Le procédé de production du paprika à partir de la Niora (Capsicum annuum L.) au Maroc consiste essentiellement en une récolte manuelle des fruits en pleine maturité, en un séchage traditionnel au soleil et en un broyage dans des unités de transformation traditionnelles et se termine par un huilage (l’enlèvement du pédoncule est facultatif). Les détails concernant les opérations de transformation sont rapportés. Dans un deuxième volet une étude comparative de la qualité du paprika provenant de trois régions productrices de l’épice au Maroc a été abordée à travers l’analyse de leurs paramètres physico-chimiques et nutritionnels, de leur composition en métabolites secondaires et de leur pouvoir antioxydant. Les paprikas des 3 provenances ont montré des valeurs d’ASTA qui variaient de 104 à144 Unités. Les principaux acides gras composant le paprika sont l'acide linoléique, l'acide palmitique et l’acide oléique. En matière de composition minérale, les paprikas issus des 3 régions sont riches en potassium, en magnésium et relativement pauvre en sodium. Le paprika d’El Kalâa des Sraghna a montré les valeurs les plus élevées en capsaicinoïdes totaux (184,97 mg/kg PS). Les meilleures capacités antioxydantes ont été obtenues par le paprika du Tadla (IC50 de 260 µg/ml pour le test de DPPH et de 43,03 µg/ml pour le test d’ABTS).

The aim of the present study was to investigate the effect of Lactobacillus plantarum adhesion to the surface of olives during storage through studying the interaction between the surfaces of the olives and L. plantarum. The results showed that the total number of adherent L. plantarum increased exponentially from 1.2×106 to 1.3×108cfu/g. Images obtained using environmental scanning electron microscopy (ESEM) after 4 days of storage revealed that the olive surface was covered with a uniform and compact biofilm constituted of L. plantarum and yeast. Physicochemical analysis of surface of L. plantarum revealed that it was hydrophilic (Giwi>0mJ/m2). The surface of the olives also appeared to be hydrophilic (Giwi=3.28mJ/m2). The electron-donor characteristics of the surfaces of L. plantarum and olive were γ−=53.1mJ/m2 and γ−=28.1mJ/m2, respectively. The formation of a protective biofilm of L. plantarum increased the hydrophilicity (from 3.28 to 46.14mJ/m2) and the electron-donor capacity (from 28.1 to 67.2mJ/m2) of the olive surface by 1 day of storage. Analysis of the impact of the biofilm that formed on the surface of the olives during storage showed a reduction in the content of undesirable planktonic microorganisms, such as fungi, which could have occurred due to competition for nutrients and oxygen or modifications in the physicochemical properties of the olives. Thus, coating the surface of olives with a natural material, such as L. plantarum, may be a first step in developing strategies to prevent their microbial colonization.

The initial microorganism adhesion on substrate is an important step for the biofilm formation. The surface properties of the stainless steel and B. cereus were characterized by the sessile drop technique. Moreover, the physicochemical properties of surface adhesion and the impact of bio adhesion to the stainless steel were determined at different time of contact (2, 4, 7, 9 and 24 h). The results showed that the strain was hydrophilic (Giwi = 3.37 mJ/m2), whereas the substratum has hydrophobic character (Giwi = −57.6 mJ/m2). Stainless steel surface presents a weak electron-donor character (γ− = 4.1 mJ/m2) conversely to B. cereus that presents an important parameter (γ− = 31.6 mJ/m2). The bio adhesion was investigated at different time of contact. The data analysis after 2 h, confirmed the adhesion of B. cereus with an amount of 10 cfu/cm2 which increased to 1.2104 cfu/cm2 after 24 h. Interestingly, despite the difference of hydropohbicity, the interaction between B. cereus and substratum was favored by the thermodynamic aspect of adhesion (ΔGadhesion < 0). Interestingly, the study of the effect of B. cereus adhesion on the stainless steel has revealed that, the substratum becomes hydrophilic (θ° = 41.3, ΔGiwi = 39.6 mJ/m2) and highly electron donor (Γ− = 52.9 mJ/m2) after 2 h of bio adhesion.

This work was carried out on the characterization of virgin olive oils from the Moroccan picholine, the main variety cultivated in this country. The picholine samples were obtained from five different locations in Tadla Azilal area (Moroccan centre): Ksiba (KS), Bradia (BR), Beni Mellal (BM), Souk Sebt (SS) and Fkih Bensalah (FBS). They were analyzed for their composition in fatty-acids, triglycerides and sterols during the crop years 2010/1011. The sterols profile of Tadla azilal virgin olive oils produced by Moroccan picholine cultivar was established by gas chromatography using a flame ionization detector. More than ten compounds were identified and characterized. As expected for virgin olive oil, the main sterols found in all olive oil zones were ?-sitosterol, ?5-avenasterol, campesterol and stigmasterol. Cholesterol, campestanol, ?7-stigmastenol and ?7-avenasterol were also found in all samples, but in lower amounts. Most of these compounds are significantly affected by the geographical origin. For the fatty acids composition, many of them were detected in the virgin olive oils of the studied zones. Indeed, the five olive oils analyzed have shown a fatty acid composition close to the EEC established limits (EEC, 2003). However, the Variations in linoleic acid contents were observed in olive oil samples of other varieties. Keywords: Tadla azilal area, Virgin Olive Oil, Moroccan Picholine, Sterols, fatty acids.

Biofilms are the most common mode of bacterial growth in nature and the formation will occur on organic or inorganic solid surfaces in contact with a liquid. The aims of this study were, by combining numeration and sessile drop technique, (i) to characterize the structural dynamics of dairy biofilm growth and the physico chemical properties on silicone and stainless steel and (ii) to evaluate the impact of bio-adhesion on chemistry of surfaces at different times of contact (2, 7, 9 and 24h). Significantly, greater biofilm volumes were observed after 48h on two materials. Gram-positive bacteria and fungal population exhibited a significantly higher biofilm organization than gram-negative (4364%). Elsewhere, after 48h, results showed a slight difference on gram-negative adhered cells on stainless steel than silicone (2.6x107cfu/cm2 and 4.7x105cfu/cm2, respectively). Moreover, the physico chemical properties of the surfaces showed that the silicone and stainless steel have a hydrophobic character (Giwi=68.28mJ/m2 and 57.6mJ/m2, respectively). Also, both the surfaces present a weak electron donor character ( =2.2mJ/m2 and 4.1mJ/m2, respectively). The real-time investigation of the impact of dairy biofilm on the physico chemical properties of the materials has shown a decrease of hydrophobicity degree of the silicone surface that becomes hydrophilic (Giwi=11.47mJ/m2) after 7h and the increase of electron donor character ( =75.8mJ/m2). Elsewhere, bio-adhesion on stainless steel was accompanied with a decrease of hydrophobicity degree of the surface, which becomes hydrophilic after 7h of contact (Giwi=6.62mJ/m2) and the increase of the electron donor character ( =44.8mJ/m2). While, after 24h of contact, results showed a decrease of the hydrophilicity degree and surface energy components of silicone and stainless steel that become hydrophobic (Giwi=21.2mJ/m2 and Giwi=56.51mJ/m2, respectively) and weak electron donor ( =14.0 and 2.3mJ/m2, respectively).

Initial microbial adhesion to surfaces is a complicated process that is affected by a number of factors. An important property of a solution that may influence adhesion is pH. The surface properties of the cedar wood were characterized by the sessile drop technique. Moreover, the interfacial free energy of surface adhesion to the cedar wood was determined under pH values (2, 3, 5, 7, 9 and 11). The results showed that cedar wood examined at different pH levels could be considered hydrophobic ranged from Giwi = −13.1 mJ/m2 to Giwi = −75 mJ/m2. We noted that the electron-donor character of cedar wood was important at both basic and limit acidic conditions (pH 11 and pH 3) and it decreased at intermediate pH (pH 5). The cedar wood substratum presents a weak electron acceptor under various pH’s. In addition, the adhesion of conidia from Penicilllium expansum to the cedar wood surfaces at different pH values (2, 3, 5, 7, 9 and 11) was investigated using Environmental Scanning Electron Microscopy and image analysis was assessed with the Mathlab® program. The data analysis showed that the conidia from P. expansum were strongly influenced by the pH. The maximum adhesion occurs in the pH 11 and pH 3 and decreased to 24% at pH 5.