Effects of the high pressure of homogenization on some spoiling micro-organisms, representative of fruit juice microflora, inoculated in saline solution |
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Authors: | A. Bevilacqua C. Costa M.R. Corbo M. Sinigaglia |
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Affiliation: | Department of Food Science, Faculty of Agricultural Science, Foggia University, Foggia, Italy; Istituto per la Ricerca e le Applicazioni Biotecnologiche per la Sicurezza e la Valorizzazione dei Prodotti Tipici e di Qualità(BIOAGROMED), Universitàdi Foggia, Foggia, Italy |
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Abstract: | Aims: This study was aimed to investigate the effects of a high-pressure homogenization (HPH) treatment on some micro-organisms, involved in the spoilage of fruit juices. Methods and Results: Lactobacillus plantarum , Lactobacillus brevis , Bacillus coagulans cells, Saccharomyces bayanus , Pichia membranaefaciens and Rhodotorula bacarum were separately inoculated in a saline solution (0·9% NaCl); the initial inoculum was ca. 5 log CFU ml−1. Then, the samples were processed through a homogenizer at 10–150 MPa for 1, 2 or 3 times. Yeasts were completely inactivated at 50–110 MPa with a single pass treatment, while lactic acid bacteria counts were reduced to approximately 1 log CFU ml−1 after a three-steps HPH processing. Conclusions: Yeasts were the most sensitive micro-organisms, followed by B. coagulans . On the other hand, lactic acid bacteria appeared resistant to HPH. Significance and Impact of the Study: The results of this study provided some useful information on the susceptibility of microflora of juices to homogenization; moreover, they suggested that HPH could be used successfully to inactivate yeasts. |
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Keywords: | Bacillus coagulans high-pressure homogenization juices lactic acid bacteria spoiling microflora yeasts |
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