Efficient mechanical disruption of Lactobacillus helveticus, Lactococcus lactis and Propionibacterium freudenreichii by a new high-pressure homogenizer and recovery of intracellular aminotransferase activity

2003 ◽  
Vol 30 (1) ◽  
pp. 1-5 ◽  
Author(s):  
L. V. Saboya ◽  
M.-B. Maillard ◽  
S. Lortal
Keyword(s):  
High Pressure ◽  
Lactococcus Lactis ◽  
Lactobacillus Helveticus ◽  
Propionibacterium Freudenreichii ◽  
Aminotransferase Activity ◽  
Mechanical Disruption ◽  
High Pressure Homogenizer

VELOCITY MEASUREMENTS OF TURBULENT TWO-PHASE FLOW IN A HIGH-PRESSURE HOMOGENIZER MODEL

2013 ◽  
Vol 200 (1) ◽  
pp. 93-114 ◽  
Author(s):  
Andreas Håkansson ◽  
Laszlo Fuchs ◽  
Fredrik Innings ◽  
Johan Revstedt ◽  
Christian Trägårdh ◽  
...  
Keyword(s):  
High Pressure ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Velocity Measurements ◽  
Two Phase ◽  
High Pressure Homogenizer ◽  
Turbulent Two Phase Flow

Preparation of Cellulose Nanofibrils by High-Pressure Homogenizer and Zein Composite Films

2013 ◽  
Vol 829 ◽  
pp. 534-538 ◽  
Author(s):  
Alireza Shakeri ◽  
Sattar Radmanesh
Keyword(s):  
Atomic Force Microscopy ◽  
High Pressure ◽  
Food Packaging ◽  
Cellulose Nanofibrils ◽  
Composite Films ◽  
Average Diameter ◽  
Nanocomposite Films ◽  
Force Microscopy ◽  
Atomic Force ◽  
High Pressure Homogenizer

Cellulose nanofibrils ( NF ) have several advantages such as biodegradability and safety toward human health. Zein is a biodegradable polymer with potential use in food packaging applications. It appears that polymer nanocomposites are one of the most promising applications of zein films. Cellulose NF were prepared from starting material Microcrystalline cellulose (MCC) by an application of a high-pressure homogenizer at 20,000 psi and treatment consisting of 15 passes. Methods such as atomic force microscopy were used for confirmation of nanoscale size production of cellulose. The average diameter 45 nm were observed. Zeincellulose NF nanocomposite films were prepared by casting ethanol suspensions of Zein with different amounts of cellulose NF in the 0% to 5%wt. The nanocomposites were characterized by using Fourier transform infrared spectroscopy ( FTIR ), Atomic force microscopy ( AFM ) and X-ray diffraction ( XRD ) analysis. From the FTIR spectra the various groups present in the Zein blend were monitored. The homogeneity, morphology and crystallinity of the blends were ascertained from the AFM and XRD data, respectively. The thermal resistant of the zein nanocomposite films improved as the nanocellulose content increased. These obtained materials are transparent, flexible and present significantly better physical properties than the corresponding unfilled Zein films.

scholarly journals Flash Sterilization System using a High-pressure Homogenizer.

2000 ◽  
Vol 47 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Yuzoh ASANO ◽  
Keiichi IHARA ◽  
Tetsusi MORI ◽  
Teruhiko MIZOTA ◽  
Keiji IWATSUKI ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Homogenizer

Effect of back pressure on emulsification of lipid nanodispersions in a high-pressure homogenizer

2012 ◽  
Vol 422 (1-2) ◽  
pp. 489-494 ◽  
Author(s):  
Akira Saheki ◽  
Junzo Seki ◽  
Takeo Nakanishi ◽  
Ikumi Tamai
Keyword(s):  
High Pressure ◽  
Back Pressure ◽  
High Pressure Homogenizer

Changes in Galactose and Lactic Acid Content of Sweet Whey during Storage

2004 ◽  
Vol 67 (2) ◽  
pp. 403-406 ◽  
Author(s):  
R. D. RAO ◽  
W. L. WENDORFF ◽  
K. SMITH
Keyword(s):  
Lactic Acid ◽  
Lactococcus Lactis ◽  
Lactic Acid Production ◽  
Starter Culture ◽  
Storage Conditions ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Lactobacillus Delbrueckii ◽  
The Other ◽  
Time Period

Whey is often stored or transported for a period of time prior to processing. During this time period, galactose and lactic acid concentrations may accumulate, reducing the quality of spray-dried whey powders in regard to stickiness and agglomeration. This study surveyed industry samples of Cheddar and mozzarella cheese whey streams to determine how galactose and lactic acid concentrations changed with storage at appropriate (4°C) and abuse (37.8°C) temperatures. Samples stored at 4°C did not exhibit significant increases in levels of lactic acid or galactose. Mozzarella whey accumulated the greatest amount of galactose and lactic acid with storage at 37.8°C. Whey samples derived from cheese made from single strains of starter culture were also evaluated to determine each culture's contribution to galactose and lactic acid production. Starter cultures evaluated included Streptococcus salivarius ssp. thermophilus, Lactobacillus helveticus, Lactobacillus delbrueckii ssp. bulgaricus, Lactococcus lactis ssp. cremoris, and Lactococcus lactis ssp. lactis. Whey derived from L. helveticus accumulated a significantly greater amount of lactic acid upon storage at 37.8°C as compared with the other cultures. Galactose accumulation was significantly decreased in whey from L. lactis ssp. lactis stored at 37.8°C in comparison with the other cultures. Results from this study indicate that proper storage conditions (4°C) for whey prevent accumulation of galactose and lactic acid while the extent of accumulation during storage at 37.8°C varies depending on the culture(s) used in cheese production.

scholarly journals Autolysis of Lactobacillus helveticus and Propionibacterium freudenreichii in Swiss cheeses: first evidence by using species-specific lysis markers

1998 ◽  
Vol 65 (4) ◽  
pp. 609-620 ◽  
Author(s):  
FLORENCE VALENCE ◽  
ROMAIN RICHOUX ◽  
ANNE THIERRY ◽  
AIRI PALVA ◽  
SYLVIE LORTAL
Keyword(s):  
Coenzyme A ◽  
Streptococcus Thermophilus ◽  
Lactobacillus Helveticus ◽  
Propionibacterium Freudenreichii ◽  
Swiss Cheese ◽  
Specific Lysis ◽  
Cold Room ◽  
Sds Page ◽  
Intracellular Proteins ◽  
Species Specific

Lactobacillus helveticus and Propionibacterium freudenreichii are essential starters in Swiss cheesemaking and the release of their intracellular enzymes through autolysis could significantly influence ripening. To provide evidence of this lysis, cheese made from microfiltered thermized milk inoculated with Lb. helveticus ITGLH77, Prop. freudenreichii ITGP23 and a commercial Streptococcus thermophilus was assayed. Starter viability was determined and lysis was monitored during ripening by protein analysis with SDS-PAGE of aqueous cheese extracts and by immunoblot detection of intracellular proteins: dipeptidase (PepD) for Lb. helveticus and methylmalonyl coenzyme A mutase for Prop. freudenreichii. We verified that the species specificity of these lysis markers was towards the cytoplasms of all the species currently used in Swiss cheese. Lb. helveticus exhibited an almost complete loss of viability (99·9%) from the beginning of ripening in the cold room; concomitantly PepD appeared in the cheese extracts and was detected until the end of ripening. Damaged Lb. helveticus cells were also visualized by scanning electron microscopy. In addition, free PepD was also successfully detected in commercial Swiss-related cheeses. All these results clearly demonstrated the autolysis of Lb. helveticus in Swiss cheese. Prop. freudenreichii ITGP23 grew during warm room ripening and no loss of viability was detected after maximal growth (109 cfu/g cheese). Free methylmalonyl-coenzyme A mutase was detected at the end of ripening during cold storage, when the cheese extracts were concentrated 20-fold, demonstrating that the autolysis of Prop. freudenreichii was tardy and limited.

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