Preparation and characterization of nisin-loaded magnetic nanoparticles

Preparation and characterization of nisin-loaded magnetic nanoparticles

Abstracts / Journal of Biotechnology 256S (2017) S44–S116 Preparation and characterization of nisin-loaded magnetic nanoparticles Ruta Gruskiene 1 , ...

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Abstracts / Journal of Biotechnology 256S (2017) S44–S116

Preparation and characterization of nisin-loaded magnetic nanoparticles Ruta Gruskiene 1 , Tatjana Krivorotova 2 , Ramune Staneviciene 3 , Dalius Ratautas 1,4 , Elena Serviene 1,3 , Jolanta Sereikaite 1,∗ 1

Department of Chemistry and Bioengineering, Vilnius Gediminas Technical University, Vilnius, Lithuania 2 Department of Polymer Chemistry, Vilnius University, Vilnius, Lithuania 3 Laboratory of Genetics, Institute of Botany, Nature Research Centre, Vilnius, Lithuania 4 Institute of Biochemistry, Vilnius University, Vilnius, Lithuania E-mail address: [email protected] (J. Sereikaite). Nisin is a known bacteriocin approved as a food additive for food preservation. It exhibits a wide spectrum antimicrobial activity against Gram-positive bacteria. Nisin is produced by Lactococcus lactis subsp. lactis. It is a small cationic peptide composed of 34 amino acid residues. Iron oxide magnetic nanoparticles were synthesized and determined by XRD as Fe2 O3 phase (Maghemite-C). Magnetic nanoparticles were stabilized by citrate, ascorbate, gallic or glucuronic acid coating. Nisin loading on the particles was acquired by the adsorption method and confirmed by FTIR spectroscopy. The size of nisin-loaded magnetic particles was characterized by AFM and DLS methods. The antimicrobial activity of developed magnetic nanoparticles was evaluated on the model Gram-positive bacteria Bacillus subtilis by applying microbiological techniques. Nisin-loaded magnetic nanoparticles could find their application in innovative and emerging technologies as antimicrobials. Evaluation of some Romanian bread products quality in correlation with food safety Oana M˘arg˘arita Ghimpet¸eanu ∗ , Lucian Ilie, Iuliana Neagu University of Agronomical Sciences and Veterinary Medicine of Bucharest, Faculty of Veterinary Medicine, Bucharest, Romania E-mail address: ghimpe [email protected] (O.M. Ghimpet¸eanu). In Romania, bread products are a well-consumed foodstuff, so careful monitoring of food safety characteristics should be performed in order to ensure consumers health. The aim of this study was to perform a comparison between 6 types of bread products quality parameters and the legislative requirements. The bread products (white bread, whole wheat bread, brown bread, rye bread, rye bread with seeds and baguette with seeds) were collected from a large processing unit in Romania. For all types of samples, sensorial assessment (shape and volume, general aspect and colour of the crust, core porosity and structure, smell and taste) was performed. The standard methods were used, such as the weight, volume, core elasticity, humidity and acidity for evaluation. The sensorial assessment revealed normal parameters according to the type of product recipe. For the other quality parameters, the results ranged from 390 to 605 g for weight, 200 to 300 cm3 for volume, 80–91% for core elasticity, 30.9–45.6% for humidity and 3–5.5◦ for acidity. Analysis of


results demonstrated that all bread samples respected the product specifications imposed by the legislation and producer. Effect of magnesium salts addition on white wheat flour dough rheological properties Georgiana Gabriela Codina 1,∗ , Dumitru Zaharia 2 , Sorina Ropciuc 1 , Adriana Dabija 1 1 Faculty of Food Engineering, “Stefan cel Mare” University, Suceava, Romania 2 S. C. Dizing S. R. L. Brusturi, Neamt¸, Romania

E-mail address: (G.G. Codina). The aim of this study was to analyze the effect of magnesium ions (100–200 mg/100 g) from lactate and gluconate salts addition in wheat flour 550 type on Farinograph, Amylograph, Falling Number and Rheofermentograph properties. Both forms of magnesium ions influenced dough rheological properties in a similar way. The increase content of magnesium salt addition produced a decrease of water absorption, degree of softening, Falling Number value, peak viscosity, maximum height of gaseous production and total CO2 volume production. A higher dough development time, stability and retention coefficient were achieved with the increase level of magnesium ions addition. The effect of magnesium ions present in gluconate salts is more prominent on all Farinograph properties having a more strengthening effect than those from lactate salt. Also, it presents a higher expansion volume of yeasted bread dough than the magnesium ions from the lactate salt. Regarding it effect on the gelatinization properties and ␣-amylase activity of the wheat flour it seems that it presents only some slightly lower differences compared to the magnesium lactate salt which decreases more the falling number value. It can be concluded that both magnesium salts present a satisfactory impact on the rheological characteristics of wheat flour dough. Acknowledgments: This work was supported by a grant of the Romanian National Authority for Scientific Research and Innovation, CNCS/CCCDI – UEFISCDI, project number PN-III-P2-2.1BG-2016-0079, within PNCDI III. Structural and physicochemical properties of emulsified alginate-based film coatings for food products Neculau Marian 1,∗ , Ceoromila Mihaela Alina 1 , Blaga Valentina Giorgiana 1 , Mustatea Gabriel 2 , Vizireanu Camelia 1 1

Department of Biotechnology, Dunarea de Jos University, Galati, Romania 2 Department of Food and Packaging, National Institute of Research and Development for Food Bioresources, Bucharest, Romania E-mail address: [email protected] (N. Marian). The usage of edible films and coatings for food products as packaging materials represent an increasing new field with numerous advantages as alternative shelf life extenders. Functioning as barriers, these edible films and coatings can easily improve the recyclability of packaging materials and may be able to substitute synthetic polymer films. Composite coatings of sodium alginate, carboxymethyl-cellulose and konjac gum were obtained by casting technique using Glycerol as plasticizer in a dosage from 0.6 g/g