The major strategies for designing surfaces that prevent fouling due to proteins, bacteria, and marine organisms are reviewed. Biofouling is of great concern in numerous applications ranging from biosensors to biomedical implants and devices, and from food packaging to industrial and marine equipment. The two major approaches to combat surface fouling are based on either preventing biofoulants from attaching or degrading them. One of the key strategies for imparting adhesion resistance involves the functionalization of surfaces with poly(ethylene glycol) (PEG) or oligo(ethylene glycol). Several alternatives to PEG-based coatings have also been designed over the past decade. While protein-resistant coatings may also resist bacterial attachment and subsequent biofilm formation, in order to overcome the fouling-mediated risk of bacterial infection it is highly desirable to design coatings that are bactericidal. Traditional techniques involve the design of coatings that release biocidal agents, including antibiotics, quaternary ammonium salts (QAS), and silver, into the surrounding aqueous environment. However, the emergence of antibiotic- and silver-resistant pathogenic strains has necessitated the development of alternative strategies. Therefore, other techniques based on the use of polycations, enzymes, nanomaterials, and photoactive agents are being investigated. With regard to marine antifouling coatings, restrictions on the use of biocide-releasing coatings have made the generation of nontoxic antifouling surfaces more important. While considerable progress has been made in the design of antifouling coatings, ongoing research in this area should result in the development of even better antifouling materials in the future.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/adma.201001215

Antifouling coatings: recent developments in the design of surfaces that prevent fouling by proteins, bacteria, and marine organisms.

Polymer surface modification for the attachment of bioactive compounds

Perspectives for chitosan based antimicrobial films in food applications

https://ciptaindomedica.files.wordpress.com/2011/01/antimicrobial-herb-and-spice-compounds-in-food.pdf

Antimicrobial herb and spice compounds in food.

Antioxidant activity has been assessed in many ways. The limitation of many newer methods is the frequent lack of an actual substrate in the procedure. The combination of all approaches with the many test methods available explains the large variety of ways in which results of antioxidant testing are reported. The measurement of antioxidant activities, especially of antioxidants that are mixtures, multifunctional or are acting in complex multiphase systems, cannot be evaluated satisfactorily by a simple antioxidant test without due regard to the many variables influencing the results. Several test procedures may be required to evaluate such antioxidant activities. A general method of reporting antioxidant activity independent of the test procedure is proposed.

http://ucce.ucdavis.edu/files/datastore/608-46.pdf

Methods for testing antioxidant activity

A case study on the use of ultrasound for the inhibition of Escherichia coli O157:H7 and Listeria monocytogenes in almond milk.

Using physical approaches for the attenuation of lactic acid bacteria in an organic rice beverage

The effects of several chemico-physical factors (pH, SO2, and ethanol concentration) on the growth and malolactic activity of Lactobacillus plantarum and Leuconostoc oenos strains, isolated from different Italian red wines, were evaluated. A large individual variability of stress resistance was observed within the two species. The isolates of L. plantarum showed, under the various conditions better growth performances with respect to Leuc. oenos. Ethanol and malic acid concentration, temperature, pH, and inoculum size were modulated according a Central Composite Design (CCD). Two representative strains of each of the two species were individually grown in the various combinations of the CCD, and their activity was evaluated by gas chromatograph on the basis of the CO2 concentration in the head space of sealed vials. The malolactic activity of the various runs were modelled according to the Gompertz equation. The Gompertz parameters, µmax and length of lag phase, were calculated in order to obtain polynomial equations. The comparison of the models obtained indicated that different factors limit the activities of the two species and that L. plantarum is more resistant to the combined action of various stresses. Having revealed a weaker dependence on the medium modifications as well as higher decarboxylation performances, L. plantarum can be considered as a more efficient alternative to Leuc. oenos for the induction of malolactic fermentation in musts.

Effects of pH, Temperature, Ethanol, and Malate Concentration on Lactobacillus plantarum and Leuconostoc oenos: Modelling of the Malolactic Activity

The study of different strategies for prolonging the shelf life of fresh minced beef patties was addressed in this work. Fresh minced beef was supplemented with thymol (THY) at levels of 250, 500 and 750 mg per kg of ground beef. Treated samples were packed using a high barrier film and stored in refrigerated conditions (4C) under ordinary atmosphere packaging and modified atmosphere packaging (MAP) conditions for 16 days. The microbiological quality decay kinetic was determined by monitoring the following microorganisms: Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria, Brochothrix thermosphacta, coliforms and total psychrotrophic viable count. Results show that THY, working alone, was effective on coliforms and Enterobacteriaceae, whereas it does not seem to inhibit to a great extent the growth of the other microbial populations. On the other hand, an increased amount of THY, under MAP conditions, had better effects on the product quality, with a consequent prolongation of the shelf life.



PRACTICAL APPLICATIONS

Great interest is developing in food bio-preservation, because of the ever-increasing needs to protect consumers' health and to valorize the naturalness and safety of food products. However, very few works have been carried out on the applications of bio-preservatives to extend the shelf life of fresh meat products. This study, therefore, was mainly initiated to evaluate the possibility of extending the shelf life of packed fresh meat patties by a combination of thymol (THY) to other extrinsic factors such as storage temperatures and modified atmosphere during packaging. Interesting results were obtained suggesting that THY can perform an efficient synergy with modified atmosphere conditions and could be advantageously utilized by the meat industry.

Milena Sinigaglia

Papers

A case study on the use of ultrasound for the inhibition of Escherichia coli O157:H7 and Listeria monocytogenes in almond milk.

Using physical approaches for the attenuation of lactic acid bacteria in an organic rice beverage

Effects of pH, Temperature, Ethanol, and Malate Concentration on Lactobacillus plantarum and Leuconostoc oenos: Modelling of the Malolactic Activity

Strategies for prolonging the shelf life of minced beef patties

Klebsiella pneumoniae as a spoilage organism in mozzarella cheese.