Hygienic quality of dehydrated aromatic herbs marketed in Southern Portugal

Dehydrated aromatic herbs are highly valued ingredients, widely used at home level and by food processing industry, frequently added to a great number of recipes in the Mediterranean countries. Despite being considered low-moisture products and classified as GRAS, during pre and post-harvesting stages of production they are susceptible of microbial contamination. In Europe an increasing number of food recalls and disease outbreaks associated with dehydrated herbs have been reported in recent years. In this study the microbial quality of 99 samples of aromatic herbs (bay leaves, basil, coriander, oregano, parsley, Provence herbs, rosemary and thyme) collected from retails shops in the region of Algarve (Southern Portugal) was assessed. All the samples were tested by conventional methods and were assayed for the total count of aerobic mesophilic microorganisms, Salmonella spp., Escherichia coli, coagulase-positive staphylococci and filamentous fungi. Almost 50 % of the herbs did not exceed the aerobic mesophilic level of 104 CFU/g. The fungi count regarded as unacceptable (106 CFU/g) was not found in any of the tested herbs, while 84 % of the samples ranged from ≤102 to 104 CFU/g. No sample was positive for the presence of Salmonella spp., Escherichia coli and staphylococci. The results are in compliance with the European Commission criteria although they point out to the permanent need of surveillance on the good standards of handling/cooking practices as well as the importance of avoiding contamination at production, retailing and distribution. The microbiological hazards associated with the pathogenic and toxigenic microbiota of dried herbs remain as a relevant public health issue, due to the fact that they are added to foods not submitted to any following lethal procedure. Control measures should be adopted in order to ensure that all phases of their supply chain respect the food safety standards.FCT: UID/BIA/04325/2019.info:eu-repo/semantics/publishedVersio

Methods of accelerated cheese ripening

Dojrzewanie sera to powolny, a w konsekwencji kosztowny proces. Zatem korzyści ekonomiczne i gospodarcze wynikające z przyspieszenia procesu dojrzewania sera są bardzo istotne. W celu przyspieszenia dojrzewania sera wykorzystywane są enzymy takie jak proteinazy, peptydazy i lipazy, jednak ich dodatek może prowadzić do powstawania niekontrolowanych reakcji biochemicznych, czego następstwem może być uzyskanie nowych cech sensorycznych sera. Od wielu lat podejmowano próby wykorzystania różnych technik do przyspieszenia dojrzewania serów. Dodatek do mleka serowarskiego enzymów mikrokapsułkowanych lub dodatek kultur bakteryjnych kwasu mlekowego o obniżonej zdolności fermentacyjnej metodami termicznymi albo modyfi kowanych genetycznie starterów wydaje się być dobrym rozwiązaniem. W pracy opisano metody dotyczące przyspieszania dojrzewania serów, do których należą: zastosowanie podwyższonej temperatury dojrzewania, stosowanie wysokich ciśnień, dodatek preparatów enzymatycznych, zastosowanie dodatkowej populacji wyselekcjonowanych drobnoustrojów, dodatek genetycznie modyfi kowanych starterów, dodatek, oprócz typowego startera, osłabionych kultur bakterii kwasu mlekowego. Scharakteryzowano wpływ wybranych metod przyspieszania dojrzewania serów na cechy smakowo-zapachowe, teksturalne i skrócenie czasu dojrzewania różnych gatunków sera.Cheese ripening has been defi ned as the controlled decomposition of a rennet coagulum of milk constituents. The ripening process of cheese is very complex and involves microbiological and biochemical changes to the curd resulting in the fl avour and texture characteristic of the particular variety. Maturation time of cheeses are very different and ripened periods ranging from about one weeks to two or more years, depending on the type of cheese. In the case of soft cheese ripening lasts from several days to two months, of hard and semi-hard cheeses from 2 to 6 months, and very hard cheeses from 1 to more than 2 years. The ripening of cheese is a slow, and consequently an expensive process. Thus, economic benefi ts of accelerating the process of cheese ripening are very important. Lactic acid bacteria play a key role during ripening and can therefore be used as accelerating agents. In order to accelerate the ripening of cheese are used enzymes such as proteases, peptidases and lipases, but, their additive can lead to uncontrolled biochemical reactions which may result in values to achieve a completely new fl avour of cheese. For many years, new approaches have been attempted to accelerate the cheese ripening. The addition to milk of encapsulated enzymes or lactic acid bacteria with thermal reduced ability to fermentation or genetically modifi ed starters it seems to be a good solution. In this paper discusses methods of accelerated cheese ripening which include: the use of elevated ripening temperature, high-pressure processing, addition of enzymes, the use of selected increased microbial populations adjuncts, addition of genetically modifi ed starters, addition of attenuated lactic acid bacteria cultures besides typical starter. Characterized the impact of selected methods accelerating cheese ripening on the characteristics of fl avour, textural and shorten the maturation of different types of cheese. Among the many methods of accelerating cheese ripening, it seems that the beside application of ready to use enzymes the increasing importance will had receive appropriate additional starters of LAB with reduced ability to fermentation by different methods, while maintaining a controlled proteolytic activity. These methods can both accelerate the maturation of the cheese and create new original fl avors of cheese

Escherichia Coli in dairy products

Gatunek Escherichia coli przyjęto za wskaźnik zanieczyszczenia fekalnego produktów spożywczych ze względu na występowanie tych drobnoustrojów w przewodzie pokarmowym i odchodach zwierząt stałocieplnych. Niektóre szczepy E. coli uznano za chorobotwórcze, gdyż wywołują szereg różnych chorób, począwszy od łagodnych biegunek, przez zapalenie jelit do poważnych chorób nerek. Szczepy chorobotwórczego serotypu E. coli O157 izolowano z odchodów zdrowych sztuk bydła, dlatego też sery produkowane z mleka niepasteryzowanego są potencjalnymi nośnikami tych drobnoustrojów. W pracy scharakteryzowano gatunek Escherichia coli, ze szczególnym uwzględnieniem serotypów chorobotwórczych w tym serotypu O157:H7. Dokonano przeglądu piśmiennictwa dotyczącego występowania chorobotwórczych szczepów Escherichia coli w mleku surowym oraz produktach mlecznych w różnych krajach oraz w Polsce. Przedstawiono wybrane przykłady występowania szczepów chorobotwórczych w mleku surowym i produktach mlecznych, przypadki zatruć wywołanych spożyciem produktów mlecznych zanieczyszczonych tymi serotypami.Escherichia coli was accepted as a faecal contamination indicator of food products because of its presence in the intestinal system and faeces of warm blooded organisms. Several E. coli strains represent pathogens with wide spectrum of illness which may ensue ranging from mild diarrhoea through colitis to severe urinary diseases. Because pathogenic E. coli O157 serotypes have been found from healthy cattle faeces, cheeses made from unpasteurized milk are potential vehicle of this microorganisms. The study characterized the specium Escherichia coli, with particular emphasis on pathogenic serotypes, including serotype O157: H7. Has reviewed the literature regarding the occurrence of pathogenic strains of Escherichia coli in raw milk and dairy products in different countries and Poland. The paper has presented selected examples of occurrence pathogenic strains in raw milk and dairy products, incidents of foodborne infections caused by the consumption of dairy products contaminated by these serotypes

Peptidase activity of selected heat-treated Lactobacillus strains

Celem niniejszej pracy było określenie aktywności amino- i dipeptydaz wybranych kultur bakterii mlekowych (Lactobacillus casei, Lactobacillus acidophilus), poddanych działaniu temperatury 50 ÷ 75 °C, przez 1, 15 i 25 min. Badane kultury Lactobacillus syntetyzowały peptydazy o podobnej specyficzności substratowej, ale z różną aktywnością. Wykazywały one wyższą aktywność aminopeptydaz w porównaniu z aktywnością dipeptydaz. Średnia aktywność dipeptydaz Lb. acidophilus była wyższa o 45 % od średniej aktywności bakterii Lb. casei. Wyższą o 25 % aktywnością aminopeptydaz charakteryzował się szczep Lb. casei. Szczep ten wykazywał największą specyficzność względem substratów: Ala-Leu, Ala-Ala, Gly-Leu, natomiast Lb. acidophilus – względem Ala-Ala oraz Ala-pNa. Najwyższą aktywność amino- i dipeptydaz Lb. casei oraz dipeptydaz Lb. acidophilus stwierdzono po obróbce termicznej bakterii przez 15 min. W przypadku amino- i dipeptydaz Lb. casei ich aktywność wynosiła odpowiednio: 5,10 i 0,83 U·min⁻¹·mg⁻¹ oraz 1,66 U·min⁻¹·mg⁻¹ – w przypadku dipeptydaz Lb. acidophilus. Z kolei średnia aktywność aminopeptydaz Lb. acidophilus wzrastała wraz z wydłużaniem czasu ogrzewania – najwyższe jej wartości uzyskano po 25 min (3,89 U·min⁻¹·mg⁻¹). Wykazano, że wydłużenie czasu obróbki termicznej wpłynęło statystycznie istotnie (p < 0,05) na wzrost aktywności aminopeptydaz badanych kultur bakterii, co wskazuje na ich wysoką termostabilność.The objective of the research study was to determine the amino- and dipeptidase activity of selected lactic acid bacteria cultures (Lactobacillus casei, Lactobacillus acidophilus) subjected to heat- treatment at temperatures ranging between 50 and 75 °C for 1, 15, and 25 minutes. The analyzed Lactobacillus cultures synthesized peptidases that had a similar substrate specificity but different activities. They showed a higher activity of aminopeptidases compared to the activity of dipeptidases. The mean dipeptidase activity of Lb. acidophilus was 45% higher than that of Lb. casei. The Lb. casei strain was characterized by a 25% higher activity of aminopeptidases. This strain exhibited the highest specificity to the Ala-Leu, Ala-Ala, and Gly-Leu substrates, whereas the Lb. acidophilus strain – to the Ala-Ala and Ala-pNA substrates. The highest activity of the amino- and dipeptidases of Lb. casei and of the dipeptidases of Lb. acidophilus was reported after the bacteria were heat-treated for 15 min. As for the amino- and dipeptidases of Lb. casei, their activity was, respectively: 5,10, and 0.83 U/min/mg, and as for the dipeptidases of Lb. acidophilus, it was 1.66 U/min/mg. The mean aminopeptidase activity of Lb. acidophilus increased along with the increasing heat-treatment time; its highest values were reached after 25 min (3.89 U/min/mg). It was proved that the increasing of the heat-treatment time significantly impacted the growth of aminopeptidase activity of lactic acid bacteria; this fact confirms their high temperature resistance

Salivary glands dysfunction and oral manifestations in diabetes and obesity - review

Diabetes mellitus (DM) is a group of metabolic disorders of multiple etiologies characterized by hyperglycemia. In 2014 it affected approximately 422 million individuals worldwide. Unfortunately, it is associated with a set of co-morbidities that contribute to a significantly reduced, i.e. 5-10 years, life expectancy. The following review will discuss the most common long-term complications of diabetes. For practical reasons we decided to narrow our interests to its very widespread, even 90-95% of the cases, form - type 2 diabetes mellitus. During the discussion particular emphasis will be placed on the salivary glands function since previous investigation has confirmed its relation to many burdensome oral diseases, while the effective medical care over diabetic patients requires better understanding of pathomechanisms of its (i.e. diabetic) oral manifestations

Iron oxides nanoparticles (IOs) exposed to magnetic field promote expression of osteogenic markers in osteoblasts through integrin alpha-3 (INTa-3) activation, inhibits osteoclasts activity and exerts anti-inflammatory action

International audienceBackgroundPrevalence of osteoporosis is rapidly growing and so searching for novel therapeutics. Yet, there is no drug on the market available to modulate osteoclasts and osteoblasts activity simultaneously. Thus in presented research we decided to fabricate nanocomposite able to: (i) enhance osteogenic differentiation of osteoblast, (i) reduce osteoclasts activity and (iii) reduce pro-inflammatory microenvironment. As a consequence we expect that fabricated material will be able to inhibit bone loss during osteoporosis.ResultsThe α-Fe2O3/γ-Fe2O3 nanocomposite (IOs) was prepared using the modified sol–gel method. The structural properties, size, morphology and Zeta-potential of the particles were studied by means of XRPD (X-ray powder diffraction), SEM (Scanning Electron Microscopy), PALS and DLS techniques. The identification of both phases was checked by the use of Raman spectroscopy and Mössbauer measurement. Moreover, the magnetic properties of the obtained IOs nanoparticles were determined. Then biological properties of material were investigated with osteoblast (MC3T3), osteoclasts (4B12) and macrophages (RAW 264.7) in the presence or absence of magnetic field, using confocal microscope, RT-qPCR, western blot and cell analyser. Here we have found that fabricated IOs: (i) do not elicit immune response; (ii) reduce inflammation; (iii) enhance osteogenic differentiation of osteoblasts; (iv) modulates integrin expression and (v) triggers apoptosis of osteoclasts.ConclusionFabricated by our group α-Fe2O3/γ-Fe2O3 nanocomposite may become an justified and effective therapeutic intervention during osteoporosis treatment

<p>Fe₃O₄ Magnetic Nanoparticles Under Static Magnetic Field Improve Osteogenesis via RUNX-2 and Inhibit Osteoclastogenesis by the Induction of Apoptosis</p>

International audiencePurpose: The presented study aimed to investigate the effects of Fe 3O 4 nanoparticles and static magnetic field on osteoblast and osteoclasts’ metabolic activity.Methods: Magnetic nanoparticles were prepared by a wet chemical co-precipitation process and analyzed using X-ray powder diffraction, high-resolution transmission electron microscope (HRTEM), dynamic light scattering (DLS), laser Doppler velocimetry, Raman and the Mössbauer spectroscopy. In vitro experiments were performed using MC3T3, 4B12 and RAW 264.7 cell lines. Cells were cultured in the presence of nanoparticles and with or without exposure to the magnetic field. Proteins were investigated with Western blotting and immunofluorescence and Western blot. Gene expression was analyzed with a quantitative real-time polymerase chain reaction.Results: Obtained particles were in the nano-range (average size around 50 nm) and had a spherical-like morphology. The typical hydrodynamic size was in the range 178– 202 nm and Zeta potential equaled – 9.51 mV. Mössbauer spectrum corresponds to the Fe+3 ions in tetrahedral (A) and Fe+3 and Fe+2 ions in octahedral (B) sites of Fe 3O 4. In vitro study revealed cytocompatibility and anti-inflammatory effects of fabricated nanoparticles. Furthermore, it was shown that nanoparticles combined with magnetic field exposure enhance osteogenic differentiation of MC3T3 cells by upregulation of RUNX-2 activity. Under the same experimental condition, nanoparticles and magnetic field decreased osteoclastogenesis of 4B12 by the induction of apoptosis through the mitochondrial-dependent pathway.Conclusion: Fe 3O 4 nanoparticles together with magnetic field can be applied for the fabrication of novel biomaterials for the treatment of bone disorders related to bone loss in which a balance between bone-forming and resorbing cells is disturb