1,721,243 research outputs found
COMPETITIVE INHIBITION OF ASPERGILLUS FLAVUS BY VOLATILE METABOLITES OF RHIZOPUS ARRHIZUS
No full textApplications 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
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
Interactions between high pressure homogenization and antimicrobial activity of lysozyme and lactoperoxidase
No full textIt was the objective of this work to evaluate the effect of high pressure homogenization on the activity of antimicrobial
enzymes such as lysozyme and lactoperoxidase against a selected group of Gram positive and Gram negative species inoculated
in skim milk.
Lactobacillus helveticus, Lactobacillus plantarum and Listeria monocytogenes were the most pressure resistant species
while Bacillus subtilis, Pseudomonas putida, Salmonella typhimurium, Staphylococcus aureus, Proteus vulgaris and
Salmonella enteritidis were found to be very sensitive to the hyperbaric treatment. The enzyme addition enhanced the
instantaneous pressure efficacy on almost all the considered species as indicated by their instantaneous viability loss following
the treatment. Moreover, the combination of the enzyme and high pressure homogenization significantly affected the recovery and growth dynamics of several of the considered species. Although L. monocytogenes was slightly sensitive to pressure, the combination of the two stress factors induced a significant viability loss within 3 h and an extension of lag phases in skim milk during incubation at 37 °C.
The hypothesis formulated in this work is that the interaction of high pressure homogenization and lysozyme or lactoperoxidase is associated to conformational modifications of the two proteins with a consequent enhancement of their activity. This hypothesis is supported by the experimental results also regarding the increased antimicrobial activity against L. plantarum of the previously pressurised lysozyme with respect to that of the native enzyme
Combined effects of ethanol, high homogenisation pressure, and temperature on cell fatty acid composition in Saccharomyces cerevisiae
No full textAlteration in cellular fatty acid composition as response to salt,acid, oxidative and thermal stresses in Lactobacillus helveticus
No full textPOTENTIAL 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
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
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
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