Yazar "Evrendilek, G. Akdemir" seçeneğine göre listele

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  • Küçük Resim
    Öğe
    EFFECT OF PULSED ELECTRIC FIELDS ON GERMINATION TUBE ELONGATION AND SPORE GERMINATION OF BOTRYTIS CINEREA INOCULATED INTO SOUR CHERRY JUICE, APRICOT AND PEACH NECTARS
    (Chiriotti Editori, 2009) Evrendilek, G. Akdemir; Tok, F. M.; Soylu, E. M.; Soylu, Soner
    Inactivation of Botrytis cinerea inoculated into sour cherry juice, apricot and peach nectars was determined by pulsed electric fields (PEF) based on the measurement of germination tube elongation, spore germination rate and light and scanning electron (SEM) mi-croscopic observations. With increasing electric field strength and processing time, germination tube elongation and spore germination were completely inhibited (P <= 0.05). Microscopic observations revealed considerable morphological alterations such as cytoplasmic coagulation, vacuolations, hyphal shriveling and protoplast leakage. PEF processing of juice/nectars was very effective to inactivate B. cinerea. This method could be used to prevent product loss in fruit juice/nectars due to B. cinerea contamination.
  • Küçük Resim
    Öğe
    High-pressure processing of Turkish white cheese for microbial inactivation
    (Int Assoc Food Protection, 2008) Evrendilek, G. Akdemir; Koca, N.; 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.
  • [ N/A ]
    Öğe
    Shelf-life evaluations of liquid foods treated by pilot plant pulsed electric field system
    (Blackwell Publishing Ltd, 2001) Evrendilek, G. Akdemir; Dantzer, W.R.; Streaker, C.B.; Ratanatriwong, P.; Zhang, Q.H.
    There is a pressing need to validate the shelf-life extension of Pulsed Electric Field (PEF) treated foods. This study was designed to evaluate the shelf-lives of cranberry juice and chocolate milk as a function of PEF and the interaction of PEF+heat treatments. Cranberry juice was exposed to PEF and PEF+heat (60C), and chocolate milk to PEF+heat (105 and 112C). Microbial analysis and color measurement were performed on untreated and treated cranberry juice and chocolate milk aseptically packaged and stored at 4, 22, and 37C for 197 and 119 days, respectively. Microbial analysis of cranberry juices demonstrated that the shelf-life of PEF and PEF+heat treated juices stored at 22 and 37C increased significantly during 197 days (p<0.05). The shelf-life of chocolate milk treated by PEF+105C and PEF+112C increased significantly at all storage temperatures (p<0.05). The PEF nor PEF+heat treatments did not result in any significant differences in color retention of either cranberry juice or chocolate milk (p>0.05). This study presented that PEF and PEF+heat treatments were very effective to increase shelf-lives of cranberry juice and chocolate milk.