期刊
FOOD MICROBIOLOGY
卷 28, 期 8, 页码 1426-1431出版社
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.fm.2011.06.013
关键词
Apple juice; High hydrostatic pressure; High pressure homogenisation; Frateuria; Fruit
The objective of this study was to assess the effect of High Pressure Homogenisation (HPH) compared with High Hydrostatic Pressure (HHP) on the microbiological quality of raw apple juice during storage at ideal (4 degrees C) and abuse (12 degrees C) temperatures. in the case of HPH, only low numbers of micro-organisms were detected after treatment at 300 MPa (typically between 2 and 3 log.ml(-1)). These were identified as Streptomyces spp., and numbers did not increase during storage of the juice for 35 days, irrespective of storage temperature. In the case of HHP, the total aerobic counts were also reduced significantly (p < 0.05) after treatment for 1 min at 500 and 600 MPa and the numbers did not increase significantly during storage at 4 degrees C. However, during storage at 12 degrees C the counts did increase significantly (p < 0.05) and by day 14 counts at 500 MPa were not significantly different from the control juice. This confirms that good temperature control is important if the full benefits of HHP treatment are to be realised. Frateuria aurantia dominated the microbiota of the HHP apple juice stored at 12 degrees C along with low levels of Bacillus and Streptomyces spp. The HPH and HHP juices both turned brown during storage indicating that neither treatment was sufficient to inactivate polyphenol oxidase. The enzyme is known to be pressure resistant and this discolouration was controlled by a heat treatment (70 degrees C for 1 min) used in commercial practice and given prior to HP treatment. (C) 2011 Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据