Microbial Inactivation and Physicochemical Properties of Ultrasound Processed Pomegranate Juice


Pala C. U. , Zorba N. N. D. , Ozcan G.

JOURNAL OF FOOD PROTECTION, cilt.78, ss.531-539, 2015 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 78 Konu: 3
  • Basım Tarihi: 2015
  • Doi Numarası: 10.4315/0362-028x.jfp-14-290
  • Dergi Adı: JOURNAL OF FOOD PROTECTION
  • Sayfa Sayıları: ss.531-539

Özet

The effects of ultrasound treatment at various amplitudes (50, 75, and 100%) and times (0, 6, 12, 18, 24, and 30 min) on Escherichia coli ATCC 25922 (a surrogate for E. coli O157:H7) and Saccharomyces cerevisiae ATCC 2366 levels and physicochemical characteristics (monomeric anthocyanins, color values, total phenolics, pH, and soluble solids) were determined in pomegranate juice. More than a 5-log inactivation of E. coli ATCC 25922 and a 1.36-log inactivation of S. cerevisiae ATCC 2366 were achieved after 30 min of ultrasound treatment at 100% amplitude. The log-linear and Weibull models were successfully used to estimate the microbial inactivation as a function of ultrasound treatment time (R-2 > 0.97). No significant changes were observed in total phenolics, pH, and soluble solids of the treated juice (P> 0.05). The ultrasound treatment for up to 30 min resulted in more than 92 and 89% anthocyanin retention at 75 and 100% amplitude, respectively. The redness (a*) of the juice did not change significantly after the ultrasound treatment at amplitudes of 75 and 100% for up to 24 and 12 min, respectively. No significant changes in L* and b* values were observed after ultrasound treatment at all amplitudes and after up to 30 min of treatment for 50 and 75% amplitudes. Small differences in juice color were noted based on total color difference scores.