Thermal and chemical inactivation of lactococcal bacteriophages

BUZRUL, Sencer
Alpas, Hami
AKÇELİK, Mustafa
Ten lactococcal bacteriophages in M 17 broth were treated by heat (72 degrees C, 15 min and 90 degrees C, 5 min), ethanol and isopropanol at concentrations of 10%, 50%. 75% and 100% (v/v). The heat treatments were not sufficient to inactivate all the bacteriophages studied whereas ethanol, which was also more efficient biocide than isopropanol, at a concentration of 75% could inactivate all the phages in I min. The 50% and 75% of ethanol were more effective than 100%, which was also observed for isopropanol. Survival curves' deviations from linearity as siginoidal shapes could be described via an empirical model with four parameters. The parameters of the model could be reduced from four to two with a slight loss of goodness-of-fit. The reduced model also provided good fit to describe the isopropanol inactivation kinetics of the phages at concentrations of 50% and 75%. This demonstration may also be a useful tool for further inactivation studies in which ethanol or other biocides are used with sufficient survival data points at selected time intervals. Although more studies should be carried out with different phages, this study confirmed the lethal effect of ethanol, commonly used to disinfect utensils and laboratory equipment, on lactoccocal bacteriophages. (c) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.


Use of Weibull frequency distribution model to describe the inactivation of Alicyclobacillus acidoterrestris by high pressure at different temperatures
BUZRUL, SENCER; Alpas, Hami; Bozoglu, F (Elsevier BV, 2005-01-01)
The survival curves of Alicyclobacillus acidoterrestris by high hydrostatic pressure were obtained at two pressures (350 and 450 MPa) and three temperature levels (35, 45 and 50 degreesC) in BAM broth. Tailing (upward concavity) was observed in all survival curves. Weibull model was fitted to these data and goodness of fit of this model was investigated. Regression coefficients (R-2), root mean square (RMSE) values and residual plot strongly suggested that Weibull model produced good fit to the data. A bett...
OZILGEN, S; OZILGEN, M; REID, DS (Elsevier BV, 1994-01-01)
Homogeneous and heterogeneous nucleation rates of ice in aqueous systems are described in the literature with the equation J = A exp (B tau). There are a very large number of published data available for variation of the constants A and B with experimental conditions. Results of this study show that the parameters obtained in the experiments with differential scanning calorimeter and the microscopic technique may be described separately with an empirical compensation equation of the form In A = aB + b. The ...
Heat transfer during frying of potato slices
Şahin, Serpil; Bayindirli, L (Elsevier BV, 1999-01-01)
The convective heat transfer coefficient during deep-fat-frying of potatoes was determined at different temperatures. The temperature, 0.1 cm below the top and bottom surfaces of a 0.05 x 0.05 x 0.005 m potato sample was monitored over rime. The thermal conductivity and specific heat of the sample were expressed as a function of rime, and the data were analyzed using the heat transfer equation with an explicit finite difference method. Crust formation occurred primarily at the bottom surface of the potato s...
Yener, Meryem Esra; OZILGEN, M (Wiley, 1987-07-01)
Drying behavior of honey‐starch mixtures at constant external conditions were studied. Mixtures with 0, 10, 20, 30, and 40% starch and the balance in honey were coated on aluminum plates at 0.25 mm thickness and dried in a laboratory oven at 60°, 70°, and 80°C. A mass transfer model with two falling rate periods was developed. In the first falling rate period, mass transfer coefficient was a linear function of moisture content. It was a constant in the second falling rate period. Mass transfer coefficients ...
Recovery of strawberry aroma compounds by pervaporation
Isci, A; Şahin, Serpil; Şümnü, Servet Gülüm (Elsevier BV, 2006-07-01)
The main objective of this study was to determine the effects of feed temperature (30, 40, 50 degrees C), concentration (50, 100, 150 ppm), composition (different strawberry model solutions) and permeate pressure (4, 8 mbar) on recovery of strawberry aroma compounds by pervaporation. Pervaporation was performed using a hydrophobic membrane, PERVAP 1070 (PDMS). As the feed temperature increased or downstream pressure decreased, the mass flux and selectivity increased in pervaporation of methyl butyrate (MTB)...
Citation Formats
S. BUZRUL, P. OZTURK, H. Alpas, and M. AKÇELİK, “Thermal and chemical inactivation of lactococcal bacteriophages,” LWT-FOOD SCIENCE AND TECHNOLOGY, pp. 1671–1677, 2007, Accessed: 00, 2020. [Online]. Available: