble form of chitin. Chitosan samples were then characterized by Fourier transform infrared spectroscopy (FTIR) and 13 Cross polarization magic angle spinning nuclear magnetic resonance (CP/MAS)-NMR spectroscopy. The antimicrobial activity and anti-proliferative capacity of chitosan were evaluated. Antimicrobial activity assays indicated that prepared chitosan exhibited marked inhibitory activity against the bacterial and fungal strains tested. Further, cytotoxic effects of chitosan samples on human colon carcinoma cells HCT116 was evaluated using the MTT assay. Chitosan showed the antiproliferative capacity against the colon-cancer-cell HCT116 in a dose dependent manner with IC50 of 4.6mg/ml. Indeed, HCT116 cell proliferation was significantly inhibited (p<0.05) between 13.5 and 67.5% at 0.5-6mg/mL of chitosan after 24h of cell treatment. The chitosan showed high antitumor activity which seemed to be dependent on its characteristics such as acetylation degree.
Journal of Aquatic Food Product Technology | 2013
Naourez Ktari; Nahed Fakhfakh; Rafik Balti; Hayet Ben Khaled; Moncef Nasri; Ali Bougatef
We have investigated the antioxidant activities of eight hydrolysates from cuttlefish by-products obtained by treatment with various gastrointestinal proteases (chymotrypsin, trypsin, and crude alkaline enzyme extracts from cuttlefish and sardinelle) and bacterial proteases (Alcalase and crude enzymes from Bacillus pumilus A1, Bacillus mojavensis A21, and Bacillus cereus BG1). The antioxidant activities of the cuttlefish by-products protein hydrolysates (CPHs) were evaluated using various in vitro antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, and total antioxidant capacity. All hydrolysates showed different degrees of hydrolysis (DH) and varying degrees of antioxidant activity. Among the different hydrolysates, cuttlefish crude enzyme hydrolysate exhibited the highest antioxidant activity, followed by sardinelle crude enzyme and Alcalase hydrolysates. Further, CPHs with different degrees of hydrolysis were prepared by treatment with proteolytic enzymes from cuttlefish, sardinelle, and B. mojavensis A21. All hydrolysates showed a greater antioxidative activity as indicated by all the methods considered. In addition, antioxidant activity in hydrolysates was positively correlated with the increase of DH. The results of this study indicated that CPHs might be a good candidate for further investigation in developing new antioxidants.
Food Research International | 2015
Benoit Cudennec; Rafik Balti; Rozenn Ravallec; Juliette Caron; Ali Bougatef; Pascal Dhulster; Naima Nedjar
Abstract Two cuttlefish ( Sepia officinalis ) viscera protein hydrolysates were obtained with different enzymes extracted from cuttlefish and smooth hound ( Mustellus mustellus ). Their ability to stimulate the secretion of cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1), using the enteroendocrine STC-1 cell line, and to inhibit the DPP-IV activity during a simulated gastrointestinal digestion was assayed. The physico-chemical parameters of hydrolysates and their effects on intestinal cell viability were also determined. The hydrolysate obtained with cuttlefish enzymes (CVPH1) appeared to be the most promising for all assessed bioactivities. Thus CVPH1 was able to stimulate CCK and active GLP-1 releasing activities of enteroendocrine cells without any cytotoxicity and to inhibit DPP-IV activity. Moreover, these actions were enhanced after gastrointestinal digestion and CVPH1 was also able to inhibit the intestinal DPP-IV activity of Caco-2 cells. These very promising findings highlight, via two different mechanisms, the positive effect of CVPH1 on GLP-1 actions.
Environmental Science and Pollution Research | 2017
Lotfi Rabaoui; Radhouan El Zrelli; Rafik Balti; Lamjed Mansour; Pierre Courjault-Radé; Nabil Daghbouj; Sabiha Tlig-Zouari
Samples of Octopus vulgaris and Sepia officinalis were collected from four areas in the Gulf of Gabes, south-eastern Tunisia, and their edible tissues (mantle and arms) were analyzed for cadmium, copper, mercury, and zinc. While the concentrations of metals showed significant differences between the sampling sites, no differences were revealed between the tissues of the two species. The spatial distribution of metals analyzed showed similar pattern for both tissues of the two species, with the highest concentrations found in the central area of Gabes Gulf, and the lowest in the northern and/or southern areas. From a human health risk point of view, the highest values of estimated daily intake, target hazard quotient, and hazard index were found in the central area of Gabes Gulf. Although the results of these indices were, in general, not alarming, the health risks posed by the consumption of cephalopods on local consumers cannot be excluded.
Carbohydrate Polymers | 2017
Mohamed Ben Mansour; Rafik Balti; Véronique Ollivier; Hichem Ben Jannet; Frédéric Chaubet; Raoui M. Maaroufi
The fucosylated chondroitin sulfate (FuCS) was isolated from the sea cucumber Holothuria polii body wall and then purified by anion exchange chromatography and the structure was characterized by FT-IR and NMR spectroscopy. Anticoagulant activity was measured in plasma by classical anticoagulation tests and the thrombin generation was assessed by calibrated automated thrombography. The results showed that the FuCS obtained at a yield of 4.66% possesses high sulfate content 43% and an average molecular mass of 45.8kDa. Structural analysis revealed the presence of alternating units of chondroitine sulfate branched at position 3 of the β-d-glucuronic acid by two types of fucose 2,4-O-di and 3,4-O-disulfated residues. The FuCS exhibited a high anticoagulant effect mediated essentially by heparin cofactor II and to lesser extent by antithrombin. Moreover, the CAT assay depicted a dual effect of FuCS with a procoagulant tendency for low doses and an anticoagulant effect at higher doses.
Microbial Pathogenesis | 2018
Sabrine Kobbi; Naima Nedjar; Nourdine Chihib; Rafik Balti; Mickaël Chevalier; Amandine Silvain; Semia Ellouz Chaabouni; Pascal Dhulster; Ali Bougatef
In this work we evaluated the mode of action of six new synthesized peptides (Met-Asp-Asn; Glu-leu-Ala-Ala-Ala-Cys; Leu-Arg-Asp-Asp-Phe; Gly-Asn-Ala-Pro-Gly-Ala-Val-Ala; Ala-Leu-Arg-Met-Ser-Gly and Arg-Asp-Arg-Phe-Leu), previously identified, from the most active peptide fractions of RuBisCO peptic hydrolysate against Listeria innocua via a membrane damage mechanism. Antibacterial effect and the minimum inhibitory concentrations (MIC) of these peptides were evaluated against six strains and their hemolytic activities towards bovine erythrocytes were determined. Prediction of the secondary structure of peptides indicated that these new antibacterial peptides are characterized by a short peptide chains (3-8 amino acid) and a random coli structure. Moreover, it was observed that one key characteristic of antibacterial peptides is the presence of specific amino acids such as cysteine, glycine, arginine and aspartic acid. In addition the determination of the extracellular potassium concentration revealed that treatment with pure RuBisCO peptides could cause morphological changes of L. innocua and destruction of the cell integrity via irreversible membrane damage. The results could provide information for investigating the antibacterial model of antibacterial peptides derived from RuBisCO protein hydrolysates.
Lwt - Food Science and Technology | 2011
Kernel Jellouli; Rafik Balti; Ali Bougatef; Noomen Hmidet; Ahmed Barkia; Moncef Nasri
Lwt - Food Science and Technology | 2012
Ali Bougatef; Rafik Balti; Assaâd Sila; Rim Nasri; Ghada Graiaa; Moncef Nasri
Food Research International | 2011
Noomen Hmidet; Rafik Balti; Rim Nasri; Assaâd Sila; Ali Bougatef; Moncef Nasri
Biomedicine & Pharmacotherapy | 2016
Nadhem Sayari; Rafik Balti; Mohamed Ben Mansour; Ikram Ben Amor; Imen Graiet; J. Gargouri; Ali Bougatef