Yazar "Balasubramaniam, V. M." seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim
    Öğe
    High-pressure processing of Turkish white cheese for microbial inactivation
    (Int Assoc Food Protection, 2008) Evrendilek, Gülsün Akdemir; Koca, Nurcan; Harper, J. W.; Balasubramaniam, V. M.
    High-pressure processing (HPP) of Turkish white cheese and reduction of Listeria monocytogenes, total Enterobacteriaceae. total aerobic mesophilic bacteria, total molds and yeasts, total Lactococcus spp., and total Lactobacillus spp. were investigated. Cheese samples were produced from raw milk and pasteurized milk and were inoculated with L. monocytogenes after brining. Both inoculated (ca. 10(7) to 10(8) CFU/g) and noninoculated samples were subjected to HPP in a high-pressure food processor at 50 to 600 MPa for 5 and 10 min at 25 degrees C. Reductions in L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp.. and Lactobacillus spp. in both pasteurized- and raw-milk cheese samples and reductions in total molds and yeasts and total Enterobacteriaceae counts in raw-milk cheese samples increased with increased pressure (P <= 0.05). The maximum reduction of the L. monocytogenes count, ca. 4.9 log CFU/g, was obtained at 600 MPa. Because of the. highly inhibitory effect of pasteurization, the total molds and yeasts and total Enterobacteriaceae counts for the cheese samples produced from pasteurized milk were below the detection limit both before and after HPP There was no significant difference in inactivation of L. monocytogenes, total aerobic mesophilic bacteria, Lactococcus spp., and Lactobacillus spp. under the same treatment conditions for the raw milk and pasteurized milk cheeses and for 5- and 10-min treatment times (P > 0.05). No significant change was detected in pH or water activity of the samples before and after HPP Our findings suggest that HPP can be used effectively to reduce the microbial load in Turkish white cheese.
  • Küçük Resim
    Öğe
    Inactivation of Listeria monocytogenes and Listeria innocua in yogurt drink applying combination of high pressure processing and mint essential oils
    (Elsevier Sci Ltd, 2011) Evrendilek, Gülsün Akdemir; Balasubramaniam, V. M.
    Influences of high pressure processing (HPP) on some physical properties and on inactivation of Listeria monocytogenes and Listeria innocua in a yogurt drink (ayran) were quantified with or without addition of mint essential oil. Pressure treatment alone or combined with mint essential oil did not cause significant changes in pH, water activity, color and serum protein separation (p > 0.05). HPP of ayran samples at 600 MPa for treatment time of 300 s reduced L monocytogenes and L innocua by more than 5-log units (p <= 0.05) at ambient temperature. Addition of mint essential oil further enhanced inactivation of both bacteria by more than 1 log cfu mL(-1). Combination of mint essential oil with HPP provided a reduction in pressure treatment severity by 100-300 MPa or by 210 s to achieve the same amount of inactivation relative to HPP alone. Both Weibull distribution and log-logistic models were fitted to survival data. High pressure-processing combined with mint essential oil appeared to be a promising technique for preserving microbiologically-safe ayran with no significant impacts to product quality. (C) 2011 Elsevier Ltd. All rights reserved.