1,721,179 research outputs found
Potential of high pressure homogenisation on probiotic Caciotta cheese quality and functionality
Full text linkThe probiotic Lactobacillus paracasei A13, treated at 50 MPa sub-lethal high pressure homogenisation (HPH), was used as adjunct for producing Caciotta cheese. The cell HPH treatment was used because it has been proven to increase the in vitro strain functionality. The starters and Lb. paracasei A13 viability, the cheese hydrolytic patterns and organoleptic profiles were monitored. After cheesemaking and during ripening, the Lb. paracasei A13 gastric acid resistance in cheese and the ability of the cheese, containing HPH-treated or untreated cells, to modulate the gut mucosal immune system in mice were evaluated. Traditional Caciotta was used as controls. The HPH-treated probiotic strain maintained high viability for 14 days whilst the physico-chemical analyses on Caciotta cheese containing HPH-treated cells showed a faster ripening, compared to other cheeses. For functional properties, the 50 MPa treatment increased the Lb. paracasei gastric resistance in Caciotta, maintaining high strain viability, but IL-10 producing capacity was lost by HPH-treatment whilst IgA production was not modified.Fil: Burns, Patricia Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Patrignani, Francesca. Universidad de Bologna; ItaliaFil: Tabanelli, Giulia. Universidad de Bologna; ItaliaFil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Siroli, Lorenzo. Universidad de Bologna; ItaliaFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Gardini, Fausto. Universidad de Bologna; ItaliaFil: Lanciotti, Rosalba. Universidad de Bologna; Itali
Applications of High and Ultra High Pressure Homogenization for Food Safety
Full text linkTraditionally, the shelf-life and safety of foods have been achieved by thermal processing. Low temperature long time (LTLT) and high temperature short time (HTST) treatments are the most commonly used hurdles for the pasteurization of fluid foods and raw materials. However, the thermal treatments can reduce the product quality and freshness. Consequently, some non-thermal pasteurization process have been proposed during the last decades, including high hydrostatic pressure (HHP), pulsed electric field (PEF), ultrasound (US) and high pressure homogenization (HPH). This last technique has been demonstrated to have a great potential to provide fresh-like products with prolonged shelf-life. Moreover, the recent developments in high-pressure-homogenization technology and the design of new homogenization valves able to withstand pressures up to 350-400 MPa have opened new opportunities to homogenization processing in the food industries and, consequently, permitted the development of new products differentiated from traditional ones by sensory and structural characteristics or functional properties. For this, this review deals with the principal mechanisms of action of high pressure homogenization against microorganisms of food concern in relation to the adopted homogenizer and process parameters. In addition, the effects of homogenization on foodborne pathogenic species inactivation in relation to the food matrix and food chemico-physical and process variables will be reviewed. Also the combined use of this alternative technology with other non-thermal technologies will be considere
Valorisation of alternative protein sources by biotechnological processes and non-thermal technologies to obtain new ingredients to be used in the formulation of innovative foods.
No full textNon-thermal technologies: pulsed electric field, high hydrostatic pressure and high pressure homogenization. Application on virus inactivation
No full textBacteriophage attacks to starters in the dairy industry causes enormous economic losses. Phage inactivation have always been a matter of study; however, even combining different control strategies complete removal of phages is not possible and the real aim consist in maintaining their concentration under a critical threshold. This chapter deals with three novel technologies such as pulsed electric field, high hydrostatic pressure and high pressure homogenization. These non-thermal methods are considered the most promising in food processing due to their better preservation of flavor, essential nutrients and vitamins with respect to heat treatments. Aspects such as the principles of the technologies, applications, treatment parameters and factors that influence the inactivation extent, as well as microbial inactivation, are developed below for each technology. For this last aspect and due to the scarce available information regarding phage inactivation, not only the effect of these novel technologies on dairy bacteriophages is referred to, but also on other phages, viruses and even on others microorganisms.Fil: Capra, María Luján. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Patrignani, Francesca. Università di Bologna; ItaliaFil: Guerzoni, Maria Elisabetta. Università di Bologna; ItaliaFil: Lanciotti, Rosalba. Università di Bologna; Itali
POTENTIAL OF HIGH PRESSURE HOMOGENIZATION AND FUNCTIONAL STRAINS FOR NOVEL FUNCTIONAL DAIRY FOODS
No full textFunctional foods are one of the fastest increasing fields in the global food industry since they are positively perceived by the consumers as dietary strategy to reduce the incidence of illness in the humankind. Actually, the use of biotechnological strategies, based on the use of functional and specific strains and sustainable technologies, such as high pressure homogenization, can be a great chance to create innovation in dairy field. Critical discussion on the actual scenario will be the main topic of this chapter
Effects of sub-lethal high-pressure homogenization treatment on the outermost cellular structures and the volatile-molecule profiles of two strains of probiotic lactobacilli
Full text linkApplying sub-lethal levels of high-pressure homogenization (HPH) to lactic acid bacteria has been proposed as a method of enhancing some of their functional properties. Because the principal targets of HPH are the cell-surface structures, the aim of this study was to examine the effect of sub-lethal HPH treatment on the outermost cellular structures and the proteomic profiles of two known probiotic bacterial strains. Moreover, the effect of HPH treatment on the metabolism of probiotic cells within a dairy product during its refrigerated storage was investigated using SPME-GC-MS. Transmission electron microscopy was used to examine the microstructural changes in the outermost cellular structures due to HPH treatment. These alterations may be involved in the changes in some of the technological and functional properties of the strains that were observed after pressure treatment. Moreover, the proteomic profiles of the probiotic strains treated with HPH and incubated at 37°C for various periods showed different peptide patterns compared with those of the untreated cells. In addition, there were differences in the peaks that were observed in the low-mass spectral region (2000-3000 Da) of the spectral profiles of the control and treated samples. Due to pressure treatment, the volatile-molecule profiles of buttermilk inoculated with treated or control cells and stored at 4°C for 30 days exhibited overall changes in the aroma profile and in the production of molecules that improved its sensory profile, although the two different species imparted specific fingerprints to the product. The results of this study will contribute to understanding the changes that occur in the outermost cellular structures and the metabolism of LAB in response to HPH treatment. The findings of this investigation may contribute to elucidating the relationships between these changes and the alterations of the technological and functional properties of LAB induced by pressure treatment.Fil: Tabanelli, Giulia. Universidad de Bologna; ItaliaFil: Vernocchi, Pamela. Irccs Ospedale Pediatrico Bambino Gesu; . Universidad de Bologna; ItaliaFil: Patrignani, Francesca. Università Degli Studi Di Bologna - Sede Di Cesena;Fil: Del Chierico, Federica. Irccs Ospedale Pediatrico Bambino Gesu;Fil: Putignani, Lorenza. Irccs Ospedale Pediatrico Bambino Gesu;Fil: Vinderola, Celso Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Reinheimer, Jorge Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Lactología Industrial. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Instituto de Lactología Industrial; ArgentinaFil: Gardini, Fausto. Universidad de Bologna; Italia. Università Degli Studi Di Bologna - Sede Di Cesena;Fil: Lanciotti, Rosalba. Universidad de Bologna; Italia. Università Degli Studi Di Bologna - Sede Di Cesena
Effects of sub-lethal concentrations of thyme and oregano essential oils, carvacrol, thymol, citral and trans-2-hexenal on membrane fatty acid composition and volatile molecule profile of Listeria monocytogenes, Escherichia coli and Salmonella enteritidis
Full text linkThe aim of this work was to investigate the modifications of cell membrane fatty acid composition and
volatile molecule profiles of Listeria monocytogenes, Salmonella enteritidis, Escherichia coli, during growth
in the presence of different sub-lethal concentrations of thyme and oregano essential oils as well as carvacrol,
thymol, trans-2-hexenal and citral. The results evidenced that the tested molecules induced
noticeable modifications of membrane fatty acid profiles and volatile compounds produced during the
growth. Although specific differences in relation to the species considered were identified, the tested
compounds induced a marked increase of some membrane associated fatty acids, particularly unsaturated
fatty acids, trans-isomers, and specific released free fatty acids. These findings can contribute to the
comprehension of the stress response mechanisms used by different pathogenic microorganisms often
involved in food-borne diseases in relation to the exposure to sub-lethal concentrations of natural
antimicrobials
Possible application in food industry of a recently isolated exopolysaccharydes producing bifidobacterial species
No full textHealth awareness among consumers have recently generated more demands for low-fat or fat-free
dairy products. However, since milk fat contrìbutes to the flavor, body and texture development
of the dairy products, removal leads to textural and functional defects in low fat fermented milk
products. ln this perspective, the exopolysaccharides (EPS) produced by food grade lactic acid
bacteria (LAB) have gained much importance as biothickeners and texturizers. EPS producing LAB as
'biothickeners' should offer natural, more acceptable and a preferred approach to many additives.
EPS ìmpart highly desirable rheological changes in the food matrix such as increased viscosity,
improved texture and reduced syneresis. Further, EPS may ìnduce positive physiological responses
ìncludìng lower cholesterol levels, reduced formation of pathogenic biofilms, modulation of adhesion
to epithelial cells and increased levels of bifidobacterio showing a prebiotic potential. Hence, the
choice of EPS producing starter cultures seems to give several advantages over nonproducing
ones. Bifidobocterium aesculapi, a novel species recently described, resulted able to ferment
lactose as well as producing an exocellular gelling matrix, which was identified and quantified as
EPS. Seven strains of B. aesculapii and the type strains of the two related species 8. stellenboschense
and B. scardovii were tested for their abilìty to ferment whoìe milk. Texture parameters (Textureanalyzer),
volatile aromatic compounds (detected by GC/MS-So|id Phase Micro Exraction) and pH
were assayed. B. aesculapii strains fermented whole milk conferring to the obtained products the
highest viscosity index, hardness, consistency and cohesiveness values. The volatile profiles showed
quali-quantitative differences among the samples and, from a sensoriaI point of view, they represent
a specific product fingerprinting. However, 2,3 butanedione, 3-hyd roxy-2-buta none, 2-butanone,
propanone and acetic acid were the most representative detected molecules. The data obtained
suggest that B. aesculapii, belonging to probiotic bacteria, should be tested for further application
in food ìndustry
Contribution of Two Different Packaging Material to Microbial Contamination of Peaches: Implications in Their Microbiological Quality
Full text linkAim: Aim of this work was understanding the microbial transfer dynamics from packaging to packed peaches in relation to the packaging used. Method and Results: A challenge test was performed, inoculating Escherichia coli, Pseudomonas spp. and Saccharomyces cerevisiae on cardboards and RPC (Reusable Plastic Containers), and monitoring their cell loads on fruits according to a probabilistic model and a Response Surface Methodology (RSM) in relation to several independent variables (number of fruit lesions, fruit temperature storage and commercialization time). The data recorded on packed peaches for Pseudomonas and S. cerevisiae were modeled to fit the second order model to study the main, interactive and quadratic effects of the independent variables on the cell loads of target microorganisms as well as on the shelf-life of the fruits in relation to packaging material used. The data collected for E. coli were codified as presence (1) or absence (0) and modeled with a logistic regression analysis to assess the probability of E. coli transferring from packaging to fruits in relation to the adopted variables. The data showed a higher contamination frequency of the fruits packed in plastic than in cardboard. Increasing the storage temperature and the number of lesions, the probability of transferring of E. coli from packaging materials to fruits increased, independently on commercialization time or packaging used. For Pseudomonas, the contamination levels detected on fruits packaged in plastic were significantly higher compared to those found on fruits packed in cardboard, independently on the considered variables. The polynomial equations showed the S. cerevisiae cell loads of fruits stored in plastic was positively affected by the quadratic term of temperature. Conclusions: the use of cardboard, compared to plastic, can significantly reduce the potential of microbial transferring from packaging to fruits. The probabilistic and kinetic models used showed a higher microbiological qualities of peaches stored in cardboard boxes, independently on the independent variables considered. The best performances of cardboard, compared to plastic, was probably due to its capability to entrap microbial cells. Significance and Impact: cardboard reduces fruit contamination and increases their shelf-life with positive fallouts on fruit shelf-life and all the logistic and distribution chain
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