The ability of probiotic bacteria to adhere to the intestinal epithelium play an important role in colonization of the gastrointestinal tract, preventing their elimination by peristalsis and providing a competitive advantage in this ecosystem. To identify bacterial traits related to adhesion the probiotic strain L. acidophilus M92 was examined for autoaggregation ability and cell surface hydrophobicity L. acidophilus M92 exhibits a strong autoaggregation phenotype and also coaggregation with some pathogen microorganisms that may form a barrier that prevents their colonization. The examined probiotic strain manifests a good degree of hydrophobicity determined by microbial adhesion to hydrocarbons. Aggregation and hydrophobicity were abolished upon exposure of the cells to pronase, which suggests the possible role of cell surface layer (S-layer) proteins, approximated at 45 kDa, in a L. acidophilus M92. The relationship between autoaggregation and adhesion ability to intestinal tissue was investigated by observing the adhesivity of L. acidophilus M92 to porcine ileal epithelial cells. Removal of the S-layer proteins by extraction with 5 M LiCl reduced autaggregation and in vitro adhesion of this strain.

Adhesion and aggregation ability of probiotic strain Lactobacillus acidophilus M92

Improving functional properties of chitosan films as active food packaging by incorporating with propolis

An overview of natural antimicrobials role in food.

This is a systematic review of existing data on dietary selenium (Se) intake and status for various population groups in Europe (including the United Kingdom (UK)) and the Middle East. It includes English language systematic reviews, meta-analyses, randomised controlled trials, cohort studies, cross-sectional and case-control studies obtained through PUBMED searches from January, 2002, to November, 2014, for European data and from 1990 to November 2014, for Middle Eastern data. Reports were selected if they included data on Se intake and status. The search identified 19 European/UK studies and 15 investigations in the Middle East that reported Se intake and Se concentration in water and/or food and 48 European/UK studies and 44 investigations in the Middle East reporting Se status. Suboptimal Se status was reported to be widespread throughout Europe, the UK and the Middle East, and these results agreed with previous reports highlighting the problem. Eastern European countries had lower Se intake than Western European countries. Middle Eastern studies provided varying results, possibly due to varying food habits and imports in different regions and within differing socioeconomic groups. In conclusion, Se intake and status is suboptimal in European and Middle Eastern countries, with less consistency in the Middle East.

https://www.mdpi.com/2072-6643/7/3/1494/pdf

A Review of Dietary Selenium Intake and Selenium Status in Europe and the Middle East

Listeria monocytogenes is notorious for its ability to persistently colonize food processing and other environments. Formation of biofilms is one of the key attributes mediating such persistence. Resistance to sanitizers and other stresses may be higher in biofilm-associated L. monocytogenes than in planktonic cultures, potentially compromising the efficacy of sanitation regimes. In spite of extensive investigations on biofilm formation and approaches to inactivate L. monocytogenes, major gaps remain in our understanding of this pathogen's tolerance to disinfectants in the biofilm state. Contributing factors include the diversity and complexity of biofilms in processing plants and our still limited understanding of the microbial ecology of the processing plant ecosystem, together with the multitude of mechanisms that can mediate disinfectant tolerance and persistence of biofilm-associated cells. Further insights are expected as novel tools continue to become employed to characterize the microbiome of L. monocytogenes-harboring biofilms in food processing environments and elucidate responses to disinfectants at the genomic, transcriptomic and proteomic levels.

Resistance of Listeria Monocytogenes Biofilms to Sanitizing Agents

In this study, aluminium (Al), lead (Pb), cadmium (Cd), selenium (Se) and arsenic (As) contents in milk and different dairy product samples were measured. Pb, Cd, As, Al and Se contents in the milk and different dairy products ranged from 0.054 mg/kg (milk powder)-1.100 mg/kg (Kasar cheese), 0.009 mg/kg (whey powder and yogurt)-0.051 mg/kg (Tulum cheese), 0.010 mg/kg (whey powder)-0.146 mg/kg (butter), 2.848 mg/kg (ice cream)-8.778 (drained yogurt) and n.d. (ice cream, milk and whey powder, yogurt, ayran and Lor cheese)-0.434 mg/kg (Tulum cheese), respectively. The 75% of White and Kasar cheeses, 50% of Lor and 12.5% of Tulum cheese samples contained higher Pb according to the legal limits established by the Turkish Food Codex and European Communities regulation and 12.5% of Tulum cheese sample contained Cd. It was concluded that Pb contents of milk and dairy products from this region might be highly hazardous to human.

The trace metal levels in milk and dairy products consumed in middle Anatolia-Turkey.

Antibacterial effectiveness of chitosan-propolis coated polypropylene films against foodborne pathogens.

Effects of propolis on eggshell microbial activity, hatchability, and chick performance in Japanese quail (Coturnix coturnix japonica) eggs

The effect of peeled oleaster (Elaeagnus angustifolia L.) flour (PO) and unpeeled oleaster flour (UPO) in different levels (1% and 2%) on the quality parameters of set type yoghurt was investigated throughout 28 days of storage. Acidification kinetics, water holding capacity, syneresis level, textural characteristics and microstructure were firstly measured. Additionally, influence of oleaster flours on DPPH and ABTS+ radical scavenging activity and total phenolic content of yoghurt samples was also assessed. Besides, all the products were subjected to sensorial preference test. Enrichment with 2% PO and UPO reduced fermentation time by 31 and 37 min, respectively. Addition of PO and UPO increased cohesiveness and the viscosity index, furthermore, syneresis decreased. Oleaster supplementation to yoghurt significantly increased scavenging activities of DPPH and ABTS+ radicals and the highest activities were determined in yoghurts fortified with 2% UPO. The results demonstrated that yoghurt with reduced syneresis, improved functional properties, and enhanced some textural characteristics can be achieved by a 2% UPO addition. Also, surprisingly yoghurts containing 2% UPO had similar consumer overall preference scores comparing to plain yoghurt.

Fortification of set-type yoghurts with Elaeagnus angustifolia L. flours: Effects on physicochemical, textural, and microstructural characteristics

This study was performed to evaluate the effectiveness of benzalkonium chloride combined with ultrasound in eliminating Listeria monocytogenes biofilm from polystyrene surface. The test strain of L. monocytogenes, previously classified as strong biofilm producer, was grown to form biofilm in tryptic soy broth at 20°C for 6 days in polystyrene specimen containers. The biofilms formed on surface of containers were treated with ultrasound alone, benzalkonium chloride (100 and 400 mg l(-1)) alone and their combination for three different exposure times (1, 5 and 15 min) at room temperature. Sonication was performed using an ultrasound bath at a constant ultrasound frequency of 35 kHz. After treatments, levels of biofilm biomass and viable cells in biofilm were determined using crystal violet staining and XTT assays, respectively. The combined treatment of ultrasound and benzalkonium chloride resulted in significant (P < 0·05) more decrease in the level of viable cells in the L. monocytogenes biofilm compared to individual treatments of benzalkonium chloride. Our results suggest that the combination of benzalkonium chloride with ultrasound is useful approach for the elimination of L. monocytogenes biofilms from plastic surfaces.

Durmuş Sert

Papers

The trace metal levels in milk and dairy products consumed in middle Anatolia-Turkey.

Antibacterial effectiveness of chitosan-propolis coated polypropylene films against foodborne pathogens.

Effects of propolis on eggshell microbial activity, hatchability, and chick performance in Japanese quail (Coturnix coturnix japonica) eggs

Fortification of set-type yoghurts with Elaeagnus angustifolia L. flours: Effects on physicochemical, textural, and microstructural characteristics

Combined effect of benzalkonium chloride and ultrasound against Listeria monocytogenes biofilm on plastic surface